Blackwell Publishing Journal Backfiles 1879-2005
The effects of 1 year of intensive strength training on neuromuscular function were studied in elderly people operated for total endoprosthesis (n=30) divided into 3 groups: training pup 1 (TG1, n=11), training pup 2 (TG2, n=10) and control group (CG, n=9). After the operation, TG1 and TG2 trained every second day and the training was controlled by training diaries, and CG performed only conventional exercises by themselves. The overall volume of training in TG2 was 30% greater than in TG1. Neuromuscular function was examined by measuring maximal electromyography (EMG) and maximum voluntary isometric and dynamic strength of the knee extensor and flexor muscles. The range of motion of the knee joint and the cross-sectional area (CSA) of the knee extensor muscles were also measured. After the preoperative tests, the same measurements were repeated 3, 6, 12, 24 and 52 weeks postoperatively. After the dramatic decreases in maximal isometric torque and EMG-activity during the first postoperative weeks in all groups, TG2 showed the most remarkable improvement in neuromuscular function. For instance, the maximum isometric extension torque measured at 90° knee angle increased between the 24th and 52nd weeks. The increase in the EMG-activity of the rectus femoris muscle was Significant between the 12th and 24th weeks. The CEA of the knee extensor muscles in TG2 was greater 1 year after the operation compared with the preoperative value. The intra- and extra-articular swelling of the knee joint may have irritated the free nerve endings, leading to reflex inhibition with a concomitant decrease in EMG and strength of the knee extensor muscles. Because TG2 demonstrated the most remarkable improvement in neuromuscular function after the first postoperative weeks, intensive training programs can be successfully used in rehabilitation after a major knee operation, even in elderly people.
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