Differences in spinal and pelvic postural parameters in two different racial groups, measured using Surface Topography

Needof the study:

The sagittal plane contour of the spine plays animportant role in the normal function of the spine. Maintenance of the sagittalspino-pelvic balance is found to be the result of combined effort of osteo-articularand myo-fascial structures of the spinal column, the pelvis and the lower limbmuscles. A proper assessment of spinal posture can facilitate early detectionof postural aberrations and institution of adequate preventive and correctivemeasures.1.2

Human population is subdivided into a plethora ofethnic groups and races distributed worldwide. An ethnic group or ethnicity is asocially defined category of people who identifywith each other based on common ancestral, social, cultural ornational experience3, whereas Race, as a socialconcept, is a group of people who share similar anddistinct physical characteristics such as bone structure and skin, hair,or eye color.4

Ethnicity plays an important role in thedifferentiation of anthropometric values.5 Multiple studies havebeen described in the literature that have analyzed the inter- ethnicanthropometric and spinal postural parametric differences in humans as well asin cadavers. 5 – 9 But based on these studies it is still unclearwhether or not race plays a role in the variability of pelvic morphology andspino-pelvic anatomy.

Malaysia is a multi-racial country withmore than 70 identified ethnic groups. These ethnic groups are broadlyclassified into four major groups namely Bumiputera (inclusive of Malay andIndigenous), Chinese, Indians and Others (include non-Malaysian citizen). TheChinese Malaysians are Malysian citizens of Han Chinese ancestry, descendentsof Han Chinese who arrived between the early and mid-20th century.They constitute about 22.9 per cent of the entire Malaysian population.10

For the detection of changes in spinal posture, thegold standard remains to be , the clinical examination along with radiologicaltechniques such as X Ray, CT and MRI until today. The radiation from thesediagnostic procedures leads to a very critical deployment for conductingmultiple examinations, particularly in young individuals. For this reason,simple, but inaccurate and poorly reliable methods were developed for spinalpostural analysis like the kyphometer or the curve ruler. 11

A precise radiation free and inexpensive method fordetecting the spinal posture was then developed in early 1980’s, called SurfaceTopography, based on the technology of Raster-stereography (RSG). The surfacecontour analysis occurs from the projection of raster lines on the back of thepatient. Assignment of concave and convex areas to curved light patternsenables automatic detection of anatomical landmarks. The system is able tocalculate a 3D model of the human spine, by means of certain anatomical fixedpoints of the human body. Clinically relevant spinal and pelvic posturalparameters such as the trunk inclination, the kyphosis and the lordosis angles ofthe spine can be determined by this technique. Thus surface topography offersan alternative method of detecting spinal postural parameters because it isside effect and contact-free, non invasive, fast and objective.11

The differences in spinal and pelvic posturalparameters in two different racial groups obtained using the non- invasive andradiation free technology of Surface Topography haven’t been previouslyanalyzed. The aim of the present study is to describe the spinal and pelvicpostural parameters in a sample of healthy Chinese-origin Malaysian volunteersand to compare with that obtained from an age matched healthy Indianpopulation. Our findings may provide greater insight into the influence ofethnicity or racial differences in assessment of spinal posture as well asmanagement of spinal disorders.