Evaluation of hypertonia with the use of a gravity‐driven ergograph

A gravity‐driven ergograph is described for recording movement at a joint to which constant torque force is applied by various weights. The joint to be tested is put in a horizontal position to eliminate the effect of gravity. The force of gravity of varying weights suspended by a cable supplies a constant, reproducible acceleration which moves the limb, stretching the muscle. The amount of movement in response to the force applied reflects the amount of spasticity. Even in the relatively stable environment of hospitalized patients, marked variations in spasticity have been recorded from day to day. The changes with oral medications so far have been well within variations during control periods. The technique has potential value in quantitating spasticity.