12.04.09 - Study of muscle reflexes in Delft
A sudden stretch of a muscle usually results in two reflexes: the M1 response, which takes place almost imediately, and the M2 response that starts with a short delay. Both can be measured by means of electromyography.
The M1 response originates from the monosynaptic Ia afferent reflex pathway, that also causes the well-known knee reflex.
Less is known about the M2 response. In this study by Schuurmans and others (Delft University of Technology) studied the possible contribution of the Ia afferent pathway to the M2 response was investigated.
Participants had to do a number of pertubation tasks with a wrist manipulator. The measurements were compared to a computer model of the M1 and M2 responses. The results showed that the activation of the M2 response takes place, depends primarily on the stretch duration of the muscle.
These findings have recently been published in Experimental Brain Research in the article ‘The monosynaptic Ia afferent pathway can largely explain the stretch duration effect of the long latency M2 response’.