Spinal Stenosis: What Is It and Why Does It Cause Pain When You Walk?
Spinal stenosis is a narrowing of the spaces inside your spine. This puts pressure on the nerves that run through it. It most often affects the lower back or neck. Its main sign is pain, heaviness or cramping in the legs that gets worse when you walk and eases when you sit down or lean forwards.
Key points
- Spinal stenosis means the canal or openings in the spine have become too narrow for the nerves passing through them.
- The most common cause in adults is normal wear and tear of the joints and discs over time.
- Symptoms often depend on posture. Standing and walking tend to make them worse. Sitting or bending forwards eases them.
- Standing, weight-bearing imaging can show how your spine behaves under load. Scans taken lying down can miss this.
- ScanAlign provides diagnostic imaging only, not treatment. Your results help guide the right next step with your specialist.
You may have been told you have spinal stenosis. Or you may notice leg pain that eases when you sit. This page explains what is happening inside your spine, and how whole-body standing imaging can add to the picture.
What is spinal stenosis?
Spinal stenosis is a slow narrowing of the spinal canal, the bony tunnel that protects your spinal cord and the nerves branching off it. When that space gets smaller, the nerves get squeezed. This can happen in the central canal, in the smaller side tunnels (called foramina) where single nerves exit, or in both.
The condition is most common in the lumbar spine (lower back). There it tends to affect the nerves that run down into your legs. It can also happen in the cervical spine (neck), where it may affect the arms or hands. Some people have narrowing in more than one area at the same time.
What are the symptoms of spinal stenosis?
Symptoms depend on which part of the spine is affected and how much the nerves are pressed. Many people with mild narrowing on a scan have no symptoms at all. When symptoms do appear, they tend to follow a pattern you can recognise.
An aching, heavy or cramping feeling in one or both legs when you walk or stand. This is often called neurogenic claudication.
Symptoms ease quickly when you sit down, lean on a shopping trolley, or bend forwards. This opens up the spinal canal slightly.
Pins and needles, numbness, or a feeling of weakness in the legs (lumbar) or hands and arms (cervical).
Over months or years, the distance you can walk comfortably may slowly get shorter.
When to seek urgent help
If you develop sudden numbness in the groin area, difficulty controlling your bladder or bowels, or leg weakness that is quickly getting worse, contact your doctor or go to the nearest emergency department straight away. These symptoms may point to a rare but serious condition called cauda equina syndrome, which needs immediate medical attention.
What causes spinal stenosis?
The most common cause is wear and tear that comes with age, sometimes called degenerative change. As the spine ages, several structures can thicken or bulge inwards. This reduces the space left for the nerves.
Discs lose water and may bulge into the canal.
New bone growth at the joints can push into the canal or foramina.
The ligamentum flavum, which lines the canal, can thicken and fold inwards.
The facet joints at the back of each vertebra can enlarge with arthritis.
Less often, stenosis can come from a spondylolisthesis (where one vertebra slips forward on the one below) or from a naturally narrow canal that a person is born with. When the spine loses its normal alignment, the narrowing can get worse under load. That is why posture and overall spinal balance matter.
How does standing imaging help assess spinal stenosis?
Standing, weight-bearing imaging shows your spine the way it really works, under the pull of gravity and the load of your body weight. This matters for stenosis because the narrowing often changes with your position.
When you lie down for a standard MRI or CT scan, your muscles relax and the load comes off the spine. Disc bulges may shrink slightly, and the canal can look a little wider than it really is in daily life. Standing up reverses this. Gravity presses on the discs, the ligaments fold differently, and any slippage between vertebrae may increase. In other words, the very position that triggers your symptoms is the one that lying-down imaging does not capture.
An EOS scan captures your full skeleton from head to feet in a single standing image, using about 90% less radiation than a standard X-ray, around ten times less. This whole-body view also shows how other areas of the spine and pelvis may be compensating for the stenosis. Your body is a connected chain. A narrowed segment in the lower back can change the way you stand. This shifts load to your hips, knees or the other side of the spine.
EOS imaging does not replace MRI. It adds a different layer of information, showing bony alignment and balance in real-life conditions. Together, the two give your specialist a much clearer picture than either one alone.
