No associations of sprint-induced hamstring activity levels and coordination patterns with sprint performance in male sprinters: A T2-Weighted MRI study

No associations of sprint-induced hamstring activity levels and coordination patterns with sprint performance in male sprinters: A T2-Weighted MRI study | 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 Short Report No associations of sprint-induced hamstring activity levels and coordination patterns with sprint performance in male sprinters: A T2-Weighted MRI study Haruto Arai, Tadashi Suga, Masafumi Terada, Yuki Kusagawa, Keishi Kuroki, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9173099/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 10 You are reading this latest preprint version Abstract Objective Superior sprint performance may require greater hamstring activity during sprinting. Additionally, synergistic coordination patterns within the hamstrings may play an important role in efficient sprinting. The main aim of this study was to examine the relationships of sprint-induced hamstring activity levels and coordination patterns with sprint performance in sprinters using T2-weighted magnetic resonance imaging (MRI). Results Twenty-six male collegiate sprinters completed a low-volume sprint protocol on an indoor track that consisted of three maximal 60-m sprints with 2-min recovery intervals and did not impair sprint performance across the trials. T2-weighted MRI scans were acquired before and after the protocol. Activity level was quantified as the percentage change in T2 for each muscle. Activity share was defined as the relative contribution of each muscle to the total hamstring T2 change. The semitendinosus showed significantly greater activity level and activity share than the other three muscles. Despite such distinct activity patterns, activity levels and shares of all four hamstring muscles were not significantly correlated to either 100-m seasonal best time or fastest 60-m sprint time. These findings suggest that sprint-induced hamstring activity levels and coordination patterns assessed by T2-weighted MRI are not necessarily associated with superior sprint performance in male sprinters. Sprint time Biceps femoris Semitendinosus Semimembranosus Activity level Activity share Hamstring strain injury Functional magnetic resonance imaging Figures Figure 1 INTRODUCTION Superior sprint performance is associated with greater lower-limb muscle activity during sprinting ( 1 – 3 ). In particular, hamstring activity plays pivotal roles in generating forces during the late swing and early stance phases of sprinting ( 1 , 2 , 4 , 5 ). Consistent with these findings, the hamstring muscles, particularly the semitendinosus (ST), show greater hypertrophy in sprinters than in untrained individuals relative to other lower-limb muscles ( 6 – 8 ), and their size is associated with sprint performance in sprinters ( 7 , 9 , 10 ). These morphological findings suggest that the hamstrings are exposed to substantial mechanical and metabolic stress during sprinting, thereby supporting the interpretation that they exhibit high levels of muscle activity. Accordingly, among the lower-limb muscles, the hamstrings have been more extensively studied during sprinting using surface electromyography ( 11 , 12 ). However, surface electromyography during high-speed dynamic whole-body movements such as sprinting has several methodological limitations, particularly the increased likelihood of signal contamination due to intermuscular crosstalk ( 13 ), which may compromise the validity of measuring individual activity in the four hamstring muscles. Therefore, surface electromyography poses substantial challenges for the assessment of hamstring activity during maximal sprinting. T2-weighted magnetic resonance imaging (MRI) is a useful tool for assessing muscle activity based on exercise-induced increases in transverse relaxation time (i.e., T2) ( 14 ). Previous studies have reported lower-limb muscle activity during various exercises using T2-weighted MRI ( 15 ). However, research examining lower-limb muscle activity during sprinting remains limited because a specialized research environment is required to allow T2-weighted MRI measurements immediately after exercise. To the best of our knowledge, Bourne et al. ( 16 ) were the first to report lower-limb muscle activity, including that of all four hamstring muscles, during sprinting in male athletes, although their participants were not sprinters. Subsequently, Yoshimoto et al. ( 17 ) examined activity in the 13 thigh muscles, including the hamstrings, during sprinting in male sprinters. These two previous studies clearly demonstrated non-uniform activity across the hamstrings, with the greatest activity observed in the ST ( 16 , 17 ). Nevertheless, despite accumulating evidence suggesting a link between hamstring activity and sprint performance, it remains unclear whether sprint-induced hamstring activity levels are related to sprint performance. Therefore, clarifying this relationship would enhance our understanding of the importance of hamstring activity for superior sprint performance in sprinters. Synergistic coordination patterns within the hamstrings may contribute to superior sprint performance by facilitating efficient kinematics and enhancing torque production during knee flexion and hip extension ( 1 – 4 ). To the best of our knowledge, only a series of the studies by Schuermans et al. ( 18 , 19 ) have used T2-weighted MRI to examine hamstring coordination patterns during local knee flexion exercise and found a greater contribution of the ST activity to total hamstring activity in athletes. However, such hamstring coordination patterns during dynamic