Spasticity

Objective Measures of Spasticity

Objective testing includes both electrophysiologic studies and biometric testing. EMG, with simultaneous measure of agonist and antagonist muscles, can be used alone or in combination with gait analysis. The most widely employed electrophysiologic testing, multichannel EMG, provides quantification of the H/M ratio, F waves, the tonic vibration reflex, the flexor withdrawal response, and lumbosacral spinal evoked potentials.20-26

Although biomechanical studies, because of the cost and size of the equipment, are typically reserved for use in research studies, they can provide objective measures of spasticity. Two types of studies are the Wartenburg pendulum test, in which an electrogoniometer is used to count the number and record the pattern of the swing when the knee is released from an extended position, and the torque motor test, which measures the amplitude and frequency oscillation during flexion and extension of the wrist.18,27