Question

Basic concept for ergonomic principles to prevent stress

Answer 1

Basic concept for ergonomic principles to prevent stress

The basic principles include following

Principle 1. Maintain Neutral Posture

Neutral postures are postures where the body is aligned and balanced while either sitting or standing, placing minimal stress on the body and keeping joints aligned.

Neutral postures minimize the stress applied to muscles, tendons, nerves and bones and allows for maximum control and force production.

The opposite of a neutral posture is an awkward posture. Awkward postures move away from the neutral posture toward the extremes in range of motion. This puts more stress on the worker’s musculoskeletal system, is a contributing risk factor for Musculoskeletal Disorders (MSDs), and should be avoided.

Principle 2. Work in the Power / Comfort Zone

The power zone for lifting is close to the body, between mid-thigh and mid-chest height. This zone is where the arms and back can lift the most with the least amount of effort.

This can also be called the hand shake zone or comfort zone. The principle here is that if can shake hands with work are minimizing excessive reach and maintaining a neutral posture.

Working from the power / comfort / handshake zone ensures that are working from proper heights and reaches, which reduces MSD risk factors and allows for more efficient and pain-free work.

Now when notice workers who are working with extended reaches and at improper heights, will know they are outside their comfort zone and risk factors are present.

Principle 3. Allow for Movement and Stretching

The musculoskeletal system is often referred to as the human body’s movement system, and it is designed to move.

Working for long periods of time in a static position will cause your body to fatigue. This is what is known as static load.

For example:

Raise your hands over your head for the next 30 minutes

Remain standing in the same position for the next 8 hours

Principle 4. Reduce Excessive Force

Excessive force is one of the primary ergonomic risk factors. Many work tasks require high force loads on the human body. Muscle effort increases in response to high force requirements which increases fatigue and risk of an MSD.

There are numerous conditions that affect force, but the idea is to recognize when a job or task requires excessive force and then find ways to reduce that force.

Principle 5. Reduce Excessive Motions

Repetitive motion is another one of the primary ergonomic risk factors. Many work tasks and cycles are repetitive in nature, and are frequently controlled by hourly or daily production targets and work processes. High task repetition, when combined with other risks factors such high force and/or awkward postures, can contribute to the formation of MSD. A job is considered highly repetitive if the cycle time is 30 seconds or less.

Excessive or unnecessary motions should be reduced if at all possible. In situations where this is not possible, it is important to eliminate excessive force requirements and awkward postures.

Principle 6. Minimize Contact Stress

According to OSHA, contact stress results from continuous contact or rubbing between hard or sharp objects/surfaces and sensitive body tissue, such as soft tissue of the fingers, palms, thighs and feet. This contact creates localized pressure for a small area of the body, which can inhibit blood, nerve function, or movement of tendons and muscles.

Examples of contact stress include

resting wrists on the sharp edge of a desk or workstation while performing tasks, pressing of tool handles into the palms, especially when they cannot be put down, tasks that require hand hammering, and sitting without adequate space for the knees.

Principle 7. Reduce Excessive Vibration

Multiple studies have shown that regular and frequent exposure to vibration can lead to permanent adverse health effects, which are most likely to occur when contact with a vibrating tool or work process is a regular and significant part of a person’s job.

Hand-arm vibration can cause a range of conditions collectively known as hand-arm vibration syndrome (HAVS), as well as specific diseases such as white finger or Raynaud’s syndrome, carpel tunnel syndrome and tendinitis. Vibration syndrome has adverse circulatory and neural effects in the fingers. The signs and symptoms include numbness, pain, and blanching (turning pale and ashen).

Principle 8. Provide Adequate Lighting

Poor lighting is a common problem in the workplace that can affect a worker’s comfort level and performance. Too much or too little light makes work difficult – just imagine trying to do the jobwithout sight.

Dimly lit work areas and glare can cause eye fatigue and headaches and improperly lit areas put workers at greater risk for all types of injuries.

Providing workers with adjustable task lighting is often a simple solution to lighting problems. At a computer workstation, take steps to control screen glare, and make sure that the monitor is not placed in front of a window or a bright background.