Analysis of Work Related Skeletal Changes in the Spine: A Comparative Radiographic Study of the Lumbosacral Angle in Nurses and Computer Operators

Increased degenerative changes in the lumbar spine have been linked to various occupations. These alterations have been documented to be associated with low back pain (LBP) amongst actively engaged workers. An experimental cross sectional study was done to determine the Lumbosacral angle of young adults currently engaged in primary seated occupation (Computer operators), and primary standing and walking occupation (Nurses) in Nigeria. Lateral radiographs of seventy-six (76) healthy working volunteers (34 males = 44.7% and 42 females = 55.3%) from three strata; 24 nurses, 29 computer operators and 25 undergraduate students represented by Group1, Group2 and Control respectively, were studied in three Medical centres located in the city of Port Harcourt, Nigeria. Subjects were within the age range 18 and 45 years with mean age of 27 years. Before commencement of data collection, each participant voluntarily signed an informed consent form. Each lateral radiograph was evaluated using Fergusons method for measurement of the normal LSA. Statistical analysis were done using the computer based SPSS Version 20 with level of statistical significance set at p<0.05 (providing 95% confidence interval). The Mean±S.D values for height, weight and BMI were 1.66±0.07m, and 66.43±11.46Kg and 24.11±4.41Kgm-2 respectively. Mean LSA for whole sample was 31.00±6.23°. Considering the three groups, mean LSA values were 32.53±6.04° for group 1, 32.05±4.30° for group 2, and 29.84±8.03° for the control group. Post-Hoc multiple comparison showed no significant difference (P>0.05) in the mean LSA for the three groups. However, differences in LSA was observed between workers in group 2 &group 1 for age 18-24years and between workers in group 2 &control for age 25- 31years. Though mean LSA of this young population of subjects fell within normal range, the study demonstrates that the cumulative effect of certain professions over time may exceed the physiological weight bearing mechanisms of the spine and result in reversal or exaggeration of the normal curvatures of the lumbar spine. Sacral orientation determines global spinal configuration, hence the consequences may include moderate to severe work related musculoskeletal disorders involving all segments of the vertebral column.

Key Words: LSA = Lumbosacral angle; Fergusons method; Occupation; Lumbar spine.