Dropped Head Syndrome (DHS) causes a passively correctable neck deformation. Currently, there is no wearable orthopedic neck brace to fulfill the needs of persons suffering from DHS. Related works have made progress in this area by creating mobile neck braces that provide head support to mitigate deformation while permitting neck mobility, which enhances user-perceived comfort and quality of life. Specifically, passive designs show great potential for fully functional devices in the short term due to their inherent simplicity and compactness, although achieving suitable support presents some challenges. This work introduces a novel compliant mechanism that provides non-restrictive adjustable support for the neck's anterior and posterior flexion movements while enabling its unconstrained free rotation. The results from the experiments on non-affected persons suggest that the device provides the proposed adjustable support that unloads the muscle groups involved in supporting the head without overloading the antagonist muscle groups. Simultaneously, it was verified that the free rotation is achieved regardless of the stiffness configuration of the device.

翻译：垂头综合征（DHS）会导致一种可被动矫正的颈部变形。目前，尚无可穿戴的矫形颈托能满足DHS患者的需求。相关研究在该领域已取得进展，通过开发可移动颈托来提供头部支撑以减轻变形，同时允许颈部活动，从而提升用户感知的舒适度和生活质量。具体而言，被动式设计因其固有的简单性和紧凑性，在短期内显示出实现全功能设备的巨大潜力，尽管实现合适的支撑仍面临一些挑战。本研究提出了一种新颖的柔顺机构，该机构能为颈部的前屈和后伸运动提供非限制性的可调支撑，同时实现无约束的自由旋转。对非患病人群的实验结果表明，该装置能提供所提出的可调支撑，减轻参与支撑头部的肌群负荷，而不会过度负荷拮抗肌群。同时，验证了无论装置的刚度配置如何，均能实现自由旋转。