D. Winter, F. Prince, J. Frank, C. Powell, and K. Zabjek, Unified theory regarding A/P and M/L balance in quiet stance, J Neurophysiol, vol.75, issue.6, pp.2334-2377, 1996.

A. Gollhofer, G. Hortsmann, W. Berger, and V. Dietz, Compensation of translational and rotational perturbations in human posture: Stabilization of the centre of gravity, Neuroscience Letters, vol.105, issue.1-2, pp.73-81, 1989.
DOI : 10.1016/0304-3940(89)90014-1

G. Horstmann and V. Dietz, A basic posture control mechanism: the stabilization of the centre of gravity, Electroencephalography and Clinical Neurophysiology, vol.76, issue.2, pp.165-76, 1990.
DOI : 10.1016/0013-4694(90)90214-5

Y. Brenière, Why We Walk the Way We Do, Journal of Motor Behavior, vol.93, issue.4, pp.291-299, 1996.
DOI : 10.1016/S0166-4115(08)60740-2

A. Tagaki, E. Fujimura, and S. Sueshiro, A New Method of Statokinesigram Area Measurement: Application of a Statistically Calculated Ellipse, Vestibular and visual control on posture and locomotor equilibrium, pp.74-83, 1985.
DOI : 10.1159/000410306

D. Scott and E. Dzendolet, Quantification of sway in standing humans, Agressologie, vol.13, pp.35-40, 1972.

R. Soames, J. Atha, and R. Harding, Temporal changes in the pattern of sway as reflected in power spectral density analysis, Agressologie, vol.17, pp.15-20, 1976.

I. Farenc and P. Rougier, Analyse fr??quentielle des trajectoires du centre de gravit?? et du centre des pressions lors de la station debout immobile, ITBM-RBM, vol.21, issue.4, pp.210-216, 2000.
DOI : 10.1016/S1297-9562(00)90003-2

D. Winter, Biomechanics and motor control of human movement. 2 nd ed, 1990.

D. Winter, Human balance and posture control during standing and walking, Gait & Posture, vol.3, issue.4, pp.193-214, 1995.
DOI : 10.1016/0966-6362(96)82849-9

Y. Aramaki, D. Nazaki, K. Masani, T. Sato, K. Nakazawa et al., Reciprocal angular acceleration of the ankle and hip joints during quiet standing in humans, Experimental Brain Research, vol.136, issue.4, pp.463-73, 2001.
DOI : 10.1007/s002210000603

J. Max, Méthodes et techniques de traitement du signal et application aux mesures physiques : principes généraux et méthodes classiques, 1985.

Y. Brenière, M. Do, and S. Bouisset, Are Dynamic Phenomena Prior to Stepping Essential to Walking?, Journal of Motor Behavior, vol.18, issue.1, pp.62-69, 1987.
DOI : 10.1080/00222895.1987.10735400

J. Mizrahi, P. Solzi, H. Ring, and R. Nissel, Postural stability in stroke patients: Vectorial expression of asymmetry, sway activity and relative sequence of reactive forces, Medical & Biological Engineering & Computing, vol.28, issue.2, pp.497-513, 1989.
DOI : 10.1007/BF02446228

G. Fernie and P. Holliday, Postural sway in amputees and normal subjects., The Journal of Bone & Joint Surgery, vol.60, issue.7, pp.895-903, 1978.
DOI : 10.2106/00004623-197860070-00003

I. Isakov, J. Mizrahi, H. Ring, K. Susak, and N. Hakim, Standing sway and weight bearing distribution in people with below-knee amputations, Arch Phys Med Rehab, vol.73, pp.174-182, 1992.

R. Dickstein, M. Nissan, T. Pillar, and D. Scheer, Foot-Ground Pressure Pattern of Standing Hemiplegic Patients, Physical Therapy, vol.64, issue.1, pp.19-23, 1984.
DOI : 10.1093/ptj/64.1.19

A. Shumway-cook, D. Anson, and S. Haller, Postural sway biofeedback : its effect on reestablishing stance stability in hemiplegics patients, Arch Phys Med Rehab, vol.69, pp.395-400, 1988.

