RESUMEN
BACKGROUND: The present study examines the hand movements of children with cerebral palsy during functional tests and compares the childrens' performance with and without the aid of an orthosis that provides wrist extension and thumb abduction. METHODS: The range of motion of the trapeziometacarpal joint was assessed for 32 participants via a reflexive markers image system. Observed motions included flexion-extension and abduction-adduction motions performed in the course of four tests for manual ability; the rest position, lateral and tripod pinches and cylindrical grasp. Muscle strength and manual ability were evaluated using dynamometry and the Jebsen-Taylor test. FINDINGS: The range of motion tests for the rest position, lateral and tripod pinches and cylindrical grasp demonstrated improvements from 17% to 42% (P<0.001) for flexion/extension and from 36% to 54% for abduction/adduction (P<0.001) with the use of the orthosis. Dynamometry measurements showed that the improvement in muscle strength obtained through use of the orthosis was 50% (P<0.001). Improvements in the time required to perform the movements as determined using the Jebsen-Taylor test varied from 13% to 24% (P<0.01) for the four considered tests of manual ability. INTERPRETATION: The orthosis improved the range of motion of the trapeziometacarpal joint, muscle strength and manual ability. The combination of the three techniques may provide the basis for a quantitative assessment of hand dysfunction/improvement in cerebral palsy that will ultimately guide health professionals in their clinical interventions.