Wearable dummy to simulate joint impairment: severity-based assessment of simulated spasticity of knee joint

Physical therapists master manual examination techniques for testing impaired motor functions. We used a wearable robotic dummy joint that simulated disordered joint resistances to help physical therapists learn such techniques. This study developed a resistance model for a spasticity joint, and the dummy joint was used to present it. We assessed the simulated spasticity model using Modified Ashworth Scale (MAS), which is an evaluation criterion for spasticity seriousness that is widely used by physical therapists. The results of experiments involving two physical therapists showed that the model accurately expressed mild-to-severe symptoms of knee joint spasticity. It is expected that using the system in educational institutions for physical therapists will help students learn the typical levels of joint resistance caused by spasticity with different degrees of severity.