J. Milne, I. Lauder, Y. Harada, T. Iwahara, M. Miyamoto et al., Lumbar degenerative kyphosis. Clinical, radiological and epidemiological studies An analysis of sagittal spinal alignment in 100 asymptomatic middle and older aged volunteers The association of trunk muscle cross-sectional area and magnetic resonance image parameters with isokinetic and psychophysical lifting strength and static back muscle endurance in men, Ann Hum Biol Spine Spine J Spinal Disord, vol.1132010, pp.327-371317, 1974.

G. Duval-beaupère, C. Schmidt, and P. Cosson, and physical function in the health, aging and body composition study A Barycentremetric study of the sagittal shape of spine and pelvis: the conditions required for an economic standing position [8] L'homme debout : le rachis et son plan horizontal, scolioses, J Gerontol A Biol Sci Med Sci Ann Biomed Eng, vol.60720, pp.882-7451, 1992.

T. Wang, Z. Zheng, H. Liu, K. Zhang, and H. Wang, Correlation of adult spinal sagittal imbalance and life quality], Zhonghua Yi Xue Za Zhi, vol.92, pp.1481-1486, 2012.

K. Bianco, R. Norton, F. Schwab, J. Smith, E. Klineberg et al., Complications and intercenter variability of three-column osteotomies for spinal deformity surgery: a retrospective review of 423 patients, Neurosurg Focus, vol.36, 2014.

J. Mac-thiong, H. Labelle, E. Berthonnaud, R. Betz, and P. Roussouly, Sagittal spinopelvic balance in normal children and adolescents. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv, Spine Res Soc, vol.16, pp.227-261, 2007.

R. Vialle, N. Levassor, L. Rillardon, A. Templier, W. Skalli et al., RADIOGRAPHIC ANALYSIS OF THE SAGITTAL ALIGNMENT AND BALANCE OF THE SPINE IN ASYMPTOMATIC SUBJECTS, The Journal of Bone and Joint Surgery-American Volume, vol.87, issue.2, pp.260-267, 2005.
DOI : 10.2106/00004623-200502000-00004

C. Lee, S. Chung, K. Kang, S. Park, and S. Shin, Normal Patterns of Sagittal Alignment of the Spine in Young Adults Radiological Analysis in a Korean Population, Spine, vol.36, issue.25, pp.1648-1654, 2011.
DOI : 10.1097/BRS.0b013e318216b0fd

J. Legaye, G. Duval-beaupère, J. Hecquet, and C. Marty, Pelvic incidence: a fundamental pelvic parameter for three-dimensional regulation of spinal sagittal curves. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv, Spine Res Soc, vol.7, pp.99-103, 1998.

V. Lafage, F. Schwab, W. Skalli, N. Hawkinson, P. Gagey et al., Standing Balance and Sagittal Plane Spinal Deformity, Spine, vol.33, issue.14, pp.1572-1580, 2008.
DOI : 10.1097/BRS.0b013e31817886a2

P. Roussouly, E. Berthonnaud, and J. Dimnet, Geometrical and mechanical analysis of lumbar lordosis in an asymptomatic population: proposed classification], Rev Chir Orthop Reparatrice Appar Mot, vol.89, pp.632-641, 2003.

C. Boulay, C. Tardieu, J. Hecquet, C. Benaim, B. Mouilleseaux et al., Sagittal alignment of spine and pelvis regulated by pelvic incidence: standard values and prediction of lordosis. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv, Spine Res Soc, vol.15, pp.415-437, 2006.

F. Schwab, V. Lafage, A. Patel, and J. Farcy, Sagittal Plane Considerations and the Pelvis in the Adult Patient, Spine, vol.34, issue.17, pp.1828-1861, 2009.
DOI : 10.1097/BRS.0b013e3181a13c08

V. Lafage, F. Schwab, A. Patel, N. Hawkinson, and J. Farcy, Pelvic Tilt and Truncal Inclination, Spine, vol.34, issue.17, pp.599-606, 2009.
DOI : 10.1097/BRS.0b013e3181aad219

F. Schwab, B. Ungar, B. Blondel, J. Buchowski, J. Coe et al., Scoliosis Research Society???Schwab Adult Spinal Deformity Classification, Spine, vol.37, issue.12, pp.1077-82, 2012.
DOI : 10.1097/BRS.0b013e31823e15e2

B. Blondel, F. Schwab, B. Ungar, J. Smith, K. Bridwell et al., Impact of Magnitude and Percentage of Global Sagittal Plane Correction on Health-Related Quality of Life at 2-Years Follow-Up, Neurosurgery, vol.71, issue.2, pp.341-348, 2012.
DOI : 10.1227/NEU.0b013e31825d20c0

L. Huec, J. Leijssen, P. Duarte, M. Aunoble, and S. , Thoracolumbar imbalance analysis for osteotomy planification using a new method: FBI technique, European Spine Journal, vol.5, issue.1, pp.669-80, 2011.
DOI : 10.3171/spi.2006.5.1.9

