An analysis of symmetry of torque strength of the forearm under resisted forearm rotation in normal subjects

Purpose: To establish normative pronation and supination torque values in right-handed adults without evidence of upper-extremity dysfunction or impairment in the forearm positions of neutral, pronation, and supination. Methods: Fifty-one normal right-handed participants ages 22 to 45 years were enrolled and tested in this study using a custom device that incorporated a torque cell and a grip system that produced a digital recording of the peak torque during maximal resisted pronation and supination in positions of neutral forearm rotation, 60 degrees pronation, and 60 degrees supination. Results: The greatest peak torque strength for both male and female participants was found during resisted pronation in the supinated position. The peak torque values averaged 11.9 +/- 3.7 N(.)m on the right side and 10.4 +/- 3.3 N(.)m on the left side for men, and 6.0 +/- 1.4 N(.)m on the right side and 5.0 +/- 1.2 N(.)m on the left side for women. The weakest torque strengths were resisted pronation in the pronated position and resisted supination in the supinated position. Conclusions: Torque strength measurements are reliable and should be collected when treating patients with forearm dysfunction. Maximal torque follows the same pattern related to hand dominance as grip strength. Men generate average torque strengths that are approximately twice the magnitude of those generated by women.