Previously we discussed factors of the back sleeping. There are advantages of sleeping in the back position. Pressure is more evenly distributed over a larger surface compared to the side position. In the side position the body profile is more pronounced. There is a greater varience in your side profile vs. the back profile. In addition when you sleep on your side you put pressure into your two major joint complexes, the shoulders and hips. Your major blood vessels and nerves run through those joints and pressure builds quickly, causing discomfort that requires a position change as you sleep.
Most people are primarily side sleepers and because of pressure they change position on average 50-70 times a night. If a mattress conforms to the body profile, it will even out the pressure and thus can greatly reduce the frequency of movement.
Why are most of us side sleepers? It really is a matter of anatomy. The major movements that our bodies make are do to muscles that are paired, one pushes, while the other pulls. When the movement is at one end the other the muscle that is responsible for that motion is tight or strained, if you are in the middle of that motion range, both muscles are in a relaxed state. For example, the bicep muscle pulls and the tricep muscle pushes. When the elbow is bent it in is the middle of that motion and both the bicep and tricep can be relaxed. The same is true with the quadracep and hamstring muscles, when the knee is bent they both are relaxed. This bent knee and bent elbow can not be achieved naturally on your back, only when you turn to your side can you be in the “neutral position”.
Scientists performed studies of astronauts in space. They slept floating in “zero gravity” in space and they assumed that “neutral position”. It is also the same position that fetuses assume, and is often referred to as the “fetal position”. This position can not be acheived naturally on our back.
If the mattress conforms to the body profile whether you are on your back or side, your spine will be supported in a more natural alignment. The shoulders and hips should be allowed to drop, while the lumbar is lifted and supported, thus reducing the torque in the thorasic and lumabar vertebrae.
This conforming again is best acheived by utilization of “pocketed coils” and foams with elastic properties like “memory foam” or latex.