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Chapter 7
Postural Restoration: A Tri-Planar Asymmetrical
Framework for Understanding, Assessing, and Treating
Scoliosis and Other Spinal Dysfunctions
Susan Henning, Lisa C. Mangino and Jean Massé
Additional information is available at the end of the chapter
http://dx.doi.org/10.5772/intechopen.69037
Provisional chapter
© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,
and reproduction in any medium, provided the original work is properly cited.
DOI: 10.5772/intechopen.69037
Postural Restoration: A Tri-Planar Asymmetrical
Framework for Understanding, Assessing, and Treating
Scoliosis and Other Spinal Dysfunctions
Susan Henning, Lisa C. Mangino and Jean
Massé
Additional information is available at the end of the chapter
Abstract
Current medical practice does not recognize the inuence of innate, physiological,
human asymmetry on scoliosis and other postural disorders. Interventions meant to cor-
rect these conditions are commonly based on symmetrical models of appearance and
do not take into account asymmetric organ weight distribution, asymmetries of respira-
tory mechanics, and dominant movement paerns that are reinforced in daily functional
activities. A model of innate, human asymmetry derived from the theoretical framework
of the Postural Restoration Institute® (PRI) explicitly describes the physiological, bio-
mechanical, and respiratory components of human asymmetry. This model is impor-
tant because it gives an accurate baseline for understanding predisposing factors for the
development of postural disorders, which, without intervention, will likely progress to
structural dysfunction. Clinical tests to evaluate tri-planar musculoskeletal relationships
and function, developed by PRI, are based on this asymmetric model. These tests are
valuable for assessing patient’s status in the context of human asymmetry and in guiding
appropriate exercise prescription and progression. Balancing musculoskeletal asymme-
try is the aim of PRI treatment. Restoration of relative balance decreases pain, restores
improved alignment, and strengthens appropriate muscle function. It can also halt the
progression of dysfunction and improve respiration, quality of life, and appearance.
PRI’s extensive body of targeted exercise progressions are highly eective due to their
basis in the tri-planar asymmetric human model.
Keywords: human physiological asymmetry, spinal disorders, scoliosis, neutral posture,
right-side dominance, muscle chain activity, biomechanical model of scoliosis, sagial plane
dysfunction, hyper lumbar lordosis, scoliosis specic exercises, postural restoration, etiology
of scoliosis, kyphosis, respiratory mechanics, postural disorders
© 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
1. Introduction
Recognition of inherent physiological asymmetry has not yet been applied to the understand-
ing, assessment, or treatment of scoliosis or other spinal and postural disorders. Even without
an accurate baseline model of human form and function, interventions to correct dysfunction
can be successful; however, while a local dysfunction may be rectied, the underlying biome-
chanical imbalance will persist as will the musculoskeletal strategies developed to compen-
sate for the imbalance.
The Postural Restoration Institute® (PRI) methodology is a theoretical framework, which describes
a model of universal human anatomical and physiological asymmetry. This unique model pro-
vides a new baseline for understanding common postures, movement paerns, and respiratory
mechanics, which generate from our asymmetrical bias. It also explains the factors that support
human right-side dominance. While human asymmetry can be understood as a positive factor
that facilitates movement, overuse or misuse of the dominant muscle paern will promote pro-
gressive imbalance within the body and will likely result in dysfunction. The treatment goal for
dysfunction resulting from musculoskeletal imbalance needs to be restoration of the baseline in
which there is relative balance between the dominant and nondominant muscle paerns [1–4].
Scoliosis is an example of a tri-planar, biomechanical dysfunction. In its most common form (90%
of the cases), right thoracic convexity and left lumbar convexity [5–7], it exemplies the extreme
progression of normal human asymmetry according to the PRI model, which will be described in
this chapter. Other postural disorders such as kyphosis and lordosis, exhibiting primary sagial
plane dysfunction, also belong to the spectrum of disorders developing from unbalanced human
asymmetry. These conditions result in musculoskeletal stress, subsequent structural damage, loss
of eciency in movement and in respiratory function, as well as in a diminished quality of life.
