Originally Posted by Steven Low
Make sure you keep head neutral during exercise. Most exercises you want to look up (pullup bar chin up) squat and deadlifts etc (head up to keep lumbar curve)
That's not correct and really tightens up the neck. Keep the head neutral
Bit more stuff here wfs
YES! Careful about keeping the head neutral.
I went through a similar thing (sudden, severe headaches), especially with pull ups. I don't tip my head back now for pull ups at all. Problem solved for the most part. Some of the other movements (Double unders) can be tricky.