Place palms on the floor just outside of the feet. Step right foot back into lunge, lower hips. Step your left leg back into push-up position (top of push-up). The arms should be straight and perpendicular to the floor. Shoulders directly over the wrists, torso parallel to the floor. The feet should be on the balls. Backs of your legs and torso should form a straight line. This pose strengthens your arms. However, there is a variation of this pose, also called plank, were arms are bent at the elbows (forearms rest on the floor) and it works on abdominal muscles.