The effect of cryotherapy on eccentric plantar flexion peak torque and endurance.
OBJECTIVE
The effects of cryotherapy on eccentric torque production and muscle endurance have been controversial. Our intent was to examine the effect of cryotherapy on isokinetic eccentric plantar flexion peak torque at 30 degrees /sec and 120 degrees /sec and on endurance at 120 degrees /sec.


METHODS
SUBJECTS WERE TESTED ON AN ISOKINETIC DYNAMOMETER FOR PEAK TORQUE AND ENDURANCE AND WERE THEN RANDOMLY ASSIGNED TO ONE OF FOUR GROUPS: (a) peak torque measurements at 30 degrees /sec and 120 degrees /sec after a 30-minute 10 degrees C ice bath immersion, (b) peak torque measurements at 30 degrees /sec and 120 degrees /sec without ice bath immersion (control), (c) endurance measurement at 120 degrees /sec after a 30-minute 10 degrees C ice bath immersion, and (d) endurance measurement at 120 degrees /sec without ice bath immersion (control). Subjects completed each of the four experimental conditions with 7 to 14 days between conditions.


METHODS
Eleven male and 11 female volunteers (mean age, 23.8 +/- 3.5 years) were screened for normal ankle range of motion, past history of lower extremity injury, and contraindications to cryotherapy.


METHODS
Dependent t tests were used to analyze practice session data in order to establish reliable baseline measurements. A 2 x 2 analysis of variance (ANOVA) with repeated measures (p < .05) was used to analyze peak torque data. A one-way ANOVA (p < .05) was used to analyze endurance data in the form of total work.


RESULTS
Velocity significantly affected peak torque production, with eccentric peak torque values significantly higher at 120 degrees /sec than at 30 degrees /sec for both the control and the immersion conditions. Cryotherapy had no effect on eccentric peak torque at either 30 degrees /sec or 120 degrees /sec, but it increased eccentric total work (endurance) at 120 degrees /sec.


CONCLUSIONS
Cryotherapy has long been known to have beneficial therapeutic effects. In our study, cryotherapy did not significantly affect eccentric peak torque, but it did increase muscle endurance. An athlete can reap the beneficial effects of cryotherapy, such as pain reduction, vasoconstriction, and edema control, without compromising eccentric force production or endurance.
Iris F. Kimura is Professor and Director of the Graduate Program of Athletic Training at Temple University, Philadelphia, PA 19140.
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Kimura
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Thompson
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Gulick