Design of a body supported head rest for people with a neuromuscular disease

Abstract

People with a neuromuscular disease have to deal with decreasing muscle force as their disease progresses. Muscles around the head and neck are weakened too. As a consequence it becomes energy consuming to keep their head and neck in a forward bended position. For instance during reading, eating or doing computer work. This study proposes an analytical approach to this problem by using a simple biomechanical model of the head and neck. Analysis of forces acting around the head and neck joints resulted in a new balancing strategy for head supports. The proposed design helps the patient’s muscles in creating counteracting head and neck joint torques when the head and neck are in a forward bended position. Reaction forces are guided to the body. A prototype was designed to do a technical evaluation of the conceptual design. Measurement results show a positive indication that joint torque head weight balancing can be done by normal linear and compact torsion springs while reaction forces guided to the body are low. The design is slim, out of the face of the user, concealable underneath clothing and it can be used sitting in a (wheel)chair or while standing and walking.