A model for determining 3-D upper extremity net joint forces and moments during wheelchair propulsion

Describes the implementation of a method for the estimation of kinetic parameters imposed on and developed by the upper extremity joints during the activity of wheelchair propulsion. To calculate estimates of the three-dimensional net reaction forces and moments acting at the wrist, elbow, and shoulder joints during wheelchair propulsion, measures of upper body segment kinematics, external kinetics, and body segment anthropometry are necessary. The external forces acting on the human system were measured using an instrumented wheelchair pushrim. The kinematic data were collected by video digitization of body segment markers. Body segment anthropometric data were also collected. An anthropometric model, taking into consideration the non-proportional mass distribution of this population, was used for the estimation of body segment inertial parameters. The calculations were implemented by the use of a recursive algorithm which was previously developed. Three dimensional kinematic, kinetic, and anthropometric data were collected for 15 subjects. A sample result of the net joint force and moment calculations for these subjects is presented here