Psoas Secrets: Your Jaw and Cranium Control Your Psoas/Hip Flexors

Ventral Vagal System and Postural Instability
📌 Dysfunction in the ventral vagal system (face, mouth, tongue, larynx, visual, auditory systems) increases sympathetic trunk activity, leading to body extension.
🦴 Increased sympathetic trunk activity causes overactivity in hip flexors and lower back extensors, resulting in pelvic tilt (e.g., Left AIC pattern).
🦷 In one case study, a properly positioned dental mouth guard immediately resolved the sympathetic extension tone, allowing the subject to pass previously failed mobility tests (shoulder internal rotation, leg adduction).

Cranial-Cervical Connection to Autonomic Function
🔗 The ventral vagal system governs orientation, communication, feeding, and swallowing, heavily involving cranial nerves like the Trigeminal, Facial, Glossopharyngeal, Vagus, and Accessory nerves.
😠 A mispositioned jaw (TMJ dysfunction) acts as a threat signal to the brain, promoting extension tone and fight-or-flight sympathetic activity, often resulting in disordered breathing (neck breathing).
😠 Threats to the ventral area (e.g., missing teeth, jaw deviation, throat injury) activate the SCMs and upper trapezius, pulling the head forward into a forward head posture, which promotes neck breathing and fight-or-flight.

Impact of Extension on Musculoskeletal System
⛓️ Forward head posture or extension tone (driven by the jaw or prolonged sitting) overactivates the spinal sympathetic chain (T1 to L2), keeping back extensors and hip flexors constantly engaged, making them pelvic destabilizers.
❌ When hip flexors are constantly on due to extension, the body loses stability and deactivates true pelvic stabilizers: hamstrings, glutes, and pelvic floor.
🦵 Impaired pelvic stability compromises alternating movement patterns necessary for locomotion; stuck extension leads to movement through strain, causing overuse injuries, potentially involving the brachial plexus due to reduced thoracic space.

Neuroscience of Movement and Orientation
🧠 Correct movement and orientation rely on Neuroscience principles, not just biomechanics; the brain must experience movement to map orientation.
🧭 Sitting too much eliminates the brain's sense of gravity and orientation derived from vestibular input, head direction, and optic flow (vision).
🔄 Normal body function requires alternating cycles of hip flexor engagement balanced by glutes/hamstrings; extension breaks this alternation, leading to pelvic instability and compensatory strain.

Key Points & Insights
➡️ Jaw alignment and dental status are integral to the autonomic nervous system; malocclusion can drive the body into a chronic sympathetic fight-or-flight extension pattern.
➡️ Chronic extension inhibits the vagus nerve from exerting its calming "rest and digest" influence, keeping the body stuck in a cycle of tension and disordered breathing.
➡️ Restoring normal posture (pelvis, rib cage, spine, neck, head) via Postural Restoration activities is crucial for allowing the brain to accurately sense orientation ("where am I in space") and drop chronic tension.
➡️ If the pelvis is forward on both sides (extension), the body loses the stabilizing function of the pelvic floor, glutes, and hamstrings, potentially leading to issues like sciatic nerve impingement.

📸 Video summarized with SummaryTube.com on Feb 17, 2026, 16:30 UTC