Musculoskeletal disorders (MSDs) are the result of jobs which are poorly designed and require stressful repetitive movements of the hand, wrist, shoulder or back. Through the use of ergonomics, the science of fitting the job to the worker, musculoskeletal disorders can be prevented.
MSDs occur over a period of time, and are the result of repeated injury or
damage to the soft tissues inside the body. Soft tissues which become injured are the tendons, ligaments, muscles and nerves. Some early signs of these disorders are pain, soreness, tingling, redness, burning feeling, swelling and stiffness, and numbness in the hand, particularly at night.
What Types of Workplace Stressors and Hazards to Look For
The workplace stressors and hazards on the job that can cause MSDs are called risk factors. The risk factors that cause MSDs at work are:
Most line jobs in meatpacking, poultry and food processing plants require workers to do the same motions thousands of times a day. In a poultry plant, this can mean one worker making as many as 15,000 cuts every day, at lines speeds that can go up to 90 birds a minute.
Awkward or Stressful Body Postures
Body postures include reaching, pulling, pushing, twisting the body, stooping over or bending to the side, bending or twisting the wrist, and using a pinch grip.
Working in meatpacking, poultry and food processing plants requires a lot of strength. Holding a knife, scissors or other tool increases the forcefulness. Other factors contributing to the use of force include dull blades, slippery handles, and cutting on frozen or hard meat or product.
Infrequent or No Breaks
Breaks provide the body with a little rest from workplace stressors. Working overtime, or six to seven days a week, provides little recovery time from the damage to the soft tissues.
Other risk factors related to MSDs include vibrating tools, working in the cold, high production speeds, and short staffing.
Methods for Reducing the Risk of Developing MSDs
Through the use of ergonomics, jobs can be changed or redesigned. Awkward and stressful body postures which place so much stress on the body can be reduced or eliminated. Other risk factors such as force and repetition can also be reduced.
Through the development of an ergonomics program, in which workers, their union, and management are fully involved, a step-by-step approach can be taken to identify and correct the problems on the job as follows:
Find the High Risk Jobs: Ask yourself, “Where are people getting hurt the most?” Use the OSHA 300 Log, nurses’ logs, or results of surveys and job checklists to find high risk jobs.
Job Analysis: Look at what makes these jobs dangerous. Before high risk jobs can be changed, they must be analyzed for risk factors. Many jobs in meatpacking, poultry or food processing have multiple risk factors.
Hazard Prevention and Control: Fix the parts of the job that are causing people to get hurt. Examples of controls include:
- Providing platforms for workers to stand on, which are adjustable for individual heights;
- Using new knife designs that reduce the amount of stress when in use;
- Maintaining a schedule for sharpening knives, scissors and saw blades;
- Allowing longer training periods or breaking in time for new workers on jobs which require repetitive motion; and
- Lowering or raising conveyors to a comfortable worker level.
In chicken processing plants, automation—an ergonomic control—has helped eliminate many problem jobs for workers. For example, a leaf fat remover replaces workers who had to use a forceful pinch grip hundreds of times a day to pull the leaf fat.
Training and Education: Train all workers on the early symptoms of MSDs, the risk factors that cause MSDs and the company’s ergonomics programs.
Medical Management: Companies need to make sure that workers are encouraged to report early symptoms of MSDs, and receive early and adequate medical treatment.