Engineering Controls Database

Material Handling

Risk indicators of low-back pain include: general: heavy physical work, work postures in general; static work load: static work postures in general, prolonged sitting, standing or stooping, reaching, no variation in work posture; dynamic work load: heavy manual handling, lifting (heavy or frequent, unexpected heavy, infrequent torque), carrying, forward flexion of trunk, rotation of trunk, pushing/pulling; work environment: vibration, jolt, slipping/falling; and work content: monotony, repetitive work, work dissatisfaction.

Individual risk factors include: constitutional: age, gender, weight, back muscle strength (absolute and relative), fitness, back mobility, genetic factors; back complaints in the past, psychosocial: depression, anxiety, family problems, personality, dissatisfaction with work or social status of work, tense and fatigued after work, high degree of responsibility and mental concentration; other: degree of physical activity, smoking, alcohol, coughing, work experience.

Approximately one-half of all compensable low back pain is associated with manual materials handling tasks. Lifting has been implicated in 37 to 49 percent of the cases; pushing, 9 to 16 percent; pulling, 6 to 9 percent; and carrying, 5 to 8 percent; twisting the trunk has been reported in 9 to 18 percent of low back pain; bending in 12 to 14 percent; falling in 7 to 13 percent.

Construction, mining, transportation, and manufacturing are the occupations which show high rates of low back injuries.
Material handling jobs can lead to low back pain and low back injury.
Industry has used three general approaches to attempt to reduce the problem of low back pain including: 1) training and education, 2) job design, and 3) job placement. Control and prevention of low back pain can be accomplished through the evaluation of jobs and the identification of job risk factors. Studies have shown that good job design can reduce up to one-third of compensable low-back pain. Bending, twisting, reaching, handling of excessive loads, prolonged sitting, and exposure to vibration are the commonly recognized risk factors for back injuries. Redesign of jobs can lead to the reduction of these risk factors and good job design initially will prevent back injuries. To reduce bending, twisting, and reaching by the worker, the work should be at the optimum work level: from waist to elbow height to reduce excessive bending and reaching; the workplace should be well laid out so as to reduce twisting; sit/stand workstations should be allowed where possible with good seat design so as to reduce prolonged sitting and standing; good package design such as hand holes for better coupling by the worker, package size so the worker can hold the load close to the body, and package weight so as not to exceed human capabilities. Interim changes to reduce back injuries include job placement; strength and fitness testing; strength and fitness training (work hardening), and work enrichment, enlargement, or rotation to reduce cumulative exposure. In addition to educating and training the worker, unions, and management about risk factors which cause back injury and pain, there appears to be no clear, single solution other than good initial job design. Multiple approaches such as job redesign, worker placement, and training may be the best methods for controlling back injuries and pain.
247-05-A; 247-05-B;
4213
construction
construction worker
manual labor
manufacturing
material handling
mining
transportation