Nurse Cameron A, Wolf Derek N, Rodzak Katherine M, Teater Rachel H, Ice Chad C, Fine Shimra J, Holtzman Elisa C, Zelik Karl E
Department of Mechanical Engineering, Vanderbilt University, 2201 West End Avenue, Nashville, TN 37235.
Vanderbilt University.
J Biomech Eng. 2025 Mar 1;147(3). doi: 10.1115/1.4067579.
Achilles tendon overuse injuries are common for long-distance runners. Ankle exos (exoskeletons and exosuits) are wearable devices that can reduce Achilles tendon loading and could potentially aid in the rehabilitation or prevention of these injuries by helping to mitigate and control tissue loading. However, most ankle exos are confined to controlled lab testing and are not practical to use in real-world running. Here, we present the design of an unpowered ankle exo aimed at reducing the load on the Achilles tendon during running while also overcoming key usability challenges for runners outside the lab. We fabricated a 500-gram ankle exo prototype that attaches to the outside of a running shoe. We then evaluated the reliability, acceptability, transparency during swing phase, and offloading assistance provided during treadmill and outdoor running tests. We found that the exo prototype reliably assisted 95-99% of running steps during indoor and outdoor tests, was deemed acceptable by more than 80% of runners in terms of comfort and feel, and did not impede natural ankle dorsiflexion during leg swing for 86% of runners. During indoor tests, the exo reduced peak Achilles tendon loads for most participants during running; however, reductions varied considerably, between near zero and 12%, depending on the participant, condition (speed and slope) and the precise tendon load metric used. This next-generation ankle exo concept could open new possibilities for longitudinal and real-world research on runners, or when transitioning into the return-to-sport phase after an Achilles tendon injury.
跟腱过度使用损伤在长跑运动员中很常见。脚踝外骨骼（外骨骼装置和外骨骼套装）是可穿戴设备，能够减轻跟腱负荷，并有可能通过帮助减轻和控制组织负荷来辅助这些损伤的康复或预防。然而，大多数脚踝外骨骼仅限于在实验室控制条件下进行测试，在实际跑步中并不实用。在此，我们展示了一种无动力脚踝外骨骼的设计，旨在减轻跑步过程中跟腱的负荷，同时克服实验室外跑步者面临的关键可用性挑战。我们制作了一个500克的脚踝外骨骼原型，它可以附着在跑鞋外侧。然后，我们评估了该原型在跑步机和户外跑步测试中的可靠性、可接受性、摆动阶段的透明度以及卸载辅助功能。我们发现，该外骨骼原型在室内和室外测试中可靠地辅助了95%至99%的跑步步数，超过80%的跑步者认为其在舒适度和感觉方面是可以接受的，并且在86%的跑步者腿部摆动过程中不妨碍自然的脚踝背屈。在室内测试中，对于大多数参与者来说，该外骨骼在跑步过程中降低了跟腱的峰值负荷；然而，降低幅度差异很大，接近零至12%不等，这取决于参与者、条件（速度和坡度）以及所使用的精确肌腱负荷指标。这种下一代脚踝外骨骼概念可能为对跑步者进行纵向和实际研究，或在跟腱损伤后过渡到恢复运动阶段开辟新的可能性。
