Suggest Treatment For Feeling Of Pulsation In Knee

I am getting a pulse kind of feeling in my left knee, near thigh. Like a vibration. I have had some muscle atrophy for some time now. Am doing some PT as of a week or so ago. Walk a good bit in water and so forth. But I cannot get out of a chair without help from my arms. It s almost like a passage way has en opened or something. I wear a knee brace for stability even though I know it won t keep me from falling. It s a mental thing.