Correct seating posture is an essential ingredient to preventing spinal injury and fatigue.
The basic features of a good chair are:
• height adjustable
• pelvic tilt on seat
• lumbar support
Adjust the height of your chair such that your knees are level or just below hip height and that your feet are flat on the floor.
If your seat has a pelvic tilt, this should be set to a slight forward incline to promote a natural inward lower back curve.
Move the lumbar support so that it fits snuggly into the curve of your lower back. This will help to prevent lumbar strain and helps to maintain a straight spine and neck whilst seated.
Never sit with your legs crossed! Crossing at the ankles is a preferable alternative.