Assessment of a lower extremity training program.

The response to a lower extremity program has been studied in workmen undergoing progressive rehabilitation following injury to the lower leg or ankle region. When first seen, the isometric strength of the injured limb was substantially reduced relative to its counterpart, and aerobic power was also poor, relative to normal standards. Substantial gains of isometric strength occurred over a four- to six-week period of therapy. Measurements above the site of injury suggested a 13% gain of strength, and measurements below the injury indicated a gain of 34%. On the other hand, there were minimal changes of thigh circumference over this period. Soft tissue radiographs taken in the posteroanterior and lateral planes showed a small (1%) increase of muscle tissue and a somewhat larger (5%) loss of subcutaneous fat. Dynamic exercise at a fixed percentage of aerobic power was associated with similar subjective discomfort and a similar accumulation of lactate before and after rehabilitation.It is concluded that the apparent improvement in isometric strength over the period of rehabilitation is due to (1) initial voluntary limitation of effort and (2) increase in skill. The use of soft tissue radiographs may afford a more objective basis for the evaluation of future muscle training programs.