Phil, Another NTer just showed me this link.

Atlas joint instability: Causes, consequences and solutions - MSK Neurology

"Thick ligaments hold these joints in place, but patients with atlas misalignment often have ligament laxity after e.g whiplash injuries and/or years of improper cervical posture and movement patterns. Most of the time, despite some level of ligamentous laxity, great and lasting results can be achieved by re-establishing proper postural and cervical movement habits, as well as significantly strengthening the muscles that stabilize and syncronize the movements of the atlas joints. The key lies in changing the patient’s habits"