Ergonomic Risk Factors In The Workplace

Recent studies in the field of ergonomics identify both occupational and non-occupational risk factors which lead to MSDs.

This article focuses on occupational, ergonomic risk factors.

The most important factor that results in the formation of MSD is the balance between local soft tissue fatigue and the individual’s ability to recover from this fatigue. Sufficient blood supply is a critical factor in controlling local soft tissue fatigue.

If an adequate supply of blood flow is maintained to the soft tissues performing work, metabolic balance can be sustained and excessive fatigue can be prevented.

One important key to maintaining this critical balance is the relationship between work and human factors.

Ergonomic Risk Factors

Risk factors related to work activity and ergonomics can make it more difficult to maintain this balance, and increase the probability that some individuals may develop a MSD.

The major workplace ergonomic risk factors to consider are:

  • High Task Repetition
  • Forceful Exertions
  • Repetitive/Sustained Awkward Postures

1. High Task Repetition

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.

Control methods to consider:

  • Engineering Controls – Eliminating excessive force and awkward posture requirements will reduce worker fatigue and allow high repetition tasks to be performed without a significant increase in MSD risk for most workers.
  • Work Practice Controls – Providing safe & effective procedures for completing work tasks can reduce MSD risk. In addition, workers should be trained on proper work technique and encouraged to accept their responsibilities for MSD prevention.
  • Job Rotation – Job task enlargement is a way to reduce duration, frequency and severity of MSD risk factors. Workers can rotate between workstations and tasks to avoid prolonged periods of performing a single task, thereby reducing fatigue that can lead to MSD.
  • Counteractive Stretch Breaks – Implement rest or stretch breaks to provide an opportunity for increased circulation needed for recovery.

2. Forceful Exertions

Many work tasks require high force loads on the human body. Muscle effort increases in response to high force requirements, increasing associated fatigue which can lead to MSD.

Control methods to consider:

  • Engineering Controls – Eliminating excessive force requirements will reduce worker fatigue and the risk of MSD formation in most workers. Using mechanical assists, counter balance systems, adjustable height lift tables and workstations, powered equipment and ergonomic tools will reduce work effort and muscle exertions.
  • Work Practice Controls – Work process improvements such as using carts and dollies to reduce lifting and carrying demands, sliding objects instead of carrying or lifting, and eliminating any reaching obstruction to reduce the lever arm required to lift the object.
  • Proper Body Mechanics – Workers should be trained to use proper lifting and work techniques to reduce force requirements.

3. Repetitive/Sustained Awkward Postures

Awkward postures place excessive force on joints and overload the muscles and tendons around the effected joint. Joints of the body are most efficient when they operate closest to the mid-range motion of the joint. Risk of MSD is increased when joints are worked outside of this mid-range repetitively or for sustained periods of time without adequate recovery time.

Control methods to consider:

  • Engineering Controls – Eliminate or reduce awkward postures with ergonomic modifications that seek to maintain joint range of motion to accomplish work tasks within the mid-range of motion positions for vulnerable joints. Proper ergonomic tools should be utilized that allow workers to maintain optimal joint positions.
  • Work Practice Controls – Work procedures that consider and reduce awkward postures should be implemented. In addition, workers should be trained on proper work technique and encouraged to accept their responsibility to use their body properly and to avoid awkward postures whenever possible.
  • Job Rotation – Job rotation and job task enlargement is a way to reduce repeated and sustained awkward postures that can lead to MSD.
  • Counteractive Stretch Breaks – Implement rest or stretch breaks to provide an opportunity to counteract any repeated or sustained awkward postures and allow for adequate recovery time.

The Bottom Line

Systematically recognizing and controlling ergonomic risk factors is an important part of your company’s commitment to providing a safe place of work for all team members.

References:
http://www.optimaphysio.com/blog/ergonomic-risk-factors-in-the-workplace

http://ergo-plus.com/ergonomic-risk-factors/