Arch support insoles reduce fatigue of the lower extremity muscles in people with flatfoot during a walking task

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This study investigated whether arch support insoles (ASIs) can reduce fatigue of the lower extremity muscles during a walking task in people with flatfoot compared with flat insoles (FIs). A total of fifteen female college students with flatfoot were recruited and considered eligible for the study, with each subject fulfilling the inclusion criteria of Chippaux-Smirak index > 45%. A paired sample t test was used to compare the difference in power spectral area (PSA) of the subdivided frequency band interval of 20–140 Hz between ASIs and FIs. A Wilcoxon test was used for assessing nonnormal data. Effect size (ES) was calculated as a measure of the practical relevance of the significance by using Cohen’s d . The results showed that the PSA of the RF muscles (P < 0.05; ES = 0.90) during uphill walking and of the RF (P < 0.05; ES = 1.21) and TA muscles (P < 0.05; ES = 0.61) during downhill walking was significantly smaller for ASIs than for FIs. The current evidence suggests that ASIs alleviates RF muscle fatigue during uphill walking and relieves RF and TA muscle fatigue during downhill walking. Health sciences/Health care/Health services/Rehabilitation Health sciences/Health care/Diagnosis/Electrodiagnosis/Electromyography emg pes planus pes cavus injury prevention power spectral area electromyography biomechanics Figures Figure 1 Figure 2 Introduction The human foot supports the body while walking, which is crucial for maintaining overall health. A research report states that when women walk regularly for 150 minutes per week 1 , 53% of them experience improvements in their body mass index and overall health status. Walking not only improves stride, endurance, and perception abilities 2 but also increases gait stability 3 . Walking makes use of the arch of the foot, which is made up of the tarsal and metatarsal bones. This improves walking efficiency, protects tissues, and increases foot elasticity. Bone connections, plantar ligament support, and tendon pull are necessary for the arch's stability. Despite their strength, ligaments are unable to actively contract. Flat feet can easily result from arch collapse caused by overstretching or injury 4 . Many people who want to perform prolonged walking exercises, such as hiking, are impeded by a flatfoot, which is a major pathological foot deformation caused by the collapse of the foot medial arch 5 . The flatfoot demonstrates pronation of the subtalar joint of the ankle and knee valgus, thereby increasing the risk of injury 5 . Recent studies have shown that walking duration (10 and 20 min) has no effect of muscle fatigue on leg, but walking speed (3.6 and 5.4 mph) does 6 . It's unclear, though, if adding the factor of slope can also cause leg muscle fatigue. In preliminary studies, our team employed a plantar pressure analysis system to identify how various slopes affected the flatfoot population. We found that the use of foot orthotics could improve the walking stance time of females 7 . Unfortunately, the function of neuromuscular recruitment of the lower extremities was not observed. Walking with flat feet has been shown to cause foot pain in several studies 8 , but it is still unclear whether this is due to fatiguability of muscle or something else. To alleviate discomfort in people with flatfoot, noninvasive treatments, such as arch support insoles (ASIs) and foot taping, are often suggested to effectively reduce the rate of loading in specific foot regions, delay the time to peak eversion angle of the foot 9 , and redistribute the plantar pressure during walking 10 . ASIs may alleviate flatfoot symptoms. Foot insoles have been shown in recent studies to enhance the evaluation of walking-related fatigue and muscle activity such as tibialis anterior, rectus femoris, gastrocnemius, biceps femoris, and lumbar erector spinae 11 . Studies have indicated that walking on uphill terrains increases extensor muscle loading in the lower extremity 12 and further produces large fluctuations in kinetic energy 13 and metabolic cost 14 . Moreover, it can cause fatigue in the lower extremity muscles, which may be frequent among people with flatfoot. Few studies have evaluated downhill walking in people with flatfoot. This study investigated whether ASIs can reduce lower extremity muscle fatigue during uphill and downhill walking in people with flatfoot. We hypothesized that compared with a flat insole (FIs), ASIs would effectively reduce muscle activity in people with flatfoot during uphill and downhill walking. Materials and Methods Participants Fifteen female college students (age: 19.7 ± 4.3 years, height: 160.1 ± 6.0 cm, weight: 56.5 ± 6.7 kg) diagnosed with flatfoot (Chippaux–Smirak index: 64% ± 9%) were recruited for the study, without lower limb injuries, and without a history of surgery within 1 year were included. All participants provided written informed consent prior to inclusion in the study. The Chippaux–Smirak index for each participant’s static footprint was calculated as the foot width at the narrowest point divided by that at the widest point times 100 15 . CSI = foot narrowest point/ foot widest point x100 Participants with Chippaux–Smirak index greater than 45% for both feet were considered to have flatfoot 16 . A priori sample size was calculated using G*Power (3.1.9.2, Franz Faul, University of Kiel, Kiel, Germany), with a power level of 80% and an α level of 0.05 17 . The expected effect size (ES) was calculated using mean (− 1.90 and − 0.83) and standard deviation (1.60 and 1.10) of the median frequency of the rectus femoris (RF) muscle when the participants used ASIs or FIs 18 . This study was approved by the Institutional Review Board of Antai Medical Care Corporation, Antai Tian-Sheng Memorial Hospital (TSMH, approval number 16-107-B1). All methods were performed in accordance with the relevant guidelines and regulations. Procedures The participants were requested to wear the same type of shoes (Arthur Ashe Int Low Python All Over, Le Coq Sportif, France) with either a prefabricated ASIs (Footdisc, Inc., Taipei, Taiwan) or a FIs (Arthur Ashe Int Low Python All Over, Le Coq Sportif, France; Fig. 1 ) in random order and perform a 3-min warm-up on a treadmill at a self-selected pace. After the warm-up, the hair on each participant’s skin was carefully shaved and the skin was abraded and cleaned with alcohol before the attachment of surface EMG sensors (Delsys, Trigno Wireless, Inc., Boston, MA, USA). The sensors were adhered parallel to the muscle belly of the participant’s right leg following the direction of muscle fibers. The placements of sensors for the rectus femoris (RF), biceps femoris (BF), gastrocnemius (GAS), and tibialis anterior (TA) muscles were performed as described by Cram et al. 19 . Subsequently, the participants were instructed to perform 6-min