Muscular coordination and strength training. Implications for injury rehabilitation

Strength training is commonly used in the rehabilitation of muscles atrophied as a result of injury and/or disuse. Studies on the effects of conventional leg extension training in healthy subjects have shown the changes to be very task-specific to the training manoeuvre itself. After conventional leg extension training for the quadriceps muscle the major improvement was in weightlifting ability with only small increases in isometric strength. The maximum dynamic force and power output during sprint cycling showed no improvement. These results suggest that the major benefit of this type of training is learning to coordinate the different muscle groups involved in the training movement rather than intrinsic increases in strength of the muscle group being trained. Other studies have shown changes in strength to be specific to the length and speed at which the muscle has been trained. The implication for rehabilitation is that strength training for isolated muscle groups may not be the most effective way of increasing functional ability. As the major changes are task-specific it may be better to incorporate the training into task-related practice. This would have the advantage of strengthening the muscle groups affected whilst increasing performance in those activities which are required in daily life.