B. Amblard, C. Assaiante, H. Lekhel, and A. Marchand, A Statistical Approach to Sensorimotor Strategies: Conjugate Cross-Correlations, Journal of Motor Behavior, vol.26, issue.2, pp.103-115, 1994.
DOI : 10.1080/00222895.1994.9941665

B. Mandelbrot, Les objets fractals. Flammarion, p.247, 1995.

S. Université-de-savoie-thèse, J. Ufr-cism-nicolas-genthon-references-blaszcyk, K. Flis, and M. Kalejta, Postural stability control characteristics in stroke patients Control of posture and gait Why we walk the way we do Are dynamic phenomena prior to stepping essential to walking, Breniè re Journal of Motor Behavior Journal of Motor Behavior, vol.28, issue.19, pp.624-628, 1987.

O. Caron, B. Faure, and Y. Breniè-re, Estimating the centre of gravity of the body on the basis of the centre of pressure in standing posture, Journal of Biomechanics, vol.30, issue.11-12, pp.11-12, 1997.
DOI : 10.1016/S0021-9290(97)00094-8

S. Chaudhuri and A. Aruin, The effect of shoe lifts on static and dynamic postural control in individuals with hemiparesis, Archives of Physical Medicine and Rehabilitation, vol.81, issue.11, pp.1498-1503, 2000.
DOI : 10.1053/apmr.2000.17827

J. J. Collins, C. J. Deluca, T. Deschamps, A. Legros, and N. Caillou, Open-loop and closed-loop control of posture: A random-walk analysis of center-of-pressure trajectories, Experimental Brain Research, vol.95, issue.2, pp.308-318, 1993.
DOI : 10.1007/BF00229788

M. Dettman, M. Linder, and S. Sepic, Relationships among walking performance, postural stability, and functional assessments of the hemiplegic patient, American Journal of Physical Medicine, vol.66, pp.77-90, 1987.

R. Dickstein, M. Nissan, T. Pillar, and D. Scheer, Foot-Ground Pressure Pattern of Standing Hemiplegic Patients, Physical Therapy, vol.64, issue.1, pp.19-23, 1984.
DOI : 10.1093/ptj/64.1.19

R. Dickstein, Z. Dvir, and E. B. Jehosua, Automatic and voluntary lateral weight shifts in rehabilitation of hemiparetic patients, Clinical Rehabilitation, vol.4, issue.2, pp.91-99, 1994.
DOI : 10.1177/026921559400800201

G. R. Fernie and P. J. Holliday, Postural sway in amputees and normal subjects., The Journal of Bone & Joint Surgery, vol.60, issue.7, pp.895-898, 1978.
DOI : 10.2106/00004623-197860070-00003

W. H. Gage, D. A. Winter, J. S. Frank, and A. L. Adkin, Kinematic and kinetic validity of the inverted pendulum model in quiet standing, Gait & Posture, vol.19, issue.2, pp.124-132, 2004.
DOI : 10.1016/S0966-6362(03)00037-7

N. Genthon and P. Rougier, Analyse biom??canique de la contribution relative de chacun des appuis dans le contr??le de la station debout non-perturb??e, ITBM-RBM, vol.24, issue.5-6, pp.238-247, 2003.
DOI : 10.1016/S1297-9562(03)00058-5

A. Geurts, M. Haart, J. Van-ness, L. Fasotti, and J. Van-limbeek, Restoration of postural symmetry following stroke, Control of Posture and Gait, pp.637-640, 2001.

I. Isakov and J. Mizrahi, Bilateral simultaneous measurements of standing ground reaction forces in hemiparetics, below-knee amputees, and healthy adults, Basic Applied Myology, vol.7, pp.97-101, 1997.

I. Isakov, J. Mizrahi, H. Ring, K. Susak, and N. Hakim, Standing sway and weight bearing distribution in people with below-knee amputations, Archives of Physical Medicine and Rehabilitation, vol.73, pp.174-178, 1992.

F. Kachnaoui, W. Vanbiervliet, C. Benaim, J. Peíissier, C. He´rissonhe´risson et al., Restauration de la posture e´rigeée´rigeéaprè s AVC: dissociation entre asyme´trieasyme´trie d'appui et stabilite´.stabilite´, p.341, 2002.

