The Comparison of the Effect of Deep and Superficial Heat on Healthy Ankle Joint Position Sense

Background: Heat therapy is one of the natural treatments that can affect the information transferred by the proprioceptive receptors. Heat has an effect on the conduction velocity of peripheral nerves, but the exact effect of two kinds of deep and superficial heat on the joint position sense is not known clearly. The present study aimed to compare the effect of deep and superficial heat on ankle joint position sense. Methods: Thirty healthy male students aged between 18 to 30 y/o participated in this study. Deep heat by short-wave diathermy and superficial heat by water of 42 ºC were applied for 15 minutes in two sessions for all participants. In all of the tests, active and passive ankle joint position sense in dorsiflexion and plantarflexion were measured by pedal goniometers prior to and after heat application. The Non-Parametric-Paired T-test Wilcoxon and Non-Parametric- Paired T-test Mann-Withney were used to analyze the data. Results: The superficial heat does not have any positive or negative effect on the ankle joint position sense. After the deep heat, the absolute angular error of active dorsiflexion was increased, but passive plantarflexion was decreased significantly. Comparing the two types of heat, the results revealed that the deep heat increased the absolute angular error of active dorsiflexion significantly more than superficial heat. Conclusion: According to the results, deep heat therapy improves passive ankle joint position sense in plantar flexion, but it worsens the active joint position sense of dorsiflexion. Therefore, it seems that after applying deep heat therapy on an ankle joint, exercise prescriptions need to be cautious.