Development of Pneumatic Exercise Device for the Range of Motion in the Ankle Joint

Physiotherapists provide range of motion (ROM) exercise to patients with the aim of preventing contractures and improving ROM limitation. However, it is predicted that the physical and mental burden on physiotherapists will increase due to the increase in the number of patients and the shortage of physiotherapists due to the declining birthrate and aging population in recent years. In that case, the number of patients who can receive sufficient ROM exercise decreases. Then, it develops into problems such as aggravation of contracture and difficulty in activities of daily living. To prevent these problems, many researchers have developed passive ROM exercise devices. Among them, devices using air pressure as a drive source, which are easy to reduce weight and ensure safety, are being actively developed.We have developed a passive ROM exercise device for the ankle joint that uses a pneumatic soft actuator as a drive source. In addition to plantarflexion and dorsiflexion, this device can provide supination and pronation that existing devices cannot provide. In this device, the pneumatic soft actuator directly presses the toes and heels to exercise the ankle joint. Since this actuator has high flexibility, we aim to operate it by adapting to the shape of the foot. In this research, after designing and prototyping the device, we conducted a user test on eight healthy adult males.