RehabMove 2018: RESTORATION OF ELBOW EXTENSION BY TENDON TRANSFER: EFFECT ON WHEELCHAIR MOBILITY

PURPOSE: Patient satisfaction after a reconstructive elbow extension surgery is high. However, the full biomechanical effect of this procedure related to wheelchair propulsion is essentially unknown. Analysis of biomechanical parameters may shed light on the interplay changes due to this surgery and could identify possible benefits or risk factors related to mobility. The aim of this study was to investigate the effects of a surgical elbow extension reconstruction on wheelchair propulsion characteristics in persons with tetraplegia. METHODS: One participant with tetraplegia was measured before and six months after elbow extension reconstruction. The surgical procedure undertaken was the deltoid-to-triceps transfer technique, in which the insertion of the posterior deltoid was connected via a tendon graft to the triceps tendon. At both time points the participant performed wheelchair propulsion on the treadmill with a speed of 0.56m/s and a power output of 15W. During wheelchair propulsion the applied forces were measured with an instrumented wheel during 30s while kinematics were recorded. Propulsion characteristics were analyzed over all complete pushes. RESULTS: While propelling at the constant power output, the total mean applied push force (pre 49N, post 38N) and peak applied push force (pre 67N, post 58N) decreased and was exerted in a more effective direction, represented by the higher fraction effective force (pre 62%, post 73%). The patient could apply the propulsion force over a longer push angle (pre 66°, post 74°), which resulted in a lower push frequency (pre 52 pushes/min, post 47 pushes/min). CONCLUSIONS: The surgical intervention did lead to a more effective force production during wheelchair propulsion. The lower applied forces as well as the longer and less frequent pushes after the tendon transfer are related to lower peak load on the upper extremity and are likely related to a lower risk for overload injury of the shoulder