I Have Been Experiencing Burning/numbness In My Front Thighs When

I have been experiencing burning/numbness in my front thighs when I am standing around. For example I visited the Washington DC area a few weeks ago. I was fine walking 6 to 10 miles a day but when we stopped to look at museum exhibits the front of my legs were "on fire" so I sat and tried to adjust my back to ease it. I have 3 bulging disks in my neck for 10 years causing hand and lower arm numbness and have discovered Pilates motions to relieve the symptoms but don't know where to apply stretches - or something to address the burn of standing for more that 5 minutes or so.