Evaluation of a Competition Wheelchair Based on Estimation of Muscle Activity for Forward Linear Operation by Using Inverse Dynamics Analysis

Abstract

The objective of this study was to evaluate an optimum structure for a rugby wheelchair by estimating the muscle force during forward linear operation of the wheelchair using an inverse dynamics analysis. The simulation model was represented by restraining the contact area between the frame and seat of the wheelchair and the body model. Three body model variations were constructed with different degrees of disability. Wheelchair models were also constructed by varying the range of camber angle, wheel diameter and axle positions, respectively. The effects of the design parameters for the wheelchair on the muscle force were investigated. As a result, the axle position had the strongest effect on the muscle force of the upper limbs, and it is effective to lower the axle position for reducing the muscle force required. This implies that the adjustment of the axle position leads to a reduction in risk of injury occurrence.

Evaluation of Operability for a Competition Wheelchair Using Manipulability

“…As shown in Table 1, the muscle strength of each part is set as a percentage of healthy subjects according to the class of the disability. The reason is that our previous study identified the trend that the triceps muscle plays a role in maintaining posture in addition to propulsion when the trunk muscle strength is lower [4].…”

“…Therefore, if it would be possible to evaluate competition wheelchairs by taking into account the physical load of the athlete, finding a suitable wheelchair for the athlete individually may lead to the reduction of injury risk and improvement of the performance. In our previous study [4], although the muscle activity during the forward linear operation was estimated using the musculoskeletal simulation, the wheelchair operation was expressed not by the real measured motion but by the virtual motion. In addition, the relationship between the physical load and the operability could not be discussed in detail due to a lack of sufficient accuracy validation of the simulation results as well as the virtual motion.…”