We lie down to sleep. We lie down to rest the back when increased pain occurs from activity. But HOW we lie down is the difference between helping our back pain or making it worse.
In previous posts, I've introduced the concept of "Neutral Spine". So what IS Neutral Spine? It is both:
The anatomical "mid point" position where the vertebrae, discs, nerves, muscles, tendons, and ligaments are in the least amount of tension or compression... the position where there is no irritation. Joints are not compressing nerves or discs, muscles/tendons/ligaments are not being over-stretches or pulled. It is a position of relief. There is no rounding, over arching, twisting, or sidebending.
From an experiential view point, it is the position where you feel the LEAST AMOUNT OF SYMPTOMS in your "bad spot". Whether it's pain or tension in the back, buttock, or numbness/tingling/tighness/cramping/etc in the legs or feet. With some people, they may be completely symptom-free in "neutral spine"... with others, it is the position where "it is as good as it gets".
Learning to position yourself in your neutral spine position EVERY TIME you lie down is important. It is one of the many new habits I'd like you to practice and adopt so that you can permanently reduce your low back pain.
Lying face up: When you want to lie face up, whether to rest for a few minutes, read a book, watch tv, or get on the computer, you must bend your knees in this position to put your spine in a neutral position. Make sure both knees are pointing to the ceiling and are the same height (if one knee is lower, slide that foot towards your body until knees are even).
If you want to lie in the position longer, or if you feel tension/pain in your back in the above position, then place pillows under your knees. Because we are all built differently, you will need to play with how many pillows and what thickness of pillow you will need under your knees to feel the least amount of your symptoms. Some people need to keep their knees quite high to relieve the pain or pressure in their back.
Lying on your side: Many people get into bad habits when lying on their side which irritate their spine - some round their backs too much, and some lie with 1 knee bent and 1 knee straight, which can twist the spine and irritates it.
The correct way to lie on your side is with both knees on top of each other. The top knee should not fall forward of the other knee. Also make sure the side of your top shoulder and the side of your top hip are facing the ceiling with your top arm along your side or place pillows under your top arm (this keeps the spine from twisting). Most people like to curl forward with the top arm with pulls the upper body forward, twisting the low back and leading to irritation
Also, you should place a pillow between your knees so that your top knee is as high as your top hip... again play with various pillow thickness to see what makes you feel your symptoms the least. A mild tension in your "problem spot" in your low back, held for a few hours when sleeping, will lead to increased pain later. So tune into the subtle signals.
And finally, many people tend to over-round their low back, which will irritate their low back, so you must train yourself to move towards more of an arch in your low back. This picture shows an over-flexed low back - a position that over-stretches the soft tissues of the lumbar spine and irritates bulging discs:
In order to get your spine to neutral, you must slightly lower your knees down and perform an anterior pelvic tilt [see previous post on pelvic tilts on how to perform] - this is basically arching. your low back. See the picture below:
Changing habits often feels overwhelming, but I promise with practice, over weeks to months, you can change your old sleeping patterns for the new ones, and you will notice decreased back pain when you wake in the morning. So try this: when you first lie down/go to bed, put yourself in the new correct position (and yes, it will feel strange for a while); when you are awake, or if you wake up slightly in the middle of the night, you will most likely have drifted back into the old pattern, so correct with new pattern again. In time, this new pattern will become your default, will feel much more comfortable and natural, and YOU WILL HAVE LESS PAIN!
Be patient and keep practicing.