Crossed-extensor reflex prevents you from falling when you suddenly lift one foot off the ground in response to pain.
A withdrawal reflex is the crossed extensor reflex. In the withdrawing limb, the extensors relax while the flexors contract, but in the other limb, the opposite happens.
This can be seen, for instance, when someone steps on a nail; the affected leg pulls away, while the other leg bears the weight of the entire body.
Contralateral means that the crossed extensor reflex takes place on the side of the body that is opposite from the stimulus.
Afferent nerve fiber branches travel from the stimulated side of the body to the opposite side of the spinal cord to cause this response.
They make connections with interneurons there, which then stimulate or inhibit alpha motor neurons to he muscles of the contralateral limb.
