Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to do a back handstand [title] Stretch your wrists and ankles. [step] Flexibility in these joints is crucial for your back handstand. You can do these stretches every day, and always do them before practicing your handstand.

Ending1: [substeps] Have a friend stretch your wrists, ankles, and legs. Get other friends to stretch your wrists, ankles, and feet as well. Ending2: Make sure that your wrists are not stiff to the point of tearing. [title] Get into position for the handstand. Ending3: [substeps] To stretch your wrists, sit on the floor and place your palm flat on the ground at a 90-degree angle to your arms. Gently bend your elbows and feel the stretch through your inner wrist. Ending4: [substeps] Your wrists should be in the area that has most of the impact. Your knees should be bent at a 90 degree angle, and your feet should be about shoulder width apart.

Answer format: ending1/ending2/ending3/ending4