uphill and downhill walking on a treadmill (XG-1812X; New Noble Sport Equipment Co. Ltd., Ningbo, China), with a slope of 9 degree 20 , 21 and a speed of 0.75 m/s (2.7 km/h) 20 , 21 . Uphill and downhill walking tests were performed on different days 22 , with the participants resting for 6 min between trials with different insoles. A hardness tester (Teclock GS-709N Type A, Teclock Co., Tokyo, Japan) was used to measure the hardness values of the flat insole and arch-support insole's forefoot, midfoot, and heel sections 7 (Table 1 ). Table 1 Hardness and height of the insole. Forefoot Height (pointer) (cm) Midfoot Height (pointer) (cm) Heel Height (pointer) (cm) FIs 34.2 ± 0.8 0.4 19 ± 1.2 0.4 34.8 ± 0.8 0.4 ASIs 20.6 ± 1.1 0.4 60.0 ± 0.7 2.2 20.6 ± 1.5 3.2 ----- Insert Fig. 1 around here ----- ----- Insert Table 1 around here ----- Data processing EMG data were recorded using preamplified bipolar surface EMG sensors with a 2000 Hz sampling rate. The raw EMG signals from 5 to 6 min of the 6-min walking were selected and band-pass filtered between 20 and 450 Hz for the analysis by using an EMG software (EMGworks 3.4, Delsys Inc., Boston, MA, USA). Subsequently, the signals were transformed into power spectral density by using fast Fourier transform 23 . The power spectral density was estimated using a periodogram with a 0.5-s window length and 75% overlap 24 . In the frequency domain graph, the power spectral area (PSA) was subdivided into frequency bands of 20–140 Hz 23 . Using the example of walking uphill, Fig. 2 shows the recruitment characteristics of the muscles of the lower extremities when wearing ASIs and FIs. Localized muscle fatigue is associated with a left shift toward lower frequencies in a power spectral density graph of an EMG signal, and a large PSA of the subdivided frequency band intervals represents muscle fatigue 23 . ----- Insert Fig. 2 around here ----- Statistical analysis SPSS 18.0 (SPSS Science Inc., Chicago, IL, USA) for Windows was used for statistical analysis. A Kolmogorov–Smirnov test was used to evaluate the data normality. A paired sample t test was used to compare ASIs and FIs in the subdivided frequency band of 20–140 Hz. A Wilcoxon test was used for assessing nonnormal data. The coefficient of variation (CV) was calculated for ASIs and FIs in the subdivided frequency band of 20–140 Hz. The value of coefficients of variation was calculate as follow: Coefficient of Variation (CV) = (Standard Deviation/Mean) × 100% 25 This refers to comparing variability within significantly different groups and is used to assess how reliable a particular test is 25 . In other words, the CV value may indicate the response of muscle activity. The level of significance was set at P < 0.05. ES values for the difference between ASIs and FIs were calculated for each variable as a measure of the practical relevance of the significance by using Cohen’s d . ES values between 0.20 and 0.49 were considered small, those between 0.50 and 0.79 moderate, and those 0.80 and above large 26 . Results Table 2 lists the comparisons of PSA and CV between ASIs and FIs for the RF, TA, BF, and GAS muscles. Table 2 Comparison of PSA and CV between ASI and FI (unit: Hz*V) PSA ASIs FIs CV (%) p ES ASI FI Uphill walking RF* TA BF GAS 186.08 ± 76.66 949.87 ± 452.06 237.31 ± 101.99 1228.02 ± 853.26 271.03 ± 108.63 1150.03 ± 599.84 463.96 ± 624.23 1325.02 ± 943.55 41 48 43 70 40 52 135 71 0.019 0.113 0.180 0.342 0.90 0.38 0.51 0.11 Downhill walking RF* TA* BF GAS 256.67 ± 94.09 562.42 ± 390.87 407.47 ± 502.42 284.02 ± 145.79 506.36 ± 277.50 1054.41 ± 1079.33 993.49 ± 828.72 364.27 ± 170.76 37 70 123 51 55 102 83 47 0.016 0.039 0.061 0.174 1.21 0.61 0.86 0.51 Level walking RF TA BF GAS 88.90 ± 128.92 785.10 ± 1018.13 569.37 ± 782.58 1203.85 ± 801.70 570.10 ± 1791.74 799.20 ± 1162.97 365.30 ± 409.36 1238.93 ± 841.80 145 129 137 66 314 145 112 68 0.298 0.791 0.204 0.486 0.38 0.01 0.33 0.04 * Significant difference found. PSA = power spectrum areas, ASIs = arch support insoles, FIs = flat insoles, CV = coefficient of variation, RF = rectus femoris, TA = tibialis anterior, BF = biceps femoris, GAS = gastrocnemius, p < .05. We discovered that the PSA of the RF muscles during uphill walking ( P = 0.019, ES = − 0.90) and of the RF and TA muscles during downhill walking ( P = 0.016, ES = − 1.21; P = 0.039, ES = − 0.61, respectively) was significantly smaller for ASIs than for FIs in the 20–140 Hz. The CV of the RF, TA, BF, and GAS muscles for ASI was in the range of 37–41%, 48–70%, 43–123%, and 51–70%, respectively, during uphill and downhill walking. The CV of the RF, TA, BF, and GAS muscles for FI was in the range of 40–55%, 52–102%, 83–135%, and 47–71%, respectively, during uphill and downhill walking. The CV of the RF, TA, BF, and GAS muscles for ASI and FI was in the range of 145–314%, 129–145%, 137–112%, and 66–68% during a level walking task. There was a trend that the CV of the arch support insole was smaller than that of the flat insole in the muscles during uphill and downhill walking. ----- Insert Table 2 around here ----- Discussion ASIs significantly reduced RF muscle fatigue during uphill walking and RF and TA muscle fatigue during downhill walking in people with flatfoot. The RF and TA muscles in the participants using ASIs demonstrated small CVs of the PSA, representing consistent muscle synergy for stabilization during uphill and downhill walking. Our results demonstrated that ASIs reduced RF muscle activity compared with FIs; therefore, ASIs can assist in retaining the crucial role of the RF muscle during uphill walking. The RF is a biarticular muscle among the quadriceps 27 , extending from the proximal region of the hip joint to the distal region of the knee joint 28 . It is the main knee extension muscle to support the body weight during the stance phase of the gait cycle and is essential to maintain the dynamic stability of the patellofemoral joint 29 , 30 . When walking uphill, the hip and knee extensor moments get ready to support the body weight 31 during the early stance phase. The RF muscle prepares for synergistic movement during the early stance phase of the gait cycle to control body weight shift 32 , and the hip extensor moment increases with the incremental slope in uphill walking to elevate the body’s center of mass 33 , 34 . RF activation can increase with the incremental slope of uphill walking because the extension of the corresponding knee joint by the RF assists the center of mass of the body to overcome the loading phase of the gait cycle, leading to both legs performing progressively greater positive work in terms of parallel ground reaction forces 35 . RF activation mainly provides stability to control knee extension and hip flexion during the stance-to-swing transition 36 , 27 . Moreover, it generates tension in the terminal swing in preparation for weight-bearing at initial contact and to control knee flexion during weight acceptance 27 . RF function may be augmented