Neck muscle weakness due to amyotrophic lateral sclerosis (ALS) can result in dropped head syndrome, adversely impacting the quality of life of those affected. Static neck collars are currently prescribed to hold the head in a fixed upright position. However, these braces are uncomfortable and do not allow any voluntary head-neck movements. By contrast, powered neck exoskeletons have the potential to enable head-neck movements. Our group has recently improved the mechanical structure of a state-of-the-art neck exoskeleton through a weighted optimization. To evaluate the effect of the structural changes, we conducted an experiment in which patients with ALS were asked to perform head-neck tracking tasks while using the two versions of the neck exoskeleton. We found that the neck muscle activation was significantly reduced when assisted by the structurally enhanced design compared to no assistance provided. The improved structure also improved kinematics tracking performance, allowing users to better achieve the desired head poses. In comparison, the previous design did not help reduce the muscle effort required to perform these tasks and even slightly worsened the kinematic tracking performance. It was also found that biomechanical benefits gained from using the structurally improved design were consistent across participants with both mild and severe neck weakness. Furthermore, we observed that participants preferred to use the powered neck exoskeletons to voluntarily move their heads and make eye contact during a conversation task rather than remain in a fixed upright position. Each of these findings highlights the importance of the structural design of neck exoskeletons in achieving desired biomechanical benefits and suggests that neck exoskeletons can be a viable method to improve the daily life of patients with ALS.

中文翻译：

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颈部外骨骼结构设计对肌萎缩侧索硬化症患者影响的初步研究

肌萎缩侧索硬化症 (ALS) 导致的颈部肌肉无力可导致低头综合征，对患者的生活质量产生不利影响。目前规定静态颈托将头部保持在固定的直立位置。然而，这些支架不舒服并且不允许任何头颈随意运动。相比之下，动力颈部外骨骼有潜力实现头颈运动。我们的团队最近通过加权优化改进了最先进的颈部外骨骼的机械结构。为了评估结构变化的影响，我们进行了一项实验，要求 ALS 患者在使用两种版本的颈部外骨骼时执行头颈跟踪任务。我们发现，与不提供任何帮助相比，在结构增强设计的帮助下，颈部肌肉的激活显着减少。改进的结构还提高了运动学跟踪性能，使用户能够更好地实现所需的头部姿势。相比之下，以前的设计无助于减少执行这些任务所需的肌肉力量，甚至略微恶化了运动跟踪性能。研究还发现，无论是轻度还是重度颈部无力的参与者，使用结构改进的设计所获得的生物力学益处都是一致的。此外，我们观察到参与者更喜欢使用动力颈部外骨骼在对话任务中自愿移动头部并进行眼神交流，而不是保持固定的直立位置。这些发现均强调了颈部外骨骼结构设计在实现所需生物力学益处方面的重要性，并表明颈部外骨骼可以成为改善 ALS 患者日常生活的可行方法。