Need of the study:

The sagittal plane contour of the spine plays an important role in the normal function of the spine. Maintenance of the sagittal spino-pelvic balance is found to be the result of combined effort of osteo-articular and myo-fascial structures of the spinal column, the pelvis and the lower limb muscles. A proper assessment of spinal posture can facilitate early detection of postural aberrations and institution of adequate preventive and corrective measures.^1.2

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

Ethnicity plays an important role in the differentiation of anthropometric values.⁵ Multiple studies have been described in the literature that have analyzed the inter- ethnic anthropometric and spinal postural parametric differences in humans as well as in cadavers. ^{5 – 9} But based on these studies it is still unclear whether or not race plays a role in the variability of pelvic morphology and spino-pelvic anatomy.

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

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

A precise radiation free and inexpensive method for detecting the spinal posture was then developed in early 1980’s, called Surface Topography, based on the technology of Raster-stereography (RSG). The surface contour analysis occurs from the projection of raster lines on the back of the patient. Assignment of concave and convex areas to curved light patterns enables automatic detection of anatomical landmarks. The system is able to calculate a 3D model of the human spine, by means of certain anatomical fixed points of the human body. Clinically relevant spinal and pelvic postural parameters such as the trunk inclination, the kyphosis and the lordosis angles of the spine can be determined by this technique. Thus surface topography offers an alternative method of detecting spinal postural parameters because it is side effect and contact-free, non invasive, fast and objective.¹¹

The differences in spinal and pelvic postural parameters in two different racial groups obtained using the non- invasive and radiation free technology of Surface Topography haven’t been previously analyzed. The aim of the present study is to describe the spinal and pelvic postural parameters in a sample of healthy Chinese-origin Malaysian volunteers and to compare with that obtained from an age matched healthy Indian population. Our findings may provide greater insight into the influence of ethnicity or racial differences in assessment of spinal posture as well as management of spinal disorders.