<s>[INST] I tripped and hit my knee (with a good amount of force) yesterday. It hurt really bad at first and when I tried to stand up my knee didn t want straighten so I laid on the floor a little longer until the pain eased up some. Today it is really bothering me. It is painful to bend or straighten my leg. Walking is difficult as well. The pain in directly on my knee cap and below. I have pins and needle feeling going down my leg. What do you think I could have done to my knee? [/INST] Hi, Kindly apply a pressure bandage at the site of injury. Go to the ER of a hospital. You will possibly need x rays of the affected part. Final treatment will be decided thereafter. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Nirmal Chander Gupta, Orthopaedic Surgeon </s>