Hello,  I am a 38 yr old male w/ lumbar spinal stenosis, both foraminal and central canal areas at L5-S1,L4-L5, and L3-L4.  I am very active and would obviosly like to stay that way.  I did get a minimally invasive hemi laminectomy at all levels noted on 2/08.  I am just starting to get pain now after ~ 3 yrs.  My question...  If things progress is my only option fusion and if so can you still be fairly active after getting a fusion?
Vertebral column is built to provide you with a great deal of flexibility. When you bend, the movement is divided into bits amongst all those bones. Now say supposing three of the bones are fused (which incidentally may occur as a part of many diseases), the division of that motion is divided in less number of bones. So yes, the mobility will get restricted. However I think day to day activities should be largely unaffected.