Paper Title
Proposing an Ankle Joint Lifting Mechanism of Ankle Joint Pushing Machine Concerning About Sense of Firmness

Abstract
In this paper, an ankle joint lifting mechanism of ankle joint pushing machine concerning about sense of firmness was proposed, and the effect of the mechanism was examined in the system. The stretching of the ankle joint is an important medical treatment that physical therapist (PT's) utilize to help their patients recover their ability of walk and to prevent contracture. Since the ankle treatment requires a large amount of force (nearly equal to the subject's weight), precise angle and power controls, manual treatment by PTs has not been replaced by mechanical treatment systems. Before the ankle joint stretching treatment, the knee joint of the subject is necessary to extend straightly for maximizing the therapeutic effect of the ankle joint. However, there is few proposal to lift up the lower leg horizontally without pain. To realize the lifting up mechanism of the lower leg without pain, the developed system uses two linear actuators to ease the pain during the lift-up process. By using two actuators to lift the lower limb to horizontal position, the positional deviation between the ankle joint and rotation center of the device was measured Δ𝐲= 87 mm. On the contrary, in the condition of using a single actuator to lift the lower limb, the positional deviation was measured Δ𝐲=295 mm. There is 295-87= 208 mm distance displacement between the ankle joint and the device rotation center if a single actuator would be used to lift the lower limb process. The proposed two actuators lower limb lifting mechanism will effectively work to develop ankle joint stretching system. Keywords - Ankle Joint Pushing Unit Mechanism, Ankle Joint Stretching System With Two Linear Actuators , Change the Length System, Leg Lifting Mechanism