Le narrow lumbar canal is a condition whose frequency is constantly increasing due to the aging of the population, because it is most often secondary to a degenerative disease (therefore related to age): spinal osteoarthritis.
In some cases, this narrowing of the lumbar canal remains asymptomatic. But often, it is accompanied by various highly disabling symptoms such as lower back pain, pain in the lower limbs or even sphincter disorders.
Its management is initially based on conservative methods such as (relative) rest, the prescription of certain medications or corsets to relieve symptoms, massages, certain exercises, etc. La surgery, meanwhile, will only be considered as a last resort, after confirming that the benefit/risk balance is tilted in favor of the benefits!
It is therefore important to try all conservative solutions. One of them is to losing weight. So how might losing weight help with a narrow spinal canal? Answer in this article.
What is the "lumbar canal"?
Our column vertebral (or spine) consists of 33 vertebrae stacked on top of each other:
- 7 cervical vertebrae,
- 12 dorsal or thoracic vertebrae,
- 5 lumbar vertebrae,
- 5 sacral vertebrae fused to form the sacrum,
- 4 coccygeal vertebrae also fused together to form the coccyx.
At the level of each vertebrate cervical, dorsal and lumbar is dug a hole called « vertebral foramen ». Thus, the superposition of the vertebral foramina forms the « Spinal canal » ou « spinal canal ».
It is at the level of the spinal canal that the bone marrow spinal, its various protective envelopes (dura mater, arachnoid, cerebrospinal fluid, pia mater) and other structures (nourishing blood vessels, ligaments, spinal nerve roots, etc.).
The lumbar part of the spinal canal, which is formed by the superposition of the vertebral foramina of the 5 lumbar vertebrae, is therefore called « lumbar canal ».
When do you say it is "narrow"?
Le narrow lumbar canal ou Shrunk, also called « lumbar canal stenosis », is a set of characteristic symptoms secondary to a narrowing of the spinal canal at the level of the lumbar vertebrae.
Normally, the lumbar canal in an adult has a diameter of approximately 15 mm. It is considered "narrow" when it is less than 13 mm.
However, these figures are purely indicative, since the symptomatology does not correlate very well with the degree of narrowing.
What are the causes of narrow lumbar canal?
Le narrow lumbar canal is most often acquired. It is generally secondary to phenomena of degeneration touching the bone (the vertebrae), the intervertebral discs and the facet joints (posterior joints of the vertebrae).
Among the degenerative causes of narrow spinal canal are:
- THElumbar arthritis : it is the most common cause of narrowing of the lumbar canal. It is characterized by a degeneration of the cartilage of the vertebral joints with the formation of osteophytes. The latter are bony growths that form on the inner walls of the lumbar canal, thus reducing its diameter and compressing the spinal cord.
- Le lumbar spondylolisthesis : it is the sliding of a lumbar vertebra downwards and forwards in relation to that located below. It is often due to osteoarthritis with dislocation of the posterior vertebral joints.
- La herniated disc : a protrusion of a intervertebral disc back can cause or aggravate a narrow spinal canal.
Some people have a lumbar canal of smaller diameter from birth (congenital). Most often, they won't even know it, because they won't develop any symptoms (no cord compression, or compression that isn't significant).
However, they are more likely to develop a symptomatic narrow spinal canal in case of lumbar osteoarthritis, spondylolisthesis or herniated disc.
What are the symptoms of narrow spinal canal?
The type and degree of severity of symptoms depends on several factors, including the extent of narrowing of the spinal canal and the nature of the compressed (or irritated) structures.
Here are some of narrow spinal canal symptoms:
- Lower back pain,
- Typical pain sciatica ou cruralgia,
- Intermittent claudication (pain in the lower limbs with limping),
- Loss of sensitivity in the perineal region,
- Sphincter disorders (urinary and/or faecal incontinence),
- erectile dysfunction,
- Motor and/or sensory disorders in the lower limbs (numbness, tingling in the legs, cramps, flaccid paralysis, etc.).
