Jeffrey Knox, Department of Orthopaedic Surgery, Tripler Army Medical Center, Honolulu, USA, and others reported in The Spine Journal that occupational drivers have a significantly—although small—increased risk of developing low back pain compared with people from other occupations.
Occupational driving is already associated with low back pain, Knox et al reported, but most of the studies showing this association consist of “cross-sectional evaluations of small populations without control groups” and there is little data on the incidence rate of low back in occupational drivers. The authors noted: “This study is the first of its kind, examining the incidence rates and epidemiologic variables in a closed high-demand populations presumed be at significant risk for developing this condition.”
Reviewing data from the Defense Medical Epidemiology Database, Knox et al found that the overall incidence rate of low back pain among military vehicle operators was 54.2 per 1,000 person-years but was 48.3 per 1,000 person-years among military services members from other occupations (the study’s control group). They wrote: “Military vehicle operators had a significantly increased adjusted incidence rate ratio (IRR) of 1.15. When examining the age subcategories, we found that the IRR for motor vehicle operators compared with service members with other occupations was statistically significantly at all age categories.”
They added that the ergonomics of the vehicle environment, prolonged sitting in an awkward posture, whole-body vibration exposure, and psychosocial factors may be possible reasons for this increased risk with occupational driving.
Knox et al commented that compared with previous reports on low back pain among occupational drivers, in their study, the effect of occupational driving on the development of low back pain was diminished. They said that the reason for this diminished effect was unclear but stated: “Our active-duty population is required to maintain minimum standards of physical fitness and to adhere to height and weight standards regardless of their occupation. Decreased weight and increased core fitness may provide a protective effect against the negative effects of driving on the lumbar spine.”
Within the military vehicle operators population, female sex, junior rank, being married, and being less than 20 years of age or more than 40 years of age were all found to be risk factors for developing low back pain. Regarding the increased risk of low back among lower rank service members, Knox et al commented: “Individuals with higher rank are thought to have more control over their work environment, which may contribute to their decreased incidence of injury.” They added that the risk of low back pain associated with married occupational drivers was likely to be related to psychosocial factors, saying “the role of which is increasingly being recognised in the pathogenesis of low back pain.”
Knox told Spinal News International: “I think that because we have seen that driving is an important risk factor for lower back pain, we can now focus efforts on prevention. People involved in occupational driving should be encouraged to start and maintain an exercise programme including core strengthening and flexibility, non-impact aerobic activities, and maintenance of a healthy body weight. This should help to lessen the impact of driving and prevent the development of low back pain or help decrease the pain that they experience.”