had a laminectomy 1 year ago due to all sensation going numb from waist down after standing/walking for 5 minutes ( spinal stenosis ). that numbness has greatly improved, but now it seems like the worst thing i can do is sit on a hard surface or ride in a cramped position in a car. when i get up feet are very "heavy" and have continued weakness in legs-especially going up stairs. any ideas for helping this.