In order to maintain postural homeostasis, the body is continuously compensating, keeping itself balanced over the feet and its head over the cervical spine with the eyes level to the horizon.
The following simple experiment demonstrates this automatic, subconscious postural reflex:
This automatic reflex (tilt in posture) maintains your head over your cervical spine, your eyes level to the horizon and your weight over your feet.
Lovett (1905) described a coupling of motion between the pelvis and cranial bones (See Diagram, Lovett Reactor, below) and different vertebrae in the spine (commonly referred to as the Lovett Reactor): each vertebrae is coupled in motion with another vertebrae, the pelvis is coupled in motion to the cranium:
This continues downward to T5 which moves in the opposite direction as T6
In essence, the Lovett Reactor is a description of what occurs in the pelvis, vertebrae and cranial bones when the Righting Reflex is working correctly.
Lovett Reactor - Motion in the coccyx is coupled to motion in the cranial bones.
Blocked Lovett Reactor
If the Occiput is Locked in Extension (e.g., from trauma), the Sacrum will Nutate - Resulting in a Lordotic Spinal Curve
If the sacrum is maintained in nutation due to an occiput locked in extension, the locked occiput must be released (e.g., utilizing Cranial Sacral therapy). If one tries to reduce the sacral nutation using only a proprioceptive insole, the therapy will fail and the nutation may actually increase (See Animations below).
Mixed postural distortional pattern
Borh Proprioceptive and Cranial sacral therapy was required to reverse the distorted postural pattern.
The Interventions were done serially (not concurrently).
Lovett RM. 1905 The Mechanism of the Normal Spine and Its Relation to Scoliosis. Boston Medical and Surgical Journal, Vol CLIII, No 3.