Regarding fixed ring and floating ring pure moment application.
Crawford
Neil R
NR
D001696:Biomechanical Phenomena; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D008954:Models, Biological; D009068:Movement / Q000502:physiology*; D015203:Reproducibility of Results; D013131:Spine / Q000502:physiology*