KINEMATICAL ANALYSIS OF SHOULDER JOINT DURING ELEVATION MEASURED BY ULTRASOUND-BASED MEASURING SYSTEM

Abstract

In order to analyse shoulder joint movements, the author uses a ZEBRIS CMS-HS ultrasound-based movement sensor and a related measurement program developed by the researchers in Biomechanical Laboratory in TUB. In essence, the measurement involves the determination of the spatial position of the 16 anatomical points specified on the basis of the coordinates of ultrasound-based triplets positioned on the upper limb, the scapula, and the thorax, measured in the course of motion. Kinematic characteristics of 74 shoulder joints of 50 healthy persons were identified during elevation. A specially developed processing program was used for the calculation and analysis of humerus elevation, scapulothoracal, and glenohumeral angles, defined as angles of spatial vectors; the glenohumeral, scapulothorocal and capuloglenoid ratio to be determined therefrom; and of scapulothoracal and glenohumeral rhythm during motion. Motion of the humerus and the scapula relative to each other was characterized by the rotation center of the two bones and rigid bodies as well as their absolute and relative displacement relative to each other. The biomechanical model of the shoulder joint during elevation can be described by analysing the results of the measurements performed.