This chapter introduces the fundamental concepts of PRI’s theoretical framework and its base-
line model. It will then describe how PRI’s clinical tests can more accurately evaluate a patient’s
status by taking into account the inherent human asymmetry. These tests guide exercise prescrip-
tion and treatment progression. Some examples of exercises used in the treatment of scoliosis
have been selected to demonstrate activity progression from supported target muscle isolation,
to complex, unsupported, multiple muscle integration, all with a major emphasis on respiration.
Three case studies are presented here to illustrate this process. Many similarities exist between
PRI rehabilitation concepts and exercises and the well-known Schroth methodology [8, 9].
2. Fundamental PRI concepts
The following fundamental concepts provide a new perspective on eective restorative tech-
niques for treating scoliosis, other spinal dysfunctions, and postural disorders. The concepts
explain the PRI baseline model of innate human asymmetry. Each is discussed in detail in this
chapter: (1) human asymmetry arises from our innate anatomy and physiology and exerts
signicant inuence on human posture and movement. (2) Ideal or neutral posture results
from relative musculoskeletal balance of our asymmetrically organized body. (3) Anatomical
and physiological asymmetries evident in the respiratory system are powerful contributors to
Innovations in Spinal Deformities and Postural Disorders136
our biomechanical function. (4) Right-side dominance is the functional result of physiologi-
cal asymmetry. (5) The movement of the respiratory diaphragm and the pelvic diaphragm
(pelvic oor muscles) is synchronized during breathing. The pelvis is a primary structure that
facilitates gait. The synergistic activity of these two diaphragms links respiration and gait.
(6) Gait requires integrated muscle activity, dierent on two sides of the body, in order to
stay erect on one leg as the other advances the body through space. In the context of human
asymmetry, right-side stance phase and left-side swing phase will be most competent. (7)
Biomechanical dysfunction begins in the sagial plane.
2.1. Innate physiological human asymmetry
Studies of many aspects of human asymmetry abound in the literature [10–15]. Much of this
fascinating material is beyond the scope of this chapter. However, asymmetries of the internal
organization of the body, organ weight distribution, muscle mass, and muscle aachments are
all factors that contribute signicantly to human asymmetrical posture and movement pat-
terns. For example, the heart and its vessels share the left upper quadrant with two lobes of the
lung. The right upper quadrant is less full, housing three lung lobes. The weight of the heart is
oset by the large, heavy liver, which sits—lower than the heart—in the right lower quadrant
[14]. This weight distribution and placement dierence facilitates a gravitational shift of the
body onto the right lower extremity, thereby promoting right stance. The left lower quadrant
is less weighty because of the small spleen and usually empty stomach [1–4] (see Figure 1).
The upper and lower quadrants are separated by the respiratory diaphragm, a unique muscle
that spans the internal dimension of the body. The diaphragm is comprised of a stronger, larger,
Figure 1. Asymmetrical organ distribution. Sco72 copyright 123RF.com
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and beer-supported right leaet, and a smaller, less ecient, left leaet. The diaphragm’s
respiratory mechanics exert a powerful asymmetrical inuence on the torso. The crura of the
right leaet, which inserts onto three lumbar vertebrae L1–3, is also stronger and thicker than
the left crura, which inserts on only two lumbar vertebrae L1, 2 [16] (see Figure 2). This distribu-
tion exerts a right rotational inuence on the lumbar spine, orienting it to the right. Articulation
of the lumbar spine with the sacrum orients the sacrum to the right. Strong ligaments bonding
the sacrum to the pelvis eect right rotation of the pelvis as well. This right rotational orienta-
tion of the lower spine and pelvis is enhanced by the gravitational shift of the body over the
right leg due to the weight of the liver on the right side of the body [1–4].
Asymmetry facilitates movement. In a balanced system, asymmetry is a positive, vitalizing
force. In the human body, loss of balanced musculoskeletal function precipitates and reinforces
overuse of dominant postures and paerns because of the underlying structural bias toward
right stance, inuenced by organ placement, weight distribution, and muscle aachment. Habit
and repetition perpetuate and reinforce dysfunction. Innate physiological human asymmetry
may well be a factor in the onset and development of scoliosis and other postural disorders.
