Determining the impact of in-bed leg cycling on spinal cord excitability during the acute phase following spinal cord injury

Determining the impact of in-bed leg cycling on spinal cord excitability during the acute phase following spinal cord injury | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Determining the impact of in-bed leg cycling on spinal cord excitability during the acute phase following spinal cord injury Jean-Marc Mac-Thiong, Xavier Thibault, Andréane Richard-Denis, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9361655/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract Study Design : Prospective exploratory interventional study. Objective : This study evaluates the impact of in-bed leg cycling on spinal cord excitability during the acute phase following acute traumatic spinal cord injury (SCI). Setting : Level 1 trauma center specialized in SCI care in Montreal, Canada. Methods : Eighteen participants with traumatic SCI underwent a single 30-minute session of in-bed leg cycling during acute hospitalization, with motor assistance as needed. Using soleus H-reflex testing, H-reflex and M-wave responses were recorded pre- and post-session to assess the change in spinal cord excitability. Results : Changes in H-reflex parameters were observed after cycling even when performed passively. There were three main phenotypes but also large variability with regard to spinal cord excitability in response to cycling. Most individuals (9/18) had decreased excitability after cycling, while 6/18 individuals had increased excitability. A third group (3/18) did not exhibit any significant response to cycling. Spinal cord excitability never increased after cycling when performed 2 weeks or more after the SCI. Conclusions : Performing in-bed leg cycling during the acute phase following traumatic SCI appears to modulate spinal cord excitability, but responses are highly individualized. Health sciences/Medical research/Translational research Health sciences/Health care/Therapeutics/Rehabilitation Health sciences/Diseases/Neurological disorders/Spinal cord diseases Figures Figure 1 Figure 2 INTRODUCTION Following the acute phase of the spinal shock in spinal cord injury (SCI), disinhibition associated with dysfunction of upper motor neurons can lead to spasticity in up to 60% of individuals during acute care [ 1 ]. Spasticity and spinal hyperreflexia result from the loss of presynaptic inhibition due to the SCI [ 2 , 3 ], and are considered as signs of maladaptive plasticity (i.e. associated with poor neurofunctional recovery). They also often require treatment, cause pain, and/or impair function and quality of life [ 4 , 5 ]. Preclinical studies suggest that activity-based (or exercise) therapy can reduce spasticity and spinal hyperreflexia, potentially by encouraging adaptive over maladaptive plasticity, even when performed passively [ 6 , 7 ]. Activity-based therapy (e.g. cycling, locomotor training, etc.) after SCI stimulates recovery through a relearning process that involves task-specific repetitive neuromuscular activation below the level of the SCI [ 8 , 9 ]. There is preclinical evidence that there is an early window of opportunity within days/weeks of a SCI for which activity-based therapy is most beneficial to harness adaptive plasticity and promote recovery [ 10 , 11 ]. Rehabilitation training is mostly effective when performed early to circumvent the decline expression of plasticity-associated genes that are up-regulated directly following SCI, the degradation of neuronal function, and formation of a glial scar in the later stages [ 12 ]. Conversely, immobilization or disuse early after the SCI produces chronic spinal circuit hyper-excitability and limits recovery in animals [ 13 , 14 ]. Passive cycling has been shown to suppress the soleus H-reflex in healthy individuals, indicating its potential to modulate spinal cord excitability through activity-dependent mechanisms [ 15 ]. The H-reflex, the electrical analogue of the mechanically induced spinal stretch reflex, provides a measure of spinal cord excitability from the responsiveness of alpha motor neurons to an electrical afferent input. When associated with functional electrical stimulation, passive cycling has the potential to decrease H-reflex response and reduce spasticity in humans with chronic SCI [ 16 ]. Despite the potential for activity-based therapy to modulate spinal cord excitability – and therefore harness adaptive plasticity – early after an acute SCI, it has never been assessed in humans. The aim of this study is to examine the effect of in-bed leg cycling on spinal cord excitability through soleus H-reflex testing within days of an acute traumatic SCI. METHODS Participants Three healthy volunteers were recruited as controls to undergo the same cycling protocol as for SCI individuals, in order to perform passive cycling. Eighteen individuals with an acute traumatic SCI participated in the study during their acute hospital stay at a single Level 1 trauma center specialized in SCI care between July 1st and August 31st 2024. The protocol was approved by the institutional review board. All participants provided informed consent. Inclusion criteria were: 1) acute traumatic SCI, 2) any severity of SCI with American Spinal Injury Association Impairment Scale (AIS) grade A, B, C, or D, 3) neurological level of injury (NLI) between C1 and L1, 4) blunt (non-penetrating) trauma, 5) spinal surgery performed ≤ 48h of the injury. Exclusion criteria were: 1) condition limiting participant’s ability to engage in cycling (e.g. pelvis or lower extremity injury or deformity, etc.), 2) medical contraindication to cycling (e.g. hemodynamic instability, cardiac ischemia, etc.), 3) moderate or severe traumatic brain injury, 4) pre-existing neurological condition (e.g. cerebrovascular disease, myasthenia gravis, Parkinson’s disease, etc.). Data collection Medical charts were used to collect all baseline information including age and sex. The neurological status at the time of cycling was assessed from the International Standards in Neurological Classification of SCI (ISNCSCI) to determine the NLI, AIS grade, and motor score. The timing of assessment after the trauma and the concomitant use of baclofen for spasticity was also collected. In-bed leg cycling All participants completed a single 30-minute continuous session of in-bed leg cycling. They did not undergo another session of activity-based therapy during their acute hospitalization. During the cycling session, participants remained in their hospital bed in a semi-reclined position, with a 30˚ torso inclination (Fig. 1 ). Participants wore running shoes to prevent against harmful shear and pressure on the heels during pedaling, while the thighs were secured by cuffs inter-connected by an elastic band to prevent the knees from flaring out during pedaling. The legs were positioned in leg supports mounted onto the pedals of a motorized ergometer with an adjustable frame (Hi-Lo Stand with APT-5 ergometer, Tzora Active Systems, Beachwood, OH, USA). The ergometer was positioned so that the knee was flexed at 30˚ when the pedal reaches the 3 o’clock position. If the participant is unable to engage into active cycling due to the paralysis of the lower extremities (i.e. all individuals with AIS grade A, B or C lesions), the ergometer was then activated in its passive (motor-driven) mode until reaching a target cadence of 40 revolutions per minute. Participants were encouraged to engage in active pedaling as much as possible and as tolerated, and motor assistance was titrated to reach the target cadence. Controls were instructed not to provide any active effort from lower extremities, in order reproduce passive cycling as much as possible. Soleus H-reflex testing Soleus H-reflex testing was performed immediately before and after the cycling session while in bed. Participants remained in a semi-reclined position at a 30˚ torso inclination (same as during cycling) with legs resting fully extended on the bed, out of the pedals and without shoes. The soleus H-reflex was evoked on the right side (N.B.: all participants exhibited symmetrical impairment in the lower extremities) by applying 1 ms electrical pulses in the popliteal fossa using a DS7AH HV Current Stimulator (Digitimer, UK) and 3M 2330N surface electrodes (3M, USA). Stimulation intensity started at 3 mA and was increased by 2 mA increments until reaching 25 mA, and then by 5 mA increments until reaching a maximal stimulation of 75 mA. Each stimulation was delivered once with a 10-second interval between pulses. Electromyographic (EMG) activity was recorded from the right soleus muscle at 2,000 Hz using the Noraxon Ultium EMG Sensor System (Noraxon, AZ, USA) with Red Dot electrodes (3M, USA) according to SENIAM guidelines. The equipment (and manipulations from the assessor) was kept out of sight of participants during H-reflex testing. The assessor noted when the H-reflex was visible, while participants indicated verbally the minimal intensity for which the stimulation was felt, with the option to stop the experiment anytime if pain or discomfort occurred. The M-wave and H-reflex were recorded during reflex stimulation to assess neuromuscular function. Hmax and Mmax correspond to the maximal amplitudes of the H-reflex and M-wave, respectively, and are reached by progressively increasing the intensity of stimulation. Hmax and Mmax reflect the maximal activation of the reflex (afferent) and direct (efferent) motor pathways, respectively. Hmax/Mmax provides insight into the excitability of spinal reflex circuits modulated by the central nervous system, therefore reflecting spinal cord excitability. In addition, the H-reflex latency (time from stimulus to onset of H-wave) and H-reflex threshold (minimum stimulus required to elicit H-reflex) are also reported. H-reflex latency indicates the reflexive activation of motor neurons via Ia afferent fibers, providing a measure of the spinal reflex pathway excitability. In addition to descriptive statistics, these parameters were compared before vs. after cycling using non-parametric sign tests with a level of significance of 0.05. RESULTS Participants The three controls consisted in a 24-year-old female, a 23-year-old male, and a 19-year-old female performing a session of passive cycling. Twenty individuals with SCI were initially approached, and all consented to participate in the study. However, one individual was excluded due to imminent transfer to a rehabilitation facility the same day, such that the time available to complete the study was insufficient. Another individual dropped out after 6 minutes of cycling due to pain, and was not considered in the final analysis. The final study sample for analysis consisted of 18 male participants (Table 1 ) with a mean age of 51.7 ± 20.2 years (range: 19–81 years), who all completed the full 30-minute cycling session and H-reflex testing before and after cycling. The timing of the cycling session was 11.1 ± 10.3 days after the trauma (range: 1–41 days). There were 6 participants with AIS grade A (4 cervical and 2 thoracic NLI), 6 with grade B (5 cervical and 1 thoracic NLI), 5 with grade C (all with cervical NLI), and 1 with C4 grade D SCI. Table 1 Characteristics of participants and controls Patient ID Age Sex AIS* grade NLI † Total motor score Timing of H-reflex testing after injury Baclofen received 1 64 M B T4 38 16 No 2 71 M A T3 0 31 No 3 37 M C C5 18 41 No 4 61 M C C2 36 15 Yes 5 47 M A T6 50 10 Yes 6 76 M D C4 81 14 Yes 7 81 M A C5 11 6 Yes 8 50 M A C5 19 12 No 9 33 M B C4 16 1 No 10 24 M B C4 19 11 No 11 79 M C C5 2 5 No 12 70 M C C5 54 5 No 13 22 M B C8 48 5 No 14 32 M A C6 24 3 No 15 48 M B C6 28 5 No 16 19 M C C7 45 13 No 17 54 M A C3 8 3 No 18 62 M B C4 37 4 No Control 1 24 F - - - - - Control 2 23 M - - - - - Control 3 20 F - - - - - * American Spinal Injury Association Impairment Scale † Neurological level of injury H-reflex testing Individual parameters for H-reflex testing are presented in Table 2 . A systematic decrease in Hmax/Mmax was observed after passive cycling for all three controls (31.4%, 31.8% and 17.1% decrease). These observations correspond to a respective decrease in H-reflex amplitude by 22.0%, 19.9% and 1.6% and increase in M-wave amplitude by 13.8%, 17.5% and 18.7% after cycling. H-reflex latencies (≤0.002 seconds variation for each control) and H-reflex thresholds (≤2 mA variation for each control) remained relatively stable following cycling. Table 2 H-Reflex data before and after cycling session of participants and controls Patient ID Before cycling session After cycling session Change in Hmax/Mmax (%) H-reflex latency (seconds) H-reflex threshold (mA) Hmax/ Mmax H-reflex latency (seconds) H-reflex threshold (mA) Hmax/ Mmax 1 0.032 19 0.06 0.033 13 0.04 -37.0 2 0.035 13 0.30 0.036 9 0.25 -15.4 3 0.031 25 0.68 0.031 21 0.68 -0.4 4 0.035 15 4.49 0.036 13 0.73 -83.7 5 0.032 11 0.16 0.031 9 0.11 -30.8 6 0.039 23 0.19 0.040 23 0.13 -30.6 7 0.034 15 0.19 0.035 15 0.31 64.8 8 0.033 13 0.45 0.032 9 0.58 29.0 9 0.036 21 0.83 0.036 21 0.67 -18.9 10 0.029 23 0.42 0.029 25 0.57 36.0 11 0.038 15 0.08 0.034 13 0.06 -22.1 12 0.039 7 0.09 0.039 15 0.70 657.8 13 0.033 9 0.35 0.033 9 0.19 -46.0 14 0.040 9 0.17 0.041 9 0.18 7.9 15 0.030 25 0.50 0.030 25 0.76 50.6 16 0.038 13 0.39 0.038 15 0.40 2.8 17 0.036 15 0.18 0.038 13 0.28 54.9 18 0.028 21 0.86 0.035 30 0.27 -68.6 Control 1 0.032 11 0.31 0.032 9 0.22 -31.5 Control 2 0.032 5 0.65 0.032 5 0.44 -31.9 Control 3 0.028 23 0.52 0.030 25 0.43 -17.1 All participants required motor assistance during cycling, ranging from full assistance for individuals with AIS grades A and B SCI to minimal assistance for the individual with AIS grade D SCI. All individuals tolerated the H-reflex stimulation protocol, and there was no adverse event associated with the protocol. There was no statistical difference before vs. after cycling in Hmax (p = 0.4), Mmax (p = 0.5), H-reflex latency (p = 0.2) and H-reflex threshold (p = 0.5). Overall, Hmax/Mmax was similar statistically before (mean: 0.58 ± 1.01; median: 0.32; range: 0.06–4.49; interquartile range: 0.17–0.49) vs. after (mean: 0.31 ± 1.62; median: 0.30; range: 0.04–0.76; interquartile range: 0.18–0.65) cycling (p = 0.8). However, the individual change in Hmax/Mmax following cycling varied substantially from a decrease by 83.7% in participant #4 to an increase by 657.8% in participant #12 (Fig. 2 ). Hmax/Mmax decreased by at least 10% after cycling in 9 individuals (2 AIS grade A, 4 AIS grade B, 2 AIS grade C, 1 AIS grade D), and increased by at least 10% in 6 individuals (3 AIS grade D, 2 AIS grade B, 1 AIS grade C). The change in Hmax/Mmax after cycling was less than 10% in only 3 participants (1 AIS grade A, 2 AIS grade C). Specifically for AIS grade A participants, Hmax/Mmax increased after cycling in all individuals with a cervical NLI and decreased after cycling in all individuals with a thoracic NLI. There was no clear trend observed for participants with AIS grade B or C lesions, as opposite changes in Hmax/Mmax were observed among some participants despite having the same AIS grade and NLI. One individual with a C4 AIS grade B lesion (participant #10) had a 36.0% increase in Hmax/Mmax, while the two others with the same lesion (participants # 9 and #18) had a decrease in Hmax/Mmax by 18.9% and 68.6%, respectively. Of the 3 individuals with a C5 AIS grade C lesion, Hmax/Mmax increased by 657.8% in participant #12, while it decreased by 22.1% in participant #11 and remained stable (-0.4%) in participant #3. In the individual with mild AIS grade D SCI (C4 NLI with motor score of 81), Hmax/Mmax decreased by 30.6% after cycling, which is in the same range at the decreases in Hmax/Mmax observed in the healthy controls. Of the 9 individuals who performed cycling within a week of the injury, Hmax/Mmax decreased by at least 10% in 4 individuals (C4 AIS grade B, C8 AIS grade B, C5 AIS grade C, C4 AIS grade B), increased by at least 10% in 4 individuals (C5 AIS grade A, C5 AIS grade C, C6 AIS grade B, C3 AIS grade A), and remained stable in 1 individual (C6 AIS grade A). However, Hmax/Mmax did not increase in any of the 5 individuals performing the cycling 2 weeks or more after the injury. Of note, all 4 individuals with a cervical AIS grade A lesion were tested within 2 weeks of the injury, and had an increase in Hmax/Mmax after cycling. Of the 9 participants who performed cycling more than one week following the injury, Hmax/Mmax increased in only 2 individuals (11 days for participant #10 and 12 days for participant #8). Among the 4 participants taking baclofen to alleviate their spasticity, Hmax/Mmax decreased by 30% or more in 3 individuals (C2 AIS grade C, T6 AIS grade A, C4 AIS grade D), and increased by 64.8% in the other individual (C5 AIS grade A). Of the 10 participants younger than 60 years old, Hmax/Mmax decreased by at least 10% in 3 individuals (T6 AIS grade A, C4 AIS grade B, C8 AIS grade B), increased by 10% or more in 4 individuals (C5 AIS grade A, C4 AIS grade B, C6 AIS grade B, C3 AIS grade A), and remained within a 10% increase in 3 individuals (C5 AIS grade C, C6 AIS grade A, C7 AIS grade C). For those older than 60 years old, Hmax/Mmax decreased by at least 10% in 6 individuals (T4 AIS grade B, T3 AIS grade A, C2 AIS grade C, C4 AIS grade D, C5 AIS grade C, C4 AIS grade B), and increased by 10% or more in 2 individuals (C5 AIS grade A, C5 AIS grade C). DISCUSSION Our study reports the changes in spinal cord excitability due to early