Abstract
The sagittal morphology of the pelvis determines the amount of lordosis needed for each individual. The proper harmony of the sagittal spinal curves allows a stable balance, economical in terms of mechanical effects and muscular energy. A previous barycentremetrical laboratory study allowed us to demonstrate that the axis of gravity of the upper body segment was located behind the lumbar vertebrae and the femoral heads, thus ensuring economy and stability. The determination of the anatomical connection of the individual gravity is thus of primary importance for the evaluation of sagittal balance. Data for 42 patients without spinal pathology, previously evaluated by barycentremetry, were used to establish a predictive equation for the application point of the gravity at the level of the third lumbar vertebra (L3). This equation, using anthropometric and radiographic pelvic and spinal parameters, was integrated into a software program called Similibary. It was applied to the same 42 subjects. These results were compared in order to validate the method. No significant difference was observed between the two techniques. This easy-to-use tool allows a personalised evaluation of the sagittal balance of the spine, both through the evaluation of the harmonious relationship between the spinal curves and the pelvis, and through the location of gravity supported by the vertebral structures in L3.
Résumé
La morphologie sagittale du bassin détermine la lordose appropriée à chaque individu. Cette harmonie des courbures sagittales du rachis permet un équilibre stable et économique en terme de sollicitations mécaniques et d’efforts musculaires nécessaires à son maintien. Une étude préalable par «barycentremétrie» a permis de démontrer que l’axe de la gravité du segment corporel supérieur se projette en arrière des structures lombaires et des têtes fémorales, assurant ainsi un équilibre économique et stable. La détermination individuelle de la projection de la gravité est donc essentielle à l’évaluation de l’équilibre sagittal. Les données de 42 sujets sans pathologie rachidienne, évalués auparavant par la barycentremétrie, ont permis d’établir une équation prédictive des coordonnées d’application de la gravité supportée au niveau de la vertèbre L3. Cette équation, utilisant des données anthropométriques et des paramètres radiographiques pelviens et spinaux, fut intégrée dans un logiciel appelé «simili-barycentremétrie». Elle fut appliquée aux mêmes 42 sujets. Les résultats ont été comparés pour valider la méthode. Aucune différence significative n’a été observée.Cet outil permet une évaluation personnalisée de l’équilibre sagittal du rachis, à la fois quant à l’harmonie entre le bassin et les courbures, mais aussi quant à l’application de la gravitée supporté par les structures lombaires.
Similar content being viewed by others
References
Cosson PH, Desmoineaux P, Robain G, Duval-Beaupère G (1987) Les valeurs inertielles des segments corporels supportés par les vertèbres. Jour Biophy Biomec supl 11:52–53
Cosson PH, Duval-Beaupère G (1993) Détermination personnalisée in vivo chez l’homme des efforts exercés sur les étages vertébraux thoraciques et lombaires en position debout et assise. Rachis 5:5–12
Descamps H, Commare MC, Marty C, Hecquet J, Duval-Beaupère G (1999) Modification of pelvic angle during the human growth. Biom Hum Anthropol 17:59–63
Duval-Beaupère G, Robain G (1987) Visualization on full spine radiographs of the anatomical connections of the centre of the segmental body mass supported by each vertebra and measured in vivo. Intern Orthop 11:261–269
Duval-Beaupere G, Schmidt C, Cosson PH (1992) A barycentremetric study of the sagittal shape of spine and pelvis. Ann Biomed Engeneer 20:451–462
Duval-Beaupere G, Legaye J (2004) Composante sagittale de la statique rachidienne. Rev Rhum 71:105–119
During J, Goudfrooîj H, Keessen W (1985) Toward standards for posture. Spine 10:83–87
Eiji I (1991) Roentgenographic analysis of posture. Spine 16:750–756
Farfan H (1978) The biomechanical advantage of lordosis for upright activity. Spine 3:336–342
Gangnet N, Pomero V, Dumas R, Skalli W, Vital JM (2003) Variability of the spine and pelvis location with respect to the gravity line: a three-dimensional stereoradiographic study using a force platform. Surg Radiol Anat 25:424–433
Harrison DE, Colloca CJ et al (2005) Anterior thoracic posture increases thoracolumbar disc loading. Eur Spine J 14:234–242
Jackson RP, McManus AC (1994) Radiographic analysis of sagittal plane allignment and balance in standing volunteers and patients with low back pain matched for age, sex and size. A prospective controlled clinical study. Spine 19:1611–1618
Keller TS, Harrisson ED et al (2003) Prediction of osteoporotic spinal deformity. Spine 28:455–462
Keller TS, Colloca CJ et al (2005) Influence of spine morphology on intervertebral disc loads and stresses in asymptomatic adults: implications for the ideal spine. Spine J 5:297–309
Kiefer A, Shirazi-adi A, Parnianpour M (1997) Stability of the human spine in neutral postures. Eur Spine J 6:45–53
King Liu Y, Montroe-Laborde J et al (1971) Inertial properties of a segmental cadaver trunk : their implication in acceleration injuries. Aerospacial Med 42:650–657
La Grone MO (1988) Loss of lumbar lordosis: A complication of spinal fusion for scoliosis. Orthop Clin North Am 19:383–93
La Grone MO, Bradford DS, Moe JH, Lonstein JE, Winter RB, Ogilvie JW (1988) Treatment of symptomatic flatback after spinal fusion. J Bone Joint Surg (Am) 70:1419–1424
Legaye J, Santin JJ, Hecquet J, Marty C, Duval-Beaupère G (1993) Bras de levier de la pesanteur supportée par les vertebres lombaires. Rachis 5:13–20
Legaye J, Hecquet J, Marty C, Duval-Beaupere G (1993) Equilibre sagittal du rachis. Relations entre bassin et courbures rachidiennes sagittales en position debout. Rachis 3:215–226
Legaye J, Duval-Beaupere G, Hecquet J, Marty C (1998) The Incidence, fundamental pelvic parameter for the tridimensionnal regulation of the spinal sagittal curves. Eur Spine J 7:99–103
Mangione P, Gomez D, Senegas J (1997) Study of the course of incidence angle during growth. Eur Spine J 6:163–167
Marty C, Boisaubert B, Descamps H, Montigny JP, Legaye J, Hecquet J, Duval-Beaupère G (2002) The sagittal anatomy of the sacrum among young adults, infants and spondylolisthesis patients. Eur Spine J 11:119–125
Schultz AB, Anderson G, Ortengren R, Nachemson A (1973) Loads on the lumbar Spine validation of an biomechanical analysis, measurement of intra-discal pressure and myoelectric signals. J Bone Joint Surg 64A(5):713–720
Vaz G, Roussoully P, Berthonnaud E, Dimnet J (2002) Sagittal morphology and equilibrium of pelvis and spine. Eur Spine J 11:80–87
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Legaye, J., Duval-Beaupere, G. Gravitational forces and sagittal shape of the spine. International Orthopaedics (SICO 32, 809–816 (2008). https://doi.org/10.1007/s00264-007-0421-y
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00264-007-0421-y