Many people who have low back pain say their legs feel weak. If weakness is related to back pain, you will be able to make your leg muscles work, even though it may hurt.

True leg weakness is defined as decreased leg strength that is unrelated to pain. Weakness that occurs in only one leg may be caused by a structural defect, such as a herniated disc.

True leg weakness that comes on suddenly and affects both legs is a medical emergency, and you should see a doctor right away.

Call your doctor if you have leg weakness, especially if you are unable to bend your foot upward, get up out of a chair, or climb stairs.