Can a back or nerve problem make my knee give way?

How a nerve can make the knee buckle

The quadriceps, the muscle that holds the knee straight when you stand, is powered by the femoral nerve, which comes from nerve roots in the lower back. If a disc bulge or narrowing in the spine presses on those roots, or the nerve is irritated further down, the muscle receives a weaker signal. The knee then folds under load, even though the joint itself may be healthy.

This is less common than knee causes, but it is important not to miss, because treating the knee will not fix it.

Clues it may be a nerve

• Numbness, tingling or burning on the front of the thigh or inner shin
• Back pain, or pain that runs from the buttock or groin down the leg
• The knee buckles without pain, swelling or a twist
• The thigh looks thinner, or you struggle with stairs even though the knee does not hurt
• Weakness in other movements, such as lifting the foot or the hip
• Diabetes, which can affect the nerves to the thigh

Red flags: seek urgent care

• Weakness that is getting worse over days
• Numbness around the groin or buttocks
• New difficulty controlling the bladder or bowel
• Weakness in both legs

These can mean significant nerve compression and need emergency assessment.

Working out which it is in Doha

At Aman Hospital, Dr. Gelber examines the knee for ligament, meniscus and kneecap problems and also checks reflexes, sensation and muscle power. If the knee is sound and the findings suggest a nerve cause, he will advise an assessment with a spine or nerve specialist, with tests such as a spine MRI or nerve conduction studies.

Sometimes both exist together, for example arthritis in the knee and a narrowed spine in an older adult, and the plan addresses each.