The position of pelvis should be in the line of shooting. Hips are forward towards the target. If the pelvis is turned aside, unequal pressure on the feet occurs and the back muscles are tense which disturbs the stability of the position and concentration of the shooter because of the movement of the rifle and the muscles get tired quicker.
Body
The body is tilted rearward, all bending occurs above the waist. This should locate the rifle above the center of the support area and provide stability to the position. The purpose of assuming this position is to put the center of gravity of the rifle closer to the medium line of the body, which decreases the tension of the muscles caused by holding the rifle. The back is bent rearward and the body pointed to the right to allow the maximum involvement of the sinews and ligaments, the transfer of the center of gravity of the shooter-rifle system to the spine, and, thus, considerably release the muscles that provide the stability of the body in the area of the waist and hips.