This position is know alternately as an isometric crab. In it you keep, or attempt to keep, your torso, pelvis, and thighs parallel to the ground. Relax your head back so you don't overwork the muscles in the front of your neck. Keeping elbows straight but not locked with finger tips pointed toward your bum. This position opens the front of your chest while strengthening your triceps, glues, and hamstrings.