The role of upper extremity strength and trunk control on performance-based manual wheelchair propulsion tests in individuals with a spinal cord injury

Abstract

The association between upper extremity (U/E) and trunk strength as well as seated postural stability with wheelchair propulsion performance has not been evaluated. Consequently, it remains unknown to what extent U/E and trunk strength and seated postural stability contribute to manual wheelchair propulsion performance. Gaining additional knowledge with regards to these modifiable contributors may provide guidance to rehabilitation professionals, particularly to physiotherapists, for selecting and prioritizing therapeutic interventions aiming to improve manual wheelchair performance, aside from those focusing on developing optimal propulsion techniques To quantify the association between performance-based manual wheelchair propulsion tests (i.e., 20-m propulsion test, slalom test, and 6-min propulsion test), trunk and U/E strength as well as seated reaching capability to establish which trunk and U/E strength or seated reaching capability measures best predict performance on timed manual wheelchair propulsion tests completed at discharge from inpatient rehabilitation by individuals with a spinal cord injury (SCI). Fifteen individuals with a SCI performed the 20-meter, slalom and 6-minute wheelchair propulsion tests within 72 hours prior to discharge from comprehensive inpatient SCI rehabilitation. Trunk and U/E strength along with seated reaching capability with unilateral hand support were also measured. The relationships between the wheelchair propulsion tests and the other variables were assessed using bi-variate correlation and multiple linear regression analyses. The 20-meter propulsion-maximum velocity, slalom and 6-minute propulsion tests were moderately or strongly correlated with anterior and lateral inclination trunk strength, seated anterior reaching distance and the majority of shoulder, elbow and handgrip strength measures. Shoulder adductor strength-weakest side explained 53% of the variance on the 20-meter propulsion test-maximum velocity. Shoulder adductor strength-strongest side and forward seated reaching distance explained 71% of the variance on the slalom test. Handgrip strength explained 52% of the variance on the 6-minute propulsion test. U/E strength, especially of the shoulder adductors and handgrip, and forward seated reaching capability may be important determinants and predictors of performance during manual wheelchair propulsion tests. Specific rehabilitation interventions targeting these modifiable personal characteristics during rehabilitation may enhance manual wheelchair propulsion ability.