Design and Preliminary Evaluation of a Smart Wearable Ankle Brace with an Autonomous BOA Mechanism for Preventive Ankle Support

Abstract

Ankle sprains frequently occur during walking and are often associated with excessive inversion at foot-ground contact. Although wearable ankle robots have advanced for mobility assistance, their application to injury prevention remains relatively unexplored. This paper presents a preliminary study of a smart wearable ankle brace with an autonomous BOA mechanism for selective ankle support during walking. The proposed system combines a servo-actuated BOA-based tightening mechanism, a ratchet-based engagement architecture, and a smart insole with multimodal sensing for gait event prediction. For preliminary validation. We evaluated the mechanical performance of the system and the feasibility of the gait event prediction using data collected from healthy young participants. Experimental results showed that the mechanism generated a mean tension of $20.0 \pm 1.7 ~\mathrm{N}$ and a mean interface pressure of $25.5 \pm 5.2 ~\mathrm{N}$ at the ankle joint across 10 trials. Additionally, the gait-event prediction model achieved an overall classification accuracy of 93% on the test dataset. These findings demonstrate the preliminary feasibility of the proposed system as a wearable platform for selective ankle stabilization.