whole-body movements such as sprinting have not been investigated using T2-weighted MRI. Furthermore, it remains unclear whether hamstring coordination patterns during sprinting, as assessed not only by T2-weighted MRI but also by surface electromyography, are related to sprint performance in sprinters. Therefore, investigating this relationship could further advance our understanding of hamstring mechanics during sprinting. To address these issues, in this T2-weighted MRI study, we examined the relationships of sprint-induced hamstring activity levels and coordination patterns with sprint performance in sprinters. Consistent with most previous evidence, we hypothesized that hamstring activity levels and coordination patterns would be related to sprint performance. MAIN TEXT METHODS Participants Before the study, an a priori power analysis was performed for the primary correlation analysis between hamstring activity measure and sprint performance variable. Because previous study (Miller et al., 2021) showed a moderate correlation ( r = 0.53) between ST size and sprint performance, this value was used as the expected effect size. On this basis, a target sample size of 26 participants was set to achieve 80% statistical power at a two-tailed alpha level of 0.05. Accordingly, the present study recruited 26 well-trained male collegiate sprinters (age: 19.7 ± 1.5 years, body height: 174.4 ± 4.9 cm, body mass: 66.6 ± 4.8 kg). Their 100-m seasonal best times were 11.03 ± 0.28 s. This study was approved by the Ethics Committee of Ritsumeikan University (BKC-LSMH-2023-025) and conducted in accordance with the Declaration of Helsinki. All participants were fully informed of the purpose and potential risks of the study and provide written informed consent prior to participation. Experimental procedure On the experimental day, after arriving at the MRI laboratory, participants first lay supine in the MRI scanner for 20 min to ensure resting conditions, followed by pre-exercise T2-weighted MRI scan. Thereafter, participants performed standard and sprint-specific warm-up sessions totaling approximately 50 min. The standard warm-up consisted of low-intensity ergometer cycling, dynamic stretching, and jump exercises. The sprint-specific warm-up consisted of three submaximal sprints performed at 50% to 70% of maximal effort. The sprint protocol was then conducted 10 min after completion of the warm-up sessions. An original sprint protocol was consisted of three maximal 60-m sprints with 2-min recovery intervals. This sprint volume was relatively low compared with that used in previous studies ( 16 , 17 ), because physical and muscular fatigue with higher sprint volumes may impair sprint mechanics ( 20 ) and may alter the activity patterns of lower-limb muscles ( 21 , 22 ). The 60-m sprint times during the three trials were measured using a wireless photocell timing system (Witty System; Microgate, Bolzano, Italy). The coefficient of variation across trials was minimal (0.4 ± 0.0%), indicating that physical and muscular fatigue was effectively minimized and that participants were able to maintain maximal sprint performance. The fastest 60-m sprint time among the three trials (7.25 ± 0.19 s), together with the 100-m seasonal best time, was used as a sprint performance variable. Immediately after the final third sprint trial, participants sat or lay on a cart and were transported from the indoor track to the MRI laboratory to avoid additional mechanical and metabolic loads associated with walking and other lower-limb movements. The time interval between completion of the final sprint trial and the start of the post-exercise MRI scan was exactly 5 min for all participants. T2-weighted MRI T2-weighted images of the right thigh were acquired using a 3.0-T whole-body MRI system (MAGNETOM Skyra; Siemens Healthineers, Erlangen, Germany). Participants were positioned supine with the hips and ankles in neutral positions and the knees fully extended. A multi-spin-echo sequence was used to obtain T2-weighted images. The imaging range was defined along the longitudinal axis of the femur. The thigh length from the greater trochanter to the lateral femoral epicondyle was measured in each participant, and the midpoint (50%) of this segment was identified. Axial images were then acquired over a 30-cm region centered at this midpoint (± 15 cm). All image analyses were performed using ImageJ (Version 1.54; National Institutes of Health, MD, USA). The T2 values for each hamstring muscle were obtained from the axial slice that most closely corresponded to the anatomical muscle belly ( 17 ) (Fig. 1 ). The slice locations for each muscle were as follows: the proximal 30% of the thigh length for the ST; the middle 50% for the biceps femoris long head (BFL); and the distal 70% for the semimembranosus (SM) and biceps femoris short head (BFS). The activity levels for each muscle were defined as the changes in T2 values from pre- to post-exercise following the low-volume sprint protocol. Synergistic coordination patterns within the muscles were assessed using the relative contribution of each muscle to the total hamstring T2 change, termed the activity share ( 18 , 19 ). Statistical Analysis Data are presented as means and standard deviations. All analyses were performed using SPSS (Statistics version 30; IBM Corporation, NY, USA) or RStudio (version 2023.12.0 + 369; Posit Software PBC, MA, USA). To account for within-subject variability due to repeated measurements, a one-factor repeated-measures linear mixed-effects model fitted using restricted maximum likelihood was used to determine the main effects of muscle on hamstring activity levels or activity shares. Random intercepts were included