Hello. So two weeks ago I was at acrobatics. I did a back handspring but saw someone walking close to me so I did it sideways going off the mat. I winded up landing on the inside of my left forearm instead of normally landing on two hands. I banged it against concrete floor. It was really painful at first and was red for the entire night. I still had dance classes later that night, so I did not do anything to my arm. It was tingling and the muscle or nerve hurt when I straightened it. The next day, I woke up with a bruise forming there but the weird thin was that there was a bruise on the outside of my elbow on the top. It hurt to lift things up. It also hurt when I had to type in school. My pinky and ring finger would have sharp pain. The bruise went through its process and took about a week and a half to fully heal. Most of the pain went away but for certain things, it still hurts with a pain. The bruise is now gone but I felt the spot where I had the bruise on my inside forearm, and it is still sore when you touch it. I also noticed like a small hard lump under my skin exactly where the bruise was. What is this lump that is there?