 The experiment day starts at 7.30 a.m. with the test subject equipped with EMG electrodes and video markers. After take-off and after work is permitted, the subject goes to the experimental area where it is equipped with the SLS harness. Before each parabola, the subject stands beside the platform to adjust the zero level of the sensor about 3 second. Then the subject steps on the platform to record his weight about 3 second. 