Please choose the correct ending to complete the given sentence: Work World: [header] How to sit at work if you have back pain [title] Support your lower back. [step] One of the biggest causes of back pain at work is not properly supporting your lower back. It's best to have an adjustable chair with support, but if this isn't available, you can modify your desk space to make yourself more comfortable.

Ending1: [substeps] If your chair doesn't have back support, consider putting a pillow between your back and the chair to give your lower back extra support. You can also use this pillow to hold in an ice pack to help further alleviate your pain. Ending2: You can take up a chair by : [substeps] Making a habit of sitting on a table or bench less often. Chairs are made of metal and some of the most common back injuries involve bending over on the floor or tabletop while sitting. Ending3: [substeps] To try getting your back straightened, start by bending forward, taking small turns over a long period of time. As you bend over further, move your upper body leg to one side. Ending4: [substeps] If you are having back pain, which can require sitting or working at a desk, a modified chair can help offset this discomfort. [title] Try something that aches and pains only on your back.

Answer format: ending1/ending2/ending3/ending4