CORR Insights®: Do External Supports Improve Dynamic Balance in Patients with Chronic Ankle Instability? A Network Meta-analysis.

The paradox of the lateral ankle sprain is not that so many patients do poorly following this injury, but rather that so many do well. The likelihood of recovery is remarkable given that perceived stability of the ankle requires the contribution of many factors including foot shape, passive mechanics of the ankle in the mortise, peroneal musculature, integrity of the ankle ligaments, and the patient’s chosen activities. If there is a lesson in all this, it is that no single factor entirely determines a pain-free and stable return to full activity. Consider an athlete with completely absent lateral ankle ligaments. When her ankle is suddenly inverted, a protective reflex arc activates the peroneal muscles. No amount of physical strengthening, however vigorous, can alter the speed of nerve conduction. The normal latency for the analogous Achilles reflex arc is 35 milliseconds—more than enough time for mechanical deformation to occur [3]. Some sports and activities may lead to faster andmoreunpredictable loads on the ankle than others. Therefore, no simple mechanical or biologic algorithm by itself will ever determine which patients will benefit from reconstruction. The longdistance runner will always have a different likelihood of rehabilitation success than the basketball player.When physical therapy regimens help despite the presence of mechanical instability, they do so by focusing not only on strength, but also on proprioception. It is likely that the patient who copes with ankle instability does so by activating themuscles prior to ground contact or, as recent evidence suggests, by absorbing the mechanical load through adjacent joints [2]. The key to evaluating interventions and outcomes in such a complex system is agreeing upon common tests that each measure one component of the problem. The Star Excursion Balance Test (SEBT) has been established by our physical therapy colleagues as a reliable and reproducible test of dynamic ankle stability [6]. Think of it as a “model sport” that, in the appropriate research setting, avoids the unthinkable complexity of separately evaluating each individual sport and each individual player position or activity. In the current study, Tsikopoulos and colleagues [12] use the SEBT to answer the common question of the utility of external braces to improve dynamic ankle stability. Surprisingly, the authors did not find a benefit to isolated use of external supports in the setting of the performance laboratory. It is important to remember that this does not necessarily imply that supporting the ankle does not help avoid reinjury. Not only may the demands of any one sport differ from those of the This CORR Insights is a commentary on the article “Do External Supports Improve Dynamic Balance in Patients with Chronic Ankle Instability? A Network Meta-analysis” by Tsikopoulos and colleagues available at: DOI: 10.1097/CORR.0000000000000946. The author certifies that he (GPG) or a member of his immediate family, has received or may receive payments or benefits, during the study period, an amount of USD 10,000 to USD 100,000 from Paragon28 (Englewood, CO, USA) and an amount of < USD 10,000 from Wright Medical (Memphis, TN, USA). The author certifies that he (GPG) or a member of his immediate family, has received or may receive payments or benefits, during the study period, an amount of < USD 10,000 from Wright Medical (Memphis, TN, USA) and < USD 10,000 from Arthrex (Naples, FL, USA). The opinions expressed are those of the writer, and do not reflect the opinion or policy of CORR or The Association of Bone and Joint Surgeons. G. P. Guyton MD (✉), Foot and Ankle Division, Department of Orthopaedics, MedStar Union Memorial Hospital, 3333 North Calvert Street, Baltimore, MD 21218 USA, Email: gpguyton@gmail.com