Repetition-Based Training for Efficient Propulsion in New Manual Wheelchair Users

SIGNIFICANCE: Many individuals with a spinal cord injury (SCI) depend on the use of manual wheelchairs for mobility and for participation in activities such as personal care, transportation, and community life. Manual wheelchair propulsion requires repetitive motion of the upper extremities, which increases the level of stress on muscles and joints and causes pain that leads to overuse injuries. Upper-extremity pain and injury are major concerns for manual wheelchair users (MWUs) due to their dependence on the upper extremities for activities of daily life such as wheelchair propulsion, personal care, dressing, and transfers. Chronic overuse injuries are associated with improper biomechanics and poor ergonomics during wheelchair propulsion. As a result of the high number of MWUs who experience pain and overuse injuries in their upper extremities, the Consortium for Spinal Cord Medicine has made clinical practice guidelines that reduce the mechanical load on the upper extremities and lessen the chances of developing chronic overuse injuries.

INNOVATION: Since the clinical practice guidelines were developed, evidence-based training programs have not been introduced into clinical practice, and many new MWUs receive little to no instruction on how to properly propel their chairs. Current research on motor learning suggests that one must perform hundreds of task-specific repetitions over several sessions for changes to occur and be retained. Currently, there is limited evidence related to acquiring novel motor skills in individuals learning to propel a manual wheelchair following an SCI. A training program that produces efficient propulsion skills is crucial for clinical rehabilitation to prevent or delay the onset of secondary injuries, such as chronic overuse injuries, as well as to promote participation throughout the individual’s lifespan.

METHOD: The objective was to determine the number of propulsion repetitions necessary to produce changes in propulsion biomechanics of new MWUs with SCIs. The study used a single-subject design, and a community-based research facility served as the setting. Five new MWUs with SCIs (3 men, 2 women; aged 39.0 ± 30.0 yr) participated in this nine-session manual wheelchair training program that aimed to improve propulsion biomechanics through 5,400 propulsion repetitions.

Assessments were performed on a wheelchair dynamometer at seven levels of repetition dosing. Kinematic measurements (i.e., push loop height, push angles, cadence) were taken using video cameras and Microsoft Kinect^® systems. Kinetic measurements (i.e., peak force, average force, rate of rise) were taken with a wheelchair dynamometer system.

RESULTS: All five participants had improvements in propulsion biomechanics, which occurred in the first levels of repetition dosing (between 1,000 and 2,700 repetitions); there were variances in type of change (kinematic or kinetic).

CONCLUSION: Results suggest that proper propulsion biomechanics can be learned with appropriate dosing. The variability among participants in the type of change that occurred at different dosing levels may be due to differences in wheelchair positioning and level of injury. The impact of MWUs learning efficient propulsion is great, as engagement in daily activities depends on the health of the upper extremities.