for participants. When a significant main effect was detected, post hoc pairwise comparisons with Bonferroni adjustment were conducted to identify significant difference among the four muscles. Additionally, Pearson correlation analyses were performed as the primary analyses to examine the relationships between muscle activity measures and sprint performance variables. Statistical significance was set at P < 0.05. RESULTS The activity level was significantly greater in the ST than in the other three muscles ( Table 1 ; all P < 0.05), and greater in the BFL than in the SM ( P < 0.001). The same results were also observed for activity share. Despite such distinct muscle activity patterns, activity levels and shares of all four hamstring muscles were not significantly correlated to either 100-m seasonal personal best time or 60-m sprint time ( Table 2 ; r = -0.320−0.298, all P > 0.05). DISCUSSION This study demonstrated that the activity levels and activity shares following the sprint protocol were significantly greater in the ST than in the other three muscles. Despite the presence of non-uniform activity patterns within the hamstrings, we found no significant correlations between these muscle activity measures and sprint performance variables; therefore, our hypothesis was not supported. One possible explanation for this result is that previous studies have shown that hamstring activity measured by surface electromyography increases progressively with sprint speed ( 1 – 3 ), but have not clarified how interindividual differences in hamstring activity relate to actual sprint performance. Another possible explanation is that muscle activity patterns assessed by T2-weighted MRI may primarily reflect metabolic stress during sprinting ( 23 , 24 ) and thus may not necessarily reflect factors such as the mechanical and neuromuscular aspects of sprinting ( 23 , 25 ). Therefore, interpreting the present findings may be challenging, potentially because hamstring activity patterns during actual maximal sprinting are likely determined by complex interactions among various individual factors (e.g., technical, biomechanical, physiological, and morphological factors), which may vary among sprinters. In light of these considerations, the present study suggests that sprint-induced hamstring muscle activity levels and coordination patterns, as assessed by T2-weighted MRI, may not be related to actual sprint performance; however, to our knowledge, this is the first study to report such findings. A series of studies by Schuermans et al. ( 18 , 19 ) demonstrated a greater activity share of the ST than of the SM and biceps femoris (combined BFL and BFS) during local knee flexion exercise in contact sport athletes, which is consistent with the present findings. Furthermore, they also reported that hamstring activity levels were generally greater in the group with a history of hamstring injury than in the uninjured control group, and that the activity share of the BFL was increased in the former group ( 18 , 19 ). This synergistic coordination pattern was identified as a strong risk factor for the first occurrence or recurrence of hamstring injuries during an 18-month follow-up period ( 19 ). Their findings may help explain, at least in part, the mechanisms underlying the high incidence of hamstring injuries, particularly BFL injuries, in sprinters ( 26 , 27 ). Taken together, the present findings demonstrate heterogeneous activity patterns within the hamstrings during maximal sprinting in sprinters and may provide a basis for developing preventive strategies for hamstring strain injuries. Limitations A major limitation of this study is that female sprinters were not included. Therefore, the present findings should be interpreted as specific to male sprinters. Indeed, sprint kinematics and kinetics are known to differ between male and female sprinters ( 28 , 29 ). Furthermore, the contribution of the hamstrings to sprint performance may be lower in female sprinters than in male sprinters ( 7 , 30 ). Based on these findings, it is reasonable to speculate that T2-weighted MRI-measured hamstring activity patterns may differ between males and females during maximal sprinting. Taken together, further studies are needed to include female sprinters and to examine sex-related differences in sprint-induced hamstring activity patterns. CONCLUSION This study demonstrated non-uniform activity patterns within the hamstrings during maximal sprinting in male sprinters, as assessed by T2-weighted MRI. Despite these distinctive patterns, we found no significant relationships between hamstring activity measures and actual sprint performance variables. Therefore, the present findings suggest that sprint-induced hamstring activity levels and coordination patterns are not necessarily associated with superior sprint performance in male sprinters. Declarations Ethics approval and consent to participate This study was approved by the Ethics Committee of Ritsumeikan University (BKC-LSMH-2023-025) and conducted in accordance with the Declaration of Helsinki. All participants provided written informed consent prior to participation. Consent for publication Not applicable. Competing interests The authors declare no competing interests. FUNDING This study was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (#23K10648 to T.S). Author Contribution H.A., T.S. and M.T. conceived and designed research; H.A., T.S., M.T., Y.K., and K.K. performed experiments; H.A., and T.S. analyzed data; H.A., T.S., M.T., Y.K., K.K., M.U., and T.I. interpreted results of experiments; H.A. prepared figures; H.A. and T.S. drafted manuscript; T.S., M.T., Y.K., M.U., and T.I edited and revised manuscript; H.A., T.S., M.T., Y.K., K.K., M.U., and T.I. approved final version of manuscript. ACKNOWLEDGMENTS The authors thank the participants for their time and effort. Data Availability Data are available from the corresponding author, T.S., upon reasonable request. References Dorn TW, Schache AG, Pandy MG. Muscular strategy shift in human running: Dependence of running speed on hip and ankle muscle performance. J Exp Biol. 2012;215(11):1944–56. Higashihara A, Ono T, Kubota J, Okuwaki T, Fukubayashi T. Functional differences in the activity of the hamstring muscles with increasing running speed. J Sports Sci. 2010;28(10):1085–92. 