1 Introduct ion STUDIES ON

wheelchair propulsion have mainly been focused on physical stress or on technical improvements. Some studies have tried to combine physiological and more biomechanical techniques to find criteria for opti-misation of wheelchair design. In this analysis of the wheelchair/user interface, physiological and biomechanical measurements under known, manipulatable conditions which simulate real-life wheelchair propulsion, are needed. Measurements should not only include exact information on the applied workload, but also information on the forces applied by the user to overcome this workload and on the metabolic ost of doing so. The validity of any parameters to he measured is directly related to the verisimilitude of the simulation. An ergometer must not only allow accurate measurement of power output and applied forces, but must also simulate wheelchair driving, at least mechanically, as realistically as possible. Moreover, because comparison of different wheel-chair dimensions is required, the ergometer should allow easy adaptation of the wheelchair dimensions. A stationary ergometer is preferable, because it would facilitate the measurement of physiological and kinesiological par-ameters. First received 5th April and in final form 31st August 1989 ~) IFMBE: 1990 The demands with which such an ergometer must comply can be summarised as follows: (a) adequate simulation of frictional osses due to air and rolling resistance, velocity and slope, together leading to continuous control of workload calculated in a power balance (b) realistic simulation of the linear inertia of the wheel-chair user system (c) measurement of torques and forces exerted on rims as well as on the seat and backrest, during wheelchair propulsion (d) possibility of analysing the effect of different wheelchair configurations (e) possibility of measuring physiological and kinesio-logical parameters (movement analysis, electromyo-graphy). At present various types of wheelchair ergometer design are used. These designs can be classified as follows: (i) measurements on a track (GORDON, 1952; PEIZER e