leg cycling performed during the acute phase after traumatic SCI, as early as 1 day following the SCI. It sheds new light on the possible impact of initiating early acute activity-based therapy on spinal cord excitability and its potential to harness adaptive neuroplasticity after traumatic SCI, that have been demonstrated previously in preclinical studies. We used H-reflex testing to assess spinal cord excitability because it is recognized as a relevant tool to study plasticity of the nervous system [ 17 , 18 ]. Our study shows that after acute traumatic SCI, modulation of spinal cord excitability can be achieved from early acute cycling – as soon as 1 day after the injury –, even if performed passively in the presence of severe (or complete) paralysis of the lower extremities. This finding suggests that the afferent input (proprioceptive and plantar pressure) may be sufficient to modulate spinal cord excitability, in agreement with animal studies of early acute activity-based therapy showing that even limited sensory feedback may be sufficient to improve motor function [ 19 ]. However, it remains to be determined from future studies whether providing a full daily program of early acute activity-based therapy in the form of in-bed cycling would translate into adaptive plasticity and improved recovery. Our findings with previous studies of chronic SCI [ 16 ] showing that spinal cord excitability systematically decreases when it is assessed months or years after SCI. Our study shows that there are three main phenotypes and large variability with regard to spinal cord excitability in response to leg cycling during the acute phase days to weeks after traumatic SCI. Most individuals (9/18) had decreased excitability after cycling, although a large proportion of individuals (6/18) had increased excitability after cycling. A third group (3/18) did not exhibit any significant response from cycling. Observing different phenotypes in response to cycling within days/weeks after the SCI – as opposed to the systematic decrease when performed months/years after the SCI – suggests that starting activity-based therapy early vs. later after a SCI may result in different neuroplasticity and recovery processes, in agreement with preclinical studies showing that neurofunctional recovery is influenced by the timing at which activity-based therapy is introduced after the SCI [ 10 , 11 ]. Surprisingly, some participants with the same SCI severity had completely different responses to cycling, further suggesting that the impact of cycling remains unpredictable during the acute phase, particularly for individuals with AIS grade B and C lesions (see Fig. 2 for participants with C4 AIS grade B and C5 AIS grade C lesions). However, the response to cycling was more consistent for complete AIS grade A SCI since all 4 participants with a cervical lesion exhibited increased spinal cord excitability after cycling – including 3 with more than 10% increase –, and the 2 participants with a thoracic lesion exhibited decreased excitability. The presence of preexisting degenerative cervical myelopathy can potentially influence spinal cord excitability and the response to cycling since the 3 participants with more than 10% increase in Hmax/Mmax had underlying cervical spinal stenosis on MRI contributing to the SCI. Alternatively, the discrepancy between complete cervical and thoracic lesions could partly be explained by different pathophysiological processes involved in cervical vs. thoracic injuries considering that complete thoracic SCI are typically associated with trauma of higher energy and poorer potential for recovery [ 20 ]. As for mild AIS grade D SCI, our study does not provide definite conclusions, as there was only one participant with such injury. Nevertheless, the decrease in spinal cord excitability observed in this participant after cycling was in the same range as that observed in healthy controls. This suggests that individuals with the mildest injuries are more likely to exhibit decreased spinal cord excitability after early acute cycling, which is usually observed in normal individuals after cycling. Accordingly, our findings in healthy controls are consistent with the H-reflex attenuation normally observed during either passive or active cycling in healthy individuals [ 21 ]. We did not observe any clear tendency in the response to cycling based on age or on the concomitant use of baclofen. The impact of the timing of cycling session on the direction or magnitude of change in spinal cord excitability was not consistent throughout the entire cohort. However, there was no occurrence of increase in spinal cord excitability in any of the 5 individuals (1 AIS grade A, 1 AIS grade B, 2 AIS grade C, 1 AIS grade D) performing the cycling session 2 weeks or more after the SCI, which is similar to the observations in individuals with chronic SCI for whom spinal reflex excitability was reduced with activity-based therapy [ 22 – 25 ]. Conversely for the 13 individuals who performed their cycling session within 2 weeks of the injury, 7 had increased spinal cord excitability after cycling, 5 had decreased spinal cord excitability, and 1 did not respond to cycling. Of note, all 4 individuals with a complete AIS grade A cervical SCI performed cycling within 2 weeks of the injury and had an increase in spinal cord excitability. Further study is needed to determine whether performing cycling sessions earlier after the injury increases the probability of increasing spinal cord excitability, particularly for individuals with complete lesions for whom the spinal shock could be more severe and prolonged. Whether increasing spinal cord excitability early after the SCI is beneficial for accelerating the resolution of the spinal shock, harnessing adaptive plasticity and/or promoting recovery remains unknown, and cannot be answered from the current study. Limitations The conclusions are limited by the small number of participants, and further study is required to identify predictors of changes in spinal cord excitability due to cycling. In addition, the response to a single cycling session cannot directly be translated into the outcomes with a full program of activity-based therapy for which sustained daily sessions of cycling would be performed. It is also possible that the impact of cycling on spinal cord excitability varies along the course of activity-based therapy. Conducting a study involving a full program of activity-based therapy is therefore needed to determine the relationship between the direction (increase vs. decrease) and magnitude of change in spinal cord excitability, plasticity and recovery. Conclusion Overall, this study shows that spinal cord excitability may be modulated by in-bed leg cycling after acute spinal cord injury, even when performed passively. Performing in-bed leg cycling within 2 weeks of a traumatic SCI had variable impact on H-reflex (increase, decrease or no effect). When performed more than 2 weeks after the injury, H-reflex was more likely to be decreased after cycling. Further study is required to assess the relationship between initiating in-bed leg cycling during acute care to provide early acute activity-based therapy, neuroplasticity and recovery. Declarations DECLARATION OF INTERESTS XT received a scholarship from the PRogramme d’Excellence en Médecine pour l’Initiation en Recherche (PREMIER). FUNDING This work was supported by the PRogramme d’Excellence en Médecine pour l’Initiation en Recherche (PREMIER); by the Fonds de Recherche du Québec – Santé [grant number 309745]; and by the Medtronic Chair in Spinal Trauma at Université de Montréal. ETHICAL APPROVAL All experimental procedures were approved by the Comité d’Éthique de la recherche du CIUSSS du Nord-de-L’Île de Montréal (“Mobilisation précoce suite à une lésion médullaire”, study #2020 − 1901, approved on March 12th, 2020). Participants provided written informed consent prior to enrollment in the study. AUTHOR CONTRIBUTIONS XT was involved in data curation, formal analysis, investigation, methodology, validation, writing original draft, and reviewing & editing manuscript. DATA AVAILABILITY STATEMENT The data that support the findings of this study are not publicly available. Data are, however, available from the authors upon reasonable request and with permission from the Ethics committee. References Levasseur A, Mac-Thiong JM, Richard-Denis A. Are early clinical manifestations of spasticity associated with long-term functional outcome following spinal cord injury? A retrospective study. Spinal Cord. 2021;59(8):910–916. 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Arch Phys Med Rehabil. 