question: For about a week now I have been feeling something almost like a pulse or muscle spasm in my left knee, right above the knee cap. It comes about every 5-10 minutes and only lasts for a second or two. At times it feels like a balloon inflating and deflating. I have never had any problems with my legs before so it has been freaking me out that it may be something serious. I am overweight right now, but I am consistently losing weight through diet and exercise. Please help me figure out what is going on. Thanks!