Evidence map›Paper›PMID 41862162›Full record

ArticleJournal of sport and health science2026

Adaptations in biceps femoris long-head muscle-tendon mechanics during the Nordic hamstring exercise in response to 9 weeks of training.

Max H Andrews, Anoosha Pai S, Reed D Gurchiek, Paul W Hodges, Glen A Lichtwark, Scott L Delp, Patricio A Pincheira

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In one paragraph

Article in Journal of sport and health science, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

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5 · Who and what money

Authors and funding

7 authors.

Max H AndrewsSchool of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA. Electronic address: max.andrews@uq.net.au.
Anoosha Pai SDepartment of Bioengineering, Stanford University, Stanford, CA 94305, USA.
Reed D GurchiekDepartment of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Clemson University, Clemson, SC 29634, USA.
Paul W HodgesSchool of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
Glen A LichtwarkSchool of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia.
Scott L DelpDepartment of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA.
Patricio A PincheiraSchool of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; School of Health and Medical Sciences, The University of Southern Queensland, Ipswich, QLD 4305, Australia.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundProlonged Nordic hamstring exercise (NHE) training reduces hamstring injury risk, but the underlying mechanisms remain unclear. This study examined how NHE training alters biceps femoris long-head (BFlh) muscle-tendon unit (MTU) mechanics during the exercise, focusing on how muscle adaptations influence fascicle and sarcomere lengths during the NHE after training.

methodsTwelve recreationally active participants completed 9 weeks of supervised NHE training and 3 weeks of detraining. Knee flexor torque was measured using ankle-mounted load cells and estimated from the knee joint moment arm. BFlh fascicle lengths were assessed during the NHE using dual-transducer ultrasound, and MTU length was estimated from joint angles using markerless motion capture. Sarcomere lengths during the NHE were estimated using instantaneous BFlh fascicle length and previously calculated serial sarcomere numbers. Linear mixed-effects models analyzed changes between pre-training, post-training, and post-detraining.

resultsNine weeks of NHE training increased peak knee flexor torque by 40% (previously reported), enabling 37% greater knee extension (p = 0.012) and 4% longer MTU lengths at peak torque during the NHE (p = 0.001). BFlh fascicles reached 25% longer lengths during the NHE at peak torque after training (p < 0.001), while estimated active sarcomere lengths at peak torque were unchanged (p = 0.266). Following 3 weeks of detraining, knee flexor torque decreased by 6% (previously reported) and fascicle lengths at peak torque decreased by 14% (p < 0.001), while MTU length (p = 0.578) and estimated active sarcomere length (p = 0.753) at peak torque during the NHE did not significantly change compared to post-training.

conclusionDespite the longer fascicle lengths during the NHE after training, estimated active sarcomere length during the NHE relative to optimal sarcomere length remained similar, consistent with the addition of sarcomeres in series, which may contribute to the protective effects of NHE training.

Indexed as

Eccentric exerciseForce–length relationshipMuscle–tendon unit dynamicsSarcomerogenesis

Identifiers

PMID41862162
PMCPMC13279503

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LicenceCC BY-NC-ND
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.