In a recent study conducted in The Spine Journal, researchers revealed that low rate loading of intervertebral discs showed improved nutritional delivery.
Over the years, spine researchers have been investigating what sort of forces are optimal for the intervertebral discs of the spine. Throughout time, anti-gravity forces, like traction or decompression, has garnered support because of the findings of disc compression with x-ray, CT and MRI.
Traction had its place in history and is still used by some. Traction (or distraction) is a constant pull in an anti-gravity direction of the spine. Throughout the 1970’s gravity boots were quite popular as well as traction devices for the treatment of disc disorders. As we began to learn more, we found that the constant unloading force didn’t fix many spinal conditions. It did relieve symptoms during the procedure, but it wasn’t long lasting relief, often symptoms returning soon after the traction was released.
Intermittent traction came onto the scene in the 1980s whereby they began trying to not pull as long and utilize a strategy of intermittent unloading. Intermittent traction was at the frequency of 3, 4, 5 and even 7 minutes at a time. Interestingly, some conditions did seem to respond better at these shorter loading forces but it still did not have the outcomes they had hoped. In the 1990s, we also found out that prolonged lying down did not work so well as an unloading force as bed rest was and is considered not the best strategy for back pain.
What we are currently understanding is the intervertebral discs respond best to low rate loading as was revealed in this recent study. What these researchers looked was how the discs improve their nutritional absorption through a low rate loading force of .5Hz. This rate is one force every two seconds which can be seen here as an example. They compared this to unloading (which is similar to bed rest) and found that low rate loading is superior.
As a chiropractor, I have always looked to try to emulate the healing forces the spine experiences naturally in the body. Each disc has the natural forces of blood pressure around it as well as the frequency forces of the breath. Low rate forces to the spine have incredible promise in regenerating discs with manual chiropractic treatment. The rate these researchers investigated is closer to the natural forces that a disc experiences in the body. I find this fascinating because a study I conducted in 2010 , in the same journal, used low rate unloading forces that demonstrated disc height gains. I hope to continue to contribute to the greater understanding of optimal forces for spinal discs in the treatment of our patients.