Tread-surface Swing Mechanism of Lower Limbs Strength Training Device

This paper proposed a tread-surface swing mechanism for lower limbs strength training devices. In the standing position and the training for lower limbs, if the tread-surface angle is inappropriate, then the posture of the knee joints will be affected, and knee adduction/valgus moments, which result to knee stress, will be generated. The target trainings are the front-back crossing and the right-left spread exercises. Regarding the swing of the tread-surface, it is necessary to realize a pitch/yaw rotation and a roll/yaw rotation for the former and the latter exercises, respectively. The mechanism we proposed has a further differential mechanism that utilizes the difference between pulley diameters. The translational movement force of the tread-part is transmitted as the torque of the swing motion for pitch, roll, and yaw by the effect of the differential mechanism. The rate of the swing angle can be changed by adjusting the pulley diameter. Rehabilitation and strength training that result in small knee joint stresses and that generate large muscle load cab pose great demand from people suffering from knee joint failure.