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

摘要

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 workdata 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.