A Lofstrand crutch was instrumented with a six component load cell to measure forces and moments at the crutch. The crutch and the right upper extremity of a subject were instrumented with markers to measure their movement. The marker positions and the crutch sensor signals were recorded and synchronized by an active marker kinematic acquisition system. A biomechanical model based on rigid bodies was implemented in a biomechanic analysis software in order to calculate the variables of interest. To demonstrate the functionality of the model and the instrumentation, results of a pilot test were analyzed from one healthy individual during Lofstrand crutch assisted gait. Kinematic and kinetic joint results were consistent with the movement executed by the subject. The biomechanical model and the instrumentation presented in this work, kinematic and kinetic of upper limb joints can be described in a quantitative way.