Spinal Traction
Treating back and neck pain with spinal traction is a practice that's been around for many years. As with many medical treatments, this method has evolved with technology, but the rationale and the effects remain the same.
The goal of spinal traction is to pull the vertebrae apart from each other. The purpose is generally to create more space for nerves where they exit the spinal column or to relieve pressure on the cartilage disks between the bones or on the small spinal joints themselves. At lower intensities, it can also be used to stretch small spinal muscles. The unproven theory is that if the disks are pulled, they will regain hydration or have an influx of water. This would then make them more shock absorbent. What we do know is how much force of pull is needed to get certain areas of the spine to separate between segments. In the cervical spine (neck) it takes about 20-30 pounds of pull to achieve separation. This is a relatively narrow range because the size and weight of the head does not vary greatly. For lumbar traction the amount of pull needed to begin separation of the vertebrae is half the body weight. This means if you weigh 180 pounds, it will take 90 pounds of pull to begin getting separation of the spinal joints and bones.
Is traction effective? The research is a little mixed. For short-term symptom relief, traction seems to be appropriate for some joint-related back and neck pain, but no better than other means of treatment like stretching or joint manipulation. For pain from a disk- or arthritis-related pinched nerve, traction can be effective for some. For patients with arm pain from a pinched nerve in their neck, there are some limitations. The research indicates that if you have had the pain for less than 60 days, and it has been confirmed with an MRI, the problem can be traced to a disk and you might benefit more from intermittent traction. This means that the pull, at least 20 pounds of force, is on for no more than 1 minute, then off, then on again.
The research is less conclusive for treating low back and leg pain. This is probably because it's very difficult to get enough force on the lumbar spine to pull it because of the challenge in holding onto the upper body and lower body while applying the force. The tendency is for the harness to either be very tight or to slip. Lumbar traction has not been shown to be any better than other treatments available for lumbar pain or sciatica.
This brings us to how traction is done. Traditionally it is classified as either manual or mechanical. Manual traction is performed by another individual, usually your medical or rehabilitation provider. Mechanical traction comes in a wide variety of strategies and devices. We will first discuss the difference between sustained and intermittent traction. Intermittent traction is traction where the force of pull is used on and off. This can be done either manually or mechanically. Sustained traction is when the force of pull is held for an extended period of time, usually no more than 30 minutes. While this can be done manually, it is usually done mechanically since the force of pull can be held steady for a longer duration of time.
On the next page, learn how traction is used in medical treatment and physical therapy.
Spinal Traction in Physical Therapy
The widest variety of traction devices are for cervical traction. They range from computerized, table-based units that cost thousands of dollars and are usually found in the offices of chiropractors or physical therapists to over-the-door units that cost no more than $20. Don’t let the cost decide for you, though.
The whole idea of traction is that you keep your body relaxed while the appropriate amount of force is applied. In the case of the over-the-door pulley systems, the resistance usually comes from a weight placed on the end of the line that connects to the head harness. Typically, this weight comes from a bag of water. Keep in mind it takes at least 20 pounds of pull, which equals about 2-1/2 gallons of water. For someone with neck or arm pain, handling the weight to get themselves into the harness can be very difficult. Other devices allow you to lie down and apply traction in other ways, including use of pneumatic harnesses (air-driven like a bicycle pump).
Lumbar traction is usually administered using a large device in a clinic. However, two similar home methods are moderately popular. One is a pneumatic version that works much the same way as the cervical version and can be done anywhere. The other is the inversion table. With this machine, you strap yourself into the leg clasps then flip over and hang upside down. One of the dangers of this is that hanging upside down often causes headaches and may cause alterations in blood pressure. It often takes several sessions to get used to using this apparatus. Clinically, lumbar traction is performed with different types of machines that range from manual control to computer controlled. Some even incorporate heat sources, electrical stimulation and music or DVD players. Regardless of the bells and whistles, the premise is the same: Pull the top half and the bottom half of the body away from each other. All systems rely on the ability to get a good hold on the body segments in order to pull with enough force (at least half the body weight) to make a difference. As with cervical traction, lumbar traction can be done in either sustained or intermittent modes.
There is no clear-cut evidence that spinal traction should be the primary treatment for any particular patient or for any certain symptoms. But cervical and upper extremity symptoms seem to show the most promise in being positively affected by intermittent traction. Traction may be an appropriate tool in the treatment of your neck or back pain or even nerve pain in the arms or legs. This should not be relied upon as your primary or sole treatment. When done in conjunction with stabilization exercises, joint manipulations, postural corrections and movement corrections, your chances of seeing improvement are much greater.