SLR - August 2023 - Eric Deig, DPM
Title: The Effects of Chronic Ankle Instability on the Biomechanics of the Uninjured, Contralateral Ankle During GaitReference: Ziaei Ziabari E, Haghpanahi M, Razi M, Lubberts B, Ashkani-Esfahani S, DiGiovanni CW. The Effects of Chronic Ankle Instability on the Biomechanics of the Uninjured, Contralateral Ankle During Gait. Orthop Surg. 2022 Sep;14(9):2238-2244.
Level of Evidence: III
Reviewed by: Eric Deig, DPM
Residency Program: Ascension St. Vincent Indianapolis, Indianapolis, IN
Podiatric Relevance: Ankle sprains are amongst the most common injuries encountered by a podiatric physician. A high percentage of individuals who suffer an acute ankle sprain will go on to develop chronic ankle instability (CAI). Conservative and surgical treatment of CAI focuses primarily on the injured ankle with instability. Biomechanical changes on the injured side are well documented, however there has been an ongoing debate, as to whether or not unilateral CAI can lead to biomechanical dysfunction and injuries of the same individual’s contralateral, uninjured side. Researchers in this study hypothesized that the injured ankle in patients with CAI will affect the biomechanics of the contralateral uninjured ankle of these patients.
Method: This case control study looked at 15 patients with unilateral CAI and 15 healthy patients. The unstable and the uninjured ankles in patients in the CAI group were compared to those of the control group. Three dimensional gait was then assessed utilizing the Vicon system and biomechanical variables were measured.
Results: In patients with CAI, the injured and uninjured ankles were significantly different regarding angle-toe angle, inversion-eversion RoM, dorsi-plantar flexion in mid-stance, inversion-eversion at initial contact and terminal stance as well as the pre-swing and swing phases. In patients with CAI, the uninjured ankles showed significantly lower ankle-toe velocity and acceleration compared to both ankles of the control group. The uninjured ankles of the patients in the CAI group also showed statistically significant decreased ankle dorsiflexion and increased inversion during initial contact, loading response, mid-stance, terminal stance, pre-swing, and swing compared to the control group.
Conclusion: Results from this study suggest that unilateral CAI can affect the kinematics of the contralateral uninjured ankle. This study suggests that delayed treatment might predispose the healthy ankle to progressive biomechanical deterioration, degenerative changes, and an increased risk for similar stability issues. Based on the information presented in this study, rehabilitation protocols should include both the stable and unstable ankle.