Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to do better pushups [title] Position your arms correctly. [step] No matter your push-up style, start by placing your hands shoulder width apart. Stack your joints for the best stability.

Ending1: Raise up to the highest possible height using only the balls of your feet, balancing each arm on a flat surface. [substeps] Avoid placing your hands higher than your hips by placing them behind you as widely as possible. Ending2: Position your torso so that your heels are parallel but slightly bent over the outside of your feet, or you may be rocking a bit more than they should be. As you do so, get into a squatting position. Ending3: Place your palms on your restive wall or a wall. [substeps] In order to put up the challenge, you'll want to increase your body's non-restive ability. Ending4: Your hands should line up under your elbows and your elbows should be underneath your shoulders. [substeps] Stacking your joints helps to prevent damaged rotator cuffs and other injuries.

Answer format: ending1/ending2/ending3/ending4