2009;90(7):1218–1228. Piazza S, Gomez-Soriano J, Bravo-Esteban E, Torricelli D, Avila-Martin G, Galan-Arriero I, et al. Maintenance of cutaneomuscular neuronal excitability after leg-cycling predicts lower limb muscle strength after incomplete spinal cord injury. Clin Neurophysiol. 2016;127(6):2402–2409. Thompson AK, Wolpaw JR. H-reflex conditioning during locomotion in people with spinal cord injury. J Physiol. 2021;599(9):2453–2469. Additional Declarations There is no duality of interest Cite Share Download PDF Status: Under Review Version 1 posted Reviewer # 1 agreed at journal 20 Apr, 2026 Reviewers invited by journal 16 Apr, 2026 Editor assigned by journal 09 Apr, 2026 Submission checks completed at journal 09 Apr, 2026 First submitted to journal 08 Apr, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9361655","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":624148408,"identity":"647c144f-446c-4740-8cfb-d02eb77d606e","order_by":0,"name":"Jean-Marc Mac-Thiong","email":"data:image/png;base64,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","orcid":"https://orcid.org/0000-0003-4524-3893","institution":"Hopital du Sacre Coeur de Montreal","correspondingAuthor":true,"prefix":"","firstName":"Jean-Marc","middleName":"","lastName":"Mac-Thiong","suffix":""},{"id":624148409,"identity":"22afb32e-dd0d-468c-99dd-e018022adae4","order_by":1,"name":"Xavier Thibault","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Xavier","middleName":"","lastName":"Thibault","suffix":""},{"id":624148410,"identity":"79e0e06a-ae72-49e6-98ec-a37005dd207b","order_by":2,"name":"Andréane Richard-Denis","email":"","orcid":"https://orcid.org/0000-0003-3638-4416","institution":"Université de Montréal","correspondingAuthor":false,"prefix":"","firstName":"Andréane","middleName":"","lastName":"Richard-Denis","suffix":""},{"id":624148411,"identity":"2bcf5841-2775-4887-b27e-47d1872d20e8","order_by":3,"name":"Gerardo Tibamoso Pedraza","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Gerardo","middleName":"Tibamoso","lastName":"Pedraza","suffix":""},{"id":624148412,"identity":"ce97b3fc-f754-4654-9529-3a52fb5fc50f","order_by":4,"name":"Dorothy Barthelemy","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Dorothy","middleName":"","lastName":"Barthelemy","suffix":""},{"id":624148413,"identity":"c6e7f115-8eb8-46ea-9669-bc004dc32707","order_by":5,"name":"David Magnuson","email":"","orcid":"https://orcid.org/0000-0003-3816-3676","institution":"University of Louisville","correspondingAuthor":false,"prefix":"","firstName":"David","middleName":"","lastName":"Magnuson","suffix":""}],"badges":[],"createdAt":"2026-04-09 00:50:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9361655/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9361655/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107832331,"identity":"332ebc50-5ced-494f-bc23-046a0f16259b","added_by":"auto","created_at":"2026-04-26 15:32:14","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1091150,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eIn-bed leg cycling \u003c/strong\u003eParticipants remain in bed in a semi-reclined position with their torso inclined at 30˚ during cycling. The legs are placed in leg supports mounted on the pedals of the ergometer, while the thighs are secured by cuffs interconnected by an elastic band.\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9361655/v1/78f752dc7c3978831c166547.jpg"},{"id":107870444,"identity":"a5110fa3-fb6f-4508-9144-0e3ad7b3e124","added_by":"auto","created_at":"2026-04-27 07:39:40","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":264476,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eModulation of spinal cord excitability from cycling \u003c/strong\u003eThe change in Hmax/Mmax following the cycling session is presented for each participant with SCI, based on the severity of SCI. The timing for cycling for each participant is also presented (dash line).\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9361655/v1/948cf6b0e307645654c0bba6.jpg"},{"id":107872912,"identity":"7ad0f811-741f-4435-87d6-e1bf60e69b59","added_by":"auto","created_at":"2026-04-27 08:00:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1749817,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9361655/v1/35a4aef2-8035-4573-a37a-af5cf0f917b0.pdf"}],"financialInterests":"There is no duality of interest","formattedTitle":"Determining the impact of in-bed leg cycling on spinal cord excitability during the acute phase following spinal cord injury","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eFollowing the acute phase of the spinal shock in spinal cord injury (SCI), disinhibition associated with dysfunction of upper motor neurons can lead to spasticity in up to 60% of individuals during acute care [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Spasticity and spinal hyperreflexia result from the loss of presynaptic inhibition due to the SCI [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], and are considered as signs of maladaptive plasticity (i.e. associated with poor neurofunctional recovery). They also often require treatment, cause pain, and/or impair function and quality of life [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePreclinical studies suggest that activity-based (or exercise) therapy can reduce spasticity and spinal hyperreflexia, potentially by encouraging adaptive over maladaptive plasticity, even when performed passively [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Activity-based therapy (e.g. cycling, locomotor training, etc.) after SCI stimulates recovery through a relearning process that involves task-specific repetitive neuromuscular activation below the level of the SCI [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. There is preclinical evidence that there is an early window of opportunity within days/weeks of a SCI for which activity-based therapy is most beneficial to harness adaptive plasticity and promote recovery [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Rehabilitation training is mostly effective when performed early to circumvent the decline expression of plasticity-associated genes that are up-regulated directly following SCI, the degradation of neuronal function, and formation of a glial scar in the later stages [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Conversely, immobilization or disuse early after the SCI produces chronic spinal circuit hyper-excitability and limits recovery in animals [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePassive cycling has been shown to suppress the soleus H-reflex in healthy individuals, indicating its potential to modulate spinal cord excitability through activity-dependent mechanisms [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. The H-reflex, the electrical analogue of the mechanically induced spinal stretch reflex, provides a measure of spinal cord excitability from the responsiveness of alpha motor neurons to an electrical afferent input. When associated with functional electrical stimulation, passive cycling has the potential to decrease H-reflex response and reduce spasticity in humans with chronic SCI [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDespite the potential for activity-based therapy to modulate spinal cord excitability \u0026ndash; and therefore harness adaptive plasticity \u0026ndash; early after an acute SCI, it has never been assessed in humans. The aim of this study is to examine the effect of in-bed leg cycling on spinal cord excitability through soleus H-reflex testing within days of an acute traumatic SCI.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cp\u003e\u003cb\u003eParticipants\u003c/b\u003e Three healthy volunteers were recruited as controls to undergo the same cycling protocol as for SCI individuals, in order to perform passive cycling. Eighteen individuals with an acute traumatic SCI participated in the study during their acute hospital stay at a single Level 1 trauma center specialized in SCI care between July 1st and August 31st 2024. The protocol was approved by the institutional review board. All participants provided informed consent. Inclusion criteria were: 1) acute traumatic SCI, 2) any severity of SCI with American Spinal Injury Association Impairment Scale (AIS) grade A, B, C, or D, 3) neurological level of injury (NLI) between C1 and L1, 4) blunt (non-penetrating) trauma, 5) spinal surgery performed \u0026le;\u0026thinsp;48h of the injury. Exclusion criteria were: 1) condition limiting participant\u0026rsquo;s ability to engage in cycling (e.g. pelvis or lower extremity injury or deformity, etc.), 2) medical contraindication to cycling (e.g. hemodynamic instability, cardiac ischemia, etc.), 3) moderate or severe traumatic brain injury, 4) pre-existing neurological condition (e.g. cerebrovascular disease, myasthenia gravis, Parkinson\u0026rsquo;s disease, etc.).