Introduction: Herniation, also known as prolapse, of the intervertebral discs is a common cause of back pain and sciatica. Risk factors include genetics, trauma, and repetitive activity arising from recreation or working in physically demanding occupations. Disc herniation can limit mobility and the ability to handle and move objects, reducing the capacity to work. The aim of this rapid review was to identify and review studies that reported occupational risk factors for the development of intervertebral disc herniation in physically demanding occupations.
Method: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), and methods were detailed in a protocol published in advance. PubMed, SPORTDiscus, CINAHL, and ProQuest databases were systematically searched using terms derived from four themes: ‘disc’, ‘herniation’, ‘work’, and ‘risk’. Eligible studies were critically appraised with specific tools for each type of study design to assess their methodological quality, and a narrative synthesis of the findings was completed.
Results: Eleven articles were included that reported on physically demanding occupations and occupational tasks. Operators of earthmoving machines with high perceived workload, high vibration, and moderate spinal load were found to experience a greater 12-month incidence of lumbar disc herniation (9.6%) than drivers less exposed to these factors (2.3%; p=0.012). Results also revealed that retail workers exposed to biomechanical overload were at an increased risk of lumbar disc herniation compared to those not exposed (aOR=3.82; 95%, CI 3.08-4.74). Truck drivers exposed to loading vehicles more than three times per day appear to have a higher prevalence of cervical disc herniation than those loading their trucks less than twice a day; however, this difference was not statistically significant (OR=9.0; 95% CI, 0.4-182.8). Occupational tasks including physical overload, handling heavy loads, self-reported hard work, and exposure to moderate and high levels of manual handling of loads were all associated with increased risk of lumbar disc herniation. Additionally, handling loads with trunk inclination appears to exacerbate the risk.
Discussion: Specific physically demanding occupations and tasks with a high physical workload, a high requirement for manual materials handling, and trunk inclination appear to place workers at increased risk of disc herniation. Occupations which are perceived as involving hard work also appear to increase the risk of disc herniation. Data reporting on cervical spine disc herniations is limited, with most of the research being on lumbar spine herniations.
Impact: The identified factors and tasks known to increase the risk of disc herniation must be carefully managed in staff with existing back pathologies and as part of return-to-work plans.
Conflict of interest statement:
This research was funded by the Department of Veterans’ Affairs.