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Am J Roentgenol. 2000;174(2):393–9. Nagahara R. Normative spatiotemporal and ground reaction force data for female and male sprinting. J Sports Sci. 2023;41(12):1240–9. Slawinski J, Termoz N, Rabita G, Guilhem G, Dorel S, Morin JB, Samozino P. How 100-m event analyses improve our understanding of world-class men's and women's sprint performance. Scand J Med Sci Sports. 2017;27(1):45–54. Miller R, Balshaw TG, Massey GJ, Maeo S, Lanza MB, Haug B, Johnston M, Allen SJ, Folland JP. The muscle morphology of elite female sprint running. Med Sci Sports Exerc. 2022;54(12):2138–48. Tables Tables 1 to 2 are available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Tables.pdf Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 07 Apr, 2026 Reviews received at journal 06 Apr, 2026 Reviews received at journal 02 Apr, 2026 Reviewers agreed at journal 29 Mar, 2026 Reviewers agreed at journal 29 Mar, 2026 Reviewers invited by journal 29 Mar, 2026 Editor invited by journal 24 Mar, 2026 Editor assigned by journal 24 Mar, 2026 Submission checks completed at journal 24 Mar, 2026 First submitted to journal 19 Mar, 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. 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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-9173099","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Short Report","associatedPublications":[],"authors":[{"id":614173244,"identity":"1eaa31da-3780-41de-868e-6388ce25c1e3","order_by":0,"name":"Haruto Arai","email":"","orcid":"","institution":"Ritsumeikan University","correspondingAuthor":false,"prefix":"","firstName":"Haruto","middleName":"","lastName":"Arai","suffix":""},{"id":614173245,"identity":"afce311c-7086-4109-b8d6-02cf7d4feb96","order_by":1,"name":"Tadashi Suga","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABBElEQVRIiWNgGAWjYPACG34QeQDMZgaTbDjV8kCoNMkGkJYDJGg5DNYCtYYAsGdgfyb5pea8BH8D78PDH/4cjuZnZ2D88IOBLw+3LTxm0jLHbktIHGA3OHCw7XDuzGYGZskeBrZinFrk37BJS7DdrjMAuv7AwYbDuRsOMzBIA/2S2IDTFvZn0hL/zkmAtRz4czh3/2EG5t/4tTCYSX5sOwDVwga0hZmBDb8tB3iMrRn7kiUkDgO1nG1Lz51xmLHNsscAt1/YG9gf3vzxzU6Cv72N+UPFH+vc/v7Dh2/8qDiGM8RAgBkcOcxwPiPQSQbHEvBpYfyBRbAGr5ZRMApGwSgYUQAAToZQJTV5yHEAAAAASUVORK5CYII=","orcid":"","institution":"Ritsumeikan University","correspondingAuthor":true,"prefix":"","firstName":"Tadashi","middleName":"","lastName":"Suga","suffix":""},{"id":614173246,"identity":"eb88a5be-0877-4bc4-bedf-8c5b82a11f82","order_by":2,"name":"Masafumi Terada","email":"","orcid":"","institution":"Ritsumeikan University","correspondingAuthor":false,"prefix":"","firstName":"Masafumi","middleName":"","lastName":"Terada","suffix":""},{"id":614173252,"identity":"c626ee8a-241e-4bbf-b15d-677f86f7b4ab","order_by":3,"name":"Yuki Kusagawa","email":"","orcid":"","institution":"Ritsumeikan University","correspondingAuthor":false,"prefix":"","firstName":"Yuki","middleName":"","lastName":"Kusagawa","suffix":""},{"id":614173253,"identity":"8d462d8a-450e-4051-abf3-308668c98ee6","order_by":4,"name":"Keishi Kuroki","email":"","orcid":"","institution":"Ritsumeikan University","correspondingAuthor":false,"prefix":"","firstName":"Keishi","middleName":"","lastName":"Kuroki","suffix":""},{"id":614173254,"identity":"76485f62-65d3-4595-83e2-d29ff09ce789","order_by":5,"name":"Masahiro Umeda","email":"","orcid":"","institution":"Meiji University of Integrative Medicine","correspondingAuthor":false,"prefix":"","firstName":"Masahiro","middleName":"","lastName":"Umeda","suffix":""},{"id":614173264,"identity":"7ac381d5-adea-4c38-83c0-9a49db18ebc6","order_by":6,"name":"Tadao Isaka","email":"","orcid":"","institution":"Ritsumeikan University","correspondingAuthor":false,"prefix":"","firstName":"Tadao","middleName":"","lastName":"Isaka","suffix":""}],"badges":[],"createdAt":"2026-03-19 21:53:32","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9173099/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9173099/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106005923,"identity":"7429ae0e-6e58-4771-af9f-340c488075a2","added_by":"auto","created_at":"2026-04-02 10:49:25","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":223801,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAnalytical workflow for T2-weighted magnetic resonance imaging of hamstring activity patterns\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe T2 values for each hamstring muscle were analyzed from the axial slice that most closely approximated its anatomical muscle belly at one of three representative locations along the thigh length, defined as the distance between the greater trochanter and the lateral epicondyle. These three locations corresponded to 30% (proximal), 50% (middle), and 70% (distal) of the thigh length. Specifically, the selected slice location was at the proximal 30% of thigh length for the semitendinosus (ST), the middle 50% for the biceps femoris long head (BFL), and the distal 70% for the semimembranosus (SM) and biceps femoris short head (BFS).