during downhill walking. The use of ASIs was also beneficial for the RF muscle during downhill walking in people with flatfoot. This finding is consistent with those of studies indicating that walking on declined surfaces increased RF activation more than walking on level surfaces 37 , 38 . The activation of knee extensors increased during downhill walking 20 , 38 ; moreover, with an increased decline in slope, knee joint loading increased 39 . A study indicated that knee flexor and extensor moment increased with increased inclination during downhill walking; moreover, increased knee flexion of the leading and trailing limbs with increased ankle dorsiflexion led to decreased hip extension 40 . This may assist in the maintenance of the center of mass of the body within the base of support 40 . ASIs also reduced TA muscle activity compared with FIs, indicating that ASIs can assist in retaining TA function during downhill walking. A study indicated that TA muscle activity reduced its ability to complete ankle dorsiflexion in recreational hikers during the swing phase of the gait cycle, which may further increase the risk of trips and falls 41 . Furthermore, TA muscle activity causes knee and hip musculature to assist the lower extremity in absorbing the impact forces 41 . TA muscle activity may be associated with the continuous downward impact and ankle dorsiflexion for body support during downhill walking. During downhill walking, the center of mass of a body moves forward and far away from the base of support for the next gait cycle. A study indicated that ankle dorsiflexion and knee flexion increased with an incremental slope of downhill walking, thereby increasing the lever-arm lengths of the ground reaction force at the knee and knee extensor moments 40 . The CV of the RF and TA muscles in participants using ASIs was smaller than that in those using FIs during downhill walking. Coordination is crucial in downhill walking and depends on the activation of the lower extremity muscles 42 . The CV is a measure of the dispersion of data points around the mean 42 . The smaller CV of the RF and TA muscles in participants using ASIs may represent the consistency of muscle synergy for stabilization 43 . The results of CV and PSA, which measured muscle activity, confirmed our hypothesis that ASIs would effectively reduce RF and TA muscle activity compared with FIs. It should be noted that this study has certain limitations. First, despite the treadmill's constant speed, each participant's stride length varied and was not recorded. Second, the results might not apply to other populations because only female participants were enlisted. Third, only the static footprint index was used for evaluation, even though there are over 40 ways to assess a flatfoot 44 . Lastly, MVIC is a widely accepted standard procedure for measuring electromyography. We did not employ the MVIC method in this study because it might have an impact on our findings. We also employ the PSA area method as an alternative. Conclusion ASIs alleviated RF muscle activity during uphill walking in participants with flatfoot. Compared with FIs, ASIs relieved RF and TA muscle activity during downhill walking. Therefore, by lowering muscle activity, wearing ASIs during uphill and downhill walking exercises may help people with flat feet feel less fatigued. Declarations Data availability statement "The datasets used and/or analysed during the current study available from the corresponding author on reasonable request." Ethics statement The studies involving human participants were reviewed and approved by the Institutional Review Board of Antai Medical Care Corporation, Antai Tian-Sheng Memorial Hospital (TSMH, approval number 16-107-B1). The participants provided their written informed consent to participate in this study. Author contributions Conceptualization: Yu-ping Huang, Hsien-Te Peng. Data curation: Shapu Lu Bi. Formal analysis: Yu-ping Huang, Hsien-Te Peng, Shapu Lu Bi, Yan Wei, Yang Jeng-Sheng, De-jia Wang. Methodology: Yu-ping Huang, Hsien-Te Peng. Supervision: Shapu Lu Bi. Writing – original draft: Yu-ping Huang, Hsien-Te Peng. Writing – review & editing: Yan Wei, Yang Jeng-Sheng, Shapu Lu Bi, De-jia Wang. Funding This research was supported by the Ministry of Science and Technology of Taiwan (Grant No. MOST 106-2410-H-034-036) and was supported by the Ministry of Education of China (Grant No. 2408061632). Acknowledgments The authors acknowledge the laboratory of sports biomechanics, Chinese Culture University assisting in the preparation and management of the instrument and data. Conflict of interest The authors declare that there is no conflict of interest regarding the publication of this paper. Publisher’s note All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors, and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed, or endorsed by the publisher. References Romo-Perez, V., Souto, D. & Mota, J. 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Cite Share Download PDF Status: Published Journal Publication published 22 May, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 05 May, 2025 Reviews received at journal 29 Apr, 2025 Reviewers agreed at journal 06 Apr, 2025 Reviewers invited by journal 31 Mar, 2025 Submission checks completed at journal 27 Mar, 2025 First submitted to journal 22 Mar, 2025 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. 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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-5120168","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":436521967,"identity":"ea603c4f-0ef4-43eb-bd43-a9eb5f74c798","order_by":0,"name":"Yu-ping Huang","email":"","orcid":"","institution":"Nanning Normal University","correspondingAuthor":false,"prefix":"","firstName":"Yu-ping","middleName":"","lastName":"Huang","suffix":""},{"id":436521968,"identity":"551da45d-8e62-49a3-a8f6-b4384c0491ff","order_by":1,"name":"Dejia Wang","email":"","orcid":"","institution":"Nanning Normal University","correspondingAuthor":false,"prefix":"","firstName":"Dejia","middleName":"","lastName":"Wang","suffix":""},{"id":436521969,"identity":"2d78fa33-33f6-4393-8e76-b87b2331eb26","order_by":2,"name":"Shapu Lu Bi","email":"","orcid":"","institution":"Nanning Normal University","correspondingAuthor":false,"prefix":"","firstName":"Shapu","middleName":"Lu","lastName":"Bi","suffix":""},{"id":436521970,"identity":"ba3d33bf-d891-4741-87aa-cd223e85378f","order_by":3,"name":"Wei Yan","email":"","orcid":"","institution":"Chinese Culture University","correspondingAuthor":false,"prefix":"","firstName":"Wei","middleName":"","lastName":"Yan","suffix":""},{"id":436521972,"identity":"53b014f3-b25e-47d1-bc6b-868aa0b40dc1","order_by":4,"name":"Jeng-sheng Yang","email":"","orcid":"","institution":"Chinese Culture University","correspondingAuthor":false,"prefix":"","firstName":"Jeng-sheng","middleName":"","lastName":"Yang","suffix":""},{"id":436521974,"identity":"aa66d5c0-bbab-4391-ae70-9af2e18e2cda","order_by":5,"name":"Hsien-Te