A high sample rate, wireless instrumented wheel for measuring 3D pushrim kinetics of a racing wheelchair

Abstract

In wheelchair racing, measuring pushrim kinetics such as propulsion forces and moments is paramount for improving performance and preventing injuries. However, there is currently no instrumented racing wheel that records 3D pushrim kinetics wirelessly and at a high sample rate, which is necessary for accurately analyzing wheelchair racing biomechanics. In this work, we present an instrumented wheel that measures 3D kinetics at 2500 Hz. Bidirectional wireless communication is used to interface the wheel through a smart phone. The wheel was tested with a world-class racing athlete who propelled at maximal acceleration and maximal speed on a training roller. During acceleration, the peak total force increased continuously from 186 N to 484 N while the peak tangential force was constant at 171 N ± 15 N. At higher speeds, a counterproductive tangential force was measured during the first 15% and the last 25% of the push phase, peaking at -78 N. This wheel may be of great value for both coaches and athletes to help with planning and validating training programs and adaptations to the wheelchair such as positioning. This wheel also has very high potential for further research on wheelchair racing biomechanics and on preventing shoulder pathologies associated with this sport.

Using Wearable Sensors to Estimate Mechanical Power Output in Cyclical Sports Other than Cycling—A Review

“…However, for wheelchair propulsion, using the OptiPush or SMARTWheel for estimating mechanical power implies adding a considerable extra mass (7–9 kg per wheelchair). Chenier et al [ 29 ] designed an instrumented wheel for wheelchair racing, which also adds 5.6 kg to an already lightweight racing wheelchair (8–10 kg). As those instrumented wheels increase the total weight of the wheelchair with ~50–90%, they will influence wheelchair dynamics.…”

Optimizing Racing Wheelchair Design Through Coupled Biomechanical-Mechanical Simulation

“…Also, only the in-plane components of the force applied by the hand on the pushing rim was considered. However, the force applied by the hand is three-dimensional [15]. Therefore, the out-of-plane part of the force was neglected, and this force may be detrimental to the propulsion, so neglecting it may result in an increased wheelchair speed.…”

“…Indeed, considering the freewheel phase of the pushing cycle would lead to a more realistic propulsion phase. Also, going from a 2D model to a 3D model could help considering more than the tangential component of the force of the hand on the pushing rim [15]. Another possible evolution of the models would be to consider the shoulder and elbow as actual joints with multiple degrees of freedom [16], which would result in a more complex, but more realistic model of the propulsion.…”

A 2D lightweight instrumented wheel for assessing wheelchair functionality/activity

“…A recurring principle in the design of such measurement wheels is separating the push-rim from the wheel-rim and directly mounting it to the hub via an optimally rigid sensor unit. In some cases, off-the-shelf 3D force transducers have been used, 11 , 15 while others have applied strain gauges directly to solid metal spokes connecting the push-rim to the wheel hubs. 10 , 13 , 16 More recently, Miyazaki and colleagues used four 2D load cells between a sports push-rim and a disc-shaped adapter plate to allow the measurement unit to be mounted to different sports wheelchair wheels as desired.…”

“…To support this effort, wheelchair wheels have been instrumented with force sensors. [10][11][12][13][14][15][16][17][18][19] Most notably, the SMART Wheel12 and, later, the Optipush 18 systems have provided 3D kinetic data in many studies over the last 20 years, but since these are no longer commercially available, access to knowledge on the functional loading conditions in the upper extremities during dynamic activities has been limited to research developments.…”