Effects of Static Stretch Versus Static Stretch and Ultrasound Combined on Triceps Surae Muscle Extensibility in Healthy Women

The purpose of the study was to demonstrate for the first time on human subjects that static stretch and ultrasound (SS and US) combined increases triceps surae muscle extensibility more than SS alone. The SS and US combined consisted of seven minutes of continuous US at 1.5 W/cm2 to the muscle with SS during the seventh minute. The SS alone consisted of a 51-lb (23.1 kg) load applied for one minute. We randomly assigned 10 healthy, female subjects to each of three groups (N = 30). Each group received each of the three types of treatment (SS and US, SS, and no treatment) in a different order. Standardized goniometric measurements of active dorsiflexion were taken before and after each treatment session. The SS and US treatment increased dorsiflexion an average of 1.2 degrees, or 20%, more than the SS treatment. The SS treatment increased dorsiflexion an average of 1.3 degrees, or 27%, more than no treatment. Both increases were statistically significant.