|Photo Courtesy RSNA|
The largest medical conference in the world, held by the Radiological Society of North America (RSNA), is happening in Chicago this week. A small study presented on Monday, looking at the effects sitting has on the spine, has caused quite a media blitz around the country. Unfortunately for the public, media outlets reporting on the study misunderstand its purpose and significance.
I interviewed Dr. Francis Smith, co-author, to find out why a small study like this one (22 subjects) created such big fuss. While he couldn't answer to the media blitz, he did clarify for me exactly what he did, why he did it and what this may mean for the future of back pain medicine.
The purpose of the study was to use a new kind of MRI, called the Positional, or Upright MRI to repeat one done back in 1953. The 1953 study used x-rays to look at the impact sitting has on the spine. Both studies took pictures of the spine in several sitting positions. The 2006 study was looking for the optimal point of balance for the intervertebral disk during the action of sitting.
The information gleaned from these studies is significant because so many of us spend the better part of our lives at the computer and performing other sedentary activities. The studies are also useful because certain positions of the spine (and therefore the intervertebral disk) held long-term often precede degenerative disk disease. However, none of the people in the study actually had back pain.
The study provided updated measurements on causes of strain in the spine for those who sit for long periods of time.
The results of the study were less about how straight your spine is positioned and more about the relationship between the hip joint and the knee. If your hip is higher than your knee when you sit, this will approximate the 135 degrees the news reports mention, and is a good thing for your spine. To accomplish a hip higher than knee position, Dr. Smith recommends sitting on a gym ball instead of an office chair. You can also place a folded towel or other wedge under your sitting bones to elevate your pelvis. (See the picture above.)
In an age where 80% of back pain goes undiagnosed, this study is significant in yet another way. For back pain medicine, the Positional MRI represents advancement in technology that can enable doctors to pinpoint causes of back pain more often.
Along with his research, Dr. Smith routinely uses the Positional MRI to diagnose back pain in patients at the hospital at the University of Aberdeen in Scotland. According to Dr. Smith, the Positional MRI detects 34% more lesions in patients with back pain than does the older type of MRI, in which patients are lying down for the test. "The Positional MRI is a superb tool for looking at the spine and understanding why people get back pain," Dr. Smith told About.com.
MRIs have been around since 1980. Positional MRI's entered the market in 2002.
This small study reported at the RSNA conference is just Phase 1. According to Dr. Smith, the next step is to use the Positional MRI to look at 20-30 people who actually do have back pain.