2/05/2015

Sitting or Standing Operator Workplace?

In the design of the workplace, the position of the operator must be considered. Should the operator work from a sitting position, standing position or a combined sitting and standing position? 

Sitting is physiologically most favorable position at work and should be used whenever the nature of the work allows. When sitting, a human spends only about 5% more energy than when lying quietly. What the static muscle strain will be while sitting depends largely on the design of the chair and its connection to the workplace. Sitting, if the body is supported ideally, consumes 20% less energy than standing when doing the same job. The pressure on the spine in a sitting bent position is up to 50% less than in the upright standing. 
Workers position in workplace
Workers position in workplace
When sitting the energy consumption is reduced, and the legs are free of load. Sitting gives stability to the upper body and less strain on the cardiovascular system. According to research, people tend to sit: 
  • At the front of the chair seat 15%.
  • In the middle of the chair seat 52%.
  • On the back of the chair seat 33%.
  • Leaned back in the chair 42%, and
  • Hands resting on the table 40%.

Problems arising when sitting are the following: 
  • deviation of the spine,
  • weakening of the abdominal muscles – so-called "sitting stomach", and
  • bad effect on digestive organs.

For comfortable sitting not only the characteristics of the seat and backrest are important, but also the other factors such as feelings, relief, comfort and relaxation of the body, as well as fatigue, biomechanical conditions, stress and blood circulation. According to De Looze, Kujit-Evers and Van Dieën J. theoretical model of comfort and discomfort and its underlying factors at the human, seat and context level. 
Worker position diagram
Worker position diagram 
Where prolonged sitting at work is required, the following measures should be taken: 

1. Adopt a good sitting position by learning how to adjust the workstation to fit individual needs for specific tasks. 
2. Select a chair with: 
  • controls that are easy to operate from sitting position
  • a seat that adjusts for both height and tilt
  • a seat that does not put pressure the back of thighs or knees
  • a backrest that is shaped to support the lower back and does not give way
  • a front edge curved downwards
  • non-slip, breathable fabric on the seat
  • a stable five-point base
  • a minimum seat width of 40 cm
  • arm rests where practical, that do not interfere with free movements within the workstation
3. Adjust the chair’s height to 25-35 cm below the work surface. 
4. Introduce five minutes of exercise, such as walking for every 40 to 50 minutes of sitting. 

Standing is one of the basic positions of the body. Standing workplace is defined as the workplace at which the task is done in a relatively static standing position at one workplace. In a standing position, the body is held upright with the help of large muscles of the lower extremities and trunk. When standing with the help of the upper extremities the burden can be carried, with the movements of lower torso and legs used to enable the force to move these loads. In order to perform work tasks certain movements of the whole body must be performed, such as bending, turning and moving the trunk, reaching up and aside, while the legs remain in a relatively stable position. 

Standing, in contrast to sitting, includes the static strain of major muscle groups, so that the energy consumption is by about 10-15% higher than at rest in a lying position. But standing is a very productive position for people with regard to the fact that energy consumption and normal standing on two legs hardly require any effort. Moderately hard and difficult task should be performed while standing, because the body must use large force. In applying large forces the body uses large muscles that are found on the shoulders, back and thighs. 

A person's body is affected by the arrangement of the work area and by the tasks that he or she does while standing. The layout of the workstation, the tools, and the placement of keys, controls and displays that the worker needs to operate or observe will determine, and as rule, limit the body positions that the worker can assume while standing. As a result, the worker has fewer body positions to choose from, and the positions themselves are more rigid. This gives the worker less freedom to move around and to rest working muscles. 

Different body positions during working
Different body positions during working
The basic principles of good job design for standing work are: 
  • Change working positions frequently so that working in one position is of a reasonably short duration.
  • Avoid extreme bending, stretching and twisting.
  • Pace work appropriately.
  • Allow workers suitable rest periods to relax; exercises may also help.
  • Provide instruction on proper work practices and the use of rest breaks.

Continuous standing or sitting while working is a common source of discomfort and fatigue. Frequent changes of body positions, including alternating between sitting and standing, help to avoid fatigue. It is therefore desirable to have both standing and sitting arrangement for any work task. Whenever possible, a worker should be able to work sitting or standing at will. 

References 
  1. Colovic G (2010). Management of technology systems in the garment industry, Woodhead Publishing Ltd.
  2. Colovic G (2014). Ergonomics in the garment industry, Woodhead Publishing Limited Ltd.
  3. De Looze MP, Kujit-Evers LFM and Van Dieën J (2003), 'Sitting comfort and discomfort and the relationships with objective measures', Ergonomics, 46 (10): 985- 997.
  4. Ergonomie an Näharbeitsplätzen (2009), Berufsgenossenschaft Energie Textil Elektro, Köln
  5. European Agency for Health and Safety at Work (Available at www.europe.osha)
  6. Health and Safety Executive (Available at www.hse.gov.uk/index.htm)
  7. National Institute of Occupational Safety and Health (Available at www.cdc.gov/niosh/homepage.html)


Read more: http://textiletribune.blogspot.com/2015/02/sitting-or-standing-operator-workplace.html


2 comments:

  1. This is one of the most significant information.
    And i’m glad reading your article.
    The site style is wonderful, the article is really excellent.
    I am sending it to some
    buddies ans also sharing in delicious.For more amazing information You may get from this link prolonged sitting

    ReplyDelete
  2. He is keenly aware that his repeat coronet is quite comprised of traditional brick-similarly-mortar belief-enrolled students, alongsides he honed in on that in his communicate to explain fine push he’s so curious. spassway.de

    ReplyDelete