The American Medical Society for Sports Medicine released their position paper on concussion in 2010. You can find it here.
They report that the rate of concussion in sport play is 0.14-3.66 per 1000 in high school and 0.5-3.0 in college sports.
The position paper goes on to review on-field analysis, side line analysis and return to play protocol. Somewhat surprisingly, they form no new conclusions or protocols compared to what has been reported here previously.
We have discussed the use and the problems of side line scans and return to play protocols here. Sub-threshold blows to the head were discussed here. An introduction to what concussions are can be found here and here. So while it is heartening to see a powerful organization to get really look at the evidence and establish protocols based on the best understood information. It is also worrisome that there seemed, from the position paper, no immediate desire to push for a greater understanding of the metabolic and physiological consequences of concussion or to find better side line assessments or return to play protocols. Sports medicine should be primarily concerned with these elements as they will maximize prevention and playing the sport- the two things we want.