Frontal Plane Ankle Biomechanics: A Prospective Study On Achilles Tendon Injuries In Runners

Chronic Achilles tendon (AT) injuries represent the most prevalent type of running-related injury. Recently, a meta-analysis identified increased ankle eversion range of motion and ankle inversion at initial contact as risk factors for Achilles tendinopathy though the evidence is limited and conflicting. PURPOSE: To determine whether the ankle frontal plane biomechanics of regular runners can prospectively increase the likelihood of developing chronic AT injuries within one year. METHODS: The study involved 545 runners without a history of AT injury (females and males, aged 18 to 65 years), 12 of whom sustained AT injuries within one year. Biomechanical data were collected during overground running at a self-selected running speed using a 3-D motion capture system at baseline, alongside running distance information obtained through retrospective questionnaires. Participants were monitored for 12 months following the initial data collection, with weekly surveys regarding any sports-related injuries, including AT injuries diagnosed by a medical doctor. A binary logistic regression analysis was conducted to identify potential associations between biomechanical risk factors, and AT, while controlling for running distance, speed, age, sex, AT thickness and VISA. RESULTS: The maximal ankle inversion moment was higher in non-injured (38.34 ± 17.26) compared to injured runners (26.790 ± 3.44; P = 0.013). The maximal ankle inversion moment demonstrated a significant negative association with AT injuries (OR = 0.54, 95%CI: 0.32-0.88; P = 0.016), indicating that higher ankle inversion moments are linked to lower odds of sustaining an injury. CONCLUSION: An increased ankle inversion moment may help reveal a possible protective mechanism against the risk of developing chronic AT injuries in runners. Figure 1. Binary logistic regression model including transformed maximal ankle inversion moment controlled for running distance, age, sex, and VISA. Supported by: This abstract has been produced with the financial support of the European Union under the LERCO project (CZ.10.03.01/00/22_003/0000003) via the Operational Programme Just Transition.