Relax the shoulders and keep parallel to hips. Feet should be shoulder distance apart. Shift your weight often, but avoid leaning on either hip. When sitting, the lower back supports the entire upper body weight. Choose firmer, higher chairs rather than lower, softer ones.
Place hips as far back in the chair as possible.
Knees should be level with hips or slightly lower. Shoulders should be erect, do not lean forward. Sitting cross-legged may be comfortable for many people, just remember to lean on a wall or chair. It is important to use a firm, supporting surface when Iying down. Avoid Iying on your stomach.