Handedness Influences Passive Shoulder Range of Motion in Nonathlete Adult Women

ObjectiveThe purpose of this study was to determine whether handedness influences bilateral shoulder range of motion in nonathlete adult women.MethodsThis was an observational study. Shoulder range of motion (flexion, abduction, horizontal adduction, extension, external and internal rotation) was passively and bilaterally measured in 50 female, right-handed, and healthy university students, ranging from 20 to 29 years of age, who were not practicing repetitive activities with the upper limbs at the time of this study. The assessment was performed with a universal goniometer, twice for each subject by the same examiner. The first and second measurements were correlated using the intraclass correlation coefficient, which was high for all movements and ranged from 0.80 to 0.97. The Student t test and Wilcoxon test were used to compare the range of motion between the dominant and nondominant shoulders and the mean differences between the 2 sides. The effect of size was α = .05.ResultsThere is statistically significance difference between the 2 sides when the rotational range of motion is compared; the dominant shoulder presented increased external rotation (mean, 4.74°; 95% confidence interval, 1.61-7.87) and decreased internal rotation (mean, 3.52°; 95% confidence interval, 1.64-5.4) compared to the opposite shoulder.ConclusionDominance should be considered when shoulder rotation is evaluated even in nonathlete adult women.