抄録
We routinely prescribe a strength training program of the shoulder muscles for injured athletes, which consists in, after elevating the arm to the zero position, flexing and extending the elbow in the scapular plane grasping a rubber band, which offers a suitable resistance to the movement. This method is effective in our clinical experience.
We evaluated the work of the rotator-cuff muscles in this training through MRI(relaxation time of T2), and the purpose of this paper is to show our results. Two kinds of exercises were evaluated: the scapular plane exercise (described above), and the rotational exercise in which the athletes stretch the rubber band from the abduction-external rotation position to the elbow extended-internal rotation position. We examined the differences in strength and the relaxation time of T2 of the rotator-cuff muscles, before and after the exercise. In this experiment, ten healthy volunteers exercised until the“very, very hard level”in the Rating of Perceived Exertion. Results; The strength of abduction and external rotation was decreased after the exercise. After the scapular plane exercise, the relaxation time of T2 increased on a nerage from 30.4 ms to 34.0±2.0 at the supraspinatus (p<0.01), from 30.6 ms to 33.6 ms at the infraspinatus (p<0.01),31. O ms to 34.2 ms at the subscapularis (p<0.05).
After the rotational exercise, the results were from 31.1 ms to 33.6 ms at the supraspinatus (p<0.05), from 31.3 ms to 32.9 ms at the infraspinatus (ns),29.8 ms to 38.1 ms at the subscapularis (p<0.01). MRI suggested an excessive load at the subscapularis in the rotational exercise, but in our training, the load was divided evenly between the three rotator muscles.
Clinically, patients suffering from shoulder pain can perform this training immediately without pain. The training exercises can be modified to simulate pitching or other movements. We consider this training a good way to treat sports-related shoulder injuries.
