Norman Marcus, MD - Exercise and Low Back Pain, Carpal Tunnel Syndrome and Nerve Conduction Velocity
“For every complex problem there is an answer that is clear, simple, and wrong.” HL Mencken
Exercise has been suggested as an important part of any treatment program for chronic non-specific low back pain (NSLBP)-the kind of low back pain that most people get, where there is no obvious reason for the pain and therefore no obvious treatment. A thorough review of the literature (a systematic review) on exercise for NSLBP, was published in October of 2011. It found that there was no or only a weak correlation with changes in disability following exercise programs and improvements in pain, mobility, strength, or endurance.
Exercise is thought to work by increasing the capacity for physical activity so you would imagine that the ability to move freely with less pain and more strength would be important targets of the exercise. This was not the case. Perhaps this is why in past reviews no exercises were ever found superior to any other. It appears that no matter what exercise you do you can improve your function. Something else beside the simple concept of decreased pain and increased flexibility must account for the improvement with exercise. To completely understand how exercise helps reduce back pain we have to look at its effect on psychological factors which include fear of movement, technically called Kinesiophobia, depression and anxiety, in addition to improvements in coordination.
Our medical care system is changing. We want to have simple streamlined answers for our medical problems. This may work with some conditions but not with persistent pain. Another study, this one of patients with Carpal Tunnel Syndrome (CTS), also illustrates the complex nature of pain. CTS occurs when a nerve in the wrist, the median nerve, is squeezed in the canal (the carpal tunnel) that leads from the forearm to the wrist and hand and causes pain, numbness, weakness and loss of muscle in the hand. The squeezing interferes with the speed of conduction of electricity in the nerve; slowing can be measured in a test called a nerve conduction velocity (NCV). Surprisingly, slowed nerve conduction did not correlate with pain intensity; but depression and catastrophizing which can be measured on a catastrophizing check list and refers to attributing too much meaning to the pain, do correlate with how much pain CTS patients experience.
These studies along with previous studies that demonstrate that multi-disciplinary pain treament is consisitently superior to treatment that only addresses a physical explanation for the pain, help us understand why we are spending so much money on pain treatments and getting mediocre results . In order to successfully understand and cost-effectively treat chronic pain, we have to spend more time and resources on psychological and emotional factors that affect pain and function, rather than have our sole focus on the latest high tech surgery, spinal cord stimulation, injections, or medications.