This is a question that crops up a lot in our office. Here I will describe the variety of positions and their pros and cons.
This is the most common position
While in this position, most people find that their breathing is unobstructed (less snoring!) and the spine is kept neutral.
It is therefore considered one of the best positions for quality sleep.
Keep in mind that the height of the pillow and leg position is important.
A high pillow will force the neck out of alignment with the rest of your spine.
Similarly, twisting the legs over one another will force the pelvis into rotation. A pillow between the knees will help.
Sleeping on Back
This position is also comfortable and should not cause problems for the majority of people.
For people who experience neck pain it is important to remember that this position requires a low pillow to keep the cervical spine neutral.
There is also the possibility that this position can restrict air flow and result in snoring.
You may also find that a pillow under the knees (being careful not to block circulation) will help to relax muscles in the lower back.
Sleeping on your front
Although this position is the least common, I have found that in some individuals it is their favourite, especially if they are having problems getting to sleep. Perhaps this is because they were placed in this position as infants.
It is important to remeber that in this position the head is turned fully in one direction and can therefore cause neck strain in some individuals.
Also worth noting is the extension in the lower spine. This may cause problems for people who do not tolerate this movement well, especially if the matress is soft, because the weight of the body will further extend the lumbar spine. In this case, a pillow placed under the pelvis will reduce the amount of extension