When buying mattess, choose hard or soft?

Mattress manufacturer remind everybody must have sufficient strength and the ideal mattress can make the stress of the body parts feel soft and comfortable, the body relaxes and bed surface will not cave in, turned and effortless. Actually too hard mattress can not adapt to the need of the human body curve, can make the waist dangling above the man lay in, can't well retainer lumbar, must rely on lower back muscles to support the spine, so that the spine has been on a jiang ting tension, whole night down the spine and back muscles are not relax. Too soft mattress, people lay down the whole body will be dented, changed the human body normal spinal curve, spine bent or twisted, make relevant muscle, ligament is taut, long time not get sufficient relaxation and rest, to appear the waist sour leg pain feeling. Too hard mattress lay just head, back, hips, heels on these four points under the pressure, other parts of the body and not fully implemented, the spine is in jiang's nervous state, not to rest the spine and the effect of muscle relaxation, woke up still have the feeling of tiredness did not disappear. This mattress sleep after a long time can cause serious burden to the muscles and spinal, damage to health. In fact, can make the person feels comfortable mattress there are two main criteria: one is people no matter what kind of posture, sleep can keep the spine straight stretch; The second is the pressure equalization, man lying in the above you can fully relax.