From The Ergoweb® Learning Center

Cinching the Belts

For three weeks last summer, Vern Christensen could barely move.  He could shuffle from the kitchen to the bedroom and that was about it.  At 27, he felt three times his age, maybe older.

“If I was really careful, I could drive,” says Christensen.  “I had to kneel to brush my teeth. I couldn’t sit, I couldn’t lie down, I couldn’t stand.  It was endless pain.”
 Christensen can’t pinpoint where his injury came from — either at work or while landscaping his yard — but the fact was for three weeks, he was useless.  His job as a receiving clerk at a furniture store turned into a desk position for a while and even that hurt.  But when it was suggested that he wear a back belt before lifting again, Christensen’s answer was “no.”  He tried that before.  “They don’t work,” he says.

Christensen’s back belt theory comes from his own experience while using a back belt at a former job, but his beliefs about back belts aren’t unique.  While the tides are still ebbing away from the use of back belts for preventive measure (unless more conclusive research stating that they are effective for preventing injuries) there is still a school of thought that would argue Christensen is wrong — that in his specific reinjury situation, a back belt might help.  It’s a debate that has waged on since studies started reporting that there really was no conclusive difference in the risk of injury for a worker wearing a back belt and one who wasn’t.  As former National Institute for Occupational Safety and Health (NIOSH) employee, Dr. Richard Hughes says on the subject, “The jury is still out on primary prevention, but there is evidence that they help people who have low back symptoms.”

Hughes, now an assistant professor at the University of Michigan, has his own experience with back belts, acting as the Project Officer for a NIOSH study on back belts published in Spine last year. Hughes agrees that there is conflicting evidence on whether back belts prevent back pain.

Hughes says one reason for the ambiguity of the studies’ conclusions could be methodological flaws — none of the studies were necessarily perfect.  But Hughes does cite a 1998 study performed on airline baggage handlers that randomized workers, placed them into groups and followed them forward, that he feels could offer some additional validity.

In the study, published on December 16, 1998 in the Journal of the American Medical Association (JAMA), researchers grouped 282 subjects into four groups — a lumbar support with lifting education group, a lumbar support without education group, an education-only group, and a no intervention group. At the end of six months, the rates of injury and sick time were almost identical, leading the researcher to conclude in their study that “the use of education or lumbar supports cannot be recommended in the prevention of low back pain in industry.”

Other Options

Over 400,000 non-fatal on-the-job back injuries were recorded by U.S. Bureau of Labor in 2000 for jobs in the private sector, making back injuries the second most common type of on-the-job injury in the U.S. after strains and tears.  Statistics like these are what prompt some employers to implement policies requiring employees involved in lifting to wear back belts while on the job — hoping it might provide an extra insurance policy against back-related claims.  And hope may be all they have.

The back itself is comprised of 33 vertebrae separated by discs that act as shocks, all held together by a series of muscles and connective tissues.  All told, it creates a system that should naturally work well together.  But not all jobs require the back to do something that’s natural.

Heavy lifting, twisting, turning, repeated bending — the back doesn’t really want to work that way. According to back belt proponents, that’s why back belts exist, to compress the abdominal muscles, force proper lifting, even act as a constant reminder around the wearer’s middle.

In 1997, NIOSH published a list of answers to the theories behind the use of back belts.  According to NIOSH, none of the back-belt marketing jargon had been proven, and no evidence existed that increased intra-abdominal pressure would reduce forces on the spine or decrease the potential for back injury.  NIOSH refuted a host of other pro back belt claims as well.

In 1997, Ohio State University began a series of experiments with back belts, the first of which looked at three different types of back belts — elastic, leather and orthotic (rigid component to align spine) — and how each affected lifting.  In the initial study, the elastic belt appeared to lessen the load on the back, and only slightly.

One of the study’s authors, Ohio State University professor, Dr. William Marras, indicated in the report that while the elastic belts might offer some protection when people had their feet firmly planted on the ground prior to the lift, most work situations don’t find people lifting in that manner.  According to Marras’s study, if there is any effect caused by the elastic back belt, it is very minimal.
 In the initial study Marras’s group undertook, the subjects maintained a “planted” footing while lifting. While they noticed a decrease in spinal compression in this study, they postulated that by permitting the subjects to move around, thus mimicking a more realistic work environment, this minimal positive effect would disappear. And it did. 

Resulting Postures

While studies continually refute the claims of back belts for preventing injuries, Hughes points to one potential positive for back belts — people lift differently when wearing them.  “It’s pretty well documented,” Hughes says.  Biomechanically, a back belt alters the torso motion and that alters the lifting style.  But while change to the lifting posture might be visible, it doesn’t surface in the epidemiological data.  Although some speculate that these postural changes may result in improved lifting postures, researchers are still unable to identify a reduction in injuries.

Marras theorizes that the reason is because, as he says it, “Posture is not load.”  In other words, the postural effects may not result in reductions in spinal loading, which may be why there is no apparent reduction in injuries.

This article originally appeared in The Ergonomics Report™ on 2002-12-01.