Association between biomechanical parameters and concussion in helmeted collisions in American football: a review of the literature.
OBJECT
The authors' goal was to better define the relationship between biomechanical parameters of a helmeted collision and the likelihood of concussion.


METHODS
The English-language literature was reviewed in search of scholarly articles describing the rotational and translational accelerations observed during all monitored impact conditions that resulted in concussion at all levels of American football.


RESULTS
High school players who suffer concussion experience an average of 93.9g of translational acceleration (TA) and 6505.2 rad/s(2) of rotational acceleration (RA). College athletes experience an average of 118.4g of TA and 5311.6 rad/s(2) of RA. While approximately 3% of collisions are associated with TAs greater than the mean TA associated with concussion, only about 0.02% of collisions actually result in a concussion. Associated variables that determine whether a player who experiences a severe collision also experiences a concussion remain hypothetical at present.


CONCLUSIONS
The ability to reliably predict the incidence of concussion based purely on biomechanical data remains elusive. This study provides novel, important information that helps to quantify the relative insignificance of biomechanical parameters in prediction of concussion risk. Further research will be necessary to better define other factors that predispose to concussion.