3D SHOULDER POSITION MEASUREMENTS USING A 6-DEGREE-OF-FREEDOM ELECTROMAGNETIC TRACKING DEVICE

Objective. To describe a recording and processing methodology for obta ining kinematic data of the shoulder which meets three more criteria b esides usual requirements regarding precision and accuracy: sufficient speed, obtaining complete 3D kinematics including joint rotations, an d usage of coordinate systems based on reference points. Design. Stati c recordings of shoulder bone orientations during standardized humerus elevations based on the palpation technique using a six-degree-of-fre edom electromagnetic tracking device. Background. An easy, fast, well standardized measurement methodology for obtaining complete 3D shoulde r kinematic data is urgently needed for fundamental musculoskeletal an d clinical research. Methods. A measurement methodology was designed a nd developed. Shoulder kinematics were obtained from repeated measurem ents on 15 healthy subjects performed by two observers. Inter-trial, i nter-day, inter-observer and inter-subject variability were establishe d. Results were compared to literature. Results. Complete kinematic de scriptions were obtained. A measurement speed of about one position pe r second could be reached. The measured kinematics and accuracy of the measurements were found to be in concordance with the literature. Con clusion. All previously formulated criteria for a clinical useful meth od for obtaining shoulder kinematics have been met.