In many cases, the narrow lumbar canal does not cause no symptom. The diagnosis is then made fortuitous.
For more details on the symptoms, see our full article on the narrow lumbar canal.
How is a narrow spinal canal treated?
The management of the narrow lumbar canal appeals to many conservative treatments :
- Analgesics: from the simplest to the most powerful depending on the degree and type of pain,
- Nonsteroidal anti-inflammatory drugs,
- Relative rest: limit movements that trigger or worsen symptoms, but always stay active,
- Lumbar corset: to limit lumbar hyperlordosis (long-term wear not recommended),
- Massage: at a physiotherapist or osteopath to relieve muscle tension and reduce pain,
- Occupational therapy: adapt the environment and learn the right gestures to limit the constraints on the spine.
- Natural treatments: acupuncture, plants… This type of treatment can help manage the different symptoms.
In the event of failure of all conservative treatments, severe stenosis from the outset or rapid worsening of the stricture, a supported surgical will prevail.
What is the link between low back pain and overweight?
Whether seated or standing, our spine permanently supports the weight of the upper half of our body: the head, the neck, the upper limbs and the entire trunk. This weight is normally distributed over the various structures of the spine in a harmonious way, in particular thanks to the conformation of the latter in "S".
Le Lumbar spine, being located in the lower back, is the part of the spine that experiences the most stress. A overweight therefore generates more stress on the lumbar vertebrae and this clinically results in low back pain.
Le link between low back pain and obesity is now clearly established by various scientific studies. However, the mechanisms behind this association remain to be determined.
Indeed, scientific studies have shown that low back pain is much more common in obese subjects. They also found that weight loss, medically supervised, relieved many types of musculoskeletal pain in these people and significantly improved their quality of life.
But questions remain unanswered: by what mechanisms are these improvements obtained? What is the relationship between weight loss, changes in body composition and structural and functional abnormalities observed in subjects with obesity and low back pain? Studies are still underway to try to answer them.
Narrow lumbar canal: losing weight to relieve symptoms?
In theory, the weight loss may have a positive effect on narrow spinal canal symptoms through the following mechanisms:
- Reduced stress on the lumbar intervertebral discs, thus preventing the development or aggravation of a herniated disc.
- Reduced stress on the posterior vertebral (facet) joints, thus preventing the aggravation of lumbar vertebral osteoarthritis.
- Facilitation of spinal movements.
Even if the results differ from one person to another (depending on the severity of the narrowing, the cause, the terrain…) and are not guaranteed, it would be a shame not to try to lose a few pounds and then reassess their symptoms.
It is not always easy to lose weight when you suffer from a narrow spinal canal. The pain and other symptoms it generates sometimes discourage any physical activity.
However, it is important to ensure that you maintain a certain degree of daily activity to lose weight, or at least stabilize your weight and avoid joint stiffness.
In addition to physical activity, it is recommended to adopt a balanced and varied diet. the anti-inflammatory diet is particularly valuable in this context, as it helps provide the body with all the nutrients it needs while reducing inflammation throughout the body. It therefore allows weight loss and a reduction in pain of inflammatory origin.
 R. Pittier, C. Schizas, G. Kulik, S. Genevay, and H. RHU, “Narrow lumbar canal”.
[2 S. Genevay, P. Chevallier-Ruggeri, and A. Faundez, “Narrow lumbar canal: clinic, physiopathology and treatment. », Swiss medical journal, No 332, p. 585, 2012.
 YP Charles and J.-P. Steib, "Diagnosis and treatment of narrow lumbar canal", Therapeutic medicine, flight. 23, no 3, p. 136-144, 2017.
 MH Boukili, “MANAGEMENT OF THE NARROW LUMBAR CANAL”.
 F. Doury-Panchout and B. Fouquet, “Obesity, weight loss and low back pain”, Journal of Rheumatism Monographs, flight. 83, no 1, p. 50‑55, Feb. 2016, doi: 10.1016/j.monrhu.2015.09.004.