Back Pain Radiating Down the Leg (Sciatica): Causes, Red Flags, and How Physiotherapy Helps

Pain that starts in the lower back and shoots into the buttock, thigh, or down to the calf and foot — sometimes with numbness or tingling — is commonly called "sciatica": pain along the path of the sciatic nerve.

The good news is that many people improve without surgery when they are assessed properly and keep moving in the right way. This article explains the common causes, the warning signs that need a doctor straight away, and what physiotherapy can do.

• A bulging or herniated disc pressing on or irritating a nerve root in the lower back

• Spinal stenosis (narrowing of the spinal canal), more common from middle age, often worse with long walks or standing

• Tight or irritated deep hip muscles, which can cause buttock pain radiating down the leg without coming directly from the spine

• Long periods of sitting, poor lifting technique, or repeated bending and twisting are common triggers

• Loss of bladder or bowel control, or being unable to pass urine

• Numbness around the buttocks, groin or genitals (saddle area)

• Leg weakness that is getting worse, such as foot drop

• Pain with fever, unexplained weight loss, a history of cancer, or after a major accident

These can signal conditions that need urgent treatment — do not wait for physiotherapy.

International guidelines such as the UK's NICE guideline recommend that people with low back pain and sciatica are encouraged to stay active, with exercise as a core part of treatment, and manual therapy considered alongside exercise [1].

At the clinic, your physiotherapist will:

• Work out whether the pain comes from a nerve root, a joint or muscle, and test strength, sensation and reflexes

• Find positions or movement directions that reduce the radiating pain, and teach you to use them at home

• Use hands-on treatment and pain-relief equipment so you can move more

• Gradually build strength in the back, hips and core to lower the chance of it coming back

• Avoid long bed rest — gentle movement within comfort helps you recover faster

• Change position every 30–45 minutes if you have to sit for long

• Avoid lifting heavy objects while twisting

• Notice whether the pain is "retreating" towards the back (a good sign) or "spreading" further down the leg (get advice soon)