Abstract
Control of the standing posture of humans involves at least two distinct modes of operation to restore the body balance in the sagittal plane: the ankle strategy and the hip strategy. The objective of the study was to estimate the contribution of vestibular, visual and somatosensory feedbacks to these distinct strategies. The body dynamics was described as the motion of two linked rigid segments that represented the legs and the rest of the body. The posture controller received the inclination angles of the two body segments as inputs and regulated the moments around the ankle and hip joints. The controller had four feedback paths that were characterised by transfer functions connecting the two inputs and the two outputs. To evoke the distinct strategies, the floor conditions were varied by narrowing the support surface under the feet. A continuous pseudo-random external disturbing force was applied to the waist and the thigh independently. The inclination angles of the body segments and the ground reaction force were measured, and the transfer functions of the controller were estimated with the maximum-likelihood system identification procedure. Six healthy male adult subjects participated in the experiment. When the hip strategy became evident under the narrow support surface conditions, the transfer function relating the leg inclination angle and the ankle joint moment decreased its DC gain (16%), whereas the other three transfer functions increased the gains (20–140%) (ANOVA, p<0.05). Based on a criterion for simplicity in the modification of the posture controller, these changes suggest a new hypothesis that, when posture control becomes difficult, the central nervous system selectively activates the somatosensory feedback paths from the hip joint angle to the moments around the ankle and hip joints.
Similar content being viewed by others
References
Allum, J. H. J., Bloem, B. R., Carpenter, M. G., Hulliger, M., andHadders-Algra, M. (1998): ‘Proprioceptive control of posture: a review of new concepts’,Gait Posture,8, pp. 214–242
Astrom, K. J. (1980): ‘Maximum likelihood and prediction error methods’,Automatica,16, pp. 551–574
Bresler, B., andFrankel, J. P. (1950): ‘The forces and moments in the leg during level walking’, Trans. ASME,72, pp. 27–36
Fitzpatrick, R. C., Taylor, J. L., andMcCloskey, D. I. (1992): ‘Ankle stiffness of standing humans in response to imperceptible perturbation: reflex and task-dependent components’,J. Physiol. (Lond.),454, pp. 533–547
Forssberg, H., andHirschfeld, H. (1994): ‘Postural adjustments in sitting humans following external perturbations: muscle activity and kinematics’,Exp. Brain Res.,97, pp. 515–527
Horak, F. B., andNashner, L. M. (1986): ‘Central programming of postural movements: adaptation to altered support-surface configurations’,J. Neurophysiol.,55, pp. 1369–1381
Horak, F. B., Nashner, L. M., andDiener, H. C. (1990): ‘Postural strategies associated with somatosensory and vestibular loss’,Exp. Brain Res.,82, pp. 167–177
Kuo, A. D., andZajac, F. E. (1993): ‘Human standing posture: multijoint movement strategies based on biomechanical constraints’, inAllum, J. H. J., Allum-Mecklenburg, D. J., Harris, F. P., andProbst, R. (Eds): ‘Progress in brain research’ (Elsevier, Amsterdam, 1993),97, pp. 349–358
Kuo, A. D., Speers, R. A., Peterka, R. J., andHorak, F. B. (1998): ‘Effect of altered sensory conditions on multivariate descriptors of human postural sway’,Exp. Brain Res.,122, pp. 185–195
Mergner, T., Maurer, C., andPeterka, R. J. (2002): ‘Sensory contribution to the control of stance: posture control model’,Adv. Exp. Med. Biol.,508, pp. 147–152
Miyazaki, S. (1992): ‘A simple and practical method for evaluating overall measurement error of joint moments obtained by a force plate and position sensing device’,Frontiers Med. Biol. Eng.,4, pp. 257–270
Nashner, L. M., andMcCollum, G. (1985): ‘The organization of human postural movements: a formal basis and experimental synthesis’,Behav. Brain Sci.,8, pp. 135–172
Nashner, L. M., Shupert, C. L., andHorak, F. B. (1988): ‘Headtrunk movement coordination in the standing posture’,Prog. Brain Res.,76, pp. 243–251
Peterka, R. J. (2002): ‘Sensorimotor integration in human postural control’,J. Neurophysiol.,88, pp. 1097–1118
Peterka, R. J., andLoughlin, P. J. (2004): ‘Dynamic regulation of sensorimotor integration in human postural control’,J. Neurophysiol.,91, pp. 410–423
Runge, C. F., Shupert, C. L., Horak, F. B., andZajac, F. E. (1998): ‘Role of yestibular information in initiation of rapid postural responses’,Exp. Brain Res.,122, pp. 403–412
Runge, C. F., Shupert, C. L., Horak, F. B., andZajac, F. E. (1999): ‘Ankle and hip postural strategies defined by joint torques’,Gait Posture,10, pp. 161–170
Van der Kooij, H., Jacobs, R., Koopman, B., andGrootenboer, H. (1999): ‘A multisensory integration model of human stance control’,Biol. Cybern.,80, pp. 299–308
Van der Kooij, H., Jacobs, R., Koopman, B., andVan der Helm, F. (2001): ‘An adaptive model of sensory integration in a dynamic environment applied to human stance control’,Biol. Cybern.,84, pp. 103–115
Vaughan, C. L., Davis, B. L., andO'Conner, J. C. (1992): ‘Dynamics of human gait’ (Human Kinetics Publishers, Champaign, 1992)
Winter, D. A. (1990): ‘Biomechanics and motor control of human movement’ (Wiley, New York, 1990)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Fujisawa, N., Masuda, T., Inaoka, H. et al. Human standing posture control system depending on adopted strategies. Med. Biol. Eng. Comput. 43, 107–114 (2005). https://doi.org/10.1007/BF02345130
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02345130