Back injury

Back injuries often occur as a result in unfavourable pressures to the spine during day to day activity.

Common thoughts on back injuries conclude that these are a result of incorrect lifting methods and posture. Both of these are correct, however the precursor for these incorrect movements occurs much earlier on. The movement patterns which people adopt early in life and are hardwired thought habitual repetition, cause the development of muscle imbalances. Urbanised lifestyles most often lead to weak abdominals and hamstrings. This causes the stronger muscles which have remained strong to pull the body away from its optimal anatomical form. However people will continue to perform these repetitive actions. This results in misplaced force application within the spine, often resulting in hemerage of disks within the spinal column.

OSHA

This agency is looking at both major categories of methods for preventing lifting injuries--administrative controls and engineering controls. The former includes carefully selecting and/or training workers so they can safely perform lifting tasks. Engineering controls attempt to redesign a job so lifting becomes less hazardous.
OSHA is considering ways to help employers and employees reduce these injuries. The agency requested public comments October 2, 1986 to help it develop either guidelines or regulations for manual lifting.

Suggested administrative precautions

* Strength testing of existing workers, which one study showed can prevent up to one-third of work-related injuries by discouraging the assignment of workers to jobs that exceed their strength capabilities.
* Training employees to utilize lifting techniques that place minimum stress on the lower back.
* Physical conditioning or stretching programs to reduce the risk of muscle strain.

Suggested engineering controls

* A reduction in the size or weight of the object lifted. The parameters include maximum allowable weights for a given set of task requirements; the compactness of a package; the presence of handles, and the stability of the package being handled.

* Adjusting the height of a pallet or shelf. Lifting which occurs below knee height or above shoulder height is more strenuous than lifting between these limits. Obstructions which prevent an employee's body contact with the object being lifted also generally increase the risk of injury.

* Installation of mechanical aids such as pneumatic lifts, conveyors, and/or automated materials handling equipment.

In a recent study it was determined that up to one-third of compensable back injuries could be prevented through better job design (ergonomics).

Other factors include frequency of lifting, duration of lifting activities and type of lifting, as well as individual variables such as age, sex, body size, state of health, and general physical fitness level.

The approaches suggested include the NIOSH Work Practices Guide for Manual Lifting* employing an equation using horizontal location, vertical location, vertical travel distance and lifting frequency. Another approach puts a maximum weight limit for any single lift, or a load-moment limit which would consider the effect of the distance of the load from the worker's body. Tables of maximum weights for different percentiles of male and female workers have also been proposed.

The NIOSH (National Institute for Occupational Safety and Health) Work Practices Guide for Manual Lifting (NTIS PB 821-789-48) (Cost $17.50) is available from:

The National Technical Information Service5285 Port Royal RoadSpringfield, VA 22161

This is one of a series of fact sheets highlighting U.S. Department of Labor programs. It is intended as a general description only and does not carry the force of legal opinion.

References

* [http://www.pp.okstate.edu/ehs/training/oshaback.htm]