Note on the knee-jerk and the correlation of action of antagonistic muscles / by C. S. Sherrington.

  • Sherrington, Charles Scott, Sir, 1857-1952.
Date:
[1893]
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Licence: Public Domain Mark

Credit: Note on the knee-jerk and the correlation of action of antagonistic muscles / by C. S. Sherrington. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    Reprinted for the Author from the British Medical Journal, June lOth, 1893. FURTHER NOTE ON THE CORRELATION OF ACTION OF ANTAGONISTIC MUSCLES.^ By C. S. SHERRINGTON, M.A., M.D. F.R.S. In a previous communication^ it was shown that physiological contraction, and even mere mechanical tension of the flexor muscles of the knee, exerts considerable physiological in- fluence upon the activity of the antagonistic muscles, the extensors. For instance, the elicitation of the jerk from the extensors can be rendered impossible or difficult for a time by appropriate excitation of the flexors, and can, on the other hand, be much facilitated by flaccidity or paralysis of the latter. In order to judge whether under these circumstances the briskness of the knee-jerk varies directly with the degree of tonus of the extensor muscles, the rapidity of onset of rigor mortis has been selected as a guide to the degree of tonus obtaining in them before death. The experiments of Brown- S^quard, KoUiker, and Hermann and his pupils, have dis- covered that section of the nerve of a muscle, even when performed very shortly before the death of the animal, con- siderably delays the time of onset of rigor mortis in the muscle. After control experiments which simply verified the statements by these observers, experiments were instituted on the influence of section of the motor spinal roots upon the time of onset of rigor mortis. The examination showed that a marked delay of onset of rigor mortis was thus produced. The delay seemed to be as considerable as after section of the entire muscular nerve. The efi'ect of section of the posterior roots was next examinad, and found to be a marked retarda- tion of the onset of the rigor; the retardation was greater if the spinal cord remained intact than if the cord were pre- viously severed across in the region of the first lumbar segment. The efi'ect of placing and keeping one of the hmd limbs in the pose most favourable for elicitation of the jerk (knee fiexed) and the other limb in the posi- tion in which the jerk is restrained (knee extended) was investigated, in every case after previous severance of the spinal cord at the first lumbar segment. It was found that upon the side on which the knee had been kept fiexed the onset of rigor was delayed in the extensor muscles, whereas upon the opposite side, in which the knee had been kept ex- tended, rigor was delayed in the fiexors. This infers that the tonus of the extensors is heightened by excitation of the anta- gonistic set, and conversely. The research was also extended to the examination of the nautual association of action of antagonistic muscles about other joints than the knee. It had been noticed in an earlier series of observations^ that during excitation of the cortical areas of the hemisphere, when isolated movements of the 9 cju^ Abstract of a paper communicated to the Royal Society. * snerrington, Proceedings of the Royal Society, February 1st, 1893