Context:
Ultrasound significantly raises tissue temperature, but the time of temperature elevation is short.
Objective:
To assess the effectiveness of superficial preheating on temperature elevation and decline when using ultrasound.
Design:
Within-subjects design to test the independent variable, treatment condition; repeated-measures ANOVAs to analyze the dependent variables, temperature elevation and decline.
Setting:
Athletic training laboratory.
Intervention:
Temperature at a depth of 3.75 cm was measured during ultrasound after superficial heating and with ultrasound alone.
Subjects:
10 healthy men.
Main Outcome Measure:
Temperature was recorded every 30 s during 15 min of ultrasound and for 15 min afterward.
Results:
Temperature elevation with ultrasound was significantly greater with preheating (4.0 ± 0.21 °C) than with ultrasound alone (3.0 ± 0.22 °C). Temperature decline was not significantly different between preheating and ultrasound alone.
Conclusions:
Superficial preheating significantly increases temperature elevation but has no effect on temperature decline during a 15-min cooling period.
