Non-Custom-Fit Cervical/Neck-Shoulder Orthosis: A Novel Design, Manufacturing, and Evaluation

The cervical orthosis is a device that maintains the neck in its physiological position during the rehabilitation stage, after an injury or disease that causes severe damage to the functions of the cervical vertebrae and/or their normal alignment. A rigid orthosis of different sizes, tailored to the patient's neck size, is typically required to restore neck function by providing total contact with the patient's skin in most cases. This research introduces a novel neck orthosis of several features like adjustable in design, lightweight, and non-total contact (providing a required protection for the patient's skin), manufactured from Polylactic Acid (PLA) material using a 3D printer. The manufacturing is based on two designs, ventilated and solid/unventilated orthosis. The ventilated design saved 17.28 % of the total orthosis weight, in addition to offering a significant reduction in the warmth (irritation of the patient's skin), up to 5.26 % in contrast with the solid design of the same dimensions. The present orthosis offers a safer design, which has a factor of safety of 5.15 in contrast to other traditional total contact orthosis of only 3 for the best-case. The structural-to-ventilated ratio of the present design is twice in contrast to the traditional ones, so a safer design with optimum thermal performance is assured. Reliable flexion, extension, and lateral bending of the neck up to 2.18°, with a superior strength-weight ratio reached 31.77 N/kg mm 2 .