Biomechanics of the Cervical Spine Under Compressive Loading in Flexion and Extension: Muscles Net Moment Determination

Muscles in the cervical spine are responsible for guiding the head and for conserving its posture. The weight of the head (∼40N) exerts a continuous compressive load that should be monitored by the neck muscles. Wearing a helmet in many sports or military and work activities increases the compressive loading on the head as well as the involvement of the muscles to counterbalance the impact of this supplemental weight. The compressive load is estimated to range from 120 to 1200N [1]. This loading influences all the biomechanics of the head and neck complex and its musculature. Experimental and numerical studies were involved to determine the biomechanical response of the head and neck [2]. In this study and based on our finite element model, we aim to estimate the biomechanical impact of a compressive load varying from 0N to 100N on the head and neck complex at four positions, neutral position, 10 and 20 deg of head flexion and 10 deg of head extension. An evaluation of the required muscles net moment to conserve the head at each posture will also be done.