Peng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABAklEQVRIiWNgGAWjYDACZgaDAx//gFkHGBgbiNNieHAmWCVbApKWBLyajA/zglXyGBCnRb6decMB3h135Mz513yT+LnDRo6B/fDRDYw/DuPUYnCYreCA5JlnxpYz3m6T7D2TZszAk5Z2gyEBjxZmHoMDBmyHEzfcOLtNgrftcGKDBI8ZUMtt3A5rBmpJYDtcv+HGmWeSf4nRwnAYqOVg2+EEg/M9bNJE2QLyy8GGM88MN9xgM7aWbUszZgP5JSHtP26H9R/e/PlPxR15g/OHH95822Yjx89++NiNDzZpuB0GAQcYGCQSWCRATDYQkUBIA1gL/wHmD4QVjoJRMApGwUgEAPS1YLsuwVBjAAAAAElFTkSuQmCC","orcid":"","institution":"Chinese Culture University","correspondingAuthor":true,"prefix":"","firstName":"Hsien-Te","middleName":"","lastName":"Peng","suffix":""}],"badges":[],"createdAt":"2024-09-20 02:52:45","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5120168/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5120168/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-02623-6","type":"published","date":"2025-05-22T15:57:18+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":79753167,"identity":"874240da-07a6-4882-9a73-31dd621e0d00","added_by":"auto","created_at":"2025-04-02 09:49:45","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":367565,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(A) Arch support insoles (ASIs) and (B) flat insoles (FIs)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5120168/v1/21a4a12acf9eb27b28529df1.png"},{"id":79753168,"identity":"7dacf298-f6bd-4c65-b680-033cb1747151","added_by":"auto","created_at":"2025-04-02 09:49:45","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":404970,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eThe PSD graphs for walking uphill\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5120168/v1/a421226f2633db178a34bb58.png"},{"id":83460707,"identity":"23a1c5e7-85a1-433c-aae8-7c1e98258de9","added_by":"auto","created_at":"2025-05-26 16:13:41","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1548627,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5120168/v1/d6ac70c6-39c7-4af4-91e2-93213b828ddb.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Arch support insoles reduce fatigue of the lower extremity muscles in people with flatfoot during a walking task","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe human foot supports the body while walking, which is crucial for maintaining overall health. A research report states that when women walk regularly for 150 minutes per week \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e, 53% of them experience improvements in their body mass index and overall health status. Walking not only improves stride, endurance, and perception abilities \u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e but also increases gait stability \u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. Walking makes use of the arch of the foot, which is made up of the tarsal and metatarsal bones. This improves walking efficiency, protects tissues, and increases foot elasticity. Bone connections, plantar ligament support, and tendon pull are necessary for the arch's stability. Despite their strength, ligaments are unable to actively contract. Flat feet can easily result from arch collapse caused by overstretching or injury \u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eMany people who want to perform prolonged walking exercises, such as hiking, are impeded by a flatfoot, which is a major pathological foot deformation caused by the collapse of the foot medial arch \u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. The flatfoot demonstrates pronation of the subtalar joint of the ankle and knee valgus, thereby increasing the risk of injury \u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. Recent studies have shown that walking duration (10 and 20 min) has no effect of muscle fatigue on leg, but walking speed (3.6 and 5.4 mph) does \u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. It's unclear, though, if adding the factor of slope can also cause leg muscle fatigue. In preliminary studies, our team employed a plantar pressure analysis system to identify how various slopes affected the flatfoot population. We found that the use of foot orthotics could improve the walking stance time of females \u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. Unfortunately, the function of neuromuscular recruitment of the lower extremities was not observed. Walking with flat feet has been shown to cause foot pain in several studies \u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e, but it is still unclear whether this is due to fatiguability of muscle or something else.\u003c/p\u003e \u003cp\u003eTo alleviate discomfort in people with flatfoot, noninvasive treatments, such as arch support insoles (ASIs) and foot taping, are often suggested to effectively reduce the rate of loading in specific foot regions, delay the time to peak eversion angle of the foot \u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e, and redistribute the plantar pressure during walking \u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. ASIs may alleviate flatfoot symptoms. Foot insoles have been shown in recent studies to enhance the evaluation of walking-related fatigue and muscle activity such as tibialis anterior, rectus femoris, gastrocnemius, biceps femoris, and lumbar erector spinae \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eStudies have indicated that walking on uphill terrains increases extensor muscle loading in the lower extremity \u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e and further produces large fluctuations in kinetic energy \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e and metabolic cost \u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. Moreover, it can cause fatigue in the lower extremity muscles, which may be frequent among people with flatfoot. Few studies have evaluated downhill walking in people with flatfoot. This study investigated whether ASIs can reduce lower extremity muscle fatigue during uphill and downhill walking in people with flatfoot. We hypothesized that compared with a flat insole (FIs), ASIs would effectively reduce muscle activity in people with flatfoot during uphill and downhill walking.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eParticipants\u003c/h2\u003e \u003cp\u003eFifteen female college students (age: 19.