Two general types of adjustable bed frame models exist: manually adjustable beds and automatically adjustable beds. Manual frames must be manipulated by hand to create the right height, length, and width. Automatic adjustable beds will generally feature a remote control the user can press in order to raise, lower, or otherwise alter the shape of the frame and mattress. The best adjustable bed frame for you will generally depend on your overall needs as well as your budget for purchasing a unit. The automatic bed will be far more expensive than manually adjustable units.
The least expensive adjustable bed frame is likely to be made from inexpensive steel parts that fit carefully together. Each part will have a series of notches and tongues that work together to adjust the overall size of the frame. You can, for example, configure the adjustable bed frame to accommodate a twin size mattress, or you can expand it outward to accommodate a full or twin size mattress. The legs of the frame may also be adjustable, though frames that feature adjustable legs may be a bit more expensive. If the legs do not adjust, it is possible to buy bed risers that can be placed underneath the legs or casters to raise the frame higher off the ground.
The most expensive option for an adjustable bed frame will be an automatic adjustment frame. Such bed frames may be integrated with a special type of mattress that can bend in places a normal mattress will not bend. This allows the user to create a custom shape for optimal sleeping comfort. It may be possible, for example, to raise the back of the bed so the sleeper's head is above the rest of his body, or to raise the other end of the bed so the legs are raised up higher. The firmness of the mattress can even be adjusted on some of these types of beds.
Regardless of the type of adjustable bed frame you choose, make sure you purchase the unit from a reputable dealer, and if you are choosing an automatic bed, choose a unit made from a well-known and reputable manufacturer that offers some sort of warranty against manufacturer defects. This will protect your purchase should the unit be faulty. Be sure to take note of any return policies offered by the retailer, especially on larger, more expensive units. Smaller steel frames are generally fairly reliable, though they are generally not very attractive.