\u003c/p\u003e \u003cp\u003e \u003cb\u003eData collection\u003c/b\u003e Medical charts were used to collect all baseline information including age and sex. The neurological status at the time of cycling was assessed from the International Standards in Neurological Classification of SCI (ISNCSCI) to determine the NLI, AIS grade, and motor score. The timing of assessment after the trauma and the concomitant use of baclofen for spasticity was also collected.\u003c/p\u003e \u003cp\u003e \u003cb\u003eIn-bed leg cycling\u003c/b\u003e All participants completed a single 30-minute continuous session of in-bed leg cycling. They did not undergo another session of activity-based therapy during their acute hospitalization. During the cycling session, participants remained in their hospital bed in a semi-reclined position, with a 30˚ torso inclination (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Participants wore running shoes to prevent against harmful shear and pressure on the heels during pedaling, while the thighs were secured by cuffs inter-connected by an elastic band to prevent the knees from flaring out during pedaling. The legs were positioned in leg supports mounted onto the pedals of a motorized ergometer with an adjustable frame (Hi-Lo Stand with APT-5 ergometer, Tzora Active Systems, Beachwood, OH, USA). The ergometer was positioned so that the knee was flexed at 30˚ when the pedal reaches the 3 o\u0026rsquo;clock position. If the participant is unable to engage into active cycling due to the paralysis of the lower extremities (i.e. all individuals with AIS grade A, B or C lesions), the ergometer was then activated in its passive (motor-driven) mode until reaching a target cadence of 40 revolutions per minute. Participants were encouraged to engage in active pedaling as much as possible and as tolerated, and motor assistance was titrated to reach the target cadence. Controls were instructed not to provide any active effort from lower extremities, in order reproduce passive cycling as much as possible.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e\u003cb\u003eSoleus H-reflex testing\u003c/b\u003e Soleus H-reflex testing was performed immediately before and after the cycling session while in bed. Participants remained in a semi-reclined position at a 30˚ torso inclination (same as during cycling) with legs resting fully extended on the bed, out of the pedals and without shoes. The soleus H-reflex was evoked on the right side (N.B.: all participants exhibited symmetrical impairment in the lower extremities) by applying 1 ms electrical pulses in the popliteal fossa using a DS7AH HV Current Stimulator (Digitimer, UK) and 3M 2330N surface electrodes (3M, USA). Stimulation intensity started at 3 mA and was increased by 2 mA increments until reaching 25 mA, and then by 5 mA increments until reaching a maximal stimulation of 75 mA. Each stimulation was delivered once with a 10-second interval between pulses. Electromyographic (EMG) activity was recorded from the right soleus muscle at 2,000 Hz using the Noraxon Ultium EMG Sensor System (Noraxon, AZ, USA) with Red Dot electrodes (3M, USA) according to SENIAM guidelines. The equipment (and manipulations from the assessor) was kept out of sight of participants during H-reflex testing. The assessor noted when the H-reflex was visible, while participants indicated verbally the minimal intensity for which the stimulation was felt, with the option to stop the experiment anytime if pain or discomfort occurred. The M-wave and H-reflex were recorded during reflex stimulation to assess neuromuscular function. Hmax and Mmax correspond to the maximal amplitudes of the H-reflex and M-wave, respectively, and are reached by progressively increasing the intensity of stimulation. Hmax and Mmax reflect the maximal activation of the reflex (afferent) and direct (efferent) motor pathways, respectively. Hmax/Mmax provides insight into the excitability of spinal reflex circuits modulated by the central nervous system, therefore reflecting spinal cord excitability. In addition, the H-reflex latency (time from stimulus to onset of H-wave) and H-reflex threshold (minimum stimulus required to elicit H-reflex) are also reported. H-reflex latency indicates the reflexive activation of motor neurons via Ia afferent fibers, providing a measure of the spinal reflex pathway excitability. In addition to descriptive statistics, these parameters were compared before vs. after cycling using non-parametric sign tests with a level of significance of 0.05.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003e\u003cb\u003eParticipants\u003c/b\u003e The three controls consisted in a 24-year-old female, a 23-year-old male, and a 19-year-old female performing a session of passive cycling. Twenty individuals with SCI were initially approached, and all consented to participate in the study. However, one individual was excluded due to imminent transfer to a rehabilitation facility the same day, such that the time available to complete the study was insufficient. Another individual dropped out after 6 minutes of cycling due to pain, and was not considered in the final analysis. The final study sample for analysis consisted of 18 male participants (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) with a mean age of 51.7\u0026thinsp;\u0026plusmn;\u0026thinsp;20.2 years (range: 19\u0026ndash;81 years), who all completed the full 30-minute cycling session and H-reflex testing before and after cycling. The timing of the cycling session was 11.1\u0026thinsp;\u0026plusmn;\u0026thinsp;10.3 days after the trauma (range: 1\u0026ndash;41 days). There were 6 participants with AIS grade A (4 cervical and 2 thoracic NLI), 6 with grade B (5 cervical and 1 thoracic NLI), 5 with grade C (all with cervical NLI), and 1 with C4 grade D SCI.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCharacteristics of participants and controls\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePatient ID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSex\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAIS* grade\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNLI\u003csup\u003e\u0026dagger;\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTotal motor score\u003c/p\u003e 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colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eT3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eT6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl 2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003e* American Spinal Injury Association Impairment Scale\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003e\u0026dagger; Neurological level of injury\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eH-reflex testing\u003c/b\u003e Individual parameters for H-reflex testing are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. A systematic decrease in Hmax/Mmax was observed after passive cycling for all three controls (31.4%, 31.8% and 17.1% decrease). These observations correspond to a respective decrease in H-reflex amplitude by 22.0%, 19.9% and 1.6% and increase in M-wave amplitude by 13.8%, 17.5% and 18.7% after cycling. H-reflex latencies (\u0026le;0.002 seconds variation for each control) and H-reflex thresholds (\u0026le;2 mA variation for each control) remained relatively stable following cycling.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eH-Reflex data before and after cycling session of participants and controls\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePatient ID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eBefore cycling session\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003eAfter cycling session\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eChange in Hmax/Mmax (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eH-reflex\u003c/p\u003e \u003cp\u003elatency\u003c/p\u003e \u003cp\u003e(seconds)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eH-reflex\u003c/p\u003e \u003cp\u003ethreshold\u003c/p\u003e \u003cp\u003e(mA)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eHmax/\u003c/p\u003e \u003cp\u003eMmax\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eH-reflex\u003c/p\u003e \u003cp\u003elatency\u003c/p\u003e \u003cp\u003e(seconds)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eH-reflex\u003c/p\u003e \u003cp\u003ethreshold\u003c/p\u003e \u003cp\u003e(mA)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eHmax/\u003c/p\u003e \u003cp\u003eMmax\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.033\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-37.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.035\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.036\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-15.