It sounds like you may have a condition called spinal stenosis. Narrowing of the spinal canal puts pressure on the spinal cord causing characteristic low back and leg pain.
Extending the spine and walking make this problem worse. Bending forward and stopping activity seem to make it feel better. The leg pain or discomfort with walking is called intermittent claudication.
A laminectomy is the surgical removal of the lamina. The lamina is part of the bony ring of the vertebra that encircles the spinal cord. Removing the lamina can take the pressure of the spinal cord and reduce painful symptoms.
But 30 to 40 per cent of patients having a laminectomy still have back pain after the operation. Sometimes the pain goes away for a while, but then it comes back. It can be mild to severe.
Doctors think this is caused by the angle of the lumbar spine. A natural curve called lordosis usually exists in the low back area. Flattening of this curve may contribute to continued back pain. Loss of lumbar spine motion before surgery is also a predictor that residual back pain may be a problem post-operatively.
X-rays of the spine and preoperative testing of spinal motion may be helpful. The X-rays may be able to offer a clue as to whether or not you are in the group more likely to recover after decompressive laminectomy.