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3 years, height: 160.1\u0026thinsp;\u0026plusmn;\u0026thinsp;6.0 cm, weight: 56.5\u0026thinsp;\u0026plusmn;\u0026thinsp;6.7 kg) diagnosed with flatfoot (Chippaux\u0026ndash;Smirak index: 64% \u0026plusmn; 9%) were recruited for the study, without lower limb injuries, and without a history of surgery within 1 year were included. All participants provided written informed consent prior to inclusion in the study. The Chippaux\u0026ndash;Smirak index for each participant\u0026rsquo;s static footprint was calculated as the foot width at the narrowest point divided by that at the widest point times 100 \u003csup\u003e15\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eCSI\u0026thinsp;=\u0026thinsp;foot narrowest point/ foot widest point x100\u003c/p\u003e \u003cp\u003eParticipants with Chippaux\u0026ndash;Smirak index greater than 45% for both feet were considered to have flatfoot \u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. A priori sample size was calculated using G*Power (3.1.9.2, Franz Faul, University of Kiel, Kiel, Germany), with a power level of 80% and an α level of 0.05 \u003csup\u003e17\u003c/sup\u003e. The expected effect size (ES) was calculated using mean (\u0026minus;\u0026thinsp;1.90 and \u0026minus;\u0026thinsp;0.83) and standard deviation (1.60 and 1.10) of the median frequency of the rectus femoris (RF) muscle when the participants used ASIs or FIs \u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. This study was approved by the Institutional Review Board of Antai Medical Care Corporation, Antai Tian-Sheng Memorial Hospital (TSMH, approval number 16-107-B1). All methods were performed in accordance with the relevant guidelines and regulations.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eProcedures\u003c/h3\u003e\n\u003cp\u003eThe participants were requested to wear the same type of shoes (Arthur Ashe Int Low Python All Over, Le Coq Sportif, France) with either a prefabricated ASIs (Footdisc, Inc., Taipei, Taiwan) or a FIs (Arthur Ashe Int Low Python All Over, Le Coq Sportif, France; Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) in random order and perform a 3-min warm-up on a treadmill at a self-selected pace. After the warm-up, the hair on each participant\u0026rsquo;s skin was carefully shaved and the skin was abraded and cleaned with alcohol before the attachment of surface EMG sensors (Delsys, Trigno Wireless, Inc., Boston, MA, USA). The sensors were adhered parallel to the muscle belly of the participant\u0026rsquo;s right leg following the direction of muscle fibers. The placements of sensors for the rectus femoris (RF), biceps femoris (BF), gastrocnemius (GAS), and tibialis anterior (TA) muscles were performed as described by Cram et al. \u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. Subsequently, the participants were instructed to perform 6-min uphill and downhill walking on a treadmill (XG-1812X; New Noble Sport Equipment Co. Ltd., Ningbo, China), with a slope of 9 degree \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e,\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e and a speed of 0.75 m/s (2.7 km/h) \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e,\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e. Uphill and downhill walking tests were performed on different days \u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e, with the participants resting for 6 min between trials with different insoles. A hardness tester (Teclock GS-709N Type A, Teclock Co., Tokyo, Japan) was used to measure the hardness values of the flat insole and arch-support insole's forefoot, midfoot, and heel sections \u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \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\u003eHardness and height of the insole.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eForefoot Height\u003c/p\u003e \u003cp\u003e(pointer) (cm)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMidfoot Height\u003c/p\u003e \u003cp\u003e(pointer) (cm)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eHeel Height\u003c/p\u003e \u003cp\u003e(pointer) (cm)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFIs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e34.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8 0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e19\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2 0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e34.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8 0.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eASIs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e20.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1 0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e60.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7 2.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e20.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5 3.2\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----- Insert Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e around here -----\u003c/p\u003e\u003cp\u003e----- Insert Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e around here -----\u003c/p\u003e\u003c/p\u003e\n\u003ch3\u003eData processing\u003c/h3\u003e\n\u003cp\u003eEMG data were recorded using preamplified bipolar surface EMG sensors with a 2000 Hz sampling rate. The raw EMG signals from 5 to 6 min of the 6-min walking were selected and band-pass filtered between 20 and 450 Hz for the analysis by using an EMG software (EMGworks 3.4, Delsys Inc., Boston, MA, USA). Subsequently, the signals were transformed into power spectral density by using fast Fourier transform \u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. The power spectral density was estimated using a periodogram with a 0.5-s window length and 75% overlap \u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. In the frequency domain graph, the power spectral area (PSA) was subdivided into frequency bands of 20\u0026ndash;140 Hz \u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. Using the example of walking uphill, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the recruitment characteristics of the muscles of the lower extremities when wearing ASIs and FIs. Localized muscle fatigue is associated with a left shift toward lower frequencies in a power spectral density graph of an EMG signal, and a large PSA of the subdivided frequency band intervals represents muscle fatigue\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e----- Insert Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e around here -----\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eSPSS 18.0 (SPSS Science Inc., Chicago, IL, USA) for Windows was used for statistical analysis. A Kolmogorov\u0026ndash;Smirnov test was used to evaluate the data normality. A paired sample \u003cem\u003et\u003c/em\u003e test was used to compare ASIs and FIs in the subdivided frequency band of 20\u0026ndash;140 Hz. A Wilcoxon test was used for assessing nonnormal data. The coefficient of variation (CV) was calculated for ASIs and FIs in the subdivided frequency band of 20\u0026ndash;140 Hz. The value of coefficients of variation was calculate as follow:\u003c/p\u003e \u003cp\u003eCoefficient of Variation (CV) = (Standard Deviation/Mean) \u0026times; 100% \u003csup\u003e25\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eThis refers to comparing variability within significantly different groups and is used to assess how reliable a particular test is \u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e. In other words, the CV value may indicate the response of muscle activity. The level of significance was set at \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05. ES values for the difference between ASIs and FIs were calculated for each variable as a measure of the practical relevance of the significance by using Cohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e. ES values between 0.20 and 0.49 were considered small, those between 0.50 and 0.79 moderate, and those 0.80 and above large \u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e lists the comparisons of PSA and CV between ASIs and FIs for the RF, TA, BF, and GAS muscles.