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Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
Published on: May 1, 2018
Isokinetic work profile of shoulder flexors and extensors in sport climbers and nonclimbers
Emmy K L Wong1, Gabriel Y F Ng
1Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.
Study Design:
Cross-sectional, 2-group comparison, experimental laboratory study.
Objectives:
Examining and comparing the work profiles of the shoulder flexors and extensors between sport climbers and nonclimbers.
Background:
Sport climbing places high demands on the shoulder, which could lead to unique work profiles of the agonist/antagonist muscle groups.
Methods And Measures:
Isokinetic work output of the dominant shoulder flexors and extensors of 31 sport climbers and 27 nonclimbers were measured from 0 degrees to 180 degrees of flexion at a test speed of 60 degrees /s. Profiles for work data (concentric flexion [conFlex], eccentric flexion [eccFlex], concentric extension [conExt], eccentric extension [eccExt]) normalized to body mass, conventional work ratios (conFlex/conExt and eccFlex/eccExt), and functional work ratios (eccFlex/conExt and eccExt/conFlex) were developed for both climbers and nonclimbers.
Results:
All work profiles were different between the 2 groups (P<.001). All normalized work data were higher in climbers than nonclimbers, especially for conExt and eccExt. In the climbers, the conventional ratios were smaller than 1 for conFlex/conExt (0.74) and eccFlex/eccExt (0.74), whereas for the nonclimbers the ratios were 1.13 and 1.05, respectively. For the functional work data, the eccFlex/conExt ratio was 0.9 for the climbers compared to 1.46 for the nonclimbers. Conversely, the eccExt/conFlex ratio was much higher in the climbers (1.73) compared to the nonclimbers (1.28).
Conclusion:
The differences in work profiles for the shoulder flexors and extensors between the climbers and nonclimbers suggest training-induced adaptations, stronger shoulder flexors, and, especially, stronger extensors, resulting from the sports of climbing.
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