2.2. Neutral posture reects relative musculoskeletal balance
Webster’s New World Medical Dictionary denes “neutral posture” as the stance that is aained
when the “joints are not bent and the spine is aligned and not twisted” [17]. Neutral posture
gives rise to the concept of “ideal posture” in which the alignment of body segments involves a
minimal amount of stress and strain and which is conducive to maximal eciency in use of the
body [18, 19]. Ideal posture is critical for proper respiratory action [20]. When the body is in its
ideal or neutral alignment, diaphragmatic respiratory mechanics are optimized [16].
Due to physiological asymmetry, a neutral posture does not imply strict symmetry; rather,
it describes a position of relative structural balance and a readiness for movement in any
direction. Loss of relative musculoskeletal balance reects persistence of a structural bias
Figure 2. Diaphragm with crura. Florida Center for Instructional Technology copyright 2004–2017.
Innovations in Spinal Deformities and Postural Disorders138
resulting from habitual, repetitive muscle activity. For example, hyper lumbar lordosis is a
frequently seen, sagial plane, postural disorder. Positional alignment of the ribcage and pel-
vis has become imbalanced. The lumbar paraspinals have shortened and tightened, and the
abdominal muscles have become overlengthened and weak [19, 21]. Neither of these muscle
groups exists in their neutral or rest position. The neutral position of a muscle is equivalent
to physiological rest [19]. With hyper lumbar lordosis, all future movements will initiate from
this unbalanced basis of the skeleton (ribcage and pelvis) now supported and reinforced by
adaptive muscle imbalance. Movement into any direction will require compensation by other
muscles or will not be accomplished. Compensatory muscle activity is less ecient, energy
demands increase, and stress accumulates on poorly aligned joints. Restoration of musculo-
skeletal balance would address these multiple issues [1–4].
Respiration is a key component of posture [22–27]. Our ability to breathe eciently aects
all aspects of our daily function and our endurance for activity. Through its anatomic aach-
ments, the position and functional eciency of the respiratory diaphragm is highly dependent
on musculoskeletal posture as well as on tonic muscular activity [23]. The average person takes
21,000 breaths per day [28] with the respiratory diaphragm as a key muscle of respiration [22,
25]. Thus, the respiratory paern is powerful in its contributions to posture. Ecient respira-
tory mechanics are dependent on neutral body position and muscle function [16].
When the diaphragm is compromised, it not only causes inecient breathing paerns but
also becomes a key contributor to the persistence and progression of postural disorders,
including hyper lumbar lordosis, [29] kyphosis, forward head posture [20], and changes in
ribcage symmetry [9, 16] as seen in scoliosis.
2.3. Asymmetries of respiration
The inuence of the respiratory system is signicant and often underlies or is complicit with
scoliosis and other postural disorders. Understanding the mechanisms of breathing and how
the loss of diaphragmatic competency can precipitate biomechanical dysfunction is not su-
ciently appreciated in most current rehabilitation practices. Since the ability to exchange air is
crucial to life, the respiratory system is a core motivator for muscle activity to insure adequate
oxygenation. Within the respiratory system, the diaphragm is considered the primary muscle
of respiration; however, there are numerous accessory muscles of respiration to assist when
supplemental ventilation is needed. For instance, running places higher oxygen demands on
the body to support a higher level of physical exertion. The accessory muscles of respiration
are designed to accommodate such needs. Loss of diaphragmatic eectiveness due to postural
or biomechanical dysfunction will result in pathological, compensatory accessory muscle
recruitment [30].
The respiratory diaphragm is centrally located in our asymmetrically organized trunk. It is
highly asymmetrical in form, in muscle aachment, and in function. Most importantly, it is
uniquely positioned to directly inuence every aspect of the postural, skeletal, and muscular
core, and it inuences the position and function of all other body systems [31]. The respiratory
diaphragm is comprised of two muscles: a right and left hemidiaphragm [32], each with its
own central tendon and each innervated by a right and left phrenic nerve, respectively [16].
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Together, these two muscles span the internal dimension of the body just below the lungs.
They insert on the xiphoid process, on the inner surfaces of ribs 7–12, and on the anterior
aspect of the spine. The right leaet is larger in diameter, it has a thicker and larger central
tendon, its dome is higher, and it is beer supported than the left by the liver beneath it and
by strong right eccentric abdominal activity [31]. The right crura anchors to L1–3 on the right,
the left crura to L1, 2 on the left [16]. The diaphragm leaets also insert into the fascia overly-
ing quadratus lumborum and to the psoas muscles via the arcuate ligaments, creating a strong
functional linkage between these muscles. The superior strength, position, and function of the
right hemidiaphragm supports and is supported by the physiological right orientation via
right stance [1–4] (see Figure 3A).
