人腕关节动力肌腱的力臂值及意义探讨

Moment arms of the wrist motor tendons and its implication

目的 :测量人腕关节主要动力肌腱在腕运动过程中力臂的大小。方法 :运用 7只新鲜成人尸体上肢标本 ,将运动腕关节的肌腱和旋转电压计相连 ,在腕关节分别从屈曲至伸直 ,桡偏至尺偏过程中 ,用计算机同时记录腕动力肌腱滑动距离和腕运动角度 ,根据腱滑动距离和腕运动角度计算出肌腱平均力臂和力臂变化。结果 :桡侧腕长伸肌腱的腕桡偏力臂最大 ,桡侧腕短伸肌腱的伸腕力臂最大 ,尺侧腕伸肌腱的腕尺偏力臂最大 ,而伸腕力臂很小 ,桡侧、尺侧腕屈肌均有较大屈腕力臂 ,它们相对于伸肌桡尺偏腕关节的力臂较小。结论 :腕关节的力臂分布对腕动力肌的功效起决定作用 ,是腕正常活动方式和常见动作的生物力学基础。

Objective:To investigate the values of moment arms of wrist motor tendons.Methods:7 fresh cadaveric upper limbs were used.The wrist motor tendons were connected with rotary potentionmetric transducers to continuously record tendon excursions during wrist motion.The wrist motion was recorded by an electronic goniometer.Moment arms of tendons were calculated according to the relationship between tendon excursions and joint angulation.Results:The extensor carpi radialis longus tendon showed the largest moment arm in wrist radial deviation.The extensor carpi radialis brevis tendon had the largest moment arm in wrist extension.The extensor carpi ulnaris tendon showed the largest moment arm in ulnar deviation,but it moment arm was very small in wrist exension.Both the flexor carpi radialis and ulnaris tendons had quite large moment arms in wrist flexion,but their moment arms for wrist deviation was smaller than extensor tensons.Conclusion:Moment arms of the wrist motors play an important role in efficiency of wrist motor muscle and wrist motions.Values and distribution of moment arms in wrist motors are the biomechanical basis of wrist motion patterns and daily activity of the hand.