By Eveline Erni, P.T.

In our first article on bedroom activities (hope you didn't miss that one), we included a short but very important statement on spinal alignment: "Your spine is made up of three curves. You can feel them as a hollow area at the back of your neck, lower back and a slight roundness of the upper back." This also applies to your sleeping position.

For sleeping you must accommodate the natural curves of your back. Specifically, do not push the head forward or decrease the hollow in your lower back. Other common sleeping habits which lead to problems are putting your elbows above shoulder level (e.g., sleeping with your arm placed under your head), placing the hand under the head (reduces blood flow to the hands), and curling the fists inward as if in a fetal position (this is especially bad for individuals with carpal tunnel syndrome because it decreases blood flow and puts strain on the carpal tunnel nerve).

So how do we maintain neutral spinal alignment in our various sleeping positions? Here are the dos and don'ts:

1. On your stomach: Don't even think of sleeping on your stomach. It is impossible to maintain neutral alignment through your neck in this position. Consider training yourself to sleep another way.

2. On your back: This is a good choice, but remember to accommodate the curve in your neck. Keep only a small amount of pillow under your head (to avoid pushing your head excessively forward). The hollow in your neck is where you need the most support. You can either take a large pillow and bunch it appropriately (more under your neck and less under the head) or use an additional small, soft pillow or rolled towel for the neck.

3. On your side: Remember, the rule is to maintain the spine in neutral alignment. This is when pillows become important. All three of them. Pillow #1 should be placed under your head to lift it to a position centered on your shoulders (be sure to put more pillow under the neck than the head, so that the neck is fully supported). Pillow #2 should be hugged with your arm to decrease the strain on your shoulder, upper back and neck muscles. Finally, pillow #3 should be placed between the knees to decrease the strain on the hip and low-back muscles.