The Effects on Mechanomyography Using Cold Water Immersion of the Rectus Femoris Muscle

INTRODUCTION: Sounds emitted by muscles during contraction are an intrinsic component of the contractile mechanism. The recording of “muscle sounds” has been termed mechanomyography (MMG). Mechanomyography records the low frequency oscillations of active muscle fibers. Even though research regarding MMG components is now being readily produced from human subject data, research has not been conducted involving the effects of cold-water immersion cryotherapy on human muscle MMG signals. Therefore, the purpose of this study is to determine the effects of cold-water immersion cryotherapy on torque (Nm) and MMG amplitude (mV) of the rectus femoris. METHODS: Seven individuals participated in this study. The protocol order was: (1) two maximal voluntary contractions (MVC), (2) initial muscle temperature recording, (3) cold-water immersion protocol, (4) second muscle temperature recording, (5) two MVC's, and (6) a final muscle temperature reading. RESULTS: Temperature significantly decreased following cryotherapy. No significant difference occurred (p <0.05) between pre-torque and post-torque signals as reported by the paired samples t-test. No significant difference occurred (p <0.05) between pre-MMG and post-MMG signals as reported by the paired samples t-test. CONCLUSION: The main findings of this study indicate that torque production and the amplitude of MMG signals of the quadriceps are not affected by cold-water immersion.