What Causes Pulsation Sensation On Leg Below Knee ?

Hi, i have had a pulsation sensation in the lower part of my right leg just below my knee and above my shin for about 4 weeks now. Also i have a dull ache in the leg. This seems to start from the bottom of my back and go all down my leg. I got out of bed this morning and the leg felt very tender and my foot felt a little stiff as if i had been exercising. Also i have the pulsating feeling too this morning but its not there all the time. it seems to pulsate at random times.i have also noticed that sometimes but not very often i get a warm sensation in the leg close to where it pusates. Sometimes my leg feels a little numb as if i have bad circulation. Have you any idea what this could be.