Chronic Plantarflexor Stretching During Ankle Immobilization Helps Preserve Calf Girth, Plantarflexion Peak Torque, and Ankle Dorsiflexion Motion.

CONTEXT: Chronic plantarflexor (PF) stretching during ankle immobilization helps preserve calf girth, plantarflexion peak torque, and ankle dorsiflexion (DF) motion. Immobilization can lead to decreases in muscle peak torque, muscle size, and joint ROM. Recurrent static stretching during a period of immobilization may reduce the extent of these losses.

OBJECTIVE: To investigate the effects of chronic static stretching on PF peak torque, calf girth, and DF range of motion (ROM) after two weeks of ankle immobilization.

DESIGN: Randomized controlled clinical trial.

SETTING: Athletic training facility.

PARTICIPANTS: Thirty-six healthy college-aged (19.81±2.48) females.

INTERVENTIONS: Subjects were randomly assigned to one of three groups: control group, immobilized group (IM), and immobilized plus stretching group (IM+S). Each group participated in a familiarization period, a pre-test, and, two weeks later, a post-test. The IM group and IM+S group wore the Aircast FP Walker for two weeks on the left leg. During this time, the IM+S group participated in a stretching program, which consisted of two 10-minute stretching procedures each day for the 14 days.

MAIN OUTCOME MEASURES: One-way ANOVA was used to determine differences in the change of ankle girth, PF peak torque, and DF ROM between groups with an α level of < 0.05.

RESULTS: A significant difference was noted between groups in girth (F2,31 =5.64, P=0.009), DF ROM (F2,31 =26.13, P<0.0001), and PF peak torque (F2,31 =7.74, P=0.002). Post-hoc testing also showed a significance difference between change in calf girth of the control group compared to the IM group (P=0.007) and a significant difference in change of peak torque in the IM+S group and the IM group (P=0.001). Also, a significant difference was shown in DF ROM between the control group and IM+S group (P=0.006), the control group and the IM group (P<0.0001), and the IM+S group and the IM group (P<0.0001).

CONCLUSION: Chronic static stretching during two weeks of immobilization may decrease the loss of calf girth, ankle PF peak torque, and ankle DF ROM.