Individual Muscle Contributions to Push and Recovery Subtasks During Wheelchair PropulsionBy Rankin, Jeffery W.; Richer, W. Mark; Neptune, Richard R.; Journal of Biomechanics, Volume 44, Number 7, pages 1246-1252
Publication Date: April 2011
Study used a forward dynamics simulation of wheelchair propulsion to quantify how individuals deliver, absorb, and/or transfer mechanical power during propulsion. Experimental data were collected from 12 experienced wheelchair users aged 23 to 46 years, two of whom were female, who had full upper extremity function without pain. Participants propelled their wheelchair on a motor driven treadmill at their self-selected overground speed for 30 seconds, during which trunk and right side upper extremity kinematics, three-dimensional handrim kinetics, and shoulder and elbow electromyographic data were collected. Ten consecutive strokes were analyzed from each participant. Mean data were then averaged across participants to create representative biomechanical and muscle excitation profiles. The analysis showed that muscles contribute to either push or recovery subtasks, with the shoulder flexors being the primary contributors to the push and the shoulder extensors being the primary contributors to the recovery. In addition, significant activity from the shoulder muscles was required during the transition between push and recovery, which resulted in increased co-contraction and upper extremity demand. Thus, strengthening the shoulder flexors and promoting propulsion techniques that improve transition mechanics have much potential to reduce upper extremity demand and improve rehabilitation outcomes.
Published by: Elsevier Inc. (Website:http://www.elsevier.com)
Link to text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3086712/?tool=pmcentrez