On any given day in my office, it is likely I’ll be seeing at least a couple of folks with low back pain (LBP). Julie was typical with her complaint, “I’m just achy all day right in the small of my back. And the pain often shoots down my buttocks toward the back of my legs. Ibuprofen will give me some minor relief but it doesn’t last long. I don’t really know what started it. It’s not like I’ve been lifting pianos or anything.”
Julie’s pain was in the category we call mechanical low back pain. This is the general term that refers to any type of back pain caused by abnormal stress and strain on the muscles and other structures of the vertebral column. In terms of its symptoms, it is generally felt as an achy or stabby pain in the low back region and is worse with bending or twisting. The severity can be anywhere from mild to excruciating and may or may not radiate down toward the knees. However, if it shoots past the knees there is likely involvement of the sciatic nerve.
Mechanical LBP is exceedingly common and remains the second most common symptom-related reason for seeing a physician in the U.S. Fully 85% of the U.S. population will experience a significant episode at some point in their lifetime.
How big of a deal is it? For individuals younger than 45 years, mechanical LBP is the most common cause of disability and for those older than 45 it is the third most common cause. Total direct and indirect costs for the treatment of LBP are estimated to be $100 billion annually. Still, in the majority of cases, LBP resolves within 2-4 weeks
So, why do we get it? First, there are certain behaviors that studies have shown put people at increased risk for mechanical LBP. These include smoking, obesity, alcohol use, lack of sleep and lack of leisure-time physical activity. Then something triggers the pain. It can be as acute and obvious as trying to lift something improperly or too heavy or as subtle as just bending or twisting wrong, or sleeping in the wrong position.
What exactly is hurting? Multiple anatomic structures and elements of the lumbar spine including the vertebral bones, ligaments, tendons, disks, nerves and muscles are all suspected to have a role. There are even recent theories that certain pain-generating biochemical compounds may set in causing ongoing pain.
Specifically, 70% of all cases of mechanical LBP are thought to be due to lumbar strain or sprain (micro tears of the lumbar ligaments and muscles), 10% are due to age-related degenerative changes in disks and facet joints, 4% are due to herniated disks, 4% are due to compression fractures from osteoporosis, and 3% are due to spinal stenosis. Other causes such as spondylolisthesis (where one vertebrae shifts with respect to the one below it) account for the remaining cases.
So what should you do if you wind up with symptoms of LBP? If it’s not severe, stretching, ice for pain relief, heat to relieve muscle spasm, and OTC pain relievers such as naproxen (Aleve) or acetaminophen may be sufficient. If it goes beyond that, a visit to your physician is appropriate, even more so if there is burning pain shooting down the legs or any weakness in the legs.
For typical mechanical LBP, x-rays are not recommended unless symptoms are persisting after four weeks or so. Physical therapy, prescription anti-inflammitants, muscle relaxants, and possibly a brief course of pain relievers are part of conservative treatment. In the long haul, core strengthening, getting rid of belly fat, and avoiding improper lifting are huge helps in decreasing future episodes of mechanical LBP.
For more persistent, severe, or unusual symptoms, MRI, other imaging, or a referral for consideration of injections and other pain-relieving modalities is appropriate. Surgical interventions for mechanical LBP are the last choice for treatment. They are chosen only when the MRI findings and the symptoms line up and reveal a fixable mechanical problem, and where the patient’s symptoms are debilitating despite conservative therapy.
Mechanical LBP is likely to show up in your life at some time. You can do some things to avoid sending it a full-out invitation, but if it shows up anyways, try some OTC treatments to get rid of it. Then if it doesn’t know when to leave you alone, bring your doctor into the picture to see if together you can send it packing.