I am 62 yrs old and spend a lot of time at the computer. Recently started having tightness in back of right thigh and knee and also in front of lower leg. I have a lot of pain when I walk now. How can I alleviate this problem. Back of thigh feels almost like its bruised. I had some physical therapy on knee last year with electrical impulses and ice packs. Never had the problem with the thigh before.