Relationships among manual body functions, manual capacity, and bimanual performance using the prosthetic upper...

Most surgical techniques intervene at the level of body functions of the upper limb, aiming to improve manual capacity and activity performance. However, the nature of the relationships among these levels of functioning and evidence for hand function variables predicting performance have scarcely been investigated.

The primary aim of this study was to assess aspects of hand function and manual capacity that influence bimanual performance in children with congenital hand differences (CHDs), ranging from surgically corrected polydactyly or syndactyly to radial dysplasia. A secondary aim was to assess whether the number of items on the Prosthetic Upper Extremity Functional Index (PUFI) can be reduced without losing information on bimanual performance in this population.

A cross-sectional design was used.

One hundred six 10- to 14-year-old children with CHD participated in the study, which was conducted in a university hospital's outpatient clinic. Bimanual performance was evaluated with child self-reports on an adapted version of the PUFI, calculating ease of performance and actual use of the affected hand. Additionally, hand function and manual capacity were assessed.

The median score on ease of performance was high, and, on average, the children used their affected hand actively in 97% of all activities. Manual capacity of the nondominant hand and lateral pinch strength of the dominant hand predicted attainment of maximum PUFI scores. Nonmaximum PUFI scores were predicted by opposition strength of the nondominant hand and lateral pinch strength of the dominant hand. In addition, in this patient group, only 6 items of the PUFI explained all variance in PUFI scores.

The generalizability of the results is limited by the carefully selected age range. Second, the cross-sectional design of the study limits statements on causality on the relationships found.

Children with a CHD generally have good bimanual performance and, on average, perform activities with active use of the affected hand. Therapy directed toward increasing manual capacity and finger muscle strength might assist in improving bimanual performance in children with CHD. Furthermore, the number of items on the PUFI could be reduced from 38 to 6 items in children with CHD.