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

Abstract

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.

Implications for Rehabilitation

• Manual wheelchair propulsion is essential for many individuals with lower limb impairments; however, it often leads to upper limb pain, which can limit mobility and quality of life.

• Stroke patterns that reduce upper limb demand can help users reduce their risk of pain.

• The double loop (DL) and semi-circular (SC) stroke patterns produced the best combinations of handrim biomechanics and are therefore recommended for use.

• Due to an observed increase in elbow muscle activity, individuals who use the DL pattern are not encouraged to switch to the SC pattern.

Keywords::

• Biomechanics
• electromyography
• propulsion
• stroke pattern
• spinal cord injury
• wheelchair

Declaration of Interest: This study was funded through the National Institutes of Health by the National Institute of Child Health and Human Development (Grant#: R01HD053732). The contents of this paper do not necessarily represent the views of the National Institute of Child Health and Human Development or the National Institutes of Health. The authors declare a financial affiliation with the devices discussed in this paper. The authors are employed by MAX Mobility, LLC, which manufactures and sells the OptiPush system. By demonstrating the utility of the system, the authors could gain from a potential increase in OptiPush sales.