INSTRUMENTATION AND BIOMECHANICAL MODEL FOR KINEMATIC AND KINETIC ANALYSIS OF UPPER LIMBS DURING GAIT WITH CRUTCHES

The goal of this study was to develop a three-dimensional kinematic and kinetic model of the right upper extremity and a Lofstrand crutch in order to analyze joint displacements and loads during crutch-assisted gait. A Lofstrand crutch was instrumented with a six-component load cell to measure forces and moments at the crutch tip. The crutch and the right upper extremity of a subject were instrumented with markers to obtain kinematic data. A biomechanical model based on rigid bodies was implemented in biomechanical analysis software. To demonstrate the functionality of the model, a pilot test was conducted on one healthy individual during Lofstrand crutch-assisted gait. The shoulder extended during the support phase and flexed in the swing phase, the elbow flexed during the swing, and the wrist remained in extension throughout the cycle. In the shoulder and elbow joints, the predominant reaction forces were upward, whereas the internal force moments were flexion and extension, respectively. This tool will be useful when it comes to identifying risk factors for joint pathology associated with pattern gait, aid design or crutch overuse.