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General ergonomics guidelines

Musculoskeletal disorders (MSD) in the workplace are commonly caused by repetitive or awkward movements. Below are some basic tips for identifying ergonomic risks. Look for these characteristics of work that may be causing concerns in your workplace.

  Ergonomic Risks
1. Frequent bending or twisting of the back or neck.
2. Heavy, awkward or repetitive lifting, pushing or pulling.
3. Tasks requiring lifting either below the knees or above the shoulder.
4. Static postures - spending long periods without movement of a particular body part. This could include sitting, standing, bending, crouching, etc.
5. Working with arms above shoulder height, elbows away from the body, or reaching behind the body.
6. Repetitive or prolonged grasping and holding of objects, gripping with the wrist or elbow in an awkward position, or repetitive bending or twisting of the wrists or elbows.
7. Frequent exposure to whole-body or hand-arm vibration that has not been controlled.
8. Work surfaces that require elevation of the shoulders or stooping of the back for long periods.
9. Contact stress, where force is concentrated on a small area of the body.
10. Using any part of the body, especially your hand, as a hammer or mallet.
11 Inadequate or excessive light or glare.

Often, low-cost simple solutions can be used to correct these risk factors, like re-arranging storage shelves, changing the height of work surfaces, or re-organizing tasks to reduce unnecessary manual material handling. The most effective ergonomic solutions involve both the workers and supervisors. If further assistance is needed to evaluate a task or to develop a solution to a problem, contact Andrew Scheifele.

Understanding the Hazards

There are 3 main risk factors that can contribute to MSD’s in material handling tasks. They are:

Risk Factors  

Force

  • Refers to the amount of effort made by the muscles and the amount of pressure on a body part.
  • All work tasks require some level of force, however if the required force is higher than the capability of the muscle, it can damage muscles or associated tendons, ligaments, and joints.
  • Injury can occur from a single action that requires a very high level of force or more commonly, occurs due to moderate to high forces generated over long duration, and is more likely when the body is in an awkward posture.

Fixed or awkward postures

  • Is the position of the joints of the body during an activity.
  • “Neutral posture” is when the joints are working near the middle of their normal range of motion.
  • MSD injuries can occur when the joint is not in “neutral posture”, when the joint moves toward the end of the normal range of motion.
  • The more awkward the posture, the more strain on the joints, ligaments, discs (in the spine) and muscles, and the higher the risk of injury.
  • A "fixed posture" refers to staying in the same position for a long period of time, and injuries occur as the tissue fatigues while exerting effort to maintain the posture.

Repetition

  • The risk of MSD increases when the same body parts are used repeatedly with few breaks or chances for rest.
  • High repetition can lead to fatigue and microscopic tissue damage. If no recuperation of the tissues is allowed through rest or task rotation, injury can occur.
  • Rest allows specific body parts to recuperate.
  • If the posture is awkward, fatigue occurs much more quickly.

 * Combining the risk factors of force, awkward posture and repetition increases the risk of injury.

factors affecting msd

Occupational Health and Safety Council of Ontario (2007). Musculoskeletal Disorders Prevention Series part 3: MSD Prevention Toolbox - Final draft. Retrieved on February 15, 2008 from www.iapa.on.ca/documents/MSD_2006%20_Prevention_Toolbox.pdf