By Dr. R. Greg Lusk, DC
Spine flexion, or bending forward of the spine, has been the main movement or function discussed in the articles I've written to date, and rightly so as it is the dominant activity that produces and perpetuates low back pain. However, it's counterpart, spine extension, which often plays a relieving role for most cases of low back pain, can be a source of aggravation in others. Specifically, in a low back with prominent osteoarthritis (OA), which is the general term for degenerative disc and/or joint disease, the structural changes can result in disc space narrowing between our vertebrae, the development of bone spurs, and/or the thickening (i.e. hypertrophy) of the bony sides of the joints (facets) or other soft tissues (e.g. ligamentum flavum). Collectively, these changes can narrow the hole(s) between the vertebrae (foramen) where our spinal nerves exit and even compress the nerve(s) as it passes through the opening. Back extension exaggerates this narrowing (i.e. stenosis) further and can lead to low back and leg pain, numbness, weakness, and a reduced ability to stand or walk. Medically, this is referred to as neurogenic claudication or degenerative lumbar spinal stenosis (DLSS).
Now, since low back OA is incredibly common, particularly with increasing age, it is important to realize that this doesn't mean that back extension is bad for everyone with OA. Remember that disc bulges are in fact part of low back OA and can irritate nerves that travel down the legs, but that they often respond well to back extension exercises while being aggravated by spine flexion. This highlights the need for case by case management with investigation of the patient's symptoms and then confirmation via assessment. With respect to a patient with DLSS, it is often reported that low back or leg symptoms are aggravated with either standing or walking, but alleviated with sitting or bending forward. It may even be noted that walking while pushing a shopping cart or riding a bike, which flex the lumbar spine and open up the spaces where the nerves exit the spine, are comfortable. Assessment of ranges of motion and nerve tension in the legs are components of an examination that could then be done to increase confidence in the diagnosis of DLSS.
For patients with severe symptoms, surgery may be an option where bone and ligaments around the stenosis are removed to decompress the nerve. However, for those with mild to moderate symptoms related to DLSS there have been encouraging results published when participants completed a 6 week spine mobility boot camp. The multimodal program included manual therapies to improve mobility in the low back and hips, numerous daily exercises that promote spine flexion, and education with respect to body repositioning for symptom relief. Self-rated disability, leg pain intensity, and improved walking tolerance were improved upon completion of the program and persisted for 3.5 years. Exercises examples include lying on your back and pulling either one or both knees to your chest, pulling one knee to the chest and then leaning it across the body toward the opposite hip, seated toe touching, and riding of a stationary bike. Walking with a posterior pelvic tilt, where you rotate your pelvis to tuck your tailbone and/or raise the area where a belt buckle would rest, which opens up the lumbar joints, is an example of body repositioning during activity. Timing your baseline walking duration prior to symptom onset, and then re-checking after performing these sorts of things for a number of weeks would allow you to monitor your progress and assess the value of your effort.
This article is for general information purposes only and is not to be taken as professional medical advice.