D. Ryan, T. Protopsaltis, C. Ames, R. Hostin, E. Klineberg et al., T1 Pelvic Angle (TPA) Effectively Evaluates Sagittal Deformity and Assesses Radiographical Surgical Outcomes Longitudinally, Spine, vol.39, issue.15, pp.1203-1213, 2014.
DOI : 10.1097/BRS.0000000000000382

B. Diebo, J. Oren, V. Challier, R. Lafage, E. Ferrero et al., Global sagittal axis: a step toward full-body assessment of sagittal plane deformity in the human body, Journal of Neurosurgery: Spine, vol.25, issue.4, pp.1-6
DOI : 10.3171/2016.2.SPINE151311

C. Barrey, P. Roussouly, L. Huec, J. , D. Acunzi et al., Compensatory mechanisms contributing to keep the sagittal balance of the spine. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv, Spine Res Soc, vol.22, issue.6, pp.834-841, 2013.

C. Barrey, G. Perrin, F. Michel, J. Vital, and I. Obeid, Pedicle subtraction osteotomy in the lumbar spine: indications, technical aspects, results and complications, European Journal of Orthopaedic Surgery & Traumatology, vol.99, issue.8, pp.21-30, 2014.
DOI : 10.1016/j.otsr.2013.07.005

M. Fortin, T. Videman, L. Gibbons, and M. Battié, Paraspinal Muscle Morphology and Composition, Medicine & Science in Sports & Exercise, vol.46, issue.5, pp.893-901, 2014.
DOI : 10.1249/MSS.0000000000000179

J. Hwang, Y. Lee, D. Park, and T. Kwon, Age affects the latency of the erector spinae response to sudden loading, Clinical Biomechanics, vol.23, issue.1, 2008.
DOI : 10.1016/j.clinbiomech.2007.09.002

H. Tsuboi, Y. Nishimura, T. Sakata, H. Ohko, H. Tanina et al., Age-related sex differences in erector spinae muscle endurance using surface electromyographic power spectral analysis in healthy humans, The Spine Journal, vol.13, issue.12, pp.1928-1961, 2013.
DOI : 10.1016/j.spinee.2013.06.060

T. Ikezoe, M. Nakamura, H. Shima, Y. Asakawa, and N. Ichihashi, Association between walking ability and trunk and lower-limb muscle atrophy in institutionalized elderly women: a longitudinal pilot study, Journal of Physiological Anthropology, vol.42, issue.15, pp.31-41, 2015.
DOI : 10.1016/j.jbiomech.2009.05.011

A. Ryan and A. Harduarsingh-permaul, Effects of weight loss and exercise on trunk muscle composition in older women, Clinical Interventions in Aging, vol.9, pp.395-402, 2014.
DOI : 10.2147/CIA.S56662

E. Zoico, A. Rossi, D. Francesco, V. Sepe, A. Olioso et al., Adipose Tissue Infiltration in Skeletal Muscle of Healthy Elderly Men: Relationships With Body Composition, Insulin Resistance, and Inflammation at the Systemic and Tissue Level, The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, vol.65, issue.3, pp.295-304, 2010.
DOI : 10.1093/gerona/glp155

S. Glassman, S. Berven, K. Bridwell, W. Horton, and J. Dimar, Correlation of Radiographic Parameters and Clinical Symptoms in Adult Scoliosis, Spine, vol.30, issue.6, pp.682-690, 2005.
DOI : 10.1097/01.brs.0000155425.04536.f7

S. Imagama, Y. Matsuyama, Y. Hasegawa, Y. Sakai, Z. Ito et al., Back muscle strength and spinal mobility are predictors of quality of life in middle-aged and elderly males. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv, Spine Res Soc, vol.20, pp.954-61, 2011.

F. Araújo, R. Lucas, N. Alegrete, A. Azevedo, and H. Barros, Sagittal Standing Posture, Back Pain, and Quality of Life Among Adults From the General Population, Spine, vol.39, issue.13, pp.782-794, 2014.
DOI : 10.1097/BRS.0000000000000347

C. Lee, C. Chung, J. Jang, S. Kim, D. Chin et al., Effectiveness of deformity-correction surgery for primary degenerative sagittal imbalance: a meta-analysis, Journal of Neurosurgery: Spine, vol.27, issue.5, pp.1-12
DOI : 10.3171/2017.3.SPINE161134

S. Charosky, P. Guigui, A. Blamoutier, P. Roussouly, and D. Chopin, Complications and Risk Factors of Primary Adult Scoliosis Surgery, Spine, vol.37, issue.8, pp.693-700, 2012.
DOI : 10.1097/BRS.0b013e31822ff5c1

K. Bianco, R. Norton, F. Schwab, J. Smith, E. Klineberg et al., Complications and intercenter variability of three-column osteotomies for spinal deformity surgery: a retrospective review of 423 patients, Neurosurg Focus, vol.36, 2014.

L. Gibbons, P. Latikka, T. Videman, H. Manninen, and M. Battié, The association of trunk muscle cross-sectional area and magnetic resonance image parameters with isokinetic and psychophysical lifting strength and static back muscle endurance in men, J Spinal Disord, vol.10, pp.398-403, 1997.