\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\u003eComparison of PSA and CV between ASI and FI (unit: Hz*V)\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=\"left\" 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=\"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=\"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\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e \u003cp\u003ePSA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eASIs\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eFIs\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003eCV (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cem\u003eES\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eASI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUphill walking\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRF*\u003c/p\u003e \u003cp\u003eTA\u003c/p\u003e \u003cp\u003eBF\u003c/p\u003e \u003cp\u003eGAS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e186.08\u0026thinsp;\u0026plusmn;\u0026thinsp;76.66\u003c/p\u003e \u003cp\u003e949.87\u0026thinsp;\u0026plusmn;\u0026thinsp;452.06\u003c/p\u003e \u003cp\u003e237.31\u0026thinsp;\u0026plusmn;\u0026thinsp;101.99\u003c/p\u003e \u003cp\u003e1228.02\u0026thinsp;\u0026plusmn;\u0026thinsp;853.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e271.03\u0026thinsp;\u0026plusmn;\u0026thinsp;108.63\u003c/p\u003e \u003cp\u003e1150.03\u0026thinsp;\u0026plusmn;\u0026thinsp;599.84\u003c/p\u003e \u003cp\u003e463.96\u0026thinsp;\u0026plusmn;\u0026thinsp;624.23\u003c/p\u003e \u003cp\u003e1325.02\u0026thinsp;\u0026plusmn;\u0026thinsp;943.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e41\u003c/p\u003e \u003cp\u003e48\u003c/p\u003e \u003cp\u003e43\u003c/p\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e40\u003c/p\u003e \u003cp\u003e52\u003c/p\u003e \u003cp\u003e135\u003c/p\u003e \u003cp\u003e71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.019\u003c/p\u003e \u003cp\u003e0.113\u003c/p\u003e \u003cp\u003e0.180\u003c/p\u003e \u003cp\u003e0.342\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.90\u003c/p\u003e \u003cp\u003e0.38\u003c/p\u003e \u003cp\u003e0.51\u003c/p\u003e \u003cp\u003e0.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDownhill walking\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRF*\u003c/p\u003e \u003cp\u003eTA*\u003c/p\u003e \u003cp\u003eBF\u003c/p\u003e \u003cp\u003eGAS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e256.67\u0026thinsp;\u0026plusmn;\u0026thinsp;94.09\u003c/p\u003e \u003cp\u003e562.42\u0026thinsp;\u0026plusmn;\u0026thinsp;390.87\u003c/p\u003e \u003cp\u003e407.47\u0026thinsp;\u0026plusmn;\u0026thinsp;502.42\u003c/p\u003e \u003cp\u003e284.02\u0026thinsp;\u0026plusmn;\u0026thinsp;145.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e506.36\u0026thinsp;\u0026plusmn;\u0026thinsp;277.50\u003c/p\u003e \u003cp\u003e1054.41\u0026thinsp;\u0026plusmn;\u0026thinsp;1079.33\u003c/p\u003e \u003cp\u003e993.49\u0026thinsp;\u0026plusmn;\u0026thinsp;828.72\u003c/p\u003e \u003cp\u003e364.27\u0026thinsp;\u0026plusmn;\u0026thinsp;170.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e37\u003c/p\u003e \u003cp\u003e70\u003c/p\u003e \u003cp\u003e123\u003c/p\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e55\u003c/p\u003e \u003cp\u003e102\u003c/p\u003e \u003cp\u003e83\u003c/p\u003e \u003cp\u003e47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.016\u003c/p\u003e \u003cp\u003e0.039\u003c/p\u003e \u003cp\u003e0.061\u003c/p\u003e \u003cp\u003e0.174\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.21\u003c/p\u003e \u003cp\u003e0.61\u003c/p\u003e \u003cp\u003e0.86\u003c/p\u003e \u003cp\u003e0.51\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevel\u003c/p\u003e \u003cp\u003ewalking\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRF\u003c/p\u003e \u003cp\u003eTA\u003c/p\u003e \u003cp\u003eBF\u003c/p\u003e \u003cp\u003eGAS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e88.90\u0026thinsp;\u0026plusmn;\u0026thinsp;128.92\u003c/p\u003e \u003cp\u003e785.10\u0026thinsp;\u0026plusmn;\u0026thinsp;1018.13\u003c/p\u003e \u003cp\u003e569.37\u0026thinsp;\u0026plusmn;\u0026thinsp;782.58\u003c/p\u003e \u003cp\u003e1203.85\u0026thinsp;\u0026plusmn;\u0026thinsp;801.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e570.10\u0026thinsp;\u0026plusmn;\u0026thinsp;1791.74\u003c/p\u003e \u003cp\u003e799.20\u0026thinsp;\u0026plusmn;\u0026thinsp;1162.97\u003c/p\u003e \u003cp\u003e365.30\u0026thinsp;\u0026plusmn;\u0026thinsp;409.36\u003c/p\u003e \u003cp\u003e1238.93\u0026thinsp;\u0026plusmn;\u0026thinsp;841.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e145\u003c/p\u003e \u003cp\u003e129\u003c/p\u003e \u003cp\u003e137\u003c/p\u003e \u003cp\u003e66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e314\u003c/p\u003e \u003cp\u003e145\u003c/p\u003e \u003cp\u003e112\u003c/p\u003e \u003cp\u003e68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.298\u003c/p\u003e \u003cp\u003e0.791\u003c/p\u003e \u003cp\u003e0.204\u003c/p\u003e \u003cp\u003e0.486\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.38\u003c/p\u003e \u003cp\u003e0.01\u003c/p\u003e \u003cp\u003e0.33\u003c/p\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003e* Significant difference found. PSA\u0026thinsp;=\u0026thinsp;power spectrum areas, ASIs\u0026thinsp;=\u0026thinsp;arch support insoles, FIs\u0026thinsp;\u003cem\u003e=\u003c/em\u003e\u0026thinsp;flat insoles, CV\u0026thinsp;=\u0026thinsp;coefficient of variation, RF\u0026thinsp;=\u0026thinsp;rectus femoris, TA\u0026thinsp;=\u0026thinsp;tibialis anterior, BF\u0026thinsp;=\u0026thinsp;biceps femoris, GAS\u0026thinsp;=\u0026thinsp;gastrocnemius, \u003cem\u003ep\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;.05.