Abstract
The role of supraspinal structures in postural adjustment upon standing on stable and unstable supports was studied in healthy individuals. For this purpose, transcranial magnetic stimulation (TMS) of the motor cortex was used in the region of leg representation. The subject stood with the eyes closed on a firm floor or on an unstable support in the form of a paperweight (20 cm in height, with a base radius of 32 cm) with mobility in the sagittal direction. Electric responses of four muscles—the soleus muscle, the anterior tibial muscle, the femoral biceps muscle, and the femoral rectus muscle—were recorded. It was shown that, in all the muscles, the response to TMS upon standing on an unstable support increased by 1.8–2.7 times as compared with the response upon standing on a firm floor. Since the increase in the tonic activity of the muscles studied was statistically insignificant upon switching over from standing on a firm floor to standing on an unstable support, it is hypothesized that the increase in the amplitude of muscle responses is connected with an increased activity of the supraspinal structures or with an increase in the effectiveness of corticospinal connections. The results are discussed from the point of view of the role of the motor cortex in maintaining balance on an unstable support.
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REFERENCES
Brooks, V.B., The Neural Basis of Motor Control, N.Y.: Oxford Univ. Press, 1986.
Ioffe, M.E., Kortiko-spinal'nye mekhanizmy instrumental'nykh dvigatel'nykh reaktsii (Corticospinal Mechanisms of Instrumental Motor Reactions), Moscow: Nauka, 1975.
Ioffe, M.E., Mekhanizmy dvigatel'nogo obucheniya (Mechanisms of Motor Training), Moscow: Nauka, 1991.
Ioffe, M.E., Ivanova, N.G., Frolov, A.A., et al., On the Role of Motor Cortex in the Learned Rearrangement of Postural Coordinations, in Stance and Motion, Facts and Concepts, Gurfinkel', V.S. et al., Eds., N.Y.: Plenum, 1988, p. 213.
Gurfinkel', V.S. and El'ner, A.M., Involvement of the Secondary Motor Region of the Anterior Lobe in the Organization of Postural Components of Voluntary Movement in Humans, Neirofiziologiya, 1988, vol. 20, p. 7.
Palmer, E., Downes, L., and Ashby, P., Associated Postural Adjustments are Impaired by a Lesion of the Cortex, Neurology, 1996, vol. 46, no. 2, p. 471.
Massion, J., Role of Motor Cortex in Postural Adjustments Associated with Movements, in Integration in the Nervous System, Asanuma, H. and Wilson, V.J., Eds., Tokyo: Igaku-Shoin, 1979, p. 239.
Ouchi, Y., Okada, H., Yoshikawa, E., et al., Brain Activation during Maintenance of Standing Postures in Humans, Brain, 1999, vol. 122, no. 2, p. 329.
Ivanenko, Y.P., Levik, Y.S., Talis, V.L., and Gurfinkel', V.S., Human Equilibrium on Unstable Support: The Importance of Feet-Support Interaction, Neurosci. Lett., 1997, vol. 235, no. 3, p. 109.
Ivanenko, Y.P., Talis, V.L., and Kazennikov, O.V., Support Stability Influences Postural Responses to Muscle Vibration in Humans, Eur. J. Neurosci., 1999, vol. 11, no. 2, p. 647.
Ivanenko, Y.P., Solopova, I.A., and Levik, Y.S., The Direction of Postural Stability Affects Postural Reactions to Ankle Muscle Vibration in Humans, Neurosci. Lett., 2000, vol. 292, p. 103.
Barker, A.T., Jalinous, R., and Freeston, I.L., Noninvasive Magnetic Stimulation of the Human Motor Cortex, Lancet, 1985, vol. 1, p. 1106.
Baker, S.M., Olivier, E., and Lemon, R.M., Task-Related Variation in Corticospinal Output Evoked by Transcranial Magnetic Stimulation in the Macaque Monkey, J. Physiol., 1995, vol. 488, p. 795.
Rothwell, J.C., Thompson, P.D., Day, B.L., et al., Stimulation of the Human Motor Cortex through the Scalp, Exp. Physiol., 1991, vol. 76, p. 159.
Lemon, R.N., Johansson, R.S., and Westling, G., Corticospinal Control during Reach, Grasp, and Precision Lift in Man, J. Neurosci., 1995, vol. 15, p. 6145.
Dietz, V. and Berger, W., Spinal Coordination of Bilateral Leg Muscle Activity during Balancing, Exp. Brain Res., 1982, vol. 47, p. 172.
Fitzpatrick, R., Burke, D., and Gandevia, S.C., Task-Dependent Reflex Responses and Movement Illusions Evoked by Galvanic Vestibular Stimulation in Standing Humans, J. Physiol., 1994, vol. 478, part 2, p. 363.
Bertasi, V., Bertolasi, L., Frasson, E., and Priori, A., The Silent Period of Transcranial Magnetic Brain Stimulation Mainly Reflects the Activity of Inhibitory Circuits in the Human Motor Cortex, Exp. Brain Res., 2000, vol. 132, no. 3, p. 384.
Capaday, D., Lavoie, B.A., Barbeau, H., et al., Studies on the Corticospinal Control of Human Walking: 1. Responses to Focal Transcranial Magnetic Stimulation of the Motor Cortex, J. Neurophysiol., 1999, vol. 81, p. 129.
Shubert, M., Curt, A., Colombo, G., et al., Voluntary Control of Human Gait: Conditioning of Magnetically Evoked Motor Responses in a Precision Stepping Task, Exp. Brain Res., 1999, vol. 126, p. 583.
Lavoie, B.A., Cody, F.W., and Capaday, D., Cortical Control of Human Soleus Muscle during Voluntary and Postural Activities Studied Using Focal Magnetic Stimulation, Exp. Brain Res., 1995, vol. 103, no. 1, p. 97.
Matis, J., Gurfinkel, V.S., and Struppler, A., Facilitation of Motor Evoked Potentials by Postcontraction Response (Kohnstamm Phenomenon), Neurosci. Lett., 1996, vol. 101, p. 289.
Gurfinkel', V.S., Shik, M.L., and Kots, Ya.M., Regulyatsiya pozy cheloveka (Postural Adjustment in Humans), Moscow: Nauka, 1965.
Gurfinkel', V.S., Ivanenko, Y.P., Levik, Y.S., and Babakova, I.A., Kinesthetic Reference for Human Orthograde Posture, Neuroscience, 1995, vol. 68, p. 229.
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Solopova, I.A., Kazennikov, O.V., Deniskina, N.V. et al. Comparison of Leg Muscle Responses to Transcranial Magnetic Stimulation upon Standing on Stable and Unstable Supports. Human Physiology 28, 702–707 (2002). https://doi.org/10.1023/A:1021156423869
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DOI: https://doi.org/10.1023/A:1021156423869