Wondering whether a standing alignment scan in London could add to the scans you already have? We offer a free video consultation to talk it through.
Book a free video consultationA note about MRI. EOS imaging is excellent at showing bones, joints and overall spinal alignment. For soft tissue detail, such as discs, nerves and the ligaments inside the canal, MRI is usually the better tool. Many people with spinal stenosis benefit from both types of imaging, as each answers a different question.
What helps manage spinal stenosis?
Management depends on how severe the narrowing is and how much it affects your daily life. ScanAlign is a diagnostic imaging clinic, not a treatment provider. So the detail below is general background, not a recommendation.
- Staying active. Gentle exercise, especially activities where the spine is slightly bent forwards (like cycling or swimming), often helps keep you mobile and manage symptoms.
- Physiotherapy. A physiotherapist can guide exercises that strengthen the core and improve flexibility without irritating the nerves.
- Pain management. Your doctor or a pain specialist may suggest medicines or injections to help control symptoms while you stay active.
- Surgical options. When symptoms are severe or getting worse despite other approaches, a spinal surgeon may discuss a decompression procedure. Detailed alignment data from standing imaging can help with planning surgery.
Whatever path is right for you, accurate diagnostic imaging is the starting point. Knowing exactly where the narrowing is, how your spine is balanced, and whether other areas are compensating helps your clinical team make better decisions.
So before you start a treatment, or change the one you are on, it is worth getting a detailed diagnosis. Whether the cause sits in the pelvis, the legs or the spine changes what will actually help.
Frequently asked questions about spinal stenosis
It can range from mild (no symptoms at all) to severe (great difficulty walking). Most cases progress slowly over years. In rare cases involving cauda equina syndrome, it becomes a medical emergency that needs urgent attention.
The narrowing itself does not reverse. But symptoms can improve with the right exercise, physiotherapy and pain management. Many people manage well for years without surgery.
Lumbar stenosis affects the lower back and usually causes leg symptoms. Cervical stenosis affects the neck and can cause symptoms in the arms or hands. In severe cases it can affect balance and coordination.
Standing and walking extend the spine slightly. This can narrow the canal further and press on the nerves. Sitting or bending forwards opens the canal a little, which relieves the pressure. This pattern is very typical of lumbar stenosis.
They show different things. MRI shows soft tissues like discs and ligaments inside the canal. A standing EOS scan shows how the whole spine is aligned under load, whether a vertebra has slipped, and how the rest of the body is compensating. The two work together. They do not compete.
Yes. EOS uses about 90% less radiation than a standard X-ray, around ten times less. You can read more about safety and what to expect on our FAQs page.
No. ScanAlign is a private, self-pay clinic. You can refer yourself directly. We recommend starting with a free video consultation so we can check that the scan is suitable for your situation.
The price for patients travelling from abroad is confirmed during the free video consultation. You can also visit our FAQs page.
Indirectly, yes. When stenosis limits how your lower back moves, your hips and knees may take on extra load or move differently to compensate. This is one reason a whole-body alignment view is so valuable.
You stand comfortably inside the EOS scanner at our clinic at 19 Harley Street, London. The scan takes about 20 seconds and captures your full skeleton in one image. There is no closed tunnel and no need to lie down. A specialist radiographer supervises the whole process.
See your spine the way it really stands
A free video consultation with our team, from wherever you are, will help you understand whether standing alignment imaging is the right next step for your spinal stenosis.
Book a free video consultationWant to learn more about how whole-body standing imaging works? Visit our EOS scan overview page, or read our spine imaging guide.
Sources
- NHS. Spinal stenosis. nhs.uk. Available at: https://www.nhs.uk/conditions/spinal-stenosis/
- Lurie J, Tomkins-Lane C. Management of lumbar spinal stenosis. BMJ. 2016;352:h6234.
- Illés T, Somoskeöy S. The EOS imaging system and its uses in daily orthopaedic practice. International Orthopaedics. 2012;36(7):1405-1411.
Written by Abbas Dhami (Specialist Diagnostic Radiographer)
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.