There is no one or single body position that is recommended for sitting. Every worker can sit comfortably by adjusting the angles of their hips, knees, ankles and elbows. The following are general recommendations. Occasional changes beyond given ranges are acceptable and sometimes beneficial.

Keep the joints such as hips, knees and ankles open slightly (more than 90°).

Keep the wrists straight and aligned with the forearms.
Place the working object so that it can be seen at viewing angle of 10° to 30° below the line of sight .

Keep shoulders low and relaxed.
Keep elbows tucked in.
Tuck chin in and do not bend forward when looking down and forward.
Change positions frequently but remain within recommended ranges.
Alternate crossed legs.
Avoid bending to the side.
Avoid bending forward.
Do not slouch.
Do not sit for more than 50 minutes at a time.