Stronger relation between impairment and manual capacity in the non-dominant hand than the dominant hand in congenital hand differences; implications for surgical and therapeutic interventions.

OBJECTIVES To evaluate manual activity capacity (i.e. activity capacity to perform hand activities) and its relation with body functions of the hand and forearm in children with congenital hand differences (CHD) METHODS: We assessed 10-14 year-old children with CHD (N = 106) using a functional handgrips test. Measurements of body functions included joint mobility and muscle strength. Patient characteristics were hand dominance and severity. RESULTS We found a stronger relation between body functions and manual activity capacity in non-dominant hands than dominant hands. Dominant hands scored significantly higher on manual activity capacity than nondominant hands that were similarly impaired at body functions level. Severity of the CHD and body functions had only small effects on manual activity capacity. CONCLUSION The relation between body functions and manual activity capacity is stronger in non-dominant hands than dominant hands, indicating that improvement in body functions lead to larger changes in manual activity capacity in the non-dominant hand. This may suggest that in bilaterally-affected children surgery should be done at the non-dominant hand first since this hand would benefit most from surgery-induced body functions improvement.