Electrically evoked long-latency responses in human forearm, arm and shoulder muscles

Little is known about electrically evoked long-latency responses (LLR) in muscles other than hand muscles. We obtained LLR in forearm, arm and shoulder muscles by ipsilateral homonymous and heteronymous mixed and pure cutaneous electrical stimulation of the median or ulnar nerve in healthy subjects and in patients with focal unilateral Central Nervous System lesions. Our results point out the important role played by hand afferents in the sensorimotor coordination of multiarticulate upper limb movements.