Effect of temperature on muscle force and rate of muscle force production in men and women.

The use of heat and/or cold is common in many physical therapy treatment programs. Knowledge concerning their effect upon muscular performance would help in the design of exercise programs used with heat or cold. The purpose of this study was to investigate the effect of heating and cooling on maximum voluntary force and rate of force development in the wrist extensor muscles of men and women. The maximum rate of force development was assessed in 30 subjects under three separate conditions: 1) following immersion in a 40 degrees C water bath, 2) following immersion in a 10 degrees C water bath, and 3) a control condition. The results showed that peak force and rate of force development decreased, while time to peak force development increased in males following exposure to cold. In females, only the time to peak force development was found to be altered (increased) by cold exposure. No significant change in the speed of force development was found following heat application in either sex. Investigation of the force-time curve showed that the slope of the curve decreased following cold exposure. This study shows that cold, but not heat, application at temperatures commonly used in rehabilitation is sufficient to cause alterations in the wrist extensor muscle's ability to quickly develop isometric tension.