Why does the front of my right knee really hurt , when i kneel down on floor, yet it's fine walking, and cycling.also pains when i apply pressure.?

PrePatellar Bursitis: You probably have a condition called pre-patellar bursitis. The front of your knee, over the knee cap, is a small fluid filled sac called the pre-patellar bursa. It helps the skin glide smoothly over the underlying knee cap. Sometimes, due to inflammation and sometimes trauma such as excessive kneeling, your pre-patellar becomes enlarged and irritated. This is painful. Treatment is usually with anti inflammatory meds such as advil, (ibuprofen) ice, and removing aggravating factors such as kneeling. Should resolve in a few weeks. If it doesn't see your sports medicine doc. Good luck!