\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9173099/v1/053fd10f373cf880dcca0e63.jpg"},{"id":106402216,"identity":"95792a7b-f0c0-4ae5-9334-a915c89fca22","added_by":"auto","created_at":"2026-04-08 09:11:28","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":711453,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9173099/v1/7741bd33-ee31-4d2c-81ac-0dbdd5ea1dcc.pdf"},{"id":106005922,"identity":"16d2b473-9fbe-450f-9dc5-19143e284f50","added_by":"auto","created_at":"2026-04-02 10:49:25","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":81415,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9173099/v1/0f5b9ed0fbb203a359d20042.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"No associations of sprint-induced hamstring activity levels and coordination patterns with sprint performance in male sprinters: A T2-Weighted MRI study","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eSuperior sprint performance is associated with greater lower-limb muscle activity during sprinting (\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). In particular, hamstring activity plays pivotal roles in generating forces during the late swing and early stance phases of sprinting (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Consistent with these findings, the hamstring muscles, particularly the semitendinosus (ST), show greater hypertrophy in sprinters than in untrained individuals relative to other lower-limb muscles (\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e), and their size is associated with sprint performance in sprinters (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). These morphological findings suggest that the hamstrings are exposed to substantial mechanical and metabolic stress during sprinting, thereby supporting the interpretation that they exhibit high levels of muscle activity. Accordingly, among the lower-limb muscles, the hamstrings have been more extensively studied during sprinting using surface electromyography (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). However, surface electromyography during high-speed dynamic whole-body movements such as sprinting has several methodological limitations, particularly the increased likelihood of signal contamination due to intermuscular crosstalk (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e), which may compromise the validity of measuring individual activity in the four hamstring muscles. Therefore, surface electromyography poses substantial challenges for the assessment of hamstring activity during maximal sprinting.\u003c/p\u003e \u003cp\u003eT2-weighted magnetic resonance imaging (MRI) is a useful tool for assessing muscle activity based on exercise-induced increases in transverse relaxation time (i.e., T2) (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Previous studies have reported lower-limb muscle activity during various exercises using T2-weighted MRI (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). However, research examining lower-limb muscle activity during sprinting remains limited because a specialized research environment is required to allow T2-weighted MRI measurements immediately after exercise. To the best of our knowledge, Bourne et al. (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e) were the first to report lower-limb muscle activity, including that of all four hamstring muscles, during sprinting in male athletes, although their participants were not sprinters. Subsequently, Yoshimoto et al. (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e) examined activity in the 13 thigh muscles, including the hamstrings, during sprinting in male sprinters. These two previous studies clearly demonstrated non-uniform activity across the hamstrings, with the greatest activity observed in the ST (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Nevertheless, despite accumulating evidence suggesting a link between hamstring activity and sprint performance, it remains unclear whether sprint-induced hamstring activity levels are related to sprint performance. Therefore, clarifying this relationship would enhance our understanding of the importance of hamstring activity for superior sprint performance in sprinters.\u003c/p\u003e \u003cp\u003eSynergistic coordination patterns within the hamstrings may contribute to superior sprint performance by facilitating efficient kinematics and enhancing torque production during knee flexion and hip extension (\u003cspan additionalcitationids=\"CR2 CR3\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). To the best of our knowledge, only a series of the studies by Schuermans et al. (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e) have used T2-weighted MRI to examine hamstring coordination patterns during local knee flexion exercise and found a greater contribution of the ST activity to total hamstring activity in athletes. However, such hamstring coordination patterns during dynamic whole-body movements such as sprinting have not been investigated using T2-weighted MRI. Furthermore, it remains unclear whether hamstring coordination patterns during sprinting, as assessed not only by T2-weighted MRI but also by surface electromyography, are related to sprint performance in sprinters. Therefore, investigating this relationship could further advance our understanding of hamstring mechanics during sprinting. To address these issues, in this T2-weighted MRI study, we examined the relationships of sprint-induced hamstring activity levels and coordination patterns with sprint performance in sprinters. Consistent with most previous evidence, we hypothesized that hamstring activity levels and coordination patterns would be related to sprint performance.