Sit or Stand?

[EddieK]

I’m a third year Industrial Engineering Student and over the summer I worked in a Manufacturing facility. One of the “rules” in the plant was that employees were not allowed to sit down on the job. I’ve just started an Ergonomics class at school and wondered if the no-sitting-rule is common practice in industry. If so, is it because productivity goes down when people are sitting; or is there some other reason?

Just curious…

[jclark]

The no-sitting-rule is not a common rule in industry. It may be in certain environments because workers view sit down jobs as being easier. So this may have been the practice in your facility in order to keep the peace amongst the hourly workers. Ideally, the decision to have workers sit or stand should be based solely on the nature of the process.

Standing is more flexible to change and is preferred if a worker is assigned to operate multiple machines in a work cell or if the worker has to walk during each cycle. If the process is best performed while standing the work station should be designed such that bending and stooping are avoided. If workers will spend the majority of their time standing, anti-fatigue mats should be implemented.

If the work can be performed in one small area (i.e. a workbench or table), the seated method may be preferred. If the seated method is deemed appropriate, it is important to ensure that the working area is at the optimal height. This height should promote the neutral position for the operator. Also, sitting in one place can result in cramping. Try to build periodic large muscle movement in to the job. This can be done by assigning the operator to restock their own parts.

In summary, there is no cut-and-dry rule to having an operator sit or stand. The decision should be based on the process design. Once the decision is made, customize the work station to provide the operator with the most comfortable working conditions.

[rwilcox]

I've often felt (especially noticeable when I was in Army basic training) that standing can be MORE tiring than walking. Are there guidelines for mixing the two (may be better than all one or all the other) or for designing a workstation or process so standing is not for too long?

[Rohit Trivedi]

An ideal work place design involves operator moves to maximize productivity and minimize the extra moves, especially the "WALK". Walk is considered to be a non-value added activity.

However, as you have correctly pointed out, standing for a continuous period of time results in fatigue. A sound industrial engineering practice should take into consideration this factor while designing the work area. Any repetitive continuous activity increases fatigue and therefore decreases productivity.

It is better to have a mix of movements. For eg. an operator standing and working at a station has to move few steps to walk and get the tools from tool-board/tool-rack needed to accomplish his/her task.

[abhijit]

One major problem may result due to prolong standing is

Insufficient Blood Return in the Legs

Gravity pulls blood down into your feet. One way that blood is pushed back up to your heart is through cyclic muscle contractions, often called a "muscle pump". If the muscles are engaged in one long contraction to keep you standing, they cannot produce a muscle pump and return blood properly to your heart. Continuous muscle contractions also hinder circulation of body fluids.