The effect of deep heat on isometric strength

The effect of a 20-minute treatment of short-wave diathermy on isometric strength of the quadriceps muscle group was studied in 12 subjects over a 2-hour period. The heat treatment caused an initial decrease in isometric strength followed by an increase 30 minutes after the heat was terminated. Strength remained significantly above the control level for two hours following heat. The findings of this study suggest that the relationship between the application of short wave diathermy and the optimal time which should elapse between the heat treatment and therapeutic exercise should be examined.