Course of gross mechanical efficiency in handrim wheelchair propulsion during rehabilitation of people with spinal cord injury: a prospective cohort study

Abstract de Groot S, Dallmeijer AJ, Kilkens OJ, van Asbeck FW, Nene AV, Angenot EL, Post MW, van der Woude LH. Course of gross mechanical efficiency in handrim wheelchair propulsion during rehabilitation of people with spinal cord injury: a prospective cohort study. Objective To investigate the course of mechanical efficiency of handrim wheelchair propulsion during rehabilitation of subjects with (in)complete paraplegia and tetraplegia. Design Subjects were tested at the start of active rehabilitation (t 1 ), 3 months later (t 2 ), and when discharged from inpatient rehabilitation (t 3 ). They performed two 3-minute submaximal treadmill exercise blocks in a wheelchair. Setting Eight rehabilitation centers in the Netherlands. Participants Ninety-two people with (in)complete paraplegia and tetraplegia. Interventions Not applicable. Main Outcome Measures Mechanical efficiency values were calculated for each block. The course of mechanical efficiency was investigated using test occasions (t 1 −t 3 ), completeness and level (paraplegia or tetraplegia) of the lesion, and power output as independent variables in a multilevel regression analysis. Results Mechanical efficiency significantly increased between t 1 and t 2 only. After adding level and completeness of the lesion and their interactions with time to the model, block 2 showed that subjects with paraplegia had a significantly higher mechanical efficiency than subjects with tetraplegia. Subjects with tetraplegia improved more between t 1 and t 2 . Differences in mechanical efficiency between subjects with paraplegia and tetraplegia could not be explained by differences in absolute and relative power output levels. Conclusions Results showed a significant improvement in mechanical efficiency during the first 3 months of active rehabilitation. Subjects with paraplegia showed a higher mechanical efficiency than did subjects with tetraplegia, whereas the latter showed more improvement between t 1 and t 2 .