\u003c/p\u003e"},{"header":"MAIN TEXT","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eMETHODS\u003c/h2\u003e \u003cdiv id=\"Sec4\" class=\"Section3\"\u003e \u003ch2\u003eParticipants\u003c/h2\u003e \u003cp\u003eBefore the study, an a priori power analysis was performed for the primary correlation analysis between hamstring activity measure and sprint performance variable. Because previous study (Miller et al., 2021) showed a moderate correlation (\u003cem\u003er\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.53) between ST size and sprint performance, this value was used as the expected effect size. On this basis, a target sample size of 26 participants was set to achieve 80% statistical power at a two-tailed alpha level of 0.05. Accordingly, the present study recruited 26 well-trained male collegiate sprinters (age: 19.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5 years, body height: 174.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.9 cm, body mass: 66.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.8 kg). Their 100-m seasonal best times were 11.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28 s. This study was approved by the Ethics Committee of Ritsumeikan University (BKC-LSMH-2023-025) and conducted in accordance with the Declaration of Helsinki. All participants were fully informed of the purpose and potential risks of the study and provide written informed consent prior to participation.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e\n\u003ch3\u003eExperimental procedure\u003c/h3\u003e\n\u003cp\u003eOn the experimental day, after arriving at the MRI laboratory, participants first lay supine in the MRI scanner for 20 min to ensure resting conditions, followed by pre-exercise T2-weighted MRI scan. Thereafter, participants performed standard and sprint-specific warm-up sessions totaling approximately 50 min. The standard warm-up consisted of low-intensity ergometer cycling, dynamic stretching, and jump exercises. The sprint-specific warm-up consisted of three submaximal sprints performed at 50% to 70% of maximal effort. The sprint protocol was then conducted 10 min after completion of the warm-up sessions.\u003c/p\u003e \u003cp\u003eAn original sprint protocol was consisted of three maximal 60-m sprints with 2-min recovery intervals. This sprint volume was relatively low compared with that used in previous studies (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e), because physical and muscular fatigue with higher sprint volumes may impair sprint mechanics (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e) and may alter the activity patterns of lower-limb muscles (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). The 60-m sprint times during the three trials were measured using a wireless photocell timing system (Witty System; Microgate, Bolzano, Italy). The coefficient of variation across trials was minimal (0.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0%), indicating that physical and muscular fatigue was effectively minimized and that participants were able to maintain maximal sprint performance. The fastest 60-m sprint time among the three trials (7.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 s), together with the 100-m seasonal best time, was used as a sprint performance variable.\u003c/p\u003e \u003cp\u003eImmediately after the final third sprint trial, participants sat or lay on a cart and were transported from the indoor track to the MRI laboratory to avoid additional mechanical and metabolic loads associated with walking and other lower-limb movements. The time interval between completion of the final sprint trial and the start of the post-exercise MRI scan was exactly 5 min for all participants.\u003c/p\u003e\n\u003ch3\u003eT2-weighted MRI\u003c/h3\u003e\n\u003cp\u003eT2-weighted images of the right thigh were acquired using a 3.0-T whole-body MRI system (MAGNETOM Skyra; Siemens Healthineers, Erlangen, Germany). Participants were positioned supine with the hips and ankles in neutral positions and the knees fully extended. A multi-spin-echo sequence was used to obtain T2-weighted images. The imaging range was defined along the longitudinal axis of the femur. The thigh length from the greater trochanter to the lateral femoral epicondyle was measured in each participant, and the midpoint (50%) of this segment was identified. Axial images were then acquired over a 30-cm region centered at this midpoint (\u0026plusmn;\u0026thinsp;15 cm).\u003c/p\u003e \u003cp\u003eAll image analyses were performed using ImageJ (Version 1.54; National Institutes of Health, MD, USA). The T2 values for each hamstring muscle were obtained from the axial slice that most closely corresponded to the anatomical muscle belly (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The slice locations for each muscle were as follows: the proximal 30% of the thigh length for the ST; the middle 50% for the biceps femoris long head (BFL); and the distal 70% for the semimembranosus (SM) and biceps femoris short head (BFS). The activity levels for each muscle were defined as the changes in T2 values from pre- to post-exercise following the low-volume sprint protocol. Synergistic coordination patterns within the muscles were assessed using the relative contribution of each muscle to the total hamstring T2 change, termed the activity share (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eData are presented as means and standard deviations. All analyses were performed using SPSS (Statistics version 30; IBM Corporation, NY, USA) or RStudio (version 2023.12.0\u0026thinsp;+\u0026thinsp;369; Posit Software PBC, MA, USA). To account for within-subject variability due to repeated measurements, a one-factor repeated-measures linear mixed-effects model fitted using restricted maximum likelihood was used to determine