Cross-education after unilateral resistance training for forearm rotation

Objective To investigate the extent of cross-education between the pronation and supination muscles of the right and left forearms after unilateral isometric training. Methods Twenty healthy young girls were randomized into a training group and a control group using a random number table. The training group underwent isometric training of their right forearms for six weeks, while the control group continued ordinary life without exercises. Pronation peak torque (PPT) and supination peak torque (SPT) were assessed before and after the training for both groups. Results The differences in PPT or SPT between the training group and the control group were not significant before the training program. When the training had been completed, however, the average PPT and SPT on right side of those trained of course had increased significantly compared to before training or to the control group. More significantly, the average PPT and SPT on the left side in the training group were also significantly better than before training or in the control group after training. Conclusion Unilateral isometric training of the forearm pronation and supination muscles for six weeks can significantly increase muscle strength bilaterally, indicating good cross-education. Key words: Cross-education; Maximum voluntary contraction; Strength training