A Neck Orthosis with Multi-Directional Variable Stiffness for Persons with Dropped Head Syndrome

TL;DR

This paper introduces a novel multi-directional variable stiffness neck orthosis designed for persons with Dropped Head Syndrome, providing adjustable support and free rotation, potentially improving comfort and muscle unloading.

Contribution

It presents a new compliant mechanism that offers adjustable support for neck flexion while allowing free rotation, addressing a gap in wearable orthoses for DHS.

Findings

Device provides adjustable support unloading neck muscles.

Supports free rotation regardless of stiffness configuration.

Experimental results show improved muscle unloading.

Abstract

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.