Abstract
In 15 patients with spastic hemiparesis the development of tension of calf muscles in relation to their electrical activation and their stretching period was studied on both sides during locomotion. Only in the spastic leg did isolated small biphasic potentials appear in the gastrocnemius E.M.G. with monosynaptic latency at the beginning of the stance phase, while the remaining gastrocnemius activation was reduced compared to the unaffected side. Perturbations of gait were followed in the spastic leg by a large monosynaptic response, while the polysynaptic reflex response was reduced. In the unaffected leg only a strong polysynaptic response appeared, which suggests a reciprocal modulation of monosynaptic and polysynaptic reflex responses. Tension development paralleled the gastrocnemius E.M.G. in the unaffected leg, while in the spastic leg tension was more closely correlated to muscle stretch. It is concluded that in spasticity the exaggerated monosynaptic reflexes represent only a small part of leg extensor activation during gait and that the tension development does not depend on these reflexes.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Berardelli A., Hallett M., Kaufman C., Fine E., Berenberg W., Simon S. R. Stretch reflexes of triceps surae in normal man. J Neurol Neurosurg Psychiatry. 1982 Jun;45(6):513–525. doi: 10.1136/jnnp.45.6.513. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Berardelli A., Sabra A. F., Hallett M., Berenberg W., Simon S. R. Stretch reflexes of triceps surae in patients with upper motor neuron syndromes. J Neurol Neurosurg Psychiatry. 1983 Jan;46(1):54–60. doi: 10.1136/jnnp.46.1.54. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dietz V., Berger W. Normal and impaired regulation of muscle stiffness in gait: a new hypothesis about muscle hypertonia. Exp Neurol. 1983 Mar;79(3):680–687. doi: 10.1016/0014-4886(83)90032-8. [DOI] [PubMed] [Google Scholar]
- Dietz V., Quintern J., Berger W. Electrophysiological studies of gait in spasticity and rigidity. Evidence that altered mechanical properties of muscle contribute to hypertonia. Brain. 1981 Sep;104(3):431–449. doi: 10.1093/brain/104.3.431. [DOI] [PubMed] [Google Scholar]
- Gottlieb G. L., Agarwal G. C. Response to sudden torques about ankle in man: myotatic reflex. J Neurophysiol. 1979 Jan;42(1 Pt 1):91–106. doi: 10.1152/jn.1979.42.1.91. [DOI] [PubMed] [Google Scholar]
- Herman R. The myotatic reflex. Clinico-physiological aspects of spasticity and contracture. Brain. 1970;93(2):273–312. doi: 10.1093/brain/93.2.273. [DOI] [PubMed] [Google Scholar]
- Knutsson E., Richards C. Different types of disturbed motor control in gait of hemiparetic patients. Brain. 1979 Jun;102(2):405–430. doi: 10.1093/brain/102.2.405. [DOI] [PubMed] [Google Scholar]
- Morin C., Katz R., Mazieres L., Pierrot-Deseilligny E. Comparison of soleus H reflex facilitation at the onset of soleus contractions produced voluntarily and during the stance phase of human gait. Neurosci Lett. 1982 Nov 16;33(1):47–53. doi: 10.1016/0304-3940(82)90128-8. [DOI] [PubMed] [Google Scholar]