Isokinetic Work Profile of Shoulder Flexors and Extensors in Sport Climbers and Non-climbers

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 non-climbers. 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 non-climbers were measured from 0^o to 180^o of flexion at a test speed of 60^o/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 non-climbers. RESULTS: All work profiles were different between the 2 groups (P<.001). All normalized work data were higher in climbers than non-climbers 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 non-climbers, 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 non-climbers. Conversely, the eccExt/conFlex ratio was much higher in the climbers (1.73) compared to the non-climbers (1.28). CONCLUSION: The differences in work profiles for the shoulder flexors and extensors between the climbers and non-climbers suggest training-induced adaptations, stronger shoulder flexors and especially extensors, resulting from the sports of climbing.

J Orthop Sports Phys Ther., Epub 29 May 2008. doi:10.2519/jospt.2008.2779

The authors examine and compare the work profiles of the shoulder flexors and extensors between sport climbers and non-climbers.