Symmetry of the elbow kinematics during racing wheelchair propulsion

The purpose of this study was to establish whether bilateral symmetry exist s during wheelchair propulsion in the elbow movement pattern of trained whe elchair racers. Seven endurance-trained wheelchair racers volunteered to pa rticipate in the study. Each subject was recorded by two-dimensional video analysis while pushing on a single-roller wheelchair ergometer at 14 mph (6 .58 ms(-1)) in their own racing wheelchair. The range of elbow flexion, elb ow orientation and selected timing parameters including cycle time and time spent in contact with the handrim (propulsion phase) were obtained from bo th left and right sides. Wilcoxon Matched-Pairs Signed-Ranks tests determin ed the differences between the left and right sagittal plane images of whee lchair propulsion. Furthermore, the Bland-Altman method determined the agre ement between the left and right sagittal plane images. The results indicat ed that the propulsion phase, elbow height and elbow angular displacement c haracteristics were not significantly different between right and left side s. The right elbow was higher than the left during the recovery phase, but the magnitude of this difference was only 0.03 m (N.S). Factors associated with chair design and the athlete's posture may have contributed to the sma ll differences noted between left and right sides. In conclusion, the resul ts appear to suggest that the assumption of bilateral symmetry of the elbow movement pattern during wheelchair propulsion is valid for the group. Howe ver, it is important to note that asymmetries exist in individuals and furt her research is warranted.