Johanson, MA, Catlin, PA, Baer, J, Hovermale, H, Phouthavong, P; Emory University, Atlanta, GA. majohan@emory.edu.

PURPOSE: The purpose of this study was to determine the effect of subtalar joint position during gastrocnemius stretching on ankle dorsiflexion range of motion. BACKGROUND: Gastrocnemius muscle stretching is a commonly prescribed intervention to prevent or treat lower extremity overuse injuries. Differences in ankle dorsiflexion range of motion gains may result from gastrocnemius stretching with the subtalar joint maintained in a supinated versus pronated position. Gastrocnemius stretching in subtalar pronation may result in dorsiflexion increases at the midtarsal and subtalar joints, possibly affecting dorsiflexion increases at the talocrural joint. SUBJECTS: Thirty-three subjects with passive ankle dorsiflexion range of motion between five and twelve degrees were recruited from the Metro Atlanta region via convenience sampling. METHODS: Subjects were randomly assigned to perform gastrocnemius stretching on one leg maintaining the subtalar joint in either supination or pronation, while the opposite leg served as the control. Subjects performed a standard static weightbearing gastrocnemius stretching exercise of 30 seconds duration for 5 repetitions 2 times daily for 3 weeks. A template provided both visual and tactile cues to assist subjects in maintaining the subtalar joint in either pronation or supination during the gastrocnemius stretching exercise. Non-weightbearing and weightbearing ankle dorsiflexion range of motion were measured with the subtalar joint positioned in anatomical zero before and after the stretching program. ANALYSIS: Three-way repeated measures analysis of variance was used to compare non-weightbearing and weightbearing ankle dorsiflexion among group, time, and leg. RESULTS: Gastrocnemius stretching performed in either pronation or supination significantly increased ankle dorsiflexion range of motion (p<0.05), but there was no significant difference in the dorsiflexion gains between the group that stretched while maintaining the subtalar joint in supination compared with the group that maintained the subtalar joint in pronation (p>0.05). CONCLUSIONS: Position of the subtalar joint during gastrocnemius stretching does not appear to influence gains in ankle dorsiflexion range of motion. FUNDING SOURCE: None.

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