Neurophysiological Hierarchy – Jacksonian Dissolution

Jacksonian Dissolution (named after the neurologist John Hughlings Jackson, 1835–1911) provides an elegant neurophysiological confirmation of what is already biomechanically logical. Newer functions such as upright gait, precise hand movements, or complex coordination are inherently less stable because they are built upon evolutionarily older patterns. If verticality were truly equal to original horizontality, it would remain just as reliable under stress as older protective functions—but it does not.

Anyone who trains only the visible “apps” without strengthening the safety net of archaic patterns risks collapse under instability. The mechanics of the horizontal operating system are decisive; the vertical app runs on top of it.

Verticality is a sophisticated surface built on a primordial foundation. Ignore the foundation, and the app will inevitably crash.

Jacksonian Dissolution states that under stress or illness, the most recently acquired functions fail first, while more robust patterns—flexor reflexes, curling, withdrawal—re-emerge. The nervous system dissolves in reverse order of its development. What was learned last is lost first. Fine coordination and upright posture are phylogenetically young and energetically expensive; flexor patterns, protective tension, and contraction are ancient. In life-threatening situations, safety always overrides performance.

If archaic patterns—such as the Moro reflex or the Symmetrical Tonic Neck Reflex (STNR)—are not properly integrated, the foundation remains unstable. These reflexes are early-life automatic programs that support survival and the development of posture and movement. Over time, they are cortically inhibited, integrated, and superseded by more complex control.

They do not disappear—they are layered over and regulated.

If they are not well embedded, the body receives “interference signals” from older reflex programs. Attempting to force verticality without proper primitive spinal organization is like running high-performance software on faulty hardware. The result is chronic tension.

When integration is incomplete, a subtle instability emerges. The body attempts modern movement while older programs remain active in the background, intermittently interfering. These disruptions are rarely dramatic; they appear as reduced movement quality rather than obvious dysfunction. Under stress, the phenomenon intensifies, and the system regresses toward older patterns.

This reveals a fundamental property of the nervous system: it is hierarchically organized. Newer functions—upright posture, fine motor control—are powerful but fragile. Older programs are simpler but more robust. When regulation between these levels is compromised, conflict arises. The system oscillates between precision and protection.

An incompletely integrated Moro reflex may push the system into rapid alarm responses—altering breathing, muscle tone, and attention. The body becomes reactive and less differentiated. Similarly, the STNR can disrupt coordination between upper and lower body, particularly in movements requiring fine integration of posture and dynamics.

The result is an unstable foundation: the visible structure lacks load-bearing capacity. The body compensates through increased tension, simplification, and avoidance—strategies that limit adaptability. True stability does not emerge at the level of visible movement, but from the integrity of its foundation. Archaic reflexes are part of that foundation.

From Practice

When I lift one leg and bend it, it almost functions like a rudder. Do you know anything about that?

Absolutely. In movements like the Beast, abducting one leg introduces a steering function often compared in biomechanics to a rudder or stabilizer. By moving the leg laterally, you shift your center of mass. In unstable three- or two-point positions (e.g., when a diagonal hand lifts), the bent leg acts as a ballast element, preventing the pelvis from tipping toward the unsupported side. Like a boat’s rudder, it helps control or initiate rotational forces (torque), especially during dynamic transitions.

This immediately activates the gluteus medius and minimus—the primary stabilizers of the pelvis. Without them, your “vertical app” (the torso) would collapse with every step.

Each leg is partly governed by its own neural circuitry in the spinal cord—so-called Central Pattern Generators.

I mean the Scorpion Reach.

The Scorpion Reach extends your metaphor further—into vector control.

In this movement, the leg is not just a counterweight but a powerful lever arm that tensions the entire myofascial chain.

The Leg as a “Torsional Rudder”

While your hands and stance leg grip the ground (the foundation), the lifted leg acts as a steering rudder, introducing controlled rotation into the spine. By bending and lifting it backward and upward, you generate torque. This rudder determines how much load is transferred into the supporting shoulder. It becomes a finely tunable tool for balancing mobility (hip/lumbar spine) and stability (shoulder girdle).

Deep Front Line vs. Back Line

Here the link to Jacksonian Dissolution becomes clear. The Scorpion Reach imposes a strong stretch on the anterior chain (hip flexors, abdominals), while the posterior chain (glutes, spinal extensors) must actively engage.

The “rudder” pulls you out of the archetypal protective flexion pattern. It is, in many ways, the opposite of the archaic safety response that curls the body inward. You are using a primitive movement pattern to actively counter primitive protection.

Diagonal Integration

Neurophysiologically, the Scorpion Reach is a demonstration of contralateral organization. Force travels diagonally from the supporting hand to the opposite foot. The lifted leg acts as a dynamic pointer, continuously informing the nervous system about spatial position (proprioception). If the “rudder” becomes uncontrolled, trunk tension collapses.

Notice your breathing at the highest point of the movement. This is where the system often tries to revert to safety patterns—holding the breath, clenching the jaw. Only when you can continue breathing calmly have you truly integrated the vertical app into the horizontal operating system.

The Biomechanical Insight

In the Scorpion Reach, the leg functions like a crane boom: the further it moves away, the greater the load placed on the “tower”—your trunk–shoulder complex.