Comprehensively Quantifying and Ranking The Effects of Neck Muscles Under Various Fiber Activations In Low-Speed Head Impacts

Abstract Neck musculature plays a critical role in attenuating head motion during dynamic impacts, yet structure-specific contributions remain poorly quantified. This study used a detailed GHBMC finite-element head-neck model to evaluate how muscles, ligaments, and vertebrae share internal energy during low-severity head impacts. Seven impact directions were analyzed under three neuromuscular conditions: passive (unanticipated), active-fast (power-based), and active-slow (endurance-based) at 3m/s velocity. In passive neck models deep muscles contributed more during lateral and oblique impacts, whereas superficial muscles dominated in the sagittal plane. Passive and active-slow cases shifted internal-energy share toward the cervical spine and ligaments, implying greater mechanical demand on these structures. Individual muscle-level analysis identified direction-specific dominant muscles, with sternocleidomastoid consistently the largest single contributor and additional deep and superficial muscles entering the dominant group depending on direction. Active muscle neck models increased muscular energy absorption, particularly in sagittal impacts, accompanied by reductions in linear acceleration of the head. Overall, this study quantifies the roles of deep and superficial neck muscles in stabilizing the head and identifies priority muscles, informing targeted neuromuscular training and personalized protective strategies.