Relationship between physical work load and lumbar disc herniation.

Lumbar disc herniation (LDH) is a disabling problem. This retrospective case control study was done to evaluate the possible relevance of physical work load with Lumbar Disc Herniation. We have performed this study in the Spinal Surgery Unit of Department of Orthopaedic Surgery at BSMMU, Dhaka from July 2007 to June 2010 where 200 cases with Lumbar Disc Herniation and 200 control subjects matched by age, gender and area of residence were taken and analyzed. Chi-square test was computed for sex, area of residence, type of physical work and effort at work, whereas Odds ratio was computed for physical work load, stress at work and daily working period. The highest odds ratio (OR) was with the physical work load (OR: 03.48, CI: 01.84-06.59), hard work (OR: 03.14, CI: 01.74-05.65) and working period of >8 hours (OR: 01.34, CI: 0.75-02.38). Odds ratio for heavy load carrying at work was 03.48 and less job satisfaction or stress at work was 02.45. There was a statistically significant positive association between cumulative exposure of physical work load and lumbar disc herniation indicating an increased occurrence of herniation in heavy physical work load and occupation requiring harder efforts.