Dynamic shoulder flexion strength: for use in occupational risk analysis and clinical assessment.

Abstract

Given the likelihood of increased risk of musculoskeletal injury when joint torque strength demands approach the maximum isometric torque, this study determined the flexion torque strength capabilities of the shoulder in young men and women. To our knowledge this is the first study to report dynamic shoulder flexion torques. Peak static flexion torque values were collected at shoulder angles of 0° (anatomical position) and 45° of flexion in 25 female and 26 male subjects seated in an upright position. Dynamic concentric and eccentric shoulder flexion torques were collected at 50° s(-1) angular velocity from 0° to each subject's comfortable flexion limit on a KIN-COM dynamometer. Results indicated that for both static and dynamic strength measures, female subjects produced, on average, half of the torque output of males. Mean male flexion torques were: static at 0° = 89.9 N m; static at 45° = 68.6 N m; dynamic at 45° = 46.9 N m (concentric); dynamic at 45° = 75.3 N m (eccentric).