The invariance of upper limb terminal was shown in the result and the affecting factors were discussed . function synergy among the upper limb joints angles was defined by using the fitting parameter matrix 指出了触点运动中上肢终端轨迹的不变性,探讨了终端轨迹和运动质量的影响因素,定义了上肢关节角度间的功能协调元。