I have pain in my knee when kneeling. It began about 5 weeks ago, as I was kneeling and stretching forward at the same time to reach something on the floor. I thought I was kneeling on a pin it was such a sharp pain, but after searching the floor I found that there was nothing on the floor. My knee does not hurt while walking, or going up or down stairs, only when kneeling or flexing my leg past 90 degrees, then I get the sharp pain again. It sometimes feels numb. The pain is below the kneecap and to the outside of my right leg. Could this be what is referred to as housemaid s knee or could it be something more serious. I am a 55 year old woman in good health, and only weigh 137 lbs.