Hello,
Horses, love em but they can sure mess us up..
(minor Concussion as a teen from my best horse buddy)

Have you read info about upper cervical adjusting, atlas/ axis, c1 c2 etc?
It's done by chiropractors with specialized training - not at all like the general chiro adjustments, upper cervical is very gentle with slight adjustments.

some info -
www.upcspine.com

www.nucca.com

or use the forum search link in my siggy to locate more posts here on upper cervical or nucca etc.