An Elusive Research Subject
Mattress makers offer a dizzying array of options. There are foam and conventional coil mattresses, combinations of these, and water beds. There are firm, medium, and soft mattresses.
Researching mattresses can stump experts, precisely because so many variables are involved. Still, orthopedists may have to face questions about these selections from their patients, particularly those wondering whether a new mattress will reduce their back pain.
It might. In one study, 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.
But would any new bed be better than an old one? The researchers noted that data from previous studies comparing foam with coil mattresses and water beds are mixed. So are there specific qualities that patients should look for?
Measuring Differences Between Mattresses
James DeVocht, DC, PhD, chiropractor and biomedical engineer at the Palmer Center for Chiropractic Research in Davenport, Iowa, dove into the mattress question more than a decade ago at the request of King Koil Licensing Company (Willowbrook, Illinois), which wanted to know whether measurable differences between mattresses could be found.
Dr DeVocht and his colleagues looked at two measures of mattress quality in four mattresses. First, they examined how well the mattresses distributed weight by measuring maximum pressure distribution patterns generated by volunteers lying supine on the mattress. Then they measured the degree of spinal distortion induced when the volunteers lay in the side posture position. For testing, they put all of the mattresses on a King Koil box spring.
They found lowest maximum pressure at both the thoracic and pelvic regions in the Perfect Contour Extraordinaire Dorchester (King Koil), followed by the Posturepedic Afton Plush (Sealy; Trinity, North Carolina), then the Beautyrest Calibri Firm (Simmons; Atlanta, Georgia) and the Perfect Sleeper Southdale (Serta; Hoffman Estates, Illinois).
On the other hand, they found greater distortions in the spine at the T1/T3 region in people lying on the King Koil mattress compared with all the other mattresses. At the T6/T8 region, they found the greatest distortions in people lying on the King Koil and Sealy mattresses.
"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."
And it wasn't clear whether either factor—maximum pressure or spinal distortion—had health effects. "The real question is whether that makes a difference in your sleep quality," says Dr DeVocht.
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.
But which factors?
Medscape Orthopedics © 2016 WebMD, LLC
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: What's the Best Mattress for Back Pain? - Medscape - Jul 27, 2016.