The Effect of Ankle Bracing on Kinematics in Simulated Sprain and Drop Landings. A Double-Blind, Placebo-Controlled Study

SLR - March 2020 - Bradley Jimerson

Reference: Alison N. Agres, PhD, Marios Chrysanthou, BSc, and Peter C. Raffalt, PhD. The Effect of Ankle Bracing on Kinematics in Simulated Sprain and Drop Landings. A Double-Blind, Placebo-Controlled Study. The American Journal of Sports Medicine 2019;47(6):1480–1487

Scientific Literature Review

Reviewed By: Bradley Jimerson, DPM
Residency Program: Christus St. Patrick Hospital – Lake Charles, LA

Podiatric Relevance: Lateral ankle ligament injuries are one of the most common sports related injuries treated by Podiatrists and can lead to chronic pain and instability. Lateral ankle ligament injuries also carry with them a high rate of reinjury. Multiple treatment modalities are available for physicians, but controversy exists over which is most effective at treating and preventing reinjury. This study evaluated the effectiveness of ankle bracing on frontal plane rotation of the ankle, taking into account a placebo effect of shame bracing. The authors hypothesized that active and placebo bracing would both be capable of reducing frontal plane angles during a sudden inversion stress. Investigators secondarily wished to evaluate the effect ankle bracing has on sagittal plane motion of the ankle and knee.

Methods: Sixteen participants with a history of lateral ankle sprains within the last 12 months were enrolled in the study. Patients completed a Foot and Ankle Outcome Score prior to the study to determine how their ankle injury has affected their lives. Patients then attended two sessions and performed a single leg drop test and an inversion tilt test using a custom built platform that recreated a sudden inversion force on the tested ankle. Patients completed each test unbraced again using a custom built ankle brace that would either resist or allow frontal plane motion using a removable module. Participants and investigators were blinded to whether or not each participant’s brace contained this module. Using reflective markers to capture three-dimensional kinematics, the sagittal motion of the ankle and knee was evaluated during the single leg drop test and the frontal motion of the ankle was evaluated during the inversion tilt test.  

Results:
  • The Inversion Tilt Test showed significantly lower frontal plane angles in the actively braced ankle compared to an unbraced limb at various points in the test at high inversion speeds (p<.001), similar to those seen in an inversion ankle injury. The placebo brace showed no significant difference at the same speeds.
  • Foot and Ankle Outcomes scores showed that a lateral ankle sprain most effected participants quality of life and participation in sports. Less in regards to pain and activities of daily life.
  • The Single Leg Drop test showed no significant differences in sagittal plane motion at the ankle or knee between the active, placebo or unbraced study.
Conclusions: The authors concluded that the active brace did protect against excess inversion, and these effects were not due to the mere fact that participants were wearing a brace. When treating lateral ankle ligament injuries it is important for physicians to understand the most effective options for treatment and prevention of reinjury. While other studies have raised questions about the effectiveness of taping and other modalities in treatment and prevention, this study supports that the use of appropriate ankle bracing can be effective in reducing frontal plane motion during inversion stress and thus can assist in treatment and prevention of lateral ankle ligament injuries.