Balance and gait disorders are the second leading cause of falls, which, along with consequent injuries, are reported as major public health problems all over the world. For patients who do not require mechanical support, vibrotactile feedback interfaces have proven to be a successful approach in restoring balance. Most of the existing strategies assess trunk or head tilt and velocity or plantar forces, and are limited to the analysis of stance. On the other hand, central to balance control is the need to maintain the body's centre of pressure (CoP) within feasible limits of the support polygon (SP), as in standing, or on track to a new SP, as in walking. Hence, this paper proposes an exploratory study to investigate whether vibrotactile feedback can be employed to lead human CoP during walking. The ErgoTac-Belt vibrotactile device is introduced to instruct the users about the direction to take, both in the antero-posterior and medio-lateral axes. An anticipatory strategy is adopted here, to give the users enough time to react to the stimuli. Experiments on ten healthy subjects demonstrated the promising capability of the proposed device to guide the users' CoP along a predefined reference path, with similar performance as the one achieved with visual feedback. Future developments will investigate our strategy and device in guiding the CoP of elderly or individuals with vestibular impairments, who may not be aware of or, able to figure out, a safe and ergonomic CoP path.

翻译：平衡与步态障碍是全球范围内跌倒及其相关损伤的第二大诱因，已被列为重大公共卫生问题。对于无需机械辅助支持的患者，振动触觉反馈接口已被证明是恢复平衡的有效方法。现有策略大多通过评估躯干或头部倾斜角、速度或足底压力，且局限于站立姿态分析。然而，平衡控制的核心在于将身体压力中心（CoP）维持在支撑多边形（SP）的可行范围内（如站立时），或在行走时将其引导至新的SP路径上。为此，本文提出一项探索性研究，旨在验证振动触觉反馈能否在行走过程中引导人体CoP。我们引入了ErgoTac-Belt振动触觉装置，通过前后轴与内外侧轴两个方向向用户发出指令，并采用前瞻性策略为用户提供充足的反应时间。对十名健康受试者的实验表明，该装置能够沿预设参考路径有效引导用户CoP，其性能与视觉反馈相当。未来研究将探索该策略与装置在引导老年或前庭功能障碍患者（这类人群可能无法感知或辨识安全且符合人体工学的CoP路径）CoP方面的应用。