The respiratory “Zone of Apposition” (ZOA) is the region of interface between the hemi-
diaphragm and the inner surface of ribs 7–12 [16, 33]. Apposition refers to multiple layers of
muscles with diering ber orientation lying adjacent to one another. The ZOA facilitates
inhalation by generating tension between the muscle layers, which promotes external rota-
tion of the ribs, complementing the action of the external intercostals. As the central tendons
contract and descend, the hemidiaphragms displace caudally while the ribcage expands and
externally rotates. The ZOA diminishes in volume with this activity. Simultaneously, the
abdominal viscera are displaced caudally enabling lung expansion [16, 33] (see Figure 3B).
Exhalation reverses this process. Shortening of the internal intercostals and of the lateral
abdominal musculature reduces ribcage dimension. The hemidiaphragms relax and recoil
upward returning to their domed congurations. Then, in a position of potential energy, the
hemidiaphragms are ready to piston down again, thereby creating a vacuum, which will
draw air into the lungs. Additionally, the diminished volume of the pleural cavity aids in
expelling depleted air from the lungs [16, 33] (see Figure 3B).
Figure 3. (A) Functional relationship of diaphragm, psoas, quadratus lumborum, and right stance illustration created by
Elizabeth Noble for the PRI copyright. Used with permission from the PRI. Copyright 2017, www.posturalrestoration.com.
(B) Respiratory mechanics of inspiration and expiration. www.wikimedia.org
Innovations in Spinal Deformities and Postural Disorders140
Application of these respiratory mechanics to the biomechanical model of innate human
asymmetry gives a more realistic understanding of our functional baseline. The three layers
of lateral abdominals: transverse abdominis, internal, and external obliques, taken together,
insert cephalically on the costal cartilage of ribs 5–12 and caudally on the ipsilateral iliac crest.
These lateral abdominal muscles link the ribcage and pelvis, and they are critical components
of posture and respiration [25, 26]. As described previously, shifting of weight to the right
leg and orientation of the lumbar spine and pelvis to the right result in anterior rotation of
the left hemipelvis. When the left hemipelvis is chronically anteriorly rotated, these lateral
abdominal bers will be adaptively overlengthened and weak. (In some cases, the right hemi-
pelvis will also rotate anteriorly to avoid the strain of this asymmetry, resulting in bilateral
compensatory and pathologic anterior pelvic rotation). The weakened, lateral abdominal
muscles cannot maintain balance between the anterior ribcage and the pelvis. Without the
anchoring action of the lateral abdominals, the anterior ribcage migrates further into elevation
and external rotation mimicking thoracic position on inhalation [1–4].
This positioning has consequences for respiratory mechanics. When the left ribcage is in a
chronic state of inhalation (expanded ribcage), the diaphragm is obligatorily in its descended
state of inhalation as well. This chronic positioning limits diaphragmatic ascension on exha-
lation, thereby reducing the left ZOA. Consequently, the diaphragm loses its eectiveness
for inspiration. Additionally, as the left anterior ribcage elevates, the diaphragm’s domed
conguration decreases and its bers take on a more aened, diagonal orientation, elevated
anteriorly, resulting in further loss of the left ZOA. In this altered state, when the diaphragm
contracts, it pulls the lumbar spine forward and reinforces anterior ribcage elevation. Having
lost eciency as a respiratory muscle, the diaphragm now functions more as a postural exten-
sor muscle promoting progressive lumbar lordosis [29] (see Figure 4). Left anterior ribcage
ares are commonly seen clinically and are exaggerated in patients with scoliosis. These ares
indicate hyperination of the left lung due to insuciency of the left lateral abdominals.
Figure 4. Positional consequences for respiratory mechanics. Illustration by Erica Bevin for James Anderson and the PRI.
Copyright 2017 PRI®.
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The right hemipelvis conguration is opposite relative to the left; it is posteriorly rotated.
