Please choose the correct ending to complete the given sentence: Health: [header] How to treat spinal stenosis [title] Do back stretches to keep your back flexible and relaxed. [step] Lie down on your back and pull your knees to your chest. You should feel a stretch in your lower back.

Ending1: Hold it for a few seconds before lowering to the floor. [substeps] Do 5 to 10 repetitions of this exercise every morning for fifteen to twenty minutes before bed. Ending2: If possible, do these stretches while sitting. Rather than standing in a chair, sit on a set of yoga cushions or directly on a mat. Ending3: As you relax, notice how the muscles in your back really work, especially the ones that are " flat. " in order to stop tension from running into the ligaments and you can also think about making a note of which muscles feel tense and which ones feel looser. Ending4: Stay in this position for 30 seconds and then slowly release your knees. Perform this stretch 4-6 times, once a day.

Answer format: ending1/ending2/ending3/ending4