Based on the linked source; automatically prepared and checked against the original report.
Study design
Researchers compared wheel-acceleration and hand-acceleration methods in 33 adults with paraplegia or tetraplegia who propelled their own wheelchairs on a secured test stand. Participants completed preferred, slower and faster self-selected conditions, with ten central cycles analyzed from each trial. Wheel markers and a right-hand inertial sensor supplied the measurements.
Different phase definitions
The wheel method identified propulsion from zero crossings in angular acceleration, representing the push phase. The hand method used continuous wavelet analysis of triaxial acceleration to estimate contact-related events. It did not directly measure hand–pushrim contact or applied force, so the two approaches captured related but distinct biomechanical events.
Speed-dependent results
Hand-based propulsion duration was 0.13 seconds longer overall, while recovery duration was 0.13 seconds shorter. Differences were greatest during slower propulsion: propulsion-duration bias was 0.19 seconds, compared with 0.09 seconds during fast propulsion. Hand-based start and end events also occurred later, by 0.06 and 0.19 seconds overall. The study reports that propulsion speed significantly affected these discrepancies, although propulsion frequency did not differ significantly between methods. Three participants’ slow trials were excluded after hand-event detection failed. The findings support caution when comparing studies that define propulsion phases using different signals.
