Contents I. Introduction
At least more than one million people are gait disorder in Japan. Many kinds of walker have been developing so far for gait training and/also supporting walking motion though, they are used by grasping the front (Fig. 1 (a)) or the back part of them in order to hold trunk. It makes forward tilting or backward tilting of the upper half body and comes to difficult to keep right posture for walking. To avoid falling and decrease the load, underwater gait training (Fig. 1 (b)) and also hanging type treadmill (Fig. 1 (c)) are applied. These are expensive and required a special facility. Moreover there are few examples of an active walker which is used if people have no muscular force for walking. Locomat [1] by ETH and robotics stepper by NASA and UCLA [2] are good and only examples for the active walker which consists of treadmill and manipulator attached to the body. They are very sophisticated though, they are very expensive and cannot use in daily life. Although wheel chair is normally used for people who is gait disorder, it makes disuse syndrome (amyotrophia, arthrogryposis and impediment of the circulatory system) and therefore to keep upright position and walking are very crucial indeed.
