PART 1 of 4: Inadequate back strength: the main reason for chronic back pain
From my experience over the years, inadequate back strength is a main reason that patients develop chronic debilitating back pain. There are four main reasons most people have not developed an optimal amount of back strength: 1) the main stabilizing muscles of the spine become weakened with age—particularly in patients with chronic pain who voluntarily or involuntarily shut down their back muscles, 2) with standard core exercises it is difficult to control the resistance through the entire range of motion and to sequentially apply a measurable, heavier resistance, 3) many people lead sedentary lifestyles and/ or have spine-weakening bad posture, both of which can lead to permanent problems, and 4) it takes hard work to build muscle.
Let’s discuss the first of these four reasons:
1) the main stabilizing muscles of the spine become weakened
There is a very significant difference that needs to be taken into account when strengthening the core spinal muscles versus other muscles in the body. The core muscular system is divided into two components: a local system with deep, stout muscles that run between each vertebrae and act to stabilize them, and a second system with superficial, longer muscles that span many different vertebrae, allowing them to propel the spine and generate motion of the entire body.
The shorter muscles, such as the multifidus, act to stabilize vertebrae. These are selectively weakened in patients with back pain and with age. The longer muscles act to move the whole spine. When strengthening a painful spine, it is important to isolate the stabilizing muscle to prevent the longer muscles from doing all of the work.
In several studies, authors used computer and physical models of the cervical spine to show that activating only the superficial, long muscles resulted in instability, especially with respect to upright posture. (references 1,2) They also concluded that activation of deep muscles was necessary for spinal stability. Without this active muscular system supporting the spine, the passive joints themselves (which include the disc and the smaller facet joints) would crumble under the weight of just five to 10 pounds. So this active muscular system and its neural control system are critical to spinal health.
How do these systems work together in practice? Imagine your spine as a crane or heavy earth-moving machine. When this machine has to move a heavy item from one area to another, it must first attach itself with extending footholds so that its base is stable before it can extend the arm of the crane in order to pull up a weight. This is similar to the system in your spine, where you need the smaller muscles to be active and working well to hold together the individual vertebrae. The longer muscles can then adequately propel the body forward or help lift an item off the floor. Here is a way to gauge the strength of your stabilizing muscles: If you notice when you bend that you cannot bend fully, or if you experience a “hitch” that requires you to bend your hips or knees to complete the bend, you likely have a stability problem in your spine due to weakness of these stabilizing muscles.
People who need to improve their stability may also develop periodic spasms or find it difficult to sit or stand for longer periods of time. I have found that patients sometimes develop hip, knee, or shoulder pain in their attempt to compensate for the core weakness. Fortunately, all of these symptoms point to a deficit in stability that can be resolved through appropriate targeted strengthening. As you age, however, these stability muscles can selectively weaken. They can also become weakened when you experience pain because you may consciously or unconsciously try to avoid using them. In any case, we can expect these deep stability muscles in our back to serve us well for bending and moving over a lifetime only if we ensure they stay strong.
The other key muscles are the muscles around the abdomen, such as the oblique abdominal muscles and the transversus abdominis. These muscles act as a corset that helps to support the spine. Weight lifters use abdominal braces to prevent injury, and they are often prescribed for patients with back pain. Although I agree with the use of braces for weight lifters or for those whose jobs involve heavy lifting, these braces also weaken the key abdominal muscles and are not recommended for regular use.
You may ask, “Well, what about the six-pack abdominal muscles (also called the rectus abdominis)? I thought those were key.” Although I would still recommend strengthening these “mirror muscles”— so called because they, like the pectoral muscles in the chest and biceps in the arms, are the muscles people can see—ironically they are the least important in stabilizing the spine!
Sometimes We Need Sustained, Supervised “Medical Exercise”
Many years ago, my mentor in non-operative treatment, Dr. Vert Mooney, believed that as spine surgeons we needed to be much more involved with non-operative care in general and therapeutic exercise in particular. He was a believer in not only high intensity training, but inclusion of exercise in medical treatment similar to how we dose medication that we prescribe and measure its effect. He introduced me to the work of Arthur Jones and Med-X medical exercise equipment. This equipment isolates the back muscles, allows strengthening throughout the range of motion, and is the most scientifically studied. We have had experience using this and other machines in our SpineZone clinics for over 12 years.
An important difference between Arthur Jones and his predecessors (as well as others who currently treat back pain through strengthening) is that Jones developed ways to isolate the spinal muscles and strengthen the stabilizing muscles by safely ratcheting up the stress on the muscle. The key to this isolation is to immobilize the pelvis while doing back strengthening. If the pelvis is free to move, the spinal muscles don’t have to contract to extend the spine.
Even though some standard core exercises can be helpful in maintaining back strength, in back pain patients, this isolation is much better accomplished through the use of medical grade machine-based stabilization exercises. There have been multiple peer-reviewed research studies showing the enlargement of the deep stabilizing muscles of the spine with these machines. We have submitted the research findings (on patients at our SpineZone clinics) on the response of the muscle to isolated, high intensity machine-based exercise for presentation at an international meeting.
1. Daru, K. R. 1989. “Computer simulation and static analysis of the human head, neck and upper torso.” Arizona State University.
2. Winters J. M. and J. D. Peles. 1990. “Neck muscle activity and 3-D head kinematics during quasi-static and dynamic tracking movements.” In Multiple Muscle Systems: Biomechanics and Movement Organization, edited by Woo, S. L.-Y. and J. M. Winters, New York: Springer-Verlad.