B. E. Maki, P. J. Holliday, and A. K. Topper, A Prospective Study of Postural Balance and Risk of Falling in An Ambulatory and Independent Elderly Population, Journal of Gerontology, vol.49, issue.2, pp.72-84, 1994.
DOI : 10.1093/geronj/49.2.M72

B. B. Mandelbrot and J. Van-ness, Fractional Brownian Motions, Fractional Noises and Applications, SIAM Review, vol.10, issue.4, pp.422-437, 1968.
DOI : 10.1137/1010093

J. Mizrahi and Z. Susak, Bi-lateral reactive force patterns in postural sway activity of normal subjects, Biological Cybernetics, vol.28, issue.4, pp.297-305, 1989.
DOI : 10.1007/BF00204127

J. Mizrahi, P. Solzi, H. Ring, and R. Nissel, Postural stability in stroke patients: Vectorial expression of asymmetry, sway activity and relative sequence of reactive forces, Medical & Biological Engineering & Computing, vol.28, issue.2, pp.181-190, 1989.
DOI : 10.1007/BF02446228

J. Okubo, I. Watanabe, and J. B. Baron, Study on influences of the plantar mechanoreceptor on body sways, Agressologie, vol.21, pp.61-69, 1980.

R. J. Peterka, Postural control model interpretation of stabilogram diffusion analysis, Biological Cybernetics, vol.82, issue.4, pp.335-343, 2000.
DOI : 10.1007/s004220050587

H. Ring and J. Mizrahi, Bilateral Postural Sway in Stroke Patients: New Parameters for Assessing and Predicting Locomotor Outcome, Neurorehabilitation and Neural Repair, vol.5, issue.3, pp.175-179, 1991.
DOI : 10.1177/136140969100500304

G. Rode, C. Tiliket, and D. Boisson, Predominance of postural imbalance in left hemiparetic patients, Scandinavian Journal of Rehabilitation Medicine, vol.29, pp.11-16, 1997.

P. Rougier, Influence of visual feedback on successive control mechanisms in upright quiet stance in humans assessed by fractional Brownian motion modelling, Neuroscience Letters, vol.266, issue.3, pp.157-160, 1999.
DOI : 10.1016/S0304-3940(99)00272-4

P. Rougier, . Article, . N. In, P. Genthon, and . Rougier, Automatic determination of the transition between successive control mechanism in upright stance assessed by, Journal of Biomechanics Archives of Physiology and Biochemistry, vol.38, issue.107, pp.2037-2049, 1999.

P. Rougier, Visual feedback induces opposite effects on elementary centre of gravity and centre of pressure minus centre of gravity motions in undisturbed upright stance, Clinical Biomechanics, vol.18, issue.4, pp.341-349, 2003.
DOI : 10.1016/S0268-0033(03)00003-2

P. Rougier and O. Caron, Center of Gravity Motions and Ankle Joint Stiffness Control in Upright Undisturbed Stance Modeled Through a Fractional Brownian Motion Framework, Journal of Motor Behavior, vol.75, issue.4, pp.405-413, 2000.
DOI : 10.1086/296465

P. Rougier and I. Farenc, Adaptative effects of loss of vision on upright undisturbed stance, Brain Research, vol.871, issue.2, pp.165-174, 2000.
DOI : 10.1016/S0006-8993(00)02357-X

P. Rougier, C. Burdet, I. Farenc, and L. Berger, Backward and forward leaning postures modelled by an fBm framework, Neuroscience Research, vol.41, issue.1, pp.41-50, 2001.
DOI : 10.1016/S0168-0102(01)00257-7

T. Schmalz, S. Blumentritt, and R. Jarasch, Energy expenditure and biomechanical characteristics of lower limb amputee gait:, Gait & Posture, vol.16, issue.3, pp.255-263, 2002.
DOI : 10.1016/S0966-6362(02)00008-5

A. Shumway-cook, D. Anson, and S. Haller, Postural sway biofeedback: its effect on reestablishing stance stability in hemiplegics patients, Archives of Physical and Medicine Rehabilitation, vol.69, pp.395-400, 1988.

D. P. Thomas and R. J. Whitney, Postural movements during normal standing in man, Journal of Anatomy, vol.93, pp.75-86, 1959.

D. A. Winter, Human balance and posture control during standing and walking, Gait & Posture, vol.3, issue.4, pp.193-214, 1995.
DOI : 10.1016/0966-6362(96)82849-9

D. A. Winter, F. Prince, J. S. Frank, C. Powell, and K. F. Zabjek, Unified theory regarding A/P and M/L balance in quiet stance, Journal of Neurophysiology, vol.75, pp.2334-2343, 1996.

