Isokinetic testing of biceps strength and endurance in dominant versus nondominant upper extremities

BackgroundThe strength and endurance of the contralateral biceps muscle can serve as a useful comparison for the operative limb following distal biceps repairs, mid-substance repairs, or tenotomy or tenodesis of the long head. There are limited data available on the effect of handedness on biceps strength and endurance.HypothesisThe dominant upper extremity has greater elbow flexion and supination peak torque and endurance.Materials and methodsSubjects with no history of prior upper extremity injury or limitations completed isokinetic testing of biceps flexion and supination peak torque and endurance on a Biodex machine. A paired student t test was used to compare peak torque and endurance for both supination and flexion for the dominant and nondominant upper extremities. The results were analyzed for the entire group, and for male and female subjects separately as well.ResultsA power analysis revealed that 5 subjects were needed to achieve 80% power. Twenty subjects (10 male, 10 female) were tested. No significant difference was detected for peak torque or endurance for supination or flexion between the dominant and nondominant upper extremities. No difference was detected when the group was analyzed as a whole, nor when men and women were analyzed separately.ConclusionsThe dominant and nondominant upper extremities demonstrate similar peak torque and endurance for supination and flexion. The normal contralateral upper extremity can be used as a matched control in the evaluation of post operative biceps isokinetic strength and endurance without adjusting results for handedness.