On the biomechanics of human hip complex in vivo--I. Kinematics for determination of the maximal voluntary hip complex sinus.

In recent years, multisegmented mathematical models of the total human body have gained increasing attention in view of the high cost of experiments with human cadavers and/or anthropometric dummies. While these models can simulate very complicated load-motion situations, their effectiveness depends heavily on the proper biomechanical description and modeling of the major articulating joints of the human body. In a research effort to obtain the in vivo biomechanical joint property data suitable for incorporation into these models, the senior author and his associates recently developed a new kinematic and force data collection methodology by means of sonic emitters. By applying and extending this data collection methodology, this paper in Part I presents kinematics for determination of the maximal voluntary hip complex sinus. An overdeterminate number of sonic emitters is utilized and the 'most accurate' three-dimensional kinematic data set is selected by first establishing a selection criterion. Quantitative results obtained from three male subjects are presented in a functional expansion form relative to a locally-defined joint axis system as well as in the form of globographic representation relative to the torso-fixed axis system.