Office Ergonomics or The Lack of It : Part I
A large number of people who seek medical help for their musculoskeletal problems usually present with neck, shoulder and back pains. These clients are often deskbound at work. With the increase use of computers, it is no wonder the incidence of spinal pains is on the rise.
The repetitive stress associated with our work environment can be minimized with an understanding of the flaws of mass produced furniture; combined with a little effort and common sense in altering and re-organizing our work station. Below are some of the office complaints regarding ergonomics most office workers express.
Ergonomic Complaint 1: Shoulder Muscles
When I work at the desk, my shoulder muscles become tight and achy. I have a huge knot in my shoulder muscles. Get a sore neck at the end of the day.
Most tables and work benches are made far too tall for our Asian build as the parts to the furniture are cut to anglo-saxon fit. Most table heights are between 75cm to 80cm high, where 69 cm is more appropriate for Asians. This means that for the majority in Singapore, people are working with their arms elevated and stretched forward, leading to an overuse and constant activation of their Upper Trapezius and Levator Scapulae.
These two muscles are designed to be movers – to raise the shoulders or to pull the head back to the centre. They perform poorly when tasked for activities that require muscle endurance like elevating the arm up constantly as demanded by the current work station design.
The result is the development of trigger points and tightness in these muscles, consequently increasing the compression in the cervical spine leading to pain.
Ergonomic Complaint 2: Posture
I have been told to sit into the back of the chair to improve my posture at work, but as much as I try, I always end up sitting on the edge of the seat. It just feels more comfortable.
Most chairs used by office workers are regular non-ergonomic chairs. Similar to the issue above, the office chairs are designed very poorly for the Asian population. This is unless it is an ergonomically designed chair.
Firstly, seat depth. The median thigh length of a Hong Kong Chinese male is 550mm. That of a British caucasian male is 595mm. The difference between the two ethnic groups is significant. Unless the depth of mass-produced chairs are made adjustable, there will be many for whom the chairs do not fit.
In Singapore, chair ergonomics are poor. Most chairs are too deep. One should be able to sit all the way into the back of the chair and have a gap of 2-3 inches between the edge of the seat pan and the back of one’s knees.
Failing this, the user will sit forward and away from the back rest. This will result in the loss of the lumbar support and promoting slouch sitting.
If the user maintains sitting into the back of an oversized chair, he or she will have to work with out-stretched arms. This will eventually lead to an overuse in the muscles around the shoulders.
Secondly, fixed arm rest. One of the common issues with arm rest is that most are not adjustable. Arm rests often get in the way when the user draws the chair closer towards the work station. This limits how close the user can get to table without losing her back support. To counter this, the user either stretches out his/her arm. This causes a flexion in the upper thoracic spine, and consequently a forward head posture or move away from the back support. If purchasing an ergonomic chair is out of the question, and the current arm rests are not adjustable, is it better to not have it?
In our opinion, we feel it is better to discard the arm rests and draw the chair in close. At the same time, have the arms rested on the table.
Lastly, feet support. Ideally, the table top should be at the same level as the elbows. To achieve this, more often than not, the height of the chair will have to be raised. Tables are already made too high, and Singaporeans being generally petite. The combination of raising the height of the chair of a chair that is already too deep results in the feet not being fully supported. The lack of support forces the abdominals work. As it is uncomfortable, the user will naturally slide forward. If the chair does not have a foot rest, a stool must therefore be used.
Continue in Part II