It may be related to nerve compression. The exact mechanism of lumbar spinal stenosis has not yet been clearly concluded and is mainly related to inadequate oxygen supply to the cauda equina and accumulation of metabolites. It is now thought that the symptoms of intermittent claudication may occur as a result of nerve root compression following lumbar spinal stenosis, dilated blood vessels near the spinal nerve roots during activity and increased blood flow, resulting in elevated pressure and ischaemia to the nerve roots in a confined space.