Introduction/Rationale: Lack of ankle dorsiflexion (DF) is a common risk factor for running injuries. Static stretching (SS) and self-myofascial release (SMR) have been shown to increase ankle DF range of motion (ROM), but their effects on electromyographic (EMG) activity and ankle kinematics in runners is inconclusive. We compared the effects of SMR and SS on gait parameters, ankle DF ROM, and gastrocnemius and tibialis EMG activity.
Methods: This was a randomized comparison study. Participants were randomly assigned to an intervention group: (1) SS, or (2) SMR. Pre-intervention, weight-bearing ankle DF was measured and participants performed baseline walking and running. Post-intervention, weight-bearing ankle DF was re-measured and post-treatment walking and running was completed. Three-dimensional motion analysis was used to evaluate kinematics, and surface EMG was used to record muscle activity and timing. Demographic data was analyzed using an independent t-test to ensure the two groups are similar. An independent t-test was used to compare data between the two groups. A paired t-test was used to compare data within each group.
Strengths/Limitations: Strengths included the originality and clinical relevance. Limitations were the inclusion of healthy subjects, multiple foot-strike patterns, and allowing participants to self-select their speed and footwear.
Relevance: The study provides new information regarding effects of SS and SMR on muscle activity and ankle kinematics in runners with tight gastrocnemius muscles, and may help determine the most effective interventions for runners at risk of overuse injury due to tight gastrocnemius muscles.