J. Guralnik, L. Ferrucci, C. Pieper, S. Leveille, K. Markides et al., Lower Extremity Function and Subsequent Disability: Consistency Across Studies, Predictive Models, and Value of Gait Speed Alone Compared With the Short Physical Performance Battery, The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, vol.55, issue.4, pp.221-231, 2000.
DOI : 10.1093/gerona/55.4.M221

O. Gille, V. Challier, H. Parent, R. Cavagna, A. Poignard et al., Degenerative lumbar spondylolisthesis. Cohort of 670??patients, and proposal of a new classification, Orthopaedics & Traumatology: Surgery & Research, vol.100, issue.6, 2014.
DOI : 10.1016/j.otsr.2014.07.006

O. Gille, H. Bouloussa, S. Mazas, C. Vergari, V. Challier et al., A new classification system for degenerative spondylolisthesis of the lumbar spine. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv Spine Res Soc, pp.10-1007, 2017.

M. De-sèze, E. Guillaud, L. Slugacz, and J. Cazalets, An examination of camptocormia assessment by dynamic quantification of sagittal posture, J Rehabil Med, vol.47, pp.72-81, 2015.

F. Schwab, V. Lafage, R. Boyce, W. Skalli, and J. Farcy, Gravity Line Analysis in Adult Volunteers, Spine, vol.31, issue.25, 2006.
DOI : 10.1097/01.brs.0000248126.96737.0f

A. Thorstensson, J. Nilsson, H. Carlson, and M. Zomlefer, Trunk movements in human locomotion, Acta Physiologica Scandinavica, vol.6, issue.Suppl. 521, pp.9-22, 1984.
DOI : 10.1097/00002060-196602000-00002

M. Syczewska, T. Oberg, and D. Karlsson, Segmental movements of the spine during treadmill walking with normal speed, Clinical Biomechanics, vol.14, issue.6, pp.384-392, 1999.
DOI : 10.1016/S0268-0033(99)00003-0

V. Feipel, D. Mesmaeker, T. Klein, P. Rooze, and M. , Three-dimensional kinematics of the lumbar spine during treadmill walking at different speeds. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv, Spine Res Soc, vol.10, pp.16-22, 2001.

T. Masquefa, N. Verdier, O. Gille, L. Boissière, I. Obeid et al., Change in acetabular version after lumbar pedicle subtraction osteotomy to correct post-operative flat back: EOS?? measurements of 38??acetabula, Orthopaedics & Traumatology: Surgery & Research, vol.101, issue.6, pp.655-664, 2015.
DOI : 10.1016/j.otsr.2015.07.013

L. Lenke, J. Engsberg, S. Ross, A. Reitenbach, K. Blanke et al., Prospective Dynamic Functional Evaluation of Gait and Spinal Balance Following Spinal Fusion in Adolescent Idiopathic Scoliosis, Spine, vol.26, issue.14, pp.330-337, 2001.
DOI : 10.1097/00007632-200107150-00020

M. De-sèze, M. Falgairolle, S. Viel, C. Assaiante, and J. Cazalets, Sequential activation of axial muscles during different forms of rhythmic behavior in man, Experimental Brain Research, vol.290, issue.Pt 2, pp.237-284, 2008.
DOI : 10.1016/j.annrmp.2005.04.009

J. Ceccato, M. De-sèze, C. Azevedo, and J. Cazalets, Comparison of Trunk Activity during Gait Initiation and Walking in Humans, PLoS ONE, vol.4, issue.12, 2009.
DOI : 10.1371/journal.pone.0008193.t001

URL : https://hal.archives-ouvertes.fr/lirmm-00429399

I. Shojaei and B. Bazrgari, Activity of Erector Spinae During Trunk Forward Bending and Backward Return: The Effects of Age, Annals of Biomedical Engineering, vol.54, issue.6, pp.1511-1520, 2017.
DOI : 10.1111/j.1532-5415.2005.00534.x

C. Hopf, M. Scheidecker, K. Steffan, F. Bodem, and P. Eysel, Gait analysis in idiopathic scoliosis before and after surgery: a comparison of the pre-and postoperative muscle activation pattern. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv, Spine Res Soc, vol.7, pp.6-11, 1998.

P. Mahaudens, X. Banse, M. Mousny, and C. Detrembleur, Gait in adolescent idiopathic scoliosis: kinematics and electromyographic analysis. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv, Spine Res Soc, vol.18, pp.512-533, 2009.

A. Holmbäck, K. Askaner, S. Holtås, D. Downham, and J. Lexell, Assessment of contractile and noncontractile components in human skeletal muscle by magnetic resonance imaging, Muscle & Nerve, vol.86, issue.2, pp.251-259, 2002.
DOI : 10.1037/0033-2909.86.2.420

A. Yavuz, A. Bora, M. Bulut, A. Batur, A. Milanlioglu et al., Acoustic Radiation Force Impulse (ARFI) elastography quantification of muscle stiffness over a course of gradual isometric contractions: a preliminary study., Medical Ultrasonography, vol.17, issue.1, pp.49-57, 2015.
DOI : 10.11152/mu.2013.2066.171.yvz