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.031\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.031\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-0.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.035\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.036\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-83.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.031\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-30.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.039\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.040\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-30.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.034\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.035\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e64.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.033\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e29.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.036\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.036\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-18.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.029\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.029\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e36.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.038\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.034\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-22.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.039\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.039\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e657.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.033\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.033\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-46.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.040\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.041\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e7.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.030\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.030\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e50.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.038\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.038\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e2.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.036\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.038\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e54.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.028\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.035\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-68.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-31.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl 2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-31.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.028\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.030\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e-17.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e All participants required motor assistance during cycling, ranging from full assistance for individuals with AIS grades A and B SCI to minimal assistance for the individual with AIS grade D SCI. All individuals tolerated the H-reflex stimulation protocol, and there was no adverse event associated with the protocol. There was no statistical difference before vs. after cycling in Hmax (p\u0026thinsp;=\u0026thinsp;0.4), Mmax (p\u0026thinsp;=\u0026thinsp;0.5), H-reflex latency (p\u0026thinsp;=\u0026thinsp;0.2) and H-reflex threshold (p\u0026thinsp;=\u0026thinsp;0.5).\u003c/p\u003e \u003cp\u003eOverall, Hmax/Mmax was similar statistically before (mean: 0.58\u0026thinsp;\u0026plusmn;\u0026thinsp;1.01; median: 0.32; range: 0.06\u0026ndash;4.49; interquartile range: 0.17\u0026ndash;0.49) vs. after (mean: 0.31\u0026thinsp;\u0026plusmn;\u0026thinsp;1.62; median: 0.30; range: 0.04\u0026ndash;0.76; interquartile range: 0.18\u0026ndash;0.65) cycling (p\u0026thinsp;=\u0026thinsp;0.8). However, the individual change in Hmax/Mmax following cycling varied substantially from a decrease by 83.7% in participant #4 to an increase by 657.8% in participant #12 (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Hmax/Mmax decreased by at least 10% after cycling in 9 individuals (2 AIS grade A, 4 AIS grade B, 2 AIS grade C, 1 AIS grade D), and increased by at least 10% in 6 individuals (3 AIS grade D, 2 AIS grade B, 1 AIS grade C). The change in Hmax/Mmax after cycling was less than 10% in only 3 participants (1 AIS grade A, 2 AIS grade C).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eSpecifically for AIS grade A participants, Hmax/Mmax increased after cycling in all individuals with a cervical NLI and decreased after cycling in all individuals with a thoracic NLI. There was no clear trend observed for participants with AIS grade B or C lesions, as opposite changes in Hmax/Mmax were observed among some participants despite having the same AIS grade and NLI. One individual with a C4 AIS grade B lesion (participant #10) had a 36.0% increase in Hmax/Mmax, while the two others with the same lesion (participants # 9 and #18) had a decrease in Hmax/Mmax by 18.9% and 68.6%, respectively. Of the 3 individuals with a C5 AIS grade C lesion, Hmax/Mmax increased by 657.8% in participant #12, while it decreased by 22.1% in participant #11 and remained stable (-0.4%) in participant #3. In the individual with mild AIS grade D SCI (C4 NLI with motor score of 81), Hmax/Mmax decreased by 30.6% after cycling, which is in the same range at the decreases in Hmax/Mmax observed in the healthy controls.\u003c/p\u003e \u003cp\u003eOf the 9 individuals who performed cycling within a week of the injury, Hmax/Mmax decreased by at least 10% in 4 individuals (C4 AIS grade B, C8 AIS grade B, C5 AIS grade C, C4 AIS grade B), increased by at least 10% in 4 individuals (C5 AIS grade A, C5 AIS grade C, C6 AIS grade B, C3 AIS grade A), and remained stable in 1 individual (C6 AIS grade A). However, Hmax/Mmax did not increase in any of the 5 individuals performing the cycling 2 weeks or more after the injury. Of note, all 4 individuals with a cervical AIS grade A lesion were tested within 2 weeks of the injury, and had an increase in Hmax/Mmax after cycling. Of the 9 participants who performed cycling more than one week following the injury, Hmax/Mmax increased in only 2 individuals (11 days for participant #10 and 12 days for participant #8).\u003c/p\u003e \u003cp\u003eAmong the 4 participants taking baclofen to alleviate their spasticity, Hmax/Mmax decreased by 30% or more in 3 individuals (C2 AIS grade C, T6 AIS grade A, C4 AIS grade D), and increased by 64.8% in the other individual (C5 AIS grade A). Of the 10 participants younger than 60 years old, Hmax/Mmax decreased by at least 10% in 3 individuals (T6 AIS grade A, C4 AIS grade B, C8 AIS grade B), increased by 10% or more in 4 individuals (C5 AIS grade A, C4 AIS grade B, C6 AIS grade B, C3 AIS grade A), and remained within a 10% increase in 3 individuals (C5 AIS grade C, C6 AIS grade A, C7 AIS grade C). For those older than 60 years old, Hmax/Mmax decreased by at least 10% in 6 individuals (T4 AIS grade B, T3 AIS grade A, C2 AIS grade C, C4 AIS grade D, C5 AIS grade C, C4 AIS grade B), and increased by 10% or more in 2 individuals (C5 AIS grade A, C5 AIS grade C).\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eOur study reports the changes in spinal cord excitability due to early leg cycling performed during the acute phase after traumatic SCI, as early as 1 day following the SCI. It sheds new light on the possible impact of initiating early acute activity-based therapy on spinal cord excitability and its potential to harness adaptive neuroplasticity after traumatic SCI, that have been demonstrated previously in preclinical studies. We used H-reflex testing to assess spinal cord excitability because it is recognized as a relevant tool to study plasticity of the nervous system [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Our study shows that after acute traumatic SCI, modulation of spinal cord excitability can be achieved from early acute cycling \u0026ndash; as soon as 1 day after the injury \u0026ndash;, even if performed passively in the presence of severe (or complete) paralysis of the lower extremities. This finding suggests that the afferent input (proprioceptive and plantar pressure) may be sufficient to modulate spinal cord excitability, in agreement with animal studies of early acute activity-based therapy showing that even limited sensory feedback may be sufficient to improve motor function [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. However, it remains to be determined from future studies whether providing a full daily program of early acute activity-based therapy in the form of in-bed cycling would translate into adaptive plasticity and improved recovery.