The right lateral abdominals are beer positioned to exhale, but are more restrictive to
inhale. Compensatory strategies to maximize breathing capacity in order to meet respi-
ratory need will then rely on the accessory muscles of respiration, including the psoas,
paraspinals, muscles of the upper back, chest, and anterior neck. With these compensatory
changes in breathing mechanics, left anterior ribcage ares and right anterior ribcage
restriction may progress along this diagonal trajectory, resulting in the common scoliosis
paern of right posterior ribcage prominence and left posterior ribcage concavity [1–4]
(see Figure 5A and B).
2.4. Right-side dominance, the functional result of physiological asymmetry
Humans almost universally exhibit right-dominant postural and movement paerns result-
ing from physiological asymmetry. Preferential standing on the right leg and increased
breathing eciency of the right hemidiaphragm are major contributors to this fundamen-
tal bias. Additionally, 90% of the population is right-handed, a dening characteristic of
humans [11, 15]. Use of the right upper extremity for manipulative and reach activity dates
far back in human history and has been correlated with early human brain asymmetrical
development [11]. Right arm swing accompanies right stance phase of gait and coordi-
nates with left leg swing-through. Right arm swing, consistent with right reach activity,
promotes left trunk rotation to balance lumbar spine and pelvis right orientation, present
in right unilateral stance. However, it is important to emphasize that handedness does not
dene side dominance [34]. Left-right asymmetry is a fundamental, ancient characteristic
of animal development present in the earliest large multicellular organisms according to
fossil records [14, 34]. Strong right-hand preference for manipulative and expressive tasks
is thought to correspond to the emergence of language. These developments occurred with
Figure 5. (A) EOS of common scoliosis paern used with permission. (B) Common costal deformity in scoliosis used
with permission from The Martindale Press, Three Dimensional Treatment for Scoliosis, 2007 by Lehnert-Schroth, C.
Innovations in Spinal Deformities and Postural Disorders142
cerebral cortical lateralization at a much later date [11, 13, 35] and dier from inherent left-
right organism asymmetry [34].
2.5. Synchronicity of respiration and gait
During breathing, the thoracic diaphragm and the pelvic diaphragm (pelvic oor muscles) func-
tion synergistically, linking gait and respiration [4, 36]. Internal obliques and transverse abdomi-
nis muscles are key participants in this process. Acting as a force couple, these lateral abdominals
assist the hamstring’s postural activity to maintain a neutral pelvis position as they simultane-
ously assist ribcage position and motion [25, 26, 31, 37]. Concurrently, lateral abdominal and
hamstring lengths are determined by pelvic position due to their respective pelvic insertions.
When the thoracic diaphragm descends for inhalation, the abdominal muscles and the mus-
cles of the pelvic oor eccentrically lengthen to allow for visceral displacement caudally [16].
As the abdominal muscles elongate, the ribcage expands and externally rotates, and the pel-
vic crest migrates forward into anterior rotation, abduction, and external rotation, while the
ischial tuberosities approximate, allowing the pelvic oor to descend. The femur remains
oriented anteriorly to keep the feet in a forward trajectory. Relative to the acetabulum, the
femur is in an externally rotated unlocked position, described as “Acetabular Femoral External
Rotation” (AFER), which facilitates the swing phase of gait [1–4] (see Figure 6).
Active exhalation relies on concentric activation of the internal obliques and transverse
abdominis muscles to assist ribcage contraction, internal rotation, and thoracic diaphrag-
matic ascension. As the lateral abdominals shorten, they assist posterior rotation, adduc-
tion, and internal rotation of the pelvis. This pelvic position assists ascension of the pelvic
oor as the ischial tuberosities move laterally as pelvic crests move medially [4, 25, 26].
The two diaphragms coordinate their pistoning activity, moving as a unit cephalically on
exhalation and caudally on inhalation. While the pelvis rotates posteriorly with adduction
Figure 6. Frontal view of left AFER and right AFIR illustration created by Elizabeth Noble for the PRI copyright. Used
with permission from the PRI®. Copyright 2017, www.posturalrestoration.com
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and internal rotation, the stance leg maintains its forward orientation. The now internally
rotated conguration of femur to acetabulum, described as “Acetabular Femoral Internal
Rotation” (AFIR), stabilizes the hip joint (see Figure 6). Muscles of the hip—hamstrings,
adductors, and gluteals—synchronize with lateral abdominals to stabilize the pelvis [1–4].
