Objective: To investigate the temperature changes in subcutaneous and intramuscular tissue during a 20-minute cold- and hot-pack contrast therapy treatment.
Design and setting: Subjects were randomly exposed to 20 minutes of contrast therapy (5 minutes of heat with a hydrocollator pack followed by 5 minutes of cold with an ice pack, repeated twice) and 20 minutes of cold therapy (ice pack only) in a university laboratory.
Subjects: Nine men and seven women with no history of peripheral vascular disease and no allergy to cephalexin hydrochloride volunteered for the study.
Measurements: Subcutaneous and intramuscular tissue temperatures were measured by 26-gauge hypodermic needle microprobes inserted into the left calf just below the skin or 1 cm below the skin and subcutaneous fat, respectively.
Results: With contrast therapy, muscular temperature did not fluctuate significantly over the 20-minute period compared with the subcutaneous temperature, which fluctuated from 8 degrees C to 14 degrees C each 5-minute interval. When subjects were treated with ice alone, muscle temperature decreased 7 degrees C and subcutaneous temperature decreased 17 degrees C over the 20-minute treatment.
Conclusions: Our results show that contrast therapy has little effect on deep muscle temperature. Therefore, if most of the physiologic effects attributed to cold and hot contrast therapy depend on substantial fluctuations in tissue temperature, contrast therapy needs to be reconsidered as a viable therapeutic modality.