\u003c/p\u003e \u003cp\u003eOur findings with previous studies of chronic SCI [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] showing that spinal cord excitability systematically decreases when it is assessed months or years after SCI. Our study shows that there are three main phenotypes and large variability with regard to spinal cord excitability in response to leg cycling during the acute phase days to weeks after traumatic SCI. Most individuals (9/18) had decreased excitability after cycling, although a large proportion of individuals (6/18) had increased excitability after cycling. A third group (3/18) did not exhibit any significant response from cycling. Observing different phenotypes in response to cycling within days/weeks after the SCI \u0026ndash; as opposed to the systematic decrease when performed months/years after the SCI \u0026ndash; suggests that starting activity-based therapy early vs. later after a SCI may result in different neuroplasticity and recovery processes, in agreement with preclinical studies showing that neurofunctional recovery is influenced by the timing at which activity-based therapy is introduced after the SCI [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSurprisingly, some participants with the same SCI severity had completely different responses to cycling, further suggesting that the impact of cycling remains unpredictable during the acute phase, particularly for individuals with AIS grade B and C lesions (see Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e for participants with C4 AIS grade B and C5 AIS grade C lesions). However, the response to cycling was more consistent for complete AIS grade A SCI since all 4 participants with a cervical lesion exhibited increased spinal cord excitability after cycling \u0026ndash; including 3 with more than 10% increase \u0026ndash;, and the 2 participants with a thoracic lesion exhibited decreased excitability. The presence of preexisting degenerative cervical myelopathy can potentially influence spinal cord excitability and the response to cycling since the 3 participants with more than 10% increase in Hmax/Mmax had underlying cervical spinal stenosis on MRI contributing to the SCI. Alternatively, the discrepancy between complete cervical and thoracic lesions could partly be explained by different pathophysiological processes involved in cervical vs. thoracic injuries considering that complete thoracic SCI are typically associated with trauma of higher energy and poorer potential for recovery [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAs for mild AIS grade D SCI, our study does not provide definite conclusions, as there was only one participant with such injury. Nevertheless, the decrease in spinal cord excitability observed in this participant after cycling was in the same range as that observed in healthy controls. This suggests that individuals with the mildest injuries are more likely to exhibit decreased spinal cord excitability after early acute cycling, which is usually observed in normal individuals after cycling. Accordingly, our findings in healthy controls are consistent with the H-reflex attenuation normally observed during either passive or active cycling in healthy individuals [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWe did not observe any clear tendency in the response to cycling based on age or on the concomitant use of baclofen. The impact of the timing of cycling session on the direction or magnitude of change in spinal cord excitability was not consistent throughout the entire cohort. However, there was no occurrence of increase in spinal cord excitability in any of the 5 individuals (1 AIS grade A, 1 AIS grade B, 2 AIS grade C, 1 AIS grade D) performing the cycling session 2 weeks or more after the SCI, which is similar to the observations in individuals with chronic SCI for whom spinal reflex excitability was reduced with activity-based therapy [\u003cspan additionalcitationids=\"CR23 CR24\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Conversely for the 13 individuals who performed their cycling session within 2 weeks of the injury, 7 had increased spinal cord excitability after cycling, 5 had decreased spinal cord excitability, and 1 did not respond to cycling. Of note, all 4 individuals with a complete AIS grade A cervical SCI performed cycling within 2 weeks of the injury and had an increase in spinal cord excitability. Further study is needed to determine whether performing cycling sessions earlier after the injury increases the probability of increasing spinal cord excitability, particularly for individuals with complete lesions for whom the spinal shock could be more severe and prolonged. Whether increasing spinal cord excitability early after the SCI is beneficial for accelerating the resolution of the spinal shock, harnessing adaptive plasticity and/or promoting recovery remains unknown, and cannot be answered from the current study.\u003c/p\u003e \u003cp\u003e \u003cb\u003eLimitations\u003c/b\u003e The conclusions are limited by the small number of participants, and further study is required to identify predictors of changes in spinal cord excitability due to cycling. In addition, the response to a single cycling session cannot directly be translated into the outcomes with a full program of activity-based therapy for which sustained daily sessions of cycling would be performed. It is also possible that the impact of cycling on spinal cord excitability varies along the course of activity-based therapy. Conducting a study involving a full program of activity-based therapy is therefore needed to determine the relationship between the direction (increase vs. decrease) and magnitude of change in spinal cord excitability, plasticity and recovery.\u003c/p\u003e "},{"header":"Conclusion","content":"\u003cp\u003e Overall, this study shows that spinal cord excitability may be modulated by in-bed leg cycling after acute spinal cord injury, even when performed passively. Performing in-bed leg cycling within 2 weeks of a traumatic SCI had variable impact on H-reflex (increase, decrease or no effect). When performed more than 2 weeks after the injury, H-reflex was more likely to be decreased after cycling. Further study is required to assess the relationship between initiating in-bed leg cycling during acute care to provide early acute activity-based therapy, neuroplasticity and recovery.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eDECLARATION OF INTERESTS\u003c/h2\u003e \u003cp\u003eXT received a scholarship from the PRogramme d\u0026rsquo;Excellence en M\u0026eacute;decine pour l\u0026rsquo;Initiation en Recherche (PREMIER).\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFUNDING\u003c/h2\u003e \u003cp\u003eThis work was supported by the PRogramme d\u0026rsquo;Excellence en M\u0026eacute;decine pour l\u0026rsquo;Initiation en Recherche (PREMIER); by the Fonds de Recherche du Qu\u0026eacute;bec \u0026ndash; Sant\u0026eacute; [grant number 309745]; and by the Medtronic Chair in Spinal Trauma at Universit\u0026eacute; de Montr\u0026eacute;al.\u003c/p\u003e \u003cp\u003e \u003cspan type=\"BoldUnderline\" class=\"BoldUnderline\" name=\"Emphasis\"\u003eETHICAL APPROVAL\u003c/span\u003e \u003c/p\u003e \u003cp\u003eAll experimental procedures were approved by the \u003cem\u003eComit\u0026eacute; d\u0026rsquo;\u0026Eacute;thique de la recherche du CIUSSS du Nord-de-L\u0026rsquo;\u0026Icirc;le de Montr\u0026eacute;al\u003c/em\u003e (\u0026ldquo;Mobilisation pr\u0026eacute;coce suite \u0026agrave; une l\u0026eacute;sion m\u0026eacute;dullaire\u0026rdquo;, study #2020\u0026thinsp;\u0026minus;\u0026thinsp;1901, approved on March 12th, 2020). Participants provided written informed consent prior to enrollment in the study.\u003c/p\u003e\u003ch2\u003eAUTHOR CONTRIBUTIONS\u003c/h2\u003e \u003cp\u003eXT was involved in data curation, formal analysis, investigation, methodology, validation, writing original draft, and reviewing \u0026amp; editing manuscript.\u003c/p\u003e\n\u003ch3\u003eDATA AVAILABILITY STATEMENT\u003c/h3\u003e\n\u003cp\u003eThe data that support the findings of this study are not publicly available. Data are, however, available from the authors upon reasonable request and with permission from the Ethics committee.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLevasseur A, Mac-Thiong JM, Richard-Denis A. Are early clinical manifestations of spasticity associated with long-term functional outcome following spinal cord injury? A retrospective study. 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Arch Phys Med Rehabil. 