Could Weakness In Legs Be Related To Degenerated Neck And Back Pain?

I have recently started having a considerable weakness in my legs, usually upper thighs. I have back pain, have had a fusion of L3 and L4 in 2000 but always some usually. i also have severe neck disk degeneration and a great amount of stiffness and grinding and pain when turning my head. I have seen a dr about both of the neck and back, but the leg weakness is new. I walk about 2 miles a day. Any way do you think the leg leanness is related?