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eWe discovered that the PSA of the RF muscles during uphill walking (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.019, ES\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.90) and of the RF and TA muscles during downhill walking (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.016, ES\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;1.21; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.039, ES\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.61, respectively) was significantly smaller for ASIs than for FIs in the 20\u0026ndash;140 Hz. The CV of the RF, TA, BF, and GAS muscles for ASI was in the range of 37\u0026ndash;41%, 48\u0026ndash;70%, 43\u0026ndash;123%, and 51\u0026ndash;70%, respectively, during uphill and downhill walking. The CV of the RF, TA, BF, and GAS muscles for FI was in the range of 40\u0026ndash;55%, 52\u0026ndash;102%, 83\u0026ndash;135%, and 47\u0026ndash;71%, respectively, during uphill and downhill walking. The CV of the RF, TA, BF, and GAS muscles for ASI and FI was in the range of 145\u0026ndash;314%, 129\u0026ndash;145%, 137\u0026ndash;112%, and 66\u0026ndash;68% during a level walking task. There was a trend that the CV of the arch support insole was smaller than that of the flat insole in the muscles during uphill and downhill walking.\u003c/p\u003e \u003cp\u003e----- Insert Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e around here -----\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eASIs significantly reduced RF muscle fatigue during uphill walking and RF and TA muscle fatigue during downhill walking in people with flatfoot. The RF and TA muscles in the participants using ASIs demonstrated small CVs of the PSA, representing consistent muscle synergy for stabilization during uphill and downhill walking.\u003c/p\u003e \u003cp\u003eOur results demonstrated that ASIs reduced RF muscle activity compared with FIs; therefore, ASIs can assist in retaining the crucial role of the RF muscle during uphill walking. The RF is a biarticular muscle among the quadriceps \u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e, extending from the proximal region of the hip joint to the distal region of the knee joint \u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e. It is the main knee extension muscle to support the body weight during the stance phase of the gait cycle and is essential to maintain the dynamic stability of the patellofemoral joint \u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e,\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e. When walking uphill, the hip and knee extensor moments get ready to support the body weight \u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e during the early stance phase. The RF muscle prepares for synergistic movement during the early stance phase of the gait cycle to control body weight shift \u003csup\u003e\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e, and the hip extensor moment increases with the incremental slope in uphill walking to elevate the body\u0026rsquo;s center of mass \u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e,\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eRF activation can increase with the incremental slope of uphill walking because the extension of the corresponding knee joint by the RF assists the center of mass of the body to overcome the loading phase of the gait cycle, leading to both legs performing progressively greater positive work in terms of parallel ground reaction forces \u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e. RF activation mainly provides stability to control knee extension and hip flexion during the stance-to-swing transition \u003csup\u003e\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e,\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e. Moreover, it generates tension in the terminal swing in preparation for weight-bearing at initial contact and to control knee flexion during weight acceptance \u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e. RF function may be augmented during downhill walking.\u003c/p\u003e \u003cp\u003eThe use of ASIs was also beneficial for the RF muscle during downhill walking in people with flatfoot. This finding is consistent with those of studies indicating that walking on declined surfaces increased RF activation more than walking on level surfaces \u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e,\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e. The activation of knee extensors increased during downhill walking \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e,\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e; moreover, with an increased decline in slope, knee joint loading increased \u003csup\u003e\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u003c/sup\u003e. A study indicated that knee flexor and extensor moment increased with increased inclination during downhill walking; moreover, increased knee flexion of the leading and trailing limbs with increased ankle dorsiflexion led to decreased hip extension \u003csup\u003e\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u003c/sup\u003e. This may assist in the maintenance of the center of mass of the body within the base of support \u003csup\u003e\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eASIs also reduced TA muscle activity compared with FIs, indicating that ASIs can assist in retaining TA function during downhill walking. A study indicated that TA muscle activity reduced its ability to complete ankle dorsiflexion in recreational hikers during the swing phase of the gait cycle, which may further increase the risk of trips and falls \u003csup\u003e\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e. Furthermore, TA muscle activity causes knee and hip musculature to assist the lower extremity in absorbing the impact forces \u003csup\u003e\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e. TA muscle activity may be associated with the continuous downward impact and ankle dorsiflexion for body support during downhill walking. During downhill walking, the center of mass of a body moves forward and far away from the base of support for the next gait cycle. A study indicated that ankle dorsiflexion and knee flexion increased with an incremental slope of downhill walking, thereby increasing the lever-arm lengths of the ground reaction force at the knee and knee extensor moments \u003csup\u003e\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe CV of the RF and TA muscles in participants using ASIs was smaller than that in those using FIs during downhill walking. Coordination is crucial in downhill walking and depends on the activation of the lower extremity muscles \u003csup\u003e\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u003c/sup\u003e. The CV is a measure of the dispersion of data points around the mean \u003csup\u003e\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u003c/sup\u003e. The smaller CV of the RF and TA muscles in participants using ASIs may represent the consistency of muscle synergy for stabilization \u003csup\u003e\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e. The results of CV and PSA, which measured muscle activity, confirmed our hypothesis that ASIs would effectively reduce RF and TA muscle activity compared with FIs.