Pulsed Shortwave Diathermy and Prolonged Long-Duration Stretching Increase Dorsiflexion Range of Motion More Than Identical Stretching Without Diathermy

Abstract

OBJECTIVE: To compare the effects of 3 treatments on ankle dorsiflexion range of motion: prolonged long-duration stretching, pulsed shortwave diathermy followed by stretching, and pulsed shortwave diathermy, stretching, and ice combined. DESIGN AND SETTING: A 2 x 5 x 15 repeated-measures (on 2 factors) design guided this study. Range-of-motion change in triceps surae flexibility was the dependent variable. The 3 independent variables were treatment group, pretest and posttest measurements, and day. Treatment group had 4 levels: control, stretching (10 minutes of stretching via the weight and pulley), diathermy and stretching (20 minutes of diathermy and 10 minutes of stretching), and diathermy, stretching, and ice (20 minutes of diathermy, 10 minutes of stretching applied after 15 minutes of diathermy, and 5 minutes of ice applied during the last 5 minutes of stretching). Each subject received 14 treatments throughout 3 weeks, with a follow-up measurement taken 6 days after the last treatment. SUBJECTS: Forty-four healthy college-student volunteers not involved in any flexibility program. MEASUREMENTS: We measured ankle dorsiflexion using a digital inclinometer before and after treatment. RESULTS: After 14 days of treatment, the range-of-motion increase was greater after heat and stretching than after stretching alone. After 6 additional days of rest, the heat and stretching range-of-motion increase was greater than that for stretching alone. CONCLUSION: Pulsed shortwave diathermy application before prolonged long-duration static stretching was more effective than stretching alone in increasing flexibility throughout 3 weeks. After 14 treatments, prolonged long-duration stretching combined with pulsed shortwave diathermy followed by ice application caused greater immediate and net range-of-motion increases than prolonged long-duration stretching alone.

Figures

Figure 1

Bottom view of the weight and pulley used to apply a constant, low-load, prolonged stretch.

Figure 2

A, We placed the inclinometer on the posterior part of the calf using the 10-cm mark as a reference point and then zeroed the inclinometer after the reading had stabilized. B, Once the inclinometer had stabilized and been zeroed, it was then placed on the plantar surface of the shoe, where a reference mark had been placed to ensure consistent positioning.

Figure 3

Pulsed shortwave diathermy setup. We centered the diathermy drum on the musculotendinous junction.

Figure 4

Pretreatment range-of-motion changes for all 5 groups on days 1 through 24.