BACKGROUND Elevated energy cost is a hallmark feature of gait in older adults. As such, older adults display a general avoidance of walking which contributes to declining health status and risk of morbidity. Exoskeletons offer a great potential for lowering the energy cost of walking, however their complexity and cost often limit their use. To overcome some of these issues, in the present work we propose a passive wearable assistive device, namely Exoband, that applies a torque to the hip flexors thus reducing the net metabolic power of wearers. METHODS Nine participants (age: 62.1 ± 5.6 yr; height: 1.71 ± 0.05 m; weight: 76.3 ± 11.9 kg) walked on a treadmill at a speed of 1.1 m/s with and without the Exoband. Metabolic power was measured by indirect calorimetry and spatio-temporal parameters measured using an optical measurement system. Heart rate and ratings of perceived exertion were recorded during data collection to monitor relative intensity of the walking trials. RESULTS The Exoband was able to provide a consistent torque (~ 0.03-0.05 Nm/kg of peak torque) to the wearers. When walking with the Exoband, participants displayed a lower net metabolic power with respect to free walking (- 3.3 ± 3.0%; p = 0.02). There were no differences in spatio-temporal parameters or relative intensities when walking with or without the Exoband. CONCLUSIONS This study demonstrated that it is possible to reduce metabolic power during walking in older adults with the assistance of a passive device that applies a torque to the hip joint. Wearable, lightweight and low-cost devices such as the Exoband have the potential to make walking less metabolically demanding for older individuals.

中文翻译：

---

使用被动髋关节屈曲装置降低老年人行走的能量消耗。

背景技术能量消耗升高是老年人步态的一个标志性特征。因此，老年人普遍避免步行，这导致健康状况下降和发病风险下降。外骨骼在降低步行能量成本方面具有巨大潜力，但其复杂性和成本往往限制其使用。为了克服其中一些问题，在目前的工作中，我们提出了一种被动可穿戴辅助设备，即 Exoband，它向髋屈肌施加扭矩，从而降低佩戴者的净代谢能力。方法 9 名参与者（年龄：62.1 ± 5.6 岁；身高：1.71 ± 0.05 m；体重：76.3 ± 11.9 kg）在使用和不使用 Exoband 的情况下以 1.1 m/s 的速度在跑步机上行走。通过间接量热法测量代谢功率，并使用光学测量系统测量时空参数。在数据收集过程中记录心率和感知用力等级，以监测步行试验的相对强度。结果 Exoband 能够为佩戴者提供一致的扭矩（峰值扭矩约为 0.03-0.05 Nm/kg）。当佩戴 Exoband 行走时，参与者表现出相对于自由行走较低的净代谢能力（- 3.3 ± 3.0%；p = 0.02）。使用或不使用 Exoband 行走时，时空参数或相对强度没有差异。结论 这项研究表明，在向髋关节施加扭矩的被动装置的帮助下，可以降低老年人行走时的代谢能力。Exoband 等可穿戴、轻便且低成本的设备有可能降低老年人步行对新陈代谢的要求。