2017;98(6):1132\u0026ndash;1138.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNardone R, Orioli A, Golaszewski S, Brigo F, Sebastianelli L, Holler Y, et al. Passive cycling in neurorehabilitation after spinal cord injury: a review. J Spinal Cord Med. 2017;40(1):8\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSandrow-Feinberg HR, Houle JD. Exercise after spinal cord injury as an agent for neuroprotection, regeneration and rehabilitation. Brain Res. 2015;1619:12\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBehrman AL, Ardolino EM, Harkema SJ. Activity-based therapy: from basic science to clinical application for recovery after spinal cord injury. J Neurol Phys Ther. 2017;41 Suppl 3:S39-S45.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBasso DM, Hansen CN. Biological basis of exercise-based treatments: spinal cord injury. PM R. 2011;3(6 Suppl 1):S73-S77.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrown AK, Woller SA, Moreno G, Grau JW, Hook MA. Exercise therapy and recovery after SCI: evidence that shows early intervention improves recovery of function. Spinal Cord. 2011;49(5):623\u0026ndash;628.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHutchinson KJ, Gomez-Pinilla F, Crowe MJ, Ying Z, Basso DM. Three exercise paradigms differentially improve sensory recovery after spinal cord contusion in rats. Brain. 2004;127(Pt 6):1403\u0026ndash;1414.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFouad K, Tetzlaff W. Rehabilitative training and plasticity following spinal cord injury. Exp Neurol. 2012;235(1):91\u0026ndash;99.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCaudle KL, Brown EH, Shum-Siu A, Burke DA, Magnuson TS, Voor MJ, et al. Hindlimb immobilization in a wheelchair alters functional recovery following contusive spinal cord injury in the adult rat. Neurorehabil Neural Repair. 2011;25(8):729\u0026ndash;739.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMorioka K, Tazoe T, Huie JR, Hayakawa K, Okazaki R, Guandique CF, et al. Disuse plasticity limits spinal cord injury recovery. iScience. 2025;28(4):112180.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMisiaszek JE, Brooke JD, Lafferty KB, Cheng J, Staines WR. Long-lasting inhibition of the human soleus H reflex pathway after passive movement. Brain Res. 1995;677(1):69\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePhadke CP, Vieira L, Mathur S, Cipriano G Jr, Ismail F, Boulias C. Impact of passive leg cycling in persons with spinal cord injury: a systematic review. Top Spinal Cord Inj Rehabil. 2019;25(1):83\u0026ndash;96.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKnikou M. The H-reflex as a probe: pathways and pitfalls. J Neurosci Methods. 2008;171(1):1\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMisiaszek JE. The H-reflex as a tool in neurophysiology: its limitations and uses in understanding nervous system function. Muscle Nerve. 2003;28(2):144\u0026ndash;160.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCourtine G, Gerasimenko Y, van den Brand R, Yew A, Musienko P, Zhong H, et al. Transformation of nonfunctional spinal circuits into functional states after the loss of brain input. Nat Neurosci. 2009;12(10):1333\u0026ndash;1342.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBourassa-Moreau E, Mac-Thiong JM, Li A, Ehrmann Feldman D, Gagnon DH, Thompson C, et al. Do patients with complete spinal cord injury benefit from early surgical decompression? Analysis of neurological improvement in a prospective cohort study. J Neurotrauma. 2016;33(3):301\u0026ndash;306.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMotl RW, Knowles BD, Dishman RK. Acute bouts of active and passive leg cycling attenuate the amplitude of the soleus H-reflex in humans. Neurosci Lett. 2003;347(2):69\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKnikou M. Plasticity of corticospinal neural control after locomotor training in human spinal cord injury. Neural Plast. 2012;2012:254948.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePhadke CP, Flynn SM, Thompson FJ, Behrman AL, Trimble MH, Kukulka CG. Comparison of single bout effects of bicycle training versus locomotor training on paired reflex depression of the soleus H-reflex after motor incomplete spinal cord injury. Arch Phys Med Rehabil. 2009;90(7):1218\u0026ndash;1228.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePiazza S, Gomez-Soriano J, Bravo-Esteban E, Torricelli D, Avila-Martin G, Galan-Arriero I, et al. Maintenance of cutaneomuscular neuronal excitability after leg-cycling predicts lower limb muscle strength after incomplete spinal cord injury. Clin Neurophysiol. 2016;127(6):2402\u0026ndash;2409.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eThompson AK, Wolpaw JR. H-reflex conditioning during locomotion in people with spinal cord injury. J Physiol. 2021;599(9):2453\u0026ndash;2469.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"spinal-cord","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"sc","sideBox":"Learn more about [Spinal Cord](http://www.nature.com/sc/)","snPcode":"41393","submissionUrl":"https://mts-sc.nature.com/cgi-bin/main.plex","title":"Spinal Cord","twitterHandle":"@journalsci","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-9361655/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9361655/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e \u003cb\u003eStudy Design\u003c/b\u003e: Prospective exploratory interventional study.\u003c/p\u003e \u003cp\u003e \u003cb\u003eObjective\u003c/b\u003e: This study evaluates the impact of in-bed leg cycling on spinal cord excitability during the acute phase following acute traumatic spinal cord injury (SCI).\u003c/p\u003e \u003cp\u003e \u003cb\u003eSetting\u003c/b\u003e: Level 1 trauma center specialized in SCI care in Montreal, Canada.\u003c/p\u003e \u003cp\u003e \u003cb\u003eMethods\u003c/b\u003e: Eighteen participants with traumatic SCI underwent a single 30-minute session of in-bed leg cycling during acute hospitalization, with motor assistance as needed. Using soleus H-reflex testing, H-reflex and M-wave responses were recorded pre- and post-session to assess the change in spinal cord excitability.\u003c/p\u003e \u003cp\u003e \u003cb\u003eResults\u003c/b\u003e: Changes in H-reflex parameters were observed after cycling even when performed passively. There were three main phenotypes but also large variability with regard to spinal cord excitability in response to cycling. Most individuals (9/18) had decreased excitability after cycling, while 6/18 individuals had increased excitability. A third group (3/18) did not exhibit any significant response to cycling. Spinal cord excitability never increased after cycling when performed 2 weeks or more after the SCI.\u003c/p\u003e \u003cp\u003e \u003cb\u003eConclusions\u003c/b\u003e: Performing in-bed leg cycling during the acute phase following traumatic SCI appears to modulate spinal cord excitability, but responses are highly individualized.\u003c/p\u003e","manuscriptTitle":"Determining the impact of in-bed leg cycling on spinal cord excitability during the acute phase following spinal cord injury","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-26 15:32:10","doi":"10.21203/rs.3.rs-9361655/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"This content is not available.","date":"2026-04-20T18:27:44+00:00","index":1,"fulltext":"This content is not available."},{"type":"reviewersInvited","content":"","date":"2026-04-16T08:25:58+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-09T11:07:32+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-09T11:05:30+00:00","index":"","fulltext":""},{"type":"submitted","content":"Spinal Cord","date":"2026-04-09T00:46:06+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"spinal-cord","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"sc","sideBox":"Learn more about [Spinal Cord](http://www.nature.com/sc/)","snPcode":"41393","submissionUrl":"https://mts-sc.nature.com/cgi-bin/main.plex","title":"Spinal Cord","twitterHandle":"@journalsci","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"26ca9700-499a-4d3c-b824-5c4d473a96cd","owner":[],"postedDate":"April 26th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":66430457,"name":"Health sciences/Medical research/Translational research"},{"id":66430458,"name":"Health sciences/Health care/Therapeutics/Rehabilitation"},{"id":66430459,"name":"Health sciences/Diseases/Neurological disorders/Spinal cord diseases"}],"tags":[],"updatedAt":"2026-04-26T15:32:11+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-26 15:32:10","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9361655","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9361655","identity":"rs-9361655","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}