[In vivo measurements of shoulder movements by a goniometer with six degrees of freedom: preliminary study]

Abstract

Purpose of the study: The purpose of this work was to develop a goniometer with six degrees of freedom (6DOF) to achieve global measurement of the main movements of the shoulder and to examine the reproducibility of the measurements obtained.

Material and methods: Movement amplitudes, inter- and intra-observer reproducibility of the methodology and the device were tested in a population of ten young subjects with asymptomatic shoulders.

Results: Maximal amplitudes obtained for each movement were: abduction 111.8 +/- 11 degrees; flexion 127.9 +/- 12.7; external rotation 86.3 +/- 14 degrees; free elevation 129.3 +/- 9 degrees. The curves traced in the plane of rotation and rotation were plotted against elevation. Comparison between amplitudes on the right and left were not significantly different.

Discussion and conclusion: This preliminary study demonstrated the potential contribution of a 6DOF-goniometer for a 3D assessment of shoulder movement. Measurements made when positioning the goniometer demonstrated good reproducibility. Our data are similar to others reported in the literature. The plane of the scapula and the position in physiological internal rotation, as described in the literature, were also observed. Studying shoulder movements, particularly their association, should provide a new means of assessing function in patients with complex disease of the shoulder joint. The device should be helpful in obtaining an objective measurement of the shoulder kinetics that would be useful for patient follow-up and assessment of corporal damage.