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Impact of exercise selection on hamstring muscle activation.
Br J Sports Med. 2017 Jul; 51(13):1021-1028.BJ

Abstract

OBJECTIVE

To determine which strength training exercises selectively activate the biceps femoris long head (BFLongHead) muscle.

METHODS

We recruited 24 recreationally active men for this two-part observational study. Part 1: We explored the amplitudes and the ratios of lateral (BF) to medial hamstring (MH) normalised electromyography (nEMG) during the concentric and eccentric phases of 10 common strength training exercises. Part 2: We used functional MRI (fMRI) to determine the spatial patterns of hamstring activation during two exercises which (1) most selectively and (2) least selectively activated the BF in part 1.

RESULTS

Eccentrically, the largest BF/MH nEMG ratio occurred in the 45° hip-extension exercise; the lowest was in the Nordic hamstring (Nordic) and bent-knee bridge exercises. Concentrically, the highest BF/MH nEMG ratio occurred during the lunge and 45° hip extension; the lowest was during the leg curl and bent-knee bridge. fMRI revealed a greater BF(LongHead) to semitendinosus activation ratio in the 45° hip extension than the Nordic (p<0.001). The T2 increase after hip extension for BFLongHead, semitendinosus and semimembranosus muscles was greater than that for BFShortHead (p<0.001). During the Nordic, the T2 increase was greater for the semitendinosus than for the other hamstring muscles (p≤0.002).

SUMMARY

We highlight the heterogeneity of hamstring activation patterns in different tasks. Hip-extension exercise selectively activates the long hamstrings, and the Nordic exercise preferentially recruits the semitendinosus. These findings have implications for strategies to prevent hamstring injury as well as potentially for clinicians targeting specific hamstring components for treatment (mechanotherapy).

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Publisher Full Text (DOI)

Authors+Show Affiliations

Bourne MN
Faculty of Health, School of Exercise and Nutrition Science, Queensland University of Technology, Brisbane, Australia. Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia. Queensland Academy of Sport, Centre of Excellence for Applied Sport Science Research, Brisbane, Australia.
Williams MD
Faculty of Life Sciences and Education, School of Health, Sport and Professional Practice, University of South Wales, Wales, UK.
Opar DA
School of Exercise Sciences, Australian Catholic University, Melbourne, Australia.
Al Najjar A
Centre for Advanced Imaging, University of Queensland, Brisbane, Australia.
Kerr GK
Faculty of Health, School of Exercise and Nutrition Science, Queensland University of Technology, Brisbane, Australia. Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
Shield AJ
Faculty of Health, School of Exercise and Nutrition Science, Queensland University of Technology, Brisbane, Australia. Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.

MeSH

AdultCross-Sectional StudiesElectromyographyExerciseHamstring MusclesHumansIsometric ContractionMagnetic Resonance ImagingMaleResistance TrainingThighYoung Adult

Pub Type(s)

Journal Article

Language

eng

PubMed ID

27467123

Citation

Bourne, Matthew N., et al. "Impact of Exercise Selection On Hamstring Muscle Activation." British Journal of Sports Medicine, vol. 51, no. 13, 2017, pp. 1021-1028.
Bourne MN, Williams MD, Opar DA, et al. Impact of exercise selection on hamstring muscle activation. Br J Sports Med. 2017;51(13):1021-1028.
Bourne, M. N., Williams, M. D., Opar, D. A., Al Najjar, A., Kerr, G. K., & Shield, A. J. (2017). Impact of exercise selection on hamstring muscle activation. British Journal of Sports Medicine, 51(13), 1021-1028. https://doi.org/10.1136/bjsports-2015-095739
Bourne MN, et al. Impact of Exercise Selection On Hamstring Muscle Activation. Br J Sports Med. 2017;51(13):1021-1028. PubMed PMID: 27467123.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Impact of exercise selection on hamstring muscle activation. AU - Bourne,Matthew N, AU - Williams,Morgan D, AU - Opar,David A, AU - Al Najjar,Aiman, AU - Kerr,Graham K, AU - Shield,Anthony J, Y1 - 2016/05/13/ PY - 2016/04/16/accepted PY - 2016/7/29/pubmed PY - 2017/8/25/medline PY - 2016/7/29/entrez KW - Exercise rehabilitation KW - Hamstrings KW - Injury prevention KW - MRI KW - Physiotherapy SP - 1021 EP - 1028 JF - British journal of sports medicine JO - Br J Sports Med VL - 51 IS - 13 N2 - OBJECTIVE: To determine which strength training exercises selectively activate the biceps femoris long head (BFLongHead) muscle. METHODS: We recruited 24 recreationally active men for this two-part observational study. Part 1: We explored the amplitudes and the ratios of lateral (BF) to medial hamstring (MH) normalised electromyography (nEMG) during the concentric and eccentric phases of 10 common strength training exercises. Part 2: We used functional MRI (fMRI) to determine the spatial patterns of hamstring activation during two exercises which (1) most selectively and (2) least selectively activated the BF in part 1. RESULTS: Eccentrically, the largest BF/MH nEMG ratio occurred in the 45° hip-extension exercise; the lowest was in the Nordic hamstring (Nordic) and bent-knee bridge exercises. Concentrically, the highest BF/MH nEMG ratio occurred during the lunge and 45° hip extension; the lowest was during the leg curl and bent-knee bridge. fMRI revealed a greater BF(LongHead) to semitendinosus activation ratio in the 45° hip extension than the Nordic (p<0.001). The T2 increase after hip extension for BFLongHead, semitendinosus and semimembranosus muscles was greater than that for BFShortHead (p<0.001). During the Nordic, the T2 increase was greater for the semitendinosus than for the other hamstring muscles (p≤0.002). SUMMARY: We highlight the heterogeneity of hamstring activation patterns in different tasks. Hip-extension exercise selectively activates the long hamstrings, and the Nordic exercise preferentially recruits the semitendinosus. These findings have implications for strategies to prevent hamstring injury as well as potentially for clinicians targeting specific hamstring components for treatment (mechanotherapy). SN - 1473-0480 UR - https://www.unboundmedicine.com/medline/citation/27467123/Impact_of_exercise_selection_on_hamstring_muscle_activation_ DB - PRIME DP - Unbound Medicine ER -