Please choose the correct ending to complete the given sentence: Health: [header] How to recover from an injured shoulder [title] Perform isometric exercises. [step] Begin your active rehabilitation with three isometric exercises (contractions that don't cause any motion). [substeps] The first exercise is done while facing a wall with your injured shoulder in-line with your upper body and your elbow bent at a 90-degree angle.

Ending1: The second exercise is done while standing facing a wall, but it is different from the first exercise in that it is not involved in any muscle contraction. While you are standing, move out and sit in a chair so your upper body is facing your wall. Ending2: Hold a contraction for 3 seconds without moving your arm. As you breathe out, hold the contraction for 4 seconds until your elbow pads (also known as " netherers ") realign. Ending3: Move up to the wall until your fist is in contact and then slowly apply pressure by pushing your first into the wall. The second exercise starts with you in the same body alignment as the first exercise, but instead, contact the wall with your elbow through to your hand. Ending4: Point your wrist at the wall and release your elbow while bending your elbow while keeping the elbow toward the wall. The second exercise is done while facing a wall with your injured shoulder in-line with your upper body and your elbow bent at a 90-degree angle against the wall.

Answer format: ending1/ending2/ending3/ending4