The immediate and short-term effects of a wrist extension orthosis on upper-extremity kinematics and range of shoulder motion.

Abstract

The purpose of this study was to investigate upper-extremity kinematics and range of shoulder motion while wearing a wrist extension orthosis compared to the free hand at initial testing and after a week's wear. A convenience sample of healthy women, ages 20-50 years, performed a stacking task and a pouring task, freehanded and splinted, at two times, 1 week apart in this counterbalanced, repeated measures design. A Motion Analysis 3-D system measured quality of movement and range of motion variables. A 2 by 2 analysis of variance (splinted vs. freehanded by time of testing) was used to analyze each variable. In both tasks, participants tended to move more slowly (p = 0.005) with less direct movements (p < .001) when wearing the orthosis. In stacking, splinted movements were also less smooth than when free-handed (p < .0001). When splinted both tasks required more shoulder abduction (p < .0001) and pouring required more shoulder flexion (p < .0001). Participants demonstrated several improvements in quality of movement and amount of shoulder motion used after a weeks' orthotic wear, indicating some adaptation to the orthosis with use. In this study, a wrist extension orthosis interfered with the quality of upper-extremity movement and required more range of shoulder movement compared to the free hand. Future research is needed to determine whether persons with upper-extremity conditions (i.e., arthritis, carpal tunnel syndrome) respond similarly to wrist orthoses. Therapists should consider discussing with patients how their wrist splint could affect their hand performance and help patients learn techniques to reduce stress on their proximal joints.