1. This preliminary report suggests the effectiveness of the technique of progressive-resistance exercise in the after-care of knee injuries and low-back strains and in the development of the muscles of the upper trunk and arms of adolescents.
2. The desirability of utilizing a therapeutic-exercise method which will not only restore muscle power, but which will also produce a considerable increase over the strength existing prior to injury, is urged.
3. Further clinical trial of progressive-resistance exercise is suggested in conditions which require that muscle power be increased.