Sitting at a desk working with computers for extended periods of time is not a comfortable or suitable position for the body. Our bodies appreciate movement, not static postures, and sitting is known to be particularly stressful on the structures of the low back. Such postures challenge the body’s ability to adapt and can lead to problems ranging from headaches and back pain to repetitive strain injuries.
Postural awareness and ergonomic desktop setup, which reduce the physical stress of desk work, contribute to improved efficiency and a reduction in the incidence of work related injury. The common sense guidelines for posture include:
- Encourage frequent change in position
- Avoid forward inclination of head/trunk
- Avoid causing upper limbs to be held raised
- Avoid twisting and asymmetrical postures
- Avoid postures that overuse joints at their limit
- Provide adequate back support
Ergonomic Desktop Setup
In setting up a work space, a number of elements need to be considered including the structure of the chair, the height of the desk and the position of the screen, keyboard and mouse, as detailed in the image below. The chair must have back support and be adjustable.
- Sit at the back of the chair so that your back is in contact with the back support and hips and knees are flexed to 90 degrees. Make sure you can fit a fist between the front of the seat and the back of your knee to avoid compressing into your knee crease.
- Make sure that the lumbar support of the chair fits into your lumbar area. Use the adjustments!
- Position chair at a 90 – 95 degree angle with the back rest firm to provide support, allowing for transfer of some weight into the back support.
- Most desk heights are fixed – so the chair needs to adjust to the desk height as well as your height. The ideal chair height allows for the upper arm to be relaxed next to the body while the elbow is flexed to 90 degrees with the forearm and hands supported comfortably on the desk and keyboard. Your thighs will be resting against the under surface of the desk, in the desk kneehole.
- Your feet should be positioned flat on the ground and shoulder width apart. A foot rest may be necessary depending on your height.
- Make sure that the arm rests do not interfere with the position of the chair at the desk. It may be advisable to choose a chair with removable arms.
- The mouse and keyboard should be kept close to in to the body to reduce tension in the shoulder from reaching forward or outwards.
- The hand and fingers should be relaxed on the mouse. Your hand should be taken off the mouse when you are not using it. Use a mouse mat for better contact. Avoid squeezing the mouse or pushing the wrist into extension while using the mouse.
- When using the keyboard, keep your wrists in a neutral position. Don’t rest your wrists on the desk while typing as this extends the wrists. Use all fingers and move the hand and forearm to get
- the keys out of reach rather than stretching the fingers. Hit the keys lightly and take your hands off the keyboard when you are not using it.
- The screen height should be at or just below eye level, straight in front of the operator at approximately arms length. Avoid glare and uneven light, and the light source should be sideways to screen.
It may be helpful to use a document holder and headset. Laptop use should be minimized as it is difficult to be properly aligned when the keyboard and the screen are co-joined. If it is necessary to use a laptop for extended periods of time, a docking station and/or separate keyboard should be considered.
But most importantly, take breaks as often as you can but at least every hour. A discussion of stretches to be performed at breaks will be available soon.