Manual Materials Handling Ergonomics
Manual Materials Handling means moving or handling things by lifting, lowering, pushing, pulling, carrying, holding, or restraining. Manual Materials Handling is also the most common cause of occupational fatigue, low back pain and lower back injuries. Seizing, holding, grasping, turning, or otherwise Working with the hand or hands. Fingers are involved only to the extent that they are an extension of the hand, such as to turn a switch or to shift automobile gears. Manual Materials Handing work contributes to a large percentage of the injury/incident reports at Brock University annually. Unsafe material handling practices can result in Musculoskeletal Disorders involving sprains and strains to the lower back, shoulders and upper limbs. They can result in protracted pain, disability, medical treatment, and financial stress for those afflicted with them. Scientific evidence shows that effective ergonomic interventions can lower the physical demands of Manual Material Handling work tasks, thereby lowering the incidence and severity of the injuries they cause. Employee morale also improves when supervisors and workers use a team approach to managing hazards and take a fresh look at how best to use energy, equipment, and exertion to get a job done in the most efficient, effective, and effortless way possible.
Importance of Manual Materials Handling Ergonomics in Industry
Manual Materials Handling may expose workers to physical conditions (e.g., force, awkward postures, and repetitive motions) that can lead to injuries wasted energy, and wasted time. To avoid this problem, your organization can directly benefit from improving the fit between the demands of work tasks and the capabilities of your workers. Remember the worker’s abilities to perform work tasks may vary because of differences in age, physical condition, strength, gender, stature and other factors. In short, changing your workplace by improving the fit can benefit your workplace by:
- Reducing or preventing injuries.
- Reducing worker’s efforts by decreasing forces lifting, handling, pushing and pulling materials.
- Reducing risk factors for musculoskeletal disorders (e.g., awkward postures from reaching into containers).
- Lowering costs by reducing or elimination production bottlenecks, error rates or rejects ,use of medical services because of musculoskeletal disorders, worker’s compensation claims, excessive worker turnover, absenteeism, and retraining.
Risks/Hazards of Manual Materials Handling
Manual Material Handling tasks may expose workers to physical risk factors. If these tasks are performed repeatedly or over long periods of time, they can lead to fatigue and injury. In addition, work may also aggravate a pre-existing problem.
Repeated or continual exposure to one or more risk factors may initially lead to fatigue and discomfort. Over time, injury to the muscles, tendons, nerves, ligaments, joints and blood vessels in parts of the body may occur. Injuries of this type are known as musculoskeletal disorders, or MSDs. MSDs are commonly in the neck, back, shoulders, elbows, wrists or hands. The damaged tissue is commonly caused by wear and tear versus a single incident. People suffering with MSDs will gradually develop symptoms and worsen over time (weeks, months, or even years). MSDs are typically made worse with repeated exertions, awkward positions, and/or forceful movements.
There are two different types of risk factors associated with the development of injuries in Manual Material Handling:
- Temperature and relative humidity
- Time constraints
- Physical conditions such as obstacles and floor surfaces
- General health
- Physical factors (height, reach, flexibility, strength, weigh, aerobic capacity, etc.)
- Pre-existing musculoskeletal problems
- Psychological factors (motivation, stress, etc.)
The task or method of handling may be hazardous when it involves:
Lifting or lowering
- For extended periods of time
- While seated or kneeling
- Immediately after prolonged flexion
- Shortly after a rest period
There are some other factors we can involve in risk or hazards
- An inability to get close to a load
- Pushing or pulling
- A poor work station design
- Carrying, pulling or moving the load over large distances
- Accuracy and precision required because of fragile loads/specific unloading locations
- Materials positioned too low or too high
- Hazardous movements or postures
The best control measure is to eliminate the need for workers to perform manual material handling tasks. Since this is not possible in most situations, improvements can be made to help eliminate the risks associated with manual material handling tasks. There are two types of improvements:
- Engineering improvements
- Administrative improvements
These include rearranging, modifying, redesigning, providing or replacing tools, equipment, workstations, packaging, parts, processes, products or materials.
