Combinations of Factors Can Increase Risks for Low Back Pain
What triggered my low back pain (LBP)? Simple question--complicated answer. Studies have found several factors that raise the risk of developing LBP. Known risk factors include:

This new study looked at all these factors over a period of 24 years in people with LBP. Researchers found that a combination of some of these risk factors made the overall risk for LBP significantly higher.

For men, the risks of LBP were excessively high when they dealt with heavy loads at work, had many demands outside of work, did sedentary work, or had a combination of poor social relationships and lots of overtime work.

Women were at especially high risk for LBP when they worked with heavy loads, did sedentary work, smoked, or had a combination of work that involved whole-body vibrations and a lack of influence over work conditions.
References
Carina Thorbjornsson, M Soc Sc, et al. Physical and Psychosocial Factors Related to Low Back Pain During a 24-Year Period. In Spine. February 1, 2000. Vol. 25. No. 3. Pp. 369-375.