腕关节等长屈曲和伸展肌力训练的交叉迁移现象及其机制研究

Inter-hand transfer of the effects of unilateral isometric resistance training for wrist flexion and extension

目的观察右腕等长屈曲和伸展训练能否产生交叉迁移现象并研究及其机制。方法将健康女性青年志愿者20例按随机数字表法分为训练组和对照组，每组10例。训练组进行6周的右腕等长屈曲和伸展训练，左腕不进行训练，对照组不进行任何训练。2组受试者均于训练前和训练6周后（训练后）测定其腕屈、伸肌等长肌力（PT）及表面肌电变化。结果训练后，训练组右腕关节最大等长屈曲和伸展PT与组内训练前和对照组训练后比较，均显著提高（P〈0．05），且训练组左腕关节最大等长屈曲和伸展PT分别为（12．9±2．0）Nm和（6．4±1．3）Nm，与组内训练前和对照组训练后比较，差异均有统计学意义（P〈0．05）。训练后，训练组右腕关节经最大等长伸展测试，其尺侧腕伸肌的AV与组内训练前和对照组训练后比较，差异均有统计学意义（P〈0．05）；且训练组左腕关节经最大等长伸展测试，其尺侧腕伸肌的iEMG与组内训练前和对照组训练后比较，差异均有统计学意义（P〈0．05）。结论右腕等长屈曲和伸展训练后可改变前臂肌群募集策略，增强双侧前臂肌力，产生交叉迁移现象。

Objective To investigate the effects on one hand of training the other with isometric wrist exten- sion and flexion training and its underlying mechanism. Methods Twenty healthy young girls were recruited and randomized into a training group and a control group with 10 subjects in each, using a random number table. The subjects in the training group were accepted isometric training of the wrist extensors and flexors on the right side once every other day, 4 days a week for 6 weeks according to a pre-programmed protocol, while those in the control group had no intervention. Peak torque and surface electromyography （sEMG） were recorded and assessed before and after 6 weeks of training. Results In the training group, the average peak torque of right wrist flexion and extension were both significantly higher than before training （within-group comparison） and higher than in the control group （between-group comparison） after 6 weeks of training. The average peak torques of the left wrist in the training group in flexion and extension were （12.9 ±2.0） Nm and （6.4± 1.3 ） Nm after training, both significantly higher than before the training and stronger than the control group. In the sEMG traces during wrist extension, after training the ascend velocity of the right extensor carpi ulnaris and the integrated area of the left extensor carpi ulnaris in the train- ing group were significantly smaller than before training and in the control group. Conclusion Unilateral isometric resistance training of the wrist muscles can transfer to the contralateral side, probably by altering muscle recruitment.