N. Accornero, M. Capozza, S. Rinalduzzi, and G. W. Manfredi, Clinical multisegmental posturography: age-related changes in stance control, Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control, vol.105, issue.3, pp.213-219, 1997.
DOI : 10.1016/S0924-980X(97)96567-X

Y. Aramaki, D. Nozaki, K. Masani, T. Sato, K. Nakazawa et al., Reciprocal angular acceleration of the ankle and hip joints during quiet standing in humans, Experimental Brain Research, vol.136, issue.4, pp.463-73, 2001.
DOI : 10.1007/s002210000603

V. E. Belen-'kii, V. S. Gurfinkel, and E. I. Pal-'tsev, [Control elements of voluntary movements], Biofizika, vol.12, issue.1, pp.135-176, 1967.

S. Bouisset and J. L. Duchene, Is body balance more perturbed by respiration in seating than in standing posture?, NeuroReport, vol.5, issue.8, pp.957-60, 1994.
DOI : 10.1097/00001756-199404000-00026

J. Cholewicki, G. K. Polzhofer, and A. Radebold, Postural control of trunk during unstable sitting, Journal of Biomechanics, vol.33, issue.12, pp.1733-1740, 2000.
DOI : 10.1016/S0021-9290(00)00126-3

G. Clement, V. S. Gurfinkel, F. Lestienne, M. I. Lipshits, and K. E. Popov, Adaptation of postural control to weightlessness, Exp Brain Res, vol.57, issue.1, pp.61-72, 1984.

J. J. Collins, D. Luca, and C. J. , Open-loop and closed-loop control of posture: A random-walk analysis of center-of-pressure trajectories, Experimental Brain Research, vol.95, issue.2, pp.308-326, 1993.
DOI : 10.1007/BF00229788

A. G. Cresswell, L. Oddsson, and A. Thorstensson, The influence of sudden perturbations on trunk muscle activity and intra-abdominal pressure while standing, Experimental Brain Research, vol.98, issue.2, 1994.
DOI : 10.1007/BF00228421

B. L. Day, M. J. Steiger, P. D. Thompson, and C. D. Marsden, Effect of vision and stance width on human body motion when standing: implications for afferent control of lateral sway., The Journal of Physiology, vol.469, issue.1, pp.479-99, 1993.
DOI : 10.1113/jphysiol.1993.sp019824

V. Dietz, A. Gollhofer, M. Kleiber, and M. Trippel, Regulation of bipedal stance: dependency on ?load? receptors, Experimental Brain Research, vol.89, issue.1, pp.229-260, 1992.
DOI : 10.1007/BF00229020

E. V. Gurfinkel, Y. M. Kots, E. I. Paltsev, and A. Feldman, The compensation of respiratory disturbances of the erect posture of man as an example of the organisation of interarticular action, pp.382-395, 1971.

R. T. Harbourne, C. Giuliani, and J. M. Neela, A kinematic and electromyographic analysis of the development of sitting posture in infants, Developmental Psychobiology, vol.19, issue.1, pp.51-64, 1993.
DOI : 10.1002/dev.420260105

E. Kantor, L. Poupard, L. Bozec, S. Bouisset, and S. , Does body stability depend on postural chain mobility or stability area?, Neuroscience Letters, vol.308, issue.2, pp.128-132, 2001.
DOI : 10.1016/S0304-3940(01)01986-3

J. Massion, Postural control system, Current Opinion in Neurobiology, vol.4, issue.6, 1994.
DOI : 10.1016/0959-4388(94)90137-6

M. P. Murray, A. A. Seireg, and S. B. Sepic, Normal postural stability and steadiness, The Journal of Bone & Joint Surgery, vol.57, issue.4, pp.510-516, 1975.
DOI : 10.2106/00004623-197557040-00012

R. J. Peterka, Postural control model interpretation of stabilogram diffusion analysis, Biological Cybernetics, vol.82, issue.4, pp.335-343, 2000.
DOI : 10.1007/s004220050587

P. Rougier, Influence of visual feedback on successive control mechanisms in upright quiet stance in humans assessed by fractional Brownian motion modelling, Neuroscience Letters, vol.266, issue.3, 1999.
DOI : 10.1016/S0304-3940(99)00272-4

