Impact of Handedness on Disability After Unilateral Upper-Extremity Peripheral Nerve Disorder

Background: Impairment of the dominant hand should lead to greater disability than impairment of the nondominant hand, but few studies have tested this directly, especially in the domain of upper-extremity peripheral nerve disorder. The aim of this study was to identify the association between hand dominance and standardized measures of disability and health status after upper-extremity peripheral nerve disorder. Methods: An existing database was reanalyzed to identify the relationship between affected-side (dominant vs nondominant) on individuals with unilateral upper-extremity peripheral nerve disorder (N = 400). Primary measure of disability was the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. Results: We found no differences in standardized measures of disability or health status between patients with affected dominant hand and patients with an affected nondominant hand. However, a post hoc exploratory analysis revealed that patients with an affected dominant hand reported substantially reduced ability to perform 2 activities in the DASH questionnaire: "write" and "turn a key." Conclusions: Following unilateral upper-extremity peripheral nerve disorder, impairment of the dominant hand (compared with impairment of the nondominant hand) is associated with reduced ability to perform specific activities, but this reduced ability is not reflected in standardized measures of disability and health status. To adequately identify disability following unilateral impairment of the dominant hand with the DASH, individual items must be used instead of the total score. New or alternative measures are also recommended.