This report showed that the analysis of the isokinetic strength test for throwing shoulder injuries could be used to determine the appropriate time for the patient to return to pitching. During the last six years, among two hundred sixtyfive players studied, one hundred fifty high school baseball players were found to be uninjured while one hundred fifteen players were found to be suffering from throwing shoulder injuries. The tests were carried out using a CybexR II Multi-Joint Dynamometer. The patients were seated with their shoulders abducted at 90 degrees and their elbows flexed at 90degrees. The shoulders were tested for their rotational strength. We observed an imbalance of isokinetic strength of the shoulder by noticing a difference between the internal and external rotational strengths. In addition, we examined the data of concentric isokinetic endurance strength that had not been reported previously. Returning to pitching was found to be highly possible when the patients corrected the imbalance of internal and external rotational strengths and their concentric isokinetic endurance strength was above 70% measured by the concentric endurance strength test. Correction of the imbalance of internal and external rotational strengths and the improvement of endurance strength were considered to be necessary to judge the appropriate time for returning to pitching.
