The role of cumulative physical work load in lumbar spine disease: risk factors for lumbar osteochondrosis and spondylosis associated with chronic complaints

Abstract

Objectives-To investigate the relation with a case-control study between symptomatic osteochondrosis or spondylosis of the lumbar spine and cumulative occupational exposure to lifting or carrying and to working postures with extreme forward bending. Methods-From two practices and four clinics were recruited 229 male patients with radiographically confirmed osteochondrosis or spondylosis of the lumbar spine associated with chronic complaints. Of these 135 had additionally had acute lumbar disc herniation. A total of 197 control subjects was recruited: 107 subjects with anamnestic exclusion of lumbar spine disease were drawn as a random population control group and 90 patients admitted to hospital for urolithiasis who had no osteochondrosis or spondylosis of the lumbar spine radiographically were recruited as a hospital based control group. Data were gathered in a structured personal interview and analysed using logistic regression to control for age, region, nationality, and other diseases aVecting the lumbar spine. To calculate cumulative forces to the lumbar spine over the entire working life, the MainzDortmund dose model (MDD), which is based on an overproportional weighting of the lumbar disc compression force relative to the respective duration of the lifting process was applied with modifications: any objects weighing >5 kg were included in the calculation and no minimum daily exposure limits were established. Calculation of forces to the lumbar spine was based on self reported estimates of occupational lifting, trunk flexion, and duration. Results-For a lumbar spine dose >9×10 6 Nh (Newton×hours), the risk of having radiographically confirmed osteochondrosis or spondylosis of the lumbar spine as measured by the odds ratio (OR) was 8.5 (95% confidence interval (95% CI) 4.1 to 17.5) compared with subjects with a load of 0 Nh. To avoid diVerential bias, forces to the lumbar spine were also calculated on the basis of an internal job exposure matrix based on the control subjects' exposure assessments for their respective job groups. Although ORs were lower with this approach, they remained significant. Conclusions-The calculation of the sum of forces to the lumbar spine is a useful tool for risk assessment for symptomatic osteochondrosis or spondylosis of the lumbar spine. The results suggest that cumulative occupational exposure to lifting or carrying and extreme forward bending increases the risk for developing symptomatic osteochondrosis or spondylosis of the lumbar spine. (Occup Environ Med 2001;58:735-746)

Biomechanical Assessment of Three Rebar Tying Techniques

“…These forces, however, are exerted on the low back for several hours each day thereby resulting in high cumulative force over many years of activity, which have been reported to increase the risk of developing a low-back disorder [10]. In addition, a recent experimental study has shown that static lumbar flexion, which occurs during extreme trunk flexion, is a risk factor for developing a low-back disorder [17].…”

“…Spinal disc pressure is known to vary depending on the amount and type (e.g., forward, sideward, twisting) of bending and external loads [10].…”

Inpatient hospital care for back disorders in relation to industry and occupation in Finland

“…There is some evidence of an association of back symptoms with objective (eg, radiological) findings of the spine (30)(31)(32). However, health care use cannot, nor can indeed any data that comprise symptoms as a component of case definition, refute the possibility that, in heavy work, symptoms are more disturbing than in light work (33).…”

Reduction of Biomechanical and Welding Fume Exposures in Stud Welding

“…1). Stud welding requires frequent bouts of prolonged stooping (Fethke et al, 2011), a posture that can lead to an elevated risk of low back pain (Punnett et al, 1991;Seidler et al, 2001;Jansen et al, 2004).This posture also frequently places the breathing zone in the buoyant plume of the welding fume (Fig. 1).…”