Hi, I hurt my knee when I ski last winter (I am the beginner so that I bent my knees so my ski in a v-shape as I down hill and I maintain that position for couple hours). I feel a lot of pressure and pain after that (cannot stand up). After couple months, I found myself cannot walk up stairs (very painful but walking is fine except going upstair). Later on, I put on the tiger palm on my knees and later I feel a lot of losen up inside my knees. But that cause even more problem later that I feel no strength at all on my knees (beside walking cannot walk up and down stair). Now, I hear popping sounds when I Kneel and cannot lift up my legs straight and hear some kinds of friction sounds inside the knee caps. Please tell me what could be wrong???