\u003c/p\u003e \u003cp\u003eIt should be noted that this study has certain limitations. First, despite the treadmill's constant speed, each participant's stride length varied and was not recorded. Second, the results might not apply to other populations because only female participants were enlisted. Third, only the static footprint index was used for evaluation, even though there are over 40 ways to assess a flatfoot \u003csup\u003e\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u003c/sup\u003e. Lastly, MVIC is a widely accepted standard procedure for measuring electromyography. We did not employ the MVIC method in this study because it might have an impact on our findings. We also employ the PSA area method as an alternative.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eASIs alleviated RF muscle activity during uphill walking in participants with flatfoot. Compared with FIs, ASIs relieved RF and TA muscle activity during downhill walking. Therefore, by lowering muscle activity, wearing ASIs during uphill and downhill walking exercises may help people with flat feet feel less fatigued.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability statement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\"The datasets used and/or analysed during the current study available from the corresponding author on reasonable request.\"\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics statement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe studies involving human participants were reviewed and approved by\u0026nbsp;the Institutional Review Board of Antai Medical Care Corporation, Antai Tian-Sheng Memorial Hospital (TSMH, approval number 16-107-B1).\u0026nbsp;The participants provided their written informed consent to participate in this study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization: Yu-ping Huang, Hsien-Te Peng.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eData curation: Shapu Lu Bi. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFormal analysis: Yu-ping Huang, Hsien-Te Peng, Shapu Lu Bi, Yan Wei, Yang Jeng-Sheng, De-jia Wang.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMethodology: Yu-ping Huang, Hsien-Te Peng.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSupervision: Shapu Lu Bi.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWriting – original draft: Yu-ping Huang, Hsien-Te Peng.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWriting – review \u0026amp; editing: Yan Wei, Yang Jeng-Sheng, Shapu Lu Bi, De-jia Wang. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was supported by the\u0026nbsp;Ministry of Science and Technology of Taiwan (Grant No. MOST 106-2410-H-034-036) and was supported by\u0026nbsp;the\u0026nbsp;Ministry of\u0026nbsp;Education of China\u0026nbsp;(Grant No.\u0026nbsp;2408061632).\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors acknowledge the laboratory of sports biomechanics, Chinese Culture University assisting in the preparation and management of the instrument and data.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that there is no conflict of interest regarding the publication of this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePublisher’s note\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors, and the reviewers. 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Paediatric flexible flat foot: how are we measuring it and are we getting it right? A systematic review. \u003cem\u003eJ. Foot Ankle Res.\u003c/em\u003e \u003cb\u003e11\u003c/b\u003e (1), 21\u0026ndash;33. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s13047-018-0264-3\u003c/span\u003e\u003cspan address=\"10.1186/s13047-018-0264-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2018).\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":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"pes planus, pes cavus, injury prevention, power spectral area, electromyography, biomechanics","lastPublishedDoi":"10.21203/rs.3.rs-5120168/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5120168/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePeople with flatfoot encounter challenges while walking. This study investigated whether arch support insoles (ASIs) can reduce fatigue of the lower extremity muscles during a walking task in people with flatfoot compared with flat insoles (FIs). A total of fifteen female college students with flatfoot were recruited and considered eligible for the study, with each subject fulfilling the inclusion criteria of Chippaux-Smirak index\u0026thinsp;\u0026gt;\u0026thinsp;45%. A paired sample \u003cem\u003et\u003c/em\u003e test was used to compare the difference in power spectral area (PSA) of the subdivided frequency band interval of 20\u0026ndash;140 Hz between ASIs and FIs. A Wilcoxon test was used for assessing nonnormal data. Effect size (ES) was calculated as a measure of the practical relevance of the significance by using Cohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e. The results showed that the PSA of the RF muscles (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05; ES\u0026thinsp;=\u0026thinsp;0.90) during uphill walking and of the RF (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05; ES\u0026thinsp;=\u0026thinsp;1.21) and TA muscles (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05; ES\u0026thinsp;=\u0026thinsp;0.61) during downhill walking was significantly smaller for ASIs than for FIs. The current evidence suggests that ASIs alleviates RF muscle fatigue during uphill walking and relieves RF and TA muscle fatigue during downhill walking.\u003c/p\u003e","manuscriptTitle":"Arch support insoles reduce fatigue of the lower extremity muscles in people with flatfoot during a walking task","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-02 09:49:40","doi":"10.21203/rs.3.rs-5120168/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-05-05T11:40:22+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-29T11:45:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"43636134835170154647784379706882885180","date":"2025-04-06T19:04:47+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-03-31T19:54:22+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-03-27T08:22:59+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-03-22T14:19:43+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c1271120-6fed-49ef-bbad-d399c8a36df6","owner":[],"postedDate":"April 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":46479578,"name":"Health sciences/Health care/Health services/Rehabilitation"},{"id":46479579,"name":"Health sciences/Health care/Diagnosis/Electrodiagnosis/Electromyography emg"}],"tags":[],"updatedAt":"2025-05-26T16:11:03+00:00","versionOfRecord":{"articleIdentity":"rs-5120168","link":"https://doi.org/10.1038/s41598-025-02623-6","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-05-22 15:57:18","publishedOnDateReadable":"May 22nd, 2025"},"versionCreatedAt":"2025-04-02 09:49:40","video":"","vorDoi":"10.1038/s41598-025-02623-6","vorDoiUrl":"https://doi.org/10.1038/s41598-025-02623-6","workflowStages":[]},"version":"v1","identity":"rs-5120168","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5120168","identity":"rs-5120168","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}