Sciatica: why your leg hurts when your back is the problem

You feel it down the back of your leg — maybe into the calf, maybe all the way to the foot. A sharp shoot, a dull ache, pins and needles, or a patch of numbness. The strange part? You never hurt your leg. The source is often your lower back.

This is the classic picture of sciatica, and it confuses people for an obvious reason: where you feel the pain is not where the problem is.

What sciatica actually is

The sciatic nerve is the longest nerve in the body. It forms from nerve roots in your lower spine, threads through your buttock, and branches down each leg to your foot. When one of those nerve roots gets irritated or pinched where it leaves the spine — often by a bulging (herniated) disc or by narrowing of the space the nerve passes through — the irritation travels the whole length of the nerve.

So “sciatica” is not really a diagnosis. It is a set of symptoms: pain, tingling, numbness, or weakness along the path of the sciatic nerve. The actual diagnosis is what is pressing on the nerve, and that is what we work to find.

Why it travels down your leg

Nerves conduct signals. When a nerve root in your back is compressed, your brain reads that signal as coming from wherever the nerve ends up — your buttock, your calf, your foot. Doctors call this radiating pain.

Exactly where you feel it is a useful clue. Pain low in the calf or the foot often points to a different nerve root than pain that stays in the buttock and thigh. That map is one of the first things we trace during an evaluation.

When to get help

Sciatica often starts after a strain, a long stretch of sitting, or a twist that went wrong — and it tends to build over days. Come in when the pain is limiting how you move, sleep, or get through your day.

A note worth making: some symptoms need urgent medical care rather than physical therapy. If you suddenly lose strength in your leg, can’t control your foot, feel numbness in your saddle area, or notice changes in your bowel or bladder, go to an emergency room right away. These can signal a more serious nerve problem, and they should not wait.

How we approach it

There is no single sciatica protocol, because there is no single cause. What helps a disc problem can aggravate a narrowing issue, which is why a hands-on assessment matters before any exercise program.

At your first visit we figure out what is irritating the nerve and which movements calm it versus which provoke it. Treatment usually combines gentle manual mobilization, specific movements matched to your pattern, and a progressive plan to strengthen the back and core so they take pressure off the nerve. You leave with measurable milestones — not a guess, and not a one-size-fits-all timeline, because recovery genuinely varies from person to person.

If pain down your leg is slowing you down, we can help. Learn more about how we treat lower back pain and sciatica, or book an appointment at our Floral Park or Carle Place office.