Modulation of postural reflexes by voluntary movement

Experiments were performed involving isometric activation/relaxation of the agonist-antagonist muscle groups about the ankle joint. It is shown that phasic changes of foot torque in the dorsal direction are associated with a transient inhibition of the soleus H-reflex which is independent of anterior tibial contraction. During phasic changes in foot torque in the plantar direction, facilitation, as opposed to disinhibition of the soleus H-reflex, is graded by soleus contraction. These results support the hypothesis that the sensitivity of the monosynaptic reflex arc is one of the controlled variables of the motor system. The stretch reflex of a shortening muscle is generally facilitated, while that of a lengthening muscle is inhibited. These hypotheses are in keeping with our present knowledge of the linkage between skeletomotor and fusimotor neurones for the organization of voluntary movements.

[1]  R W Angel,et al.  Interaction of spinal and supraspinal mechanisms during voluntary innervation of human muscle. , 1970, Experimental neurology.

[2]  H. P. Bowditch,et al.  The Knee‐jerk and its Physiological Modifications , 1890, The Journal of physiology.

[3]  G. Gottlieb,et al.  Modulation of postural reflexes by voluntary movement. II. Modulation at an inactive joint. , 1973, Journal of neurology, neurosurgery, and psychiatry.

[4]  Magladery Jw,et al.  Electrophysiological studies of nerve and reflex activity in normal man. I. Identification of certain reflexes in the electromyogram and the conduction velocity of peripheral nerve fibers. , 1950 .

[5]  L. Stark,et al.  Interactions between voluntary and postural mechanisms of thehuman motor system. , 1970, Journal of neurophysiology.

[6]  D. P. Lloyd.  CONDUCTION AND SYNAPTIC TRANSMISSION OF THE REFLEX RESPONSE TO STRETCH IN SPINAL CATS , 1943 .

[7]  C. Marsden,et al.  Servo action and stretch reflex in human muscle and its apparent dependence on peripheral sensation. , 1971, The Journal of physiology.

[8]  G. Rushworth.  The Basis of Motor Control , 1971 .

[9]  G L Gottlieb,et al.  Effects of initial conditions on the Hoffman reflex , 1971, Journal of neurology, neurosurgery, and psychiatry.

[10]  J. Paillard,et al.  Functional organization of afferent innervation of muscle studied in man by monosynaptic testing. , 1959, American journal of physical medicine.

[11]  Franklin Fearing.  The History of the Experimental Study of the Knee-Jerk , 1928 .

[12]  Gerald L. Gottlieb,et al.  Analysis of Step Tracking in Normal Human Subjects , 1969 .

[13]  Lewis Michael Nashner,et al.  Sensory feedback in human posture control , 1970 .

[14]  D. McDougal,et al.  Electrophysiological studies of nerve and reflex activity in normal man. III. The post-ischemic state. , 1950, Bulletin of the Johns Hopkins Hospital.

[15]  A. Vallbo,et al.  Muscle spindle response at the onset of isometric voluntary contractions in man. Time difference between fusimotor and skeletomotor effects , 1971, The Journal of physiology.

[16]  Magladery Jw,et al.  Electrophysiological studies of nerve and reflex activity in normal man. IV. The two-neurone reflex and identification of certain action potentials from spinal roots and cord. , 1951 .

[17]  R Llinás,et al.  Alterations of synaptic action in chromatolysed motoneurones of the cat , 1970, The Journal of physiology.

[18]  D. McDougal,et al.  Electrophysiological studies of nerve and reflex activity in normal man. II. The effects of peripheral ischemia. , 1950, Bulletin of the Johns Hopkins Hospital.

[19]  H. Táboříková,et al.  Evidence that muscle stretch evokes long-loop reflexes from higher centres , 1966 .

[20]  D. P. Lloyd.  Integrative pattern of excitation and inhibition in two-neuron reflex arcs. , 1946, Journal of neurophysiology.

[21]  A. Vallbo,et al.  Slowly adapting muscle receptors in man. , 1970, Acta physiologica Scandinavica.

[22]  P. Hoffmann.  Untersuchungen über die Eigenreflexe (Sehnenreflexe) Menschlicher Muskeln , 1922 .

[23]  J. Paillard,et al.  Autogenetic reflex effects of slow or steady stretch of the calf muscles in man , 2004, Experimental Brain Research.

[24]  J. Eccles.  The Physiology of Synapses , 1964, Springer Berlin Heidelberg.

[25]  B. L. Ginsborg.  THE PHYSIOLOGY OF SYNAPSES , 1964 .

[26]  W Rall,et al.  Dendritic location of synapses and possible mechanisms for the monosynaptic EPSP in motoneurons. , 1967, Journal of neurophysiology.

[27]  J. Eccles.  The inhibitory control of spinal reflex action. , 1967, Electroencephalography and clinical neurophysiology.

[28]  G. Gottlieb,et al.  The muscle silent period and reciprocal inhibition in man , 1972, Journal of neurology, neurosurgery, and psychiatry.

[29]  Cathala Hp,et al.  Amplitude et variabilité des réflexes monosynaptiques avant un mouvement volontaire , 1971 .

[30]  G L Gottlieb,et al.  The role of the myotatic reflex in the voluntary control of movements. , 1972, Brain research.