Evidence map›Paper›PMID 34509714›Full record

ArticleJournal of sport and health science2022

Biceps femoris long head sarcomere and fascicle length adaptations after 3 weeks of eccentric exercise training.

Patricio A Pincheira, Melissa A Boswell, Martino V Franchi, Scott L Delp, Glen A Lichtwark

Open access · diamondAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Journal of sport and health science, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 41 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
41citing papers in PubMed, 3 pooled it
12.3field-weighted citation impact, top 1% of its field
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

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

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

41 citing papers in PubMed, 3 syntheses or guidelines pooled it, 100 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
  3. Chronic Adaptations to Eccentric Cycling Training: A Systematic Review and Meta-Analysis.International journal of environmental research and public health · 2023
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  10. Eccentric Exercise and Muscle Damage: An Introductory Guide.Journal of functional morphology and kinesiology · 2026
    Review
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4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

5 authors at 3 institutions in 3 countries.

Patricio A PincheiraSchool of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD 4072, Australia. Electronic address: uqppinch@uq.edu.au.
Melissa A BoswellDepartment of Bioengineering and Mechanical Engineering, Stanford University, Stanford, CA 94305, USA.
Martino V FranchiDepartment of Biomedical Sciences, University of Padova, Padova 35122, Italy.
Scott L DelpDepartment of Bioengineering and Mechanical Engineering, Stanford University, Stanford, CA 94305, USA.
Glen A LichtwarkSchool of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
Stanford University · USUniversity of Queensland · AUUniversity of Padua · IT

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundEccentric exercise increases muscle fascicle lengths; however, the mechanisms behind this adaptation are still unknown. This study aimed to determine whether biceps femoris long head (BFlh) fascicle length increases in response to 3 weeks of eccentric exercise training are the result of an in-series addition of sarcomeres within the muscle fibers.

methodsTen recreationally active participants (age = 27 ± 3 years; mass = 70 ± 14 kg; height = 174 ± 9 cm; mean ± SD) completed 3 weeks of Nordic hamstring exercise (NHE) training on a custom exercise device that was instrumented with load cells. We collected in vivo sarcomere and muscle fascicle images of the BFlh in 2 regions (central and distal) by using microendoscopy and 3 dimension ultrasonography. We then estimated sarcomere length, sarcomere number, and fascicle length before and after the training intervention.

resultsEccentric knee flexion strength increased after the training (15%; p < 0.001; η

conclusionFascicle length adaptations appear to be heterogeneous in the BFlh in response to 3 weeks of NHE training. An increase in sarcomere length, rather than the addition of sarcomeres in series, appears to underlie increases in fascicle length in the distal region of the BFlh. The mechanism driving regional increases in fascicle and sarcomere length remains unknown, but we speculate that it may be driven by regional changes in the passive tension of muscle or connective tissue adaptations.

Indexed as

Hamstring MusclesSarcomeresAdaptation, PhysiologicalAdultExerciseHumansMuscle StrengthYoung AdultHamstringsNordic hamstring exerciseSarcomerogenesis

Identifiers

PMID34509714
PMCPMC8847943
OpenAlexW3200305254

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

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.