Lumbar spinal stenosis is a narrowing of the spinal canal that occurs with age. As the spinal canal narrows, it compresses the nerves that run through it, which can cause back pain, leg pain, and leg weakness. Spinal stenosis does not always cause symptoms. Generally, patients with spinal stenosis are comfortable if they are sitting but have more pain down their legs when they walk. Walking while leaning over a supporting object, such as a walker or shopping cart, can help ease the pain, and sitting also eases the pain.