I somehow forgeted up my right forearm doing a bear crawl during football practice last year. When I went down my forearm just started hurting like hell, I couldn't put the slightest bit of pressure on it (like pushing open a door) without getting horrid pains. Took a week before I could push something without it hurting a lot, and another for it to finally stop hurting altogether.
Holy forget that is nearly the same thing that happened to me during practice. We were doing a defensive tackling drill, 4 v 4 and had to recover the ball from the offense. I started to get up after breaking through the line and go for the ball but I twisted my elbow and it started to swell immediately, hurting after a minute or so after the drill.