Pain that comes on when walking and eases when you lean forward is a classic pattern. Here is what causes it and what can be done.
Have you been troubled by pain in your back, or pain radiating from your back through the buttocks and down the back of the thighs, that comes on specifically after standing or walking for a while?
And have you noticed something stranger still: that leaning forward on a shopping trolley eases things, and you can suddenly walk much further?
That combination points to a condition called lumbar spinal stenosis, and the trolley detail is not a coincidence.
What lumbar spinal stenosis is
Lumbar spinal stenosis is simply narrowing of the central spinal canal in the lower back, the tunnel through which all the nerves run.
To picture it: the spine is a stack of bones called vertebrae. Each is a cylindrical block of bone with an arch attached behind it, along with the knobbly projections you can feel when you press into the middle of your back. Those arches are strapped together by ligaments known as the ligamentum flavum, and together they form the canal where the nerves travel.
How the narrowing develops
With age, wear and tear, and several other factors:
- The ligamentum flavum at the back thickens or buckles
- The disc bulges or collapses
- The facet joints thicken and encroach on the canal
Any of these can narrow the space; often they combine.
The pattern of symptoms
I usually see this in patients over the age of 60.
They develop pain in the lower back, sometimes radiating through the buttocks into the thighs. Crucially, it comes on after standing or walking for a few minutes. As the condition progresses, the walking distance before symptoms begin gets shorter.
The reason the pain reaches the legs is that the nerves being compressed in the lumbar spine are the ones supplying the leg muscles.
Some patients, though, experience only back pain. The mechanism there is not fully understood. One explanation is that the lining of the nerves has its own nerve endings, and when that lining is compressed the same phenomenon occurs.
Either way, the signature is the same: symptoms on standing and walking, relief on sitting down and resting.
Now, the shopping trolley
This is the detail patients most often bring up themselves, and it tells us a great deal.
Leaning forward on a trolley lets people walk considerably further without noticing much difference. Some say they can cycle a considerable distance quite comfortably.
The explanation is mechanical. When you bend forwards, whether over a trolley or on a bicycle, you stretch the ligamentum flavum upwards and downwards. That thins it slightly and unbuckles it, creating more space around the nerves. So the symptoms settle.
It is a useful thing to notice, because it points fairly specifically towards stenosis rather than something else.
Another cause: spondylolisthesis
Narrowing can also result from a spondylolisthesis, where one bone has slipped forward relative to the one beneath it.
This usually follows excessive wear and tear of the facet joints that keep the bones aligned. As the bone slips forward, the arch at the back of the spine comes forward with it, narrowing the canal.
My treatment protocol
Physiotherapy first. I start with a course of physiotherapy, usually with a therapist I know and trust, so I can explain the scan to them directly and they understand the strategy. They typically teach stretches designed to lengthen that ligament and thin it slightly, creating space around the nerves. It is the same principle as the shopping trolley, applied deliberately.
Injections, in my experience, are less useful here. Their effect tends to be short-lived, because the narrowing is structural and an injection does little about that mechanically.
Minimal access surgery. This is a minimally invasive procedure performed under general anaesthetic through a small incision in the lower back. Working under the microscope, we undercut the overgrown ligament and some of the overgrown facet joint to create space around the nerves.
Most of the time it takes under an hour. Patients often notice their leg symptoms relieved almost immediately on the day of surgery, and I usually have them up and walking with the physiotherapists. Many go home the very next day.
The key takeaway
Our goal is to treat the patient, not the test result. Much depends on how badly your symptoms affect you, and I will usually try conservative measures with physiotherapy before considering surgery.
But if you have noticed that you can walk further leaning on a trolley, that is worth mentioning at your next appointment. It is a genuinely useful clue.
