Postural Plasticity

Brain Stem Activation for Upper-Crossed Syndrome

By Erik Dalton, PhD
[Myoskeletal Alignment Techniques]

The SAID principle (Specific Adaptation to Imposed Demands) is a classic sports medicine term that describes how physical adaptations develop when the body is placed under stress, thereby allowing the body to better handle future stressors. A common example is the tennis pro whose arm muscles, ligaments, and bones thicken in response to excessive demands from the one-sided sport. Simply put, the body gets better at doing whatever it does regularly. If that means sitting for hours in a flexion-dominant posture or performing exercises using poor form and less-than-perfect posture, the body will get better at adopting poor form and less-than-perfect posture. This is postural plasticity at work.
Poor posture may start as a “tissue issue” due to tension, trauma, or overuse injuries. Eventually, however, it manifests as a sign of functional weakness in the brain’s hardware. This weakness may stem from faulty peripheral input, inaccurate cortical processing, flawed output, or a combination of these factors. Although there are seven primary brain areas responsible for the neurology governing posture, I’d like to focus on two: one that promotes forward-head postures and another that permits these postures.

Pontomedullary Reticular Formation (PMRF)

The PMRF is a dynamic sorting and switching station located in the brain stem at the pontomedullary junction, where the pons meets the medulla (Image 1). It is considered the epicenter for postural control and “the powerhouse of posture,” according to the American Postural Institute. The PMRF houses eight cranial nerves that carry out vital motor and sensory functions, including eye-ear coordination to enhance head-righting reflexes and balanced gait.
When functioning properly, the PMRF inhibits cervicothoracic flexion, which, in turn, effectively resists gravitational exposure. Clients with PMRF disorders commonly present with an upper-crossed syndrome pattern—forward-jutted chin, internally rotated arms, protracted shoulder girdle, and thoracic spine hyperkyphosis. In this population, the PMRF is unable to neurologically resist slumping, which causes connective tissue and joint adaptations in the myoskeletal framework.
It’s best to assess for PMRF weakness with the client unaware you’re evaluating them. To accomplish this, I begin observing my client’s posture as they enter the office, looking for front-to-back and side-to-side rotational strain patterns that may indicate PMRF weakness. During the intake evaluation, I’m silently asking the client to prove to me that they do not have an upper-crossed, right motor dominant, or cross-patterned gait problem. Weeding out these common compensatory patterns in early sessions gives me a good starting point for my bodywork intervention and also provides clues to possible PMRF weakness.
For example, the client in Image 2 is asked to perform a modified table angel test, and I see that some of his upper-crossed pattern is coming from bilateral PMRF weakness. To help activate the pons and medulla, I apply a couple of graded exposure torso-extension stretches (Image 3). For those with unilateral PMRF problems, or rotational crossing patterns, I always check for vestibular imbalance side to side. Let’s look at an example of this dysfunctional pattern.

Bad Balance, Bad Posture

Massage therapists are aware of the role good balance plays in enhancing performance and avoiding falls. However, many do not realize how activation of the inner ear’s vestibular system helps our clients stand tall and move with more precision. The inner ear transmits sensory information to the pons based on the client’s head position. Therefore, head-on-neck alignment is a critical factor in improving balance. Although I teach several vestibular tests and corrections in workshops and videos, the classic Romberg Test is the simplest way to expose the weak stability side.
Notice in Image 4 how the client’s head tilts right, which forces his body to sway in that direction. This may indicate right vestibular weakness due to occipitoatlantal (O-A) alignment problems. In Image 5, I show my favorite head-on-neck myoskeletal technique for leveling the eyes and activating the vestibular system. To enhance vestibular tone at home, I recommend activities like mini-trampoline bouncing, walking on uneven surfaces, and proprioceptive enhancers such as wobble boards.

Understanding Postural Plasticity

With a healthy PMRF resisting flexion and a highly functioning vestibular system promoting extension, we’re better able to get our upper-crossed clients standing taller and moving better. Remember, your brain sets the tone for all your muscles. Like an overprotective mother, it decides how much activation to allow—and it always errs on the side of caution. The brain can activate or inhibit muscle tone and balance depending on what it determines to be the safest course. We are wired for survival. Your brain is designed to protect you and, when functioning properly, knows when too much or too little of a good thing is just right for you.

Erik Dalton, PhD, is the executive director of the Freedom from Pain Institute. Educated in massage, osteopathy, and Rolfing, he has maintained a practice in Oklahoma City, Oklahoma, for more than three decades. For more information, visit