Hello,
Weekends are sometimes slower for replies, feel free to read some of the other posts here as they might have similar ideas, tips & suggestions.

anytime there is an upper body hit of some sort the c1 / c2 could get misaligned.. for more info -

[The following Signs and Symptoms may indicate Upper Cervical (c0-c1-c2) Injury]
http://www.upcspine.com/self.htm
home page here for more info -
www.upcspine.com