These functional relationships occur during gait. Gait is a highly complex movement task,
which requires multisystem coordination and integration. Visual-vestibular, somatosen sory,
respiratory, and cardiovascular systems all give input and guidance [38]. Bio mechanically, the
challenge is to stay upright as the body advances through space balanced over one limb. When
one side is in stance phase of gait, the contralateral side is in swing phase. The opposite arm
and leg swing forward together (see Figure 7). This reciprocal extremity activity balances the
torso around a vertical axis and assures nonstressful upright balance. In stance phase, the pel-
vis and lumbar spine are rotated toward the stance leg. The trunk is rotated opposite to the
stance leg at or above the upper aspect of the diaphragm and is side bent ipsilaterally due to
ipsilateral forward arm swing and ribcage kinematics [39]. This conguration mechanically
supports shortening of the stance leg side abdominals, further assisting ribcage contraction
and diaphragmatic ascension. Ecient gait requires the right and left sides of the body to be
relatively equally competent in both stance and swing phases of gait. Gait is the best measure
of balanced, biomechanical asymmetry [2].
However, anatomical and physiological asymmetry biases the body toward greater compe-
tency in right stance. When musculoskeletal function is not relatively balanced, the left side
does not achieve full stance phase of gait or full exhalation phase of respiration, and the right
side will likely not achieve eective swing phase of gait or ecient inhalation phase of res-
piration. The daily repetitive nature of these basic activities of life reinforces and strength-
ens unbalanced asymmetrical function. Without intervention, the unequal stresses placed on
musculoskeletal elements will likely progress to structural changes.
Figure 7. Alternating reciprocal gait viewed from above used with permission from the Postural Restoration Institute®.
Copyright 2017, www.posturalrestoration.com
Innovations in Spinal Deformities and Postural Disorders144
2.6. Muscle chain activity of the right-side dominant paern
The development of muscle compensation follows a predictable paern based on the model
of human right-side dominance. Interventions to restore balance to a dysfunctional system
will be maximally eective if the underlying baseline is understood and accounted for in
the intervention. To this end, PRI describes muscle paerns based on a right-side dominant
model. These paerns identify polyarticular muscle chains within the body, dened as a
series of muscles, which overlap one another having bers in the same direction and span-
ning multiple joints and thereby working synergistically together [2].
The anterior interior chain (AIC) governs the pelvis, lumbar spine, and lower extremities (see
Figure 8A). It is so named because it is comprised of muscles located anterior to the spine and
situated within the abdominal cavity. Muscles of the AIC are active during swing phase of gait
(see Figure 8B). Swing phase of gait corresponds to the left nondominant muscle bias. The left-
side paern is, therefore, exemplied by the body’s conguration during swing phase of gait.
The biomechanical elements are already familiar from earlier description: the lumbar spine,
sacrum, and pelvis orient to the right. The left hemipelvis rotates anteriorly, abducts and
externally rotates, facilitating muscles that promote left swing through. These AIC muscles
include the left diaphragm, the left psoas major, the left iliacus, the left tensor fasciae latae,
the left biceps femoris, and the left vastus lateralis. Simultaneously, the left anterior ribcage
elevates and externally rotates as the left diaphragm aens into an inhalation position. The
Figure 8. (A) Muscles of the left anterior interior chain. Copyright—3D4 medical modied with permission by the
Postural Restoration Institute®. (B) Left anterior, interior chain in left swing phase of gait.
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left lumbar spine is pulled forward and downward by the psoas and forward and upward by
the diaphragm, resulting in increased lumbar lordosis [3] (see Figure 4).
This is the normal swing through conguration. However, when body neutrality is lost, the
left AIC paern remains tonically active. Persistence of the left swing through paern inter-
feres with full recruitment of its opposite, the muscles of left stance [31]. Consequently, left
stance performance is weakened and less stable. Left AIC paerning thereby reinforces right-
side dominance that is neurologically encoded as the new normal posture. Biomechanical
strategies to compensate for this maladaptive left stance phase often involve overuse of the
right lower extremity and/or malpositioning and stress of the left lower extremity joints. The
right AIC muscle chain is not constrained by underlying positional insuciency, and it sup-
ports right stance well. However, the eciency of right swing through may be limited due
to left-side instability during left stance as well as due to persistent overactivity of the right
adductors and lateral abdominals.
