Design, Development, and Functional Evaluation of Neck Assistive Cervical Kit: NACK

Abstract

Abstract. Neck pain is a common issue caused by prolonged static postures and cumulative fatigue, negatively impacting quality of life. While cervical collars support individuals with chronic neck injuries, there is a need for preventive solutions for healthy individuals, particularly office workers exposed to prolonged sitting and repetitive motions. The study introduces a novel ergonomic assistive device designed to reduce neck strain among office workers. Design objectives are based on the range of motion during daily activities for head motion as reported in the literature. Concept development was supported using a previously validated 20 degrees-of-freedom adams model of the cervical spine. Various design alternatives were evaluated using the model to identify the design that satisfied specific design criteria. The conceptual design was translated into a mechanical design, and a prototype was subsequently manufactured. Performance was evaluated on 20 healthy subjects using an inertial measurement unit and electromyography (EMG) sensors to compare two conditions: without device and with neck assistive cervical kit (NACK). Range of motion analysis revealed that the NACK condition reduced cervical mobility by 35.6%, 59.3%, and 53.4% in sagittal, lateral, and axial rotation directions compared to without device. Statistical analysis of EMG data using paired t-tests revealed significant reductions in muscle activation, with sternocleidomastoid activity decreasing by 23–29% maximum voluntary contraction (MVC) (p < 0.01) and upper trapezius activity decreasing by 10–15% MVC (p < 0.05). The results indicate that NACK provides support that limits excessive head movements while significantly reducing neuromuscular demand on the cervical musculature, thereby enhancing comfort and productivity in workplace environments.