The effects of four different stroke patterns on manual wheelchair propulsion and upper limb muscle strain.

PURPOSE: To evaluate the effects of stroke pattern on handrim biomechanics and upper limb electromyography (EMG) in experienced wheelchair users.
METHOD: Subjects propelled their own wheelchair on a level, motor-driven treadmill using each of four identified stroke patterns: arcing, double loop (DL), semi-circular (SC) and single loop (SL). Upper limb EMG and measurements taken from an instrumented wheelchair wheel were compared for each pattern. A one-way ANOVA with Bonferroni correction (p < 0.05) was used to check for significant differences.
RESULTS: The DL and SC patterns produced the best overall results. The DL pattern led to a significantly longer contact angle and significantly less braking moment than the SL and arcing patterns, and a significantly lower cadence than the SL pattern. The SC pattern led to a significantly longer contact angle than the SL pattern and the lowest peak force and impact of any pattern. There were no significant differences in integrated EMG (IEMG); however, the DL and arcing patterns produced lower combined IEMG values.
CONCLUSIONS: When traversing level terrain, wheelchair users should push with either the DL or SC patterns. Between the two, the DL pattern required less muscle activity and may be a better choice for experienced wheelchair users.