By muscular contraction he can create a pressure on an outward object,which,if sufficiently powerful,will set it in motion,or if it be already moving,will check or modify or altogether arrest its motion,and he can do no more.

• 靠着肌肉的收缩，人能给予外物以压力，压力如果足够强的话，可使外物产生运动，如果物体已在运动中，则可以阻止，改变或完全停止其运 动。