A novel approach using tendon vibration of the human flexor carpi radialis muscle to study spinal reflexes.

Although most muscle spindle investigations have used the cat model and invasive measurement techniques, several investigators have used microneurography to record from the Ia and II fibres in humans during tendon vibration. In these studies the muscle spindle primary endings are stimulated using transverse vibration of the tendon at reflex sub-threshold amplitudes. Others have used low amplitude vibration and the stretch evoked M-wave response to determine reflex properties during both agonist and antagonist voluntary contractions.

Tendon reflexes elicited using a computer controlled linear motor tendon hammer.

We present a novel instrumentation system for studying tendon and spinal reflexes using a commercial linear servo-motor as a precisely controlled tendon hammer. The system uses a LabVIEW-based program to both control electrical or mechanical stimuli and record and measure the resulting M and H waves. The hammer can deliver tendon taps with selected velocities, durations, frequencies and excursions.