Observe how different workers perform the same tasks to get ideas from improving work practices or organizing the work. Then consider the following improvements:
- Reduce the number of objects a worker is to handle in a day.
- Alternate heavy tasks with light tasks.
- Provide variety in jobs to eliminate or reduce repetition (over use of the same muscle groups).
- Adjust work schedules, work pace, or work practices.
- Provide small rest breaks.
- Modify work practices so that workers can perform in their “power zone” (above knees, below shoulders, close to body).
- Rotate workers through jobs that use different muscles, body parts, or postures.
- Designate heavy loads as “team lifts”.
Administrative improvements, such as job rotation, can help reduce workers’ exposure to the risk factors by limiting the amount of time workers spend on problem jobs. However, these measures may still expose workers to risk factors that can lead to injuries. For these reasons, the most effective way to eliminate problem jobs is to change them. This can be done by putting into place the appropriate engineering improvements and modifying work practices accordingly.
Workers Guidelines for Preventing Injury
When any worker start work than they should keep in mind the following things because these things will prevent the injury. These things are as follow:
The use of stretching is appropriate as part of a comprehensive ergonomic program. Stretching must not be used in place of engineering or administrative improvements
Wear appropriate clothing and footwear
- Clothes that is comfortable around hips, knees and shoulders that do not have exposed buttons or flaps
- Non-slip, steel toed shoes with broad based low heels.
For loads that are unstable and/or heavy
- Test the load for stability and weight before carrying the load.
- Use mechanical devices or equipment whenever possible (cart, dolly, etc.).
- Reduce the weight of the load by breaking into smaller parts.
- Repack containers to increase stability.
- Get help from a co-worker if needed.
Plan the lift
- Wear appropriate shoes to avoid slips, trips, and falls.
- If you wear gloves, choose the size that fits properly.
- Lift only as much as you can safely handle by yourself.
- Keep the lifts in your power zone.
- Use extra caution when lifting loads that are unstable.
- Get a secure grip and use both hands
- Tighten your abdominal muscles which will activate your core muscles to help support the lift.
- Maintain the natural inward curve of your low back (look forward when lifting to ensure you are not bending down).
- Avoid jerking by using slow, even motions.
- Keep the load as close to your body as possible.
- To the extent feasible, use your legs to push up and lift the load, not the upper body or back.
- Do not twist your body. Step to one side or the other to turn.
- Alternate heavy lifting or forceful exertion tasks with less physically demanding ones.
- Take rest breaks.
- Keep loads close to your body with loads between knuckle and chest height.
- Slide, drag, push or pull loads instead of carrying whenever possible.
- Keep your upper body as close to upright as possible.
- Clear a path and make sure you have a clear path.
- Tag/label heavy/unstable loads.
- When loads are too heavy, break up the load into smaller parts.
- Minimize carrying distance by using wheeled dollies or carts.
- Use both hands when possible.
- When carrying load with one hand, alternate hands throughout the carry.
- Increase size of handles when possible.
- Minimize twisting.
- Alternate heavy or forceful exertion tasks with less physically demanding tasks.
- Use a footrest with prolonged standing.
- Stand with your back straight.
- Plan the route where the item must be pushed / pulled. Avoid inclinations or other obstacles.
- Push and pull with the strength of your legs. Avoid pushing/pulling with your back and arms.
- Change directions by moving your feet to turn your body, minimize twisting.
- Avoid pushing/pulling items which are too heavy, if needed; divide it into smaller loads .or get help.
- Use equipment that will decrease the amount of weight needed to be pushed / pulled.
- Watch for sudden changes in resistance. Be prepared to stop.
- Adjust the position of your hands so that you are pushing / pulling with your hands at a height that is between the waist and lower chest.
- Push rather than pull when able, pushing puts less stress on the shoulders.