Isokinetic work profile of shoulder flexors and extensors in sport climbers and nonclimbers.

Abstract

Cross-sectional, 2-group comparison, experimental laboratory study. Examining and comparing the work profiles of the shoulder flexors and extensors between sport climbers and nonclimbers. Sport climbing places high demands on the shoulder, which could lead to unique work profiles of the agonist/antagonist muscle groups. 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. 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). 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.