Forward positioned head supported mass amplifies muscle activation requirements of the upper neck extensors when performing reciprocal scanning

Forward positioned head mounted technologies are becoming increasingly prevalent. This study assessed the effect of added forward positioned mass on upper neck extensor (UNE) and sternocleidomastoid (SCM) activity during reciprocal scanning. Results showed that UNE activity significantly increased with forward positioned head mass, such that sustained UNE activation was required throughout the motion. SCM activity did not increase. When generalized to a prolonged use scenario, increased and sustained UNE activity as required to stabilize and balance the forward positioned load may lead to injury via the Cinderella hypothesis.