P. Rougier, Automatic Determination of the Transition Between Successive Control Mechanisms in Upright Stance Assessed by Modelling of the Centre of Pressure, Archives of Physiology and Biochemistry, vol.8, issue.8, pp.35-42, 1999.
DOI : 10.1093/brain/107.4.1143

D. A. Winter, F. Prince, J. S. Frank, C. Powell, and K. F. Zabjek, Unified theory regarding A/P and M/L balance in quiet stance Preliminary Trial of Carisoprodol in Multiple Sclerosis, REFERENCES Ashworth B Practitioner, vol.192, pp.540-542, 1964.

N. Genthon, P. Rougier, J. Froger, J. Pélissier, and D. Pérennou, How to quantify the weight-bearing asymmetry by posturography: lateral shift of the centre of pressure or percentage of body weight on each foot ? Gait and Posture

S. Université-de-savoie-thèse, R. Ufr-cism-nicolas-genthon, . Day, . Bl, . Steiger et al., Effect of vision and stance width on human body motion when standing: implications for afferent control of lateral sway, J Physiol, vol.469, pp.479-499, 1993.

N. Genthon and P. Rougier, Analyse biom??canique de la contribution relative de chacun des appuis dans le contr??le de la station debout non-perturb??e, ITBM-RBM, vol.24, issue.5-6, pp.238-247, 2003.
DOI : 10.1016/S1297-9562(03)00058-5

A. Geurts, M. Haart, V. Ness, and J. Duyssens, A review of standing balance recovery from stroke, Gait & Posture, vol.22, issue.3, pp.267-281, 2005.
DOI : 10.1016/j.gaitpost.2004.10.002

H. Lekhel, A. Marchand, C. Assaiante, . Cremieux, and B. Amblard, Cross-correlation analysis of the lateral hip strategy in unperturbed stance, NeuroReport, vol.5, issue.10, pp.1293-1296, 1994.
DOI : 10.1097/00001756-199406020-00035

W. Mcilroy and B. Maki, Preferred placement of the feet during quiet stance: development of a standardized foot placement for balance testing, Clinical Biomechanics, vol.12, issue.1, pp.66-70, 1997.
DOI : 10.1016/S0268-0033(96)00040-X

R. Oldfield, The assessment and analysis of handedness: The Edinburgh inventory, Neuropsychologia, vol.9, issue.1, pp.97-113, 1971.
DOI : 10.1016/0028-3932(71)90067-4

D. Perennou and A. Bronstein, Balance disorders and vertigo after stroke: assessment and rehabilitation, Recovery after stroke, pp.320-398, 2005.
DOI : 10.1017/CBO9781316135297.014

D. Thomas and R. Whitney, Postural movements during normal standing in man, J Anat, vol.93, pp.524-539, 1959.

D. Winter, Human balance and posture control during standing and walking, Gait & Posture, vol.3, issue.4, pp.193-214, 1995.
DOI : 10.1016/0966-6362(96)82849-9

D. Winter, F. Prince, . Frank, . Js, . Powell et al., Unified theory regarding A/P and M/L balance in quiet stance, J Neurophysiol, vol.75, issue.6, pp.2334-2343, 1996.

N. Genthon and P. Rougier, Analyse biom??canique de la contribution relative de chacun des appuis dans le contr??le de la station debout non-perturb??e, ITBM-RBM, vol.24, issue.5-6, pp.238-247, 2003.
DOI : 10.1016/S1297-9562(03)00058-5

A. Shumway-cook, D. Anson, S. Haller, A. Shumway-cook, D. Anson et al., Postural sway biofeedback: its effect on reestablishing stance stability in hemiplegic patients Postural sway biofeedback: its effect on reestablishing stance stability in hemiplegic patients, Arch Phys Med Rehabil Arch Phys Med Rehabil, vol.69, issue.69, pp.395-400, 1988.

A. Geurts, M. De-haart, I. Van-nes, and J. Duysens, A review of standing balance recovery from stroke, Gait & Posture, vol.22, issue.3
DOI : 10.1016/j.gaitpost.2004.10.002

J. Faubert, 1School of P&OT, McGill University and Jewish Rehab Hospital Research Center (CRIR), Canada