The construction and evaluation of a low-cost isokinetic knee exerciser

Abstract

An inexpensive knee exerciser which closely approximates the performance of state-of-the-art isokinetic equipment has been constructed and a preliminary evaluation has been carried out. Unlike other exercisers, the lower limb angular velocity cannot be set a priori but, on the basis of patient performance it is possible to restrict limb velocity to within upper and lower bounds. The exerciser makes use of a shock absorber and lever mechanism which allow easy calibration of the system while elementary electronics and computer interfacing allow the measurement angle, velocity and torque in real time. A significant advantage of this exerciser over some isokinetic knee exercisers currently on the market is that limited arc rotation can be enforced. This type of limb restriction is important in many rehabilitation programs.