Meniscus is a well innervated tissue with four types of receptors. These receptors are mainly concentrated at the anterior
and posterior horns. Although they are intended to be a part in reflex arc, this function has not been thoroughly evaluated.
We hypothesized that electrical stimulation of the normal meniscus would elicit electromyographic activity of the hamstring
muscle via the reflex arc. Five adult domestic male rabbits were used in this study. Under general anesthesia, knee arthrotomy
and thigh dissection were done to expose medial meniscus and semimembranosus muscle. Menisci were stimulated by Teflon-coated
bipolar needle electrodes. Needles were placed in the posterior horn of the medial menisci. Two Teflon-coated monopolar needle
electrodes were placed in semimembranosus muscle. A four-channel electromyograph was used for recording. Two different potentials
were recorded from the target muscle. The first response had a very short distal latency and its amplitude was changing in
accordance with the strength of the stimulus, suggesting that this response was being elicited by direct muscle stimulation.
The second delayed response with less amplitude also appeared in some traces. The latency and the amplitude of this second
response were fairly stable stating that this delayed response was being generated by a reflex pathway and seen in all subjects.
Keywords Medial - Meniscus - Semimembranosus - Muscle - Reflex arc