Development of a device for prolonged muscle stretch treatment and for quantitative assessment of spasticity

The purpose of this study is to develop a quantitative measurement system to quantify the degree of spasticity and to monitor the amount of force needed during prolonged muscle stretch (PMS). The designed PMS treatment and assessment system consists of a footplate controlled by a direct-driven motor. By using this device, we can perform an evaluation on subject's ankle joint with the stretch reflex to determine the correct force needed for the PMS treatment. With this device, sinusoidal movement and ramp-and-hold stretch assessments can be performed to evaluate the treatment effects. Two major modes of PMS treatment, constant torque stretch versus constant angle stretch, are implemented. Our test battery includes three measurements to assess: (1) neurophysiological evaluation: H/M ratios of soleus muscle; F/M ratios of tibialis anterior muscle; (2) biomechanical evaluation: the parameters of stretch reflex for soleus muscle; torque and angular position of passive stretch during ankle dorsiflexion; (3) clinical evaluation: range of motion of ankle dorsiflexion, modified Ashworth scale. These tests will be performed before, after PMS and 45 minutes after PMS to comprehend the duration of curative effect. The clinical therapist can quantify the treatment intensity and evaluate treatment effects by way of the quantitative measurement system.