Claims

The psoas muscle attaches on the lumbar vertebrae and at the lesser trochanter of the femur (inner portion), allowing it to pull the femur up into hip flexion or move the pelvis into hip flexed anterior pelvic tilt position.

A tight left psoas in a shortened (concentric) position causes its proximal fibers near the spine to rotate the spine toward the right side and externally rotate the left femur, creating anterior pelvic tilt on the left with posterior pelvic positioning on the right.

A study showed that the normal human spine naturally faces the right side in most cases, meaning the left side predisposionally sits more forward and the left psoas has a structural predisposition toward tightness relative to the right side.

The 90/90 hip flexion position (90 degrees at both hip and knee) biases internal rotation of the pelvis and targets the hamstrings, adductors, and oblique muscles that collectively create posterior pelvic shift, pelvis rotation back, and leftward movement.

In the side-lying 90/90 position, the left gluteus medius muscle should activate as a distinct point just behind the greater trochanter (hip bone prominence), differentiated from the tensor fasciae latae (TFL) which runs down the side of the bone.

Right-sided hip flexor tightness occurs because the pelvis tends to be more forward on the left, biasing the right side toward internal rotation relative to left external rotation, making the right side preferentially loaded and the right gluteus maximus underdeveloped and underactive relative to the left.

Muscle tissue contains only a few percent collagen by weight, whereas tendons, ligaments, bone, and cartilage contain substantially more collagen, suggesting potential benefits of collagen supplementation may be more relevant for these non-muscle connective tissues.

The vagus nerve is the 10th cranial nerve that originates in the midbrain and distributes branches throughout the entire body including the eyes, throat, voice box, facial muscles, esophagus, heart, lungs, diaphragm, stomach, small intestine, large intestine, and pancreas, making it the largest nerve in the body.

The vagus nerve has two branches running alongside the carotid artery on both sides of the neck; applying an ice pack to the carotid area on both the left and right sides stimulates the vagus nerve and can be done as a free, accessible daily hack.

The tragus nerve (at the front of the ear) can stimulate the vagus nerve when pressed and massaged; while there are devices to do this, it can look awkward in public, so the speaker presents it as less practical than other hacks.