the main effects of muscle on hamstring activity levels or activity shares. Random intercepts were included for participants. When a significant main effect was detected, post hoc pairwise comparisons with Bonferroni adjustment were conducted to identify significant difference among the four muscles. Additionally, Pearson correlation analyses were performed as the primary analyses to examine the relationships between muscle activity measures and sprint performance variables. Statistical significance was set at \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cp\u003eThe activity level was significantly greater in the ST than in the other three muscles (\u003cb\u003eTable\u0026nbsp;1\u003c/b\u003e; all \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), and greater in the BFL than in the SM (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The same results were also observed for activity share. Despite such distinct muscle activity patterns, activity levels and shares of all four hamstring muscles were not significantly correlated to either 100-m seasonal personal best time or 60-m sprint time (\u003cb\u003eTable\u0026nbsp;2\u003c/b\u003e; \u003cem\u003er\u003c/em\u003e = -0.320\u0026minus;0.298, all \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThis study demonstrated that the activity levels and activity shares following the sprint protocol were significantly greater in the ST than in the other three muscles. Despite the presence of non-uniform activity patterns within the hamstrings, we found no significant correlations between these muscle activity measures and sprint performance variables; therefore, our hypothesis was not supported. One possible explanation for this result is that previous studies have shown that hamstring activity measured by surface electromyography increases progressively with sprint speed (\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e), but have not clarified how interindividual differences in hamstring activity relate to actual sprint performance. Another possible explanation is that muscle activity patterns assessed by T2-weighted MRI may primarily reflect metabolic stress during sprinting (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e) and thus may not necessarily reflect factors such as the mechanical and neuromuscular aspects of sprinting (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). Therefore, interpreting the present findings may be challenging, potentially because hamstring activity patterns during actual maximal sprinting are likely determined by complex interactions among various individual factors (e.g., technical, biomechanical, physiological, and morphological factors), which may vary among sprinters. In light of these considerations, the present study suggests that sprint-induced hamstring muscle activity levels and coordination patterns, as assessed by T2-weighted MRI, may not be related to actual sprint performance; however, to our knowledge, this is the first study to report such findings.\u003c/p\u003e \u003cp\u003eA series of studies by Schuermans et al. (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e) demonstrated a greater activity share of the ST than of the SM and biceps femoris (combined BFL and BFS) during local knee flexion exercise in contact sport athletes, which is consistent with the present findings. Furthermore, they also reported that hamstring activity levels were generally greater in the group with a history of hamstring injury than in the uninjured control group, and that the activity share of the BFL was increased in the former group (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). This synergistic coordination pattern was identified as a strong risk factor for the first occurrence or recurrence of hamstring injuries during an 18-month follow-up period (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). Their findings may help explain, at least in part, the mechanisms underlying the high incidence of hamstring injuries, particularly BFL injuries, in sprinters (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). Taken together, the present findings demonstrate heterogeneous activity patterns within the hamstrings during maximal sprinting in sprinters and may provide a basis for developing preventive strategies for hamstring strain injuries.\u003c/p\u003e\n\u003ch3\u003eLimitations\u003c/h3\u003e\n\u003cp\u003eA major limitation of this study is that female sprinters were not included. Therefore, the present findings should be interpreted as specific to male sprinters. Indeed, sprint kinematics and kinetics are known to differ between male and female sprinters (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e). Furthermore, the contribution of the hamstrings to sprint performance may be lower in female sprinters than in male sprinters (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e). Based on these findings, it is reasonable to speculate that T2-weighted MRI-measured hamstring activity patterns may differ between males and females during maximal sprinting. Taken together, further studies are needed to include female sprinters and to examine sex-related differences in sprint-induced hamstring activity patterns.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eThis study demonstrated non-uniform activity patterns within the hamstrings during maximal sprinting in male sprinters, as assessed by T2-weighted MRI. Despite these distinctive patterns, we found no significant relationships between hamstring activity measures and actual sprint performance variables. Therefore, the present findings suggest that sprint-induced hamstring activity levels and coordination patterns are not necessarily associated with superior sprint performance in male sprinters.