Design and validation of a smart wearable device to prevent recurrent ankle sprain

Lateral ankle sprain is one of the most common ankle injuries, especially in sports. When not treated properly, chronic ankle instability (CAI) may develop causing recurrent sprains and permanent damage to ankle ligaments. In this study, the design, implementation and validation of a smart wearable device connected to a smartphone application is described. This device can predict and prevent the occurrence of ankle sprain. Prediction of potentially harmful motion is achieved by continuous monitoring of ankle kinematics using inertial motion sensors. Detection of such a motion immediately triggers electrical stimulation of the peroneal muscles causing foot dorsiflexion, and hence prevents potential injury. The proposed device has the advantage of having a very short response time of eight milliseconds which is sufficient to halt the sprain motion. Laboratory validation testing using a custom designed trapdoor showed an accuracy of 96% in detecting and correcting hazardous motion. Furthermore, this device complies well with the design constrains of a wearable device such as small size and low power consumption. It is also low cost and unobtrusive due to the wireless connection between all components. Future work is recommended to test the clinical effectiveness of the proposed device in patients with CAI.