One of the most common ideas and tips floating around the height increase forums and boards is to increase the bed so that one will lie down at an angle, elevating the lower body, leg portion. If you put your leg at a higher position, your upper body will use the effect of gravity and your body can theoretically be stretched out.
This principle again goes back to the use of inversion tables, hanging on bars, and ankle weights. I have done posts on all of these possible ways to increase height. Gravity will indeed stretch your body out a little if the part of your body is held in place and the lower part of the body is held above the surface of the ground. The force of gravity will decompress the vertebrate and expand the intervertebral disks a little. With time, and continued use of either inversion tables, hanging on bars, and hanging upside down on bars using ankle weights will give you a very slight increase in height. During my process of increasing in height, I tried out the inversion table and hanging on a bar as well as ankle weights. My results after about 2-3 months was that I would increase in height for 0.25 inches and that will go away after only 15 minutes after standing back up again.
With raising the bed at an angle, the effects of it will be even less effective since the force of gravity is not completely applied to the body being stretched but only a fraction. From elementary high school level physics about static calculations, the force of the gravity is M*a which a= 9.81 m/s^2. When you raise the bed by an angle, say (theta), then the Force of gravity is no longer down, but pushing your body at the same angle, but by (90-theta). The force should be lowered to M*a*sin(theta) which is assuming the geometry of how the angle of force has chances is calculated correctly. Plus, you should also realize being upside down or hanging upside odwn or at angle which makes your head level be lower than your heart level will cause the blood to rush to your brain, making you feel nauseous and dizzy, and uncomfortable. If you happen to suffer from high blood pressure or some form of cardiovascular issue, doing something like trying to sleep with an elevated leg might cause certain medical issues to develop.
In conclusion, raising the bed at an gle to increase height will give extremely small negligible effects while possibly causing more serious medical problems. This technique is suggest to be not tried out unless one has made sure by medical professionals that the angle of elevation is not too great and that the person trying it out is healthy in their cardiovascular system.