Thanks for posting your query
If your friend had injury over cervical spine
region & if it is painful, then first you have to immobilse it by a cervical collar
It may be a soft tissue injury
or a cervical vertebra fracture.
So if it is a fracture, movement of neck can cause damage to the nerve root.
So you have to visit an orthopaedic surgeon
for exam. of cervical spine & xray and treatment plan according to that.