Lovett Reactor - Motion in the coccyx is coupled to motion in the cranial bones.

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).

If the Occiput is Locked in Extension (e.g., from trauma), the Sacrum will Nutate -  Resulting in a Lordotic Spinal Curve

Reference

     Lovett RM. 1905 The Mechanism of the Normal Spine and Its Relation to Scoliosis. Boston Medical and Surgical Journal, Vol CLIII, No 3.

Lovett Reactor 

  • Righting Reflex

Mixed postural distortional pattern

  • PreClinical Clubfoot Deformity 
  • Occiput locked in extension (due to trauma)  

Proprioceptive Therapy

  • Decreased the forward lean (coming from the feet) 
  • Increased the sacral nutation (coming from the locked occiput)


Borh Proprioceptive  and Cranial sacral therapy was required to reverse the distorted postural pattern. 

The Interventions were done serially (not concurrently).

Blocked Lovett Reactor


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:


  1. Stand up
  2. Move your hip to one side

  • Your ribcage automatically tilts in the opposite direction 
  • Your neck automatically tilts in the same direction as your hip


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:


Spinal Coupling:

  • C1 should move in a similar direction as L5
  • C2 should move in a similar direction as L4
  • C3 should move in a similar direction as L3
  • C4 should move in the opposite direction as L2
  • C5 should move in the opposite direction as L1


This continues downward to T5 which moves in the opposite direction as T6


Pelvic-Cranial Coupling:


  • Sacrum should move in the opposite direction as the occiput
  • The ilium should move in the oppositie direction to the ipsilateral (same side) temporal bone (e.g., an anteriorly rotated left ilium should automatically rotate the left temporal bone posteriorly)
  • The coccyx should move in the same direction as the sphenoid bone


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.