The effects of age, sex, and shoulder dominance on range of motion of the shoulder

To determine the effects of age, sex, and arm dominance on shoulder range o f motion, we measured active and passive forward elevation, abduction, inte rnal and external rotation at 90 degrees of abduction, external rotation wi th the arm adducted, and extension bilaterally in 280 subjects ranging in a ge from 4 to 70 years, linear regression analyses were performed for all mo tions except Forward elevation. This motion, which showed a nonlinear patte rn of decline with age, was evaluated with 3-way analysis of variance. Shou lder range of motion decreased with age for all measured motions with the e xception of internal rotation, which increased with age. Female subjects ha d a significantly greater range of motion than male subjects for all motion s measured. Dominant arms displayed significantly greater external rotation than nondominant, regardless of whether the arm was abducted or adducted a t the rime of measurement. However, nondominant shoulders demonstrated sign ificantly greater internal rotation and extension than dominant. No signifi cant differences were found between dominant and nondominant sides for forw ard elevation or abduction.