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e \u003cp\u003eThis study was approved by the Ethics Committee of Ritsumeikan University (BKC-LSMH-2023-025) and conducted in accordance with the Declaration of Helsinki. All participants provided written informed consent prior to participation.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication\u003c/strong\u003e \u003cp\u003eNot applicable.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eCompeting interests\u003c/strong\u003e \u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFUNDING\u003c/h2\u003e \u003cp\u003eThis study was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (#23K10648 to T.S).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eH.A., T.S. and M.T. conceived and designed research; H.A., T.S., M.T., Y.K., and K.K. performed experiments; H.A., and T.S. analyzed data; H.A., T.S., M.T., Y.K., K.K., M.U., and T.I. interpreted results of experiments; H.A. prepared figures; H.A. and T.S. drafted manuscript; T.S., M.T., Y.K., M.U., and T.I edited and revised manuscript; H.A., T.S., M.T., Y.K., K.K., M.U., and T.I. approved final version of manuscript.\u003c/p\u003e\u003ch2\u003eACKNOWLEDGMENTS\u003c/h2\u003e \u003cp\u003eThe authors thank the participants for their time and effort.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eData are available from the corresponding author, T.S., upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eDorn TW, Schache AG, Pandy MG. 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Med Sci Sports Exerc. 2022;54(12):2138\u0026ndash;48.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 2 are available in the Supplementary Files section.\u003c/p\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":"bmc-research-notes","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"resn","sideBox":"Learn more about [BMC Research Notes](http://bmcresnotes.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/resn/default.aspx","title":"BMC Research Notes","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Sprint time, Biceps femoris, Semitendinosus, Semimembranosus, Activity level, Activity share, Hamstring strain injury, Functional magnetic resonance imaging","lastPublishedDoi":"10.21203/rs.3.rs-9173099/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9173099/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eSuperior sprint performance may require greater hamstring activity during sprinting. Additionally, synergistic coordination patterns within the hamstrings may play an important role in efficient sprinting. The main aim of this study was to examine the relationships of sprint-induced hamstring activity levels and coordination patterns with sprint performance in sprinters using T2-weighted magnetic resonance imaging (MRI).\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eTwenty-six male collegiate sprinters completed a low-volume sprint protocol on an indoor track that consisted of three maximal 60-m sprints with 2-min recovery intervals and did not impair sprint performance across the trials. T2-weighted MRI scans were acquired before and after the protocol. Activity level was quantified as the percentage change in T2 for each muscle. Activity share was defined as the relative contribution of each muscle to the total hamstring T2 change. The semitendinosus showed significantly greater activity level and activity share than the other three muscles. Despite such distinct activity patterns, activity levels and shares of all four hamstring muscles were not significantly correlated to either 100-m seasonal best time or fastest 60-m sprint time. These findings suggest that sprint-induced hamstring activity levels and coordination patterns assessed by T2-weighted MRI are not necessarily associated with superior sprint performance in male sprinters.\u003c/p\u003e","manuscriptTitle":"No associations of sprint-induced hamstring activity levels and coordination patterns with sprint performance in male sprinters: A T2-Weighted MRI study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-02 10:49:21","doi":"10.21203/rs.3.rs-9173099/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-07T10:36:14+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-07T01:41:17+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-02T06:59:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"201224534992952796155448221684753102194","date":"2026-03-29T23:28:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"164527892984986054882147321571392286430","date":"2026-03-29T17:30:10+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-29T13:44:45+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-03-24T12:21:18+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-24T05:47:18+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-24T05:46:31+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Research Notes","date":"2026-03-19T21:50:13+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-research-notes","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"resn","sideBox":"Learn more about [BMC Research Notes](http://bmcresnotes.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/resn/default.aspx","title":"BMC Research Notes","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6edcaa57-381b-4533-9fb8-529a723b616a","owner":[],"postedDate":"April 2nd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2026-04-07T10:41:30+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-02 10:49:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9173099","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9173099","identity":"rs-9173099","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}