When you stumble or meet an unexpected load, eg, snagging a sleeve during some movement, rapid compensatory CNS events automatically begin 30 to 70 ms after muscle stretch. Stumbling or sleeve snags are not mentioned in volume 4 of John Desmedt's beautifully conceived and edited Progress in Clinical Neurophysiology series. But within its 22 chapters from 17 laboratories of six countries, techniques and observations on the neural machinery engaged in restoring balance, load compensation, or precise control of voluntary movements are brought into focus, using a select literature of 529 citations (1880 to 1978), 60% of which were published after 1968.
"Long loop mechanisms" in the title is catchy but has no precise meaning. The word long fits the observation that the functional stretch response (FSR: after Melville-Jones and Watt,1 1971) arrives after a muscle stretch response. In alert, undrugged subjects, long could mean latency, distance traveled, or both;
Grimm R. Cerebral Motor Control in Man: Long Loop Mechanisms. Arch Neurol. 1979;36(9):599–600. doi:10.1001/archneur.1979.00500450093028
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