This is an evaluation of cohorts of men and women in each decade of life. The study was designed to evaluate the effect of age, sex, hand dominance, and body size on forearm rotation in healthy males and females. Forearm rotation was measured in 752 healthy individuals with an age range of 20-95 years. Forearm length and limb circumference were measured with the patient seated, the shoulder at 0 degrees of abduction, and the elbow at 90 degrees of flexion.
The results indicate that mean forearm pronation in males was 70 degrees, with a standard deviation of 15 degrees. Mean supination was 100 degrees, with a standard deviation of 12 degrees. The range of forearm rotation decreased with increasing age; however, in males, this effect was not seen until the late 60’s and in females it was seen in the late 40’s. Hand dominance, forearm length, and forearm circumference did not affect the range of forearm rotation.
The data confirmed that the range of active supination is higher than the range of active pronation regardless of age or sex. In addition, this study evaluated “healthy” males and females. Several subjects considered themselves healthy even with extremely restricted pronation. In contrast, patients with restricted supination did not consider themselves healthy and did not participate the study.
The authors conclude that individual variations of range of forearm rotation is significant, that range of forearm rotation is generally greater in women and starts to decrease in women earlier than in men. In addition, range of motion was independent from side and hand dominance and comparable between sides. While their data does not prove that deficits of forearm rotation should be treated predominantly by restoration of supination, it does seem to indicate that forearm supination is more important functionally and a more critical factor in whether patients consider themselves to be healthy.