Although back braces and lumbar support are fine to wear throughout the day, as they help you when you move and complete your everyday tasks, they should not be worn when sleeping. And the main reason is that your back could well become too used to the support, and could reduce its effectiveness during the day, when you need it the most. They are also not comfortable to sleep in and can cause you more pain and strain. Unless advised by your doctor that you need to sleep in your back brace, it is a good idea to take it off until the morning.