Interesting with the jaw clenching as I also do that and it cracks too.

As Mark says, no twist the head and pop the neck adjustments, after my chiro knowing all my problems including cervical he proceeded to twist and crack my neck, just awful wanted to shoot myself in the head the next day.

Yep, the walking can make the neck inflammation worse and headache, every step...pounding...I also wear earplugs as noise sends me insane.

On a happier note, getting out in to nature is relaxing.