Farming is a very physical job - from lifting heavy and awkward objects, pushing and pulling animals, equipment and objects, to working or riding with machinery that have strong vibrations. As well, there is a tremendous amount of pressure on the farmers to work within specific time frames (for planting, harvesting, and so on), which doesn't allow for them to rest or take time off when they feel they may need it. Because of the lifestyle, researchers have assumed that farmers would be at high risk of developing back injuries and back pain, but this doesn't seem to be so.
The authors of this article reviewed the findings of a long-running study from Sweden to see if this assumption was correct. The study looked at back pain in farmers, but the researchers didn't find that lifting heavy objects played a role in back pain in the farmers. The researchers were also unable to find a connection between the psychosocial (mental and/or emotional) status of the farmers in relation to back pain, although psychosocial issues could and did play a part in sick leave and disability payments in both farmers and non-farmers.
What these findings did for researchers though, was to suggest that the previous idea that physical activity and back pain went hand-in-hand and that back pain usually was seen as a traumatic injury, wasn't true. In fact, more physical activity could actually help protect the back. Therefore, attempts to help prevent back injuries among farmers through ergonomics may be misguided, researchers suggest. This is likely because injury-prevention techniques that are taught are based on lessening the load on the back, not encouraging the back to be stronger and able to carry the load.
In 1989, S. Holmberg and colleagues studied over 1000 farmers and 769 non-farmers, comparing their musculoskeletal (bones and muscles) system. The farmers reported more injuries to the hand, forearm, lower back and hips than the non-farmers, according to the study findings. Following that study, the team looked at the impact of physical work on the musculoskeletal system and resulting symptoms. In this study, the researchers found that the farmers had fewer neck and shoulder injuries than the non-farmers. The pain was equal among both groups in the hand and forearms, and knees. Back injuries weren't as clear though.
When back pain was reported, were two contributors: lifting objects awkwardly or lifting heavy objects, but it was the awkward lifting that contributed the most to the back pain. But, the researchers pointed out that the increase in workload didn't have any impact on the back, nor did vibrations from machinery. Again, because there wasn't a clear connection between work load and back pain, the current preventative strategies wouldn't have an effect on the farmers but, rather, a broader approach would be needed. The broader approaches should include psychosocial and socioeconomic factors. As a result, Holmberg and his team undertook another study looking at these factors.
What the researchers found was, again, there didn't seem to be a connection between various psychosocial factors, social networks, or lifestyle and back pain, using medications for back pain, or taking sick leave. While all these may have an effect on back pain, they affected both farmers and non-farmers at the same rate. But, the research doesn't stop there. Dr. Gary MacFarlane, as part of a group called the European League Against Rheumatism (EULAR), undertook to study existing information on how psychosocial issues can affect not only back pain, but other musculoskeletal pain. One issue that frequently comes up in studies on psychosocial issues is how psychosocial factors can predict the severity and longevity of pain.
MacFarlane found seven reviews on the connection between psychosocial factors and back pain in the workplace. For the most part, the reviews found that there was a strong connection between high work demands, low colleague and survivor support, low job satisfaction, and back pain. However, the most recent review on the topic doesn't back up these findings. In fact, those researchers concluded that there was no such connections at all.
So, this means that researchers still don't know the role of psychosocial issues and back pain, but it's likely safer to err on the side of caution and work on the assumption that there is a connection, albeit an unproven one at this point.
The Changing View of Back Pain and Work: Insights From a Long-Running Study of Farmers. In The Back Letter. October 2008. Vol. 23. No. 10. Pp. 109-120.