Systems and methods of a safety helmet for protecting the human head against repetitive impacts, moderate impacts and severe impacts so as to significantly reduce the likelihood of both translational and rotational brain injury and concussions can be provided. The helmet can include an outer shell, an omnidirectional liner disposed within and coupled to the outer shell and configured to move relative to the outer shell, and a chinstrap coupled to the omnidirectional liner. The chinstrap coupled to the omnidirectional liner can hold a wearer's head to the omnidirectional liner and prevent the chinstrap from applying forces to the wearer while omnidirectional liner moves relative to outer shell. Other embodiments may include a chinguard with a movable chincup.