Whenever I see a patient with back ache there is a question which invariably crops up at the end of my consultation, “Doc, which mattress should I use?” So I decided to do a little bit of research.

I used to say “use a firm mattress and not a very soft one.” In good old days, it used to be a coir base and foam on the top. However, now a days mattress makers offer a dizzying array of options. There are foam, coir, spring, cotton mattresses and combinations of these. In spite of these choices, an “ideal” mattress seems to be elusive to most of us.

There are plush stores offering expensive mattresses offering various material and density mattresses whereas our traditional “gaadiwla" has almost disappeared from the scene.

I then decided to study this topic in detail. I studied the effect of a mattress on back ache and its effect on the sleeping comfort.  Researchers from Oklahoma State University in Stillwater provided 59 apparently healthy people whose beds were at least 5 years old with new beds featuring medium-firm mattresses with foam-encased springs. After 28 nights, all of the study participants said they were experiencing less back pain and shoulder stiffness—and better sleep quality, comfort, and efficiency—on the new beds!

In another study, researchers studies how well the mattresses distributed weight by measuring maximum pressure distribution patterns generated by volunteers lying supine (flat on their back) on the mattress. Then they measured the degree of spinal distortion induced when the volunteers lay in the side posture position. "It appears that the two aims of a mattress, to exhibit low maximum pressures and little spinal distortion may be at cross purposes," the investigators concluded." Design features that minimize spinal distortion may maximize maximum pressure."

Already at that time, researchers at the University of Surrey in the United Kingdom had found no associations between maximum body contact pressures at the shoulder, elbow, hip, knee, and ankle and subjective feelings of comfort. "It seems likely that subjective ratings of mattress comfort are dependent on a wider set of factors than contact pressure alone," they concluded.

Researchers in South Korea, got closer to an answer. They measured study participants' spinal curvature and pressure on different mattresses, and then asked the subjects to evaluate the mattresses. They found that the participants preferred mattresses on which the spinal curvature when lying down was similar to their spinal curvature when standing. Koreans also looked at pressure differently, examining the range of distribution of body pressure rather than maximum pressure. Participants were more comfortable when this range was narrow. They found that when the participants slept on mattresses that were deemed "comfortable," on the basis of spinal curvature and distribution of pressure, their sleep efficiency and percentage of deep sleep were higher, and the percentages of time that they woke up after going to sleep were lower.

What about firmness of a mattress? In a survey of orthopedic surgeons, 95% believed that mattresses played a role in the management of low back pain, and 76% recommended a firm mattress. So I was right in recommending a firm mattress.

Researchers at the Biomechanics Institute of Valencia, Spain, looked at firmness as well. They found that "objective firmness"—as estimated from test load/deflection, as well as "average pressure," as measured using a mannequin—correlated positively with increments in perceived firmness. They also found that objective firmness and average pressure were associated with overall comfort and with reductions in difficulty in rolling. Finally, they found that people with a higher body mass index (obese individuals) tended to be more sensitive to changes in objective firmness.

From that finding, one might conclude the firmer the mattress, the better. Patients with medium-firm mattresses had better outcomes for pain in bed, pain on rising, and disability than the patients with firm mattresses.

Putting these findings together, it would seem that mattresses that do not distort their patients' spines, distribute weight evenly, and are medium-firm in density are good to use.

Of course, few patients can bring specialized testing equipment with them to mattress stores. So it may be hard for them to know how much their spines curve and how well their weight is distributed when they lie on a mattress.

In practical terms, we now get what is known as high density foam for a mattress. The higher the density of the foam the better it is. So choose a mattress with high density foam and then sleep on it in different positions. If you feel comfortable then go for it. If you are uncomfortable then reduce the density of the foam till you find your own comfort zone. As regards to Air and water beds I would not recommend them to healthy individuals at all.

However I am still unable to answer a question posed by one of my patients “Doc , how easy it is  to find a mattress which would be comfortable to both me and my wife?” If you know the answer to this question please help me!