WTF is PRI? Postural Restoration Explained

Aug 23, 2021 | Physical Therapy

By Dr. Alex de la Paz, PT, DPT

Physical Therapist – Owner of Root & Branch Physical Therapy – Co-Owner of Root & Branch Integrative Fitness

Introduction to PRI

For those of you who are current or prior clients of Root & Branch you probably have heard the terms “PRI” or “Postural Restoration” thrown around. For those of you who are not clients of ours, you can schedule an appointment here. At Root & Branch we provide personal training and physical therapy using concepts taught by the Postural Restoration Institute in Lincoln, Nebraska. The founder of PRI is Ron Hruska, a physical therapist and arguably a Jedi Master of his craft. The Postural Restoration Institute utilizes physical therapy, podiatry, dentistry, and optometry to optimize an individual’s airway in order to help regulate and restore neuro-respiratory and neuro-muscular function. When our systems are regulated we can optimize our body’s posture, movement and performance – which can both help someone recover from and prevent chronic pain or injury. So WTF is PRI anyways?

We are Not Symmetrical

As humans we all know that we have two arms, two legs, two eyes etc. And because of this we all have a preconceived notion that we are symmetrical beings. But the reality is that we are anatomically and functionally asymmetrical – all of us are. More specifically, our heart is on the left and our liver is on the right, and because of this positioning our diaphragm is asymmetrical. Our diaphragm is our primary breathing muscle and it is attached directly in the center of us. And because of the asymmetrical orientation of our heart and liver our diaphragm is larger, thicker and has more tendons on the right side compared to the left side. And because of the shape of our heart and the liver our diaphragm is more domed on the right and flattened on the left – and doming is what our diaphragm does when it relaxes and flattening is what it does when it contracts. So therefore, our right diaphragm leaflet has the tendency to relax and our left leaflet likes to contract, when compared to each other. Why is this important you ask? Being that the diaphragm is a muscle that attaches to our spine and our ribcage, when left unchecked, it can start to orient our center to the right – for all of us. See below for a picture that illustrates the asymmetry of the diaphragm.
Illustration from TeachMeAnatomy

Movement Patterns & Muscle Chains

The diaphragm is not the only muscle at play here because functionally muscles do not contract in isolation. Functional movements work in patterns such that entire chains of muscle and fasciae are used together – and this includes muscles chains that contain the diaphragm. A great book that demonstrates the concept of myofascial chains is Anatomy Trains by Thomas Myers. The picture below has been pulled from Anatomy Trains and has been coined the Deep Front Line. As you can see the diaphragm is attached to a chain of muscles that literally connects our center to the rest of our body. Pretty cool huh?

Illustration from Anatomy Trains by Thomas Myers

The Left AIC, Right BC and Right TMCC Patterns

Due to the asymmetry of the diaphragm, and the chain of muscles it attaches to, the Postural Restoration Institute has identified and labeled three chains in the body that have a tendency to be over-active and dominate. The Left Anterior Interior Chain (Left AIC) of muscles include the diaphragm, iliacus, psoas, tensor fascia latae (TFL), vastus lateralis and biceps femoris. The Right Brachial Chain (Right BC) includes the diaphragm, intercostals, deltoids, pectoralis major and minor, triangularis sterni, sternocleidomastoid (SCM) and scaleni. And to avoid getting too complicated we will not go into detail about the Right Temporal Mandibular Cervical Chain, but by its name you can see it includes muscles of the head, jaw and neck. The term “pattern” is used because the asymmetry of the diaphragm causes the AIC on the left and the BC on the right to become overactive and dominant – this isn’t bad but left unchecked it can result in over-use of muscles and a malalignment of our skeleton. See below for a visual example of these chains of muscles and their influence on our body.

Figure 3 Copyright © 2019 Postural Restoration Institute®. Used with permission. Reference #062019.
Figure 3 Copyright © 2019 Postural Restoration Institute®.
Used with permission. Reference #082421.
Figure 4 Illustration by Elizabeth Noble for the Postural Restoration Institute®. Copyright © 2019 Postural Restoration Institute®. Used with permission. Reference #062019.
Figure 4 Illustration by Elizabeth Noble for the Postural Restoration Institute®.
Copyright © 2019 Postural Restoration Institute®.
Used with permission. Reference #082421.

How We Can Help

All muscles and muscle chains have antagonistic muscles that essentially have the opposite influences on the body. So if we have an overactive and dominant chain of muscles we can minimize it’s influence on our posture by activated the antagonist chain of muscles – essentially balancing out the system. However, because of the inherent asymmetry of our anatomy it is not possible to achieve perfect balance from left to right – we can only approach balance. At Root & Branch our physical therapists and personal trainers utilize PRI to integrate this concept so that you body is optimized before, during and after use. And when we approach balance we can minimize the possibility for pain and injury during your time with us.

So if you feel crooked or you are in pain and you would like to exercise with a community who understands your asymmetries then please do not hesitate to contact us at and (503) 308-9504. If you would like to schedule online then please click here. We look forward to seeing you!