The upper trunk muscle chain described by PRI is named the “Brachial Chain” (BC) (see
Figure 9A). The BC balances rotational forces generated by the AIC by counterrotating the
spine and ribcage to a forward direction. A right BC paern complements the left AIC pat-
tern by promoting left thoracic rotation (see Figure 9B). Counterrotation takes place in the
approximate region of T7–9 [1]. The respiratory diaphragm inserts on the inner surfaces of
ribs T7–12 and to the anterior aspect of vertebrae L1–3 on the right and L1,2 on the left. In its
normal, exhalatory rest position, the dome of the diaphragm is at about T8. Therefore, the
trunk could be considered to be the portion of the torso above the diaphragm. This counter-
rotation of the trunk is accompanied by ipsilateral side bend due to ipsilateral forward arm
swing and to ribcage kinematics [39].
Figure 9. (A) Muscle of the right brachial chain. Copyright—3D4 medical modied with permission by the Postural
Restoration Institute®. (B) Right brachial chain in left swing phase of gait.
Innovations in Spinal Deformities and Postural Disorders146
Right arm reach is facilitated by this conguration. As the mid and upper trunk turn leftward,
opposite to the right rotation of the lumbar spine and pelvis, ribcage kinematics re-form the
shape of the ribcage and its muscular aachments. Left trunk rotation results in right ribcage
approximation and internal rotation, and left ribcage expansion and external rotation [39].
This conguration encourages airow from inhalation to the already-expanded left ribcage
and lung while decreasing airow to the right internally rotated approximated side. Muscles
of the BC supporting right ribcage internal rotation include the right triangularis sterni, right
sternocleidomastoid, right scalenes, right pectoralis minor and right intercostals, and also
muscles of the right pharynx and anterior neck.
The “left AIC, right BC” paern can be understood as the normal conguration of one half
of the gait cycle, i.e., right stance. A right AIC, left BC paern would reect the other half of
the gait cycle, i.e., left stance (see Figure 10). Human physiological asymmetry and right-side
dominance predispose the body for greater right competency. Although left-side function
will never be as ecient as the right, left stance can achieve near-equal stability with muscu-
loskeletal balance or body neutrality.
This Left AIC, right BC paern explains the biomechanics predisposing the development of a
right thoracic, left lumbar spinal curvature, which describes 90% of curves [5–7] (see Figure 11A).
The left AIC, right BC paern underlies all human posture and movement (see Figure 11B). While
dierent circumstances may result in dierent pathological compensations, generating a variety
of stresses and/or structural changes, this innate human asymmetrical bias will be present [1–4].
Figure 10. Right swing phase of gait illustrating the right anterior interior chain and left brachial chain.
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2.7. Biomechanical dysfunction begins in the sagial plane
The sagial alignment of the pelvis and ribcage aects muscle length and strength through-
out the body. With any activity, the positional relationships of the structures and of the mus-
cles that aach to them change. However, when the body is at rest, the ribcage and pelvis
should be in a relative sagial neutral position with muscle groups at their resting length.
In an alternating reciprocal activity such as gait, there should be a moment of relative sagial
plane neutrality as weight shifts from one side to the other.
When this relative state of neutrality is no longer possible due to overactive right-dominant
paerning, the left AIC, right BC paern takes precedence. The left hemipelvis chronically
positioned in swing phase of gait is anteriorly rotated. The spine balances this forward
momentum with backward tilting as tonic, shortened paraspinal muscles take on the respon-
sibility of keeping the spine erect. The left psoas and iliacus muscles adaptively shorten as the
left transverse abdominis and internal oblique muscles are stretched between their insertions
on the anterior lower ribs and the now more distal iliac crest. The left anterior ribcage ares,
further weakening the overstretched left lateral abdominal muscles. With diminished opposi-
tion to left diaphragm recoil, because of lengthened abdominals and a loss of ZOA, the bers
of the left diaphragm orient more vertically, and the diaphragm assumes a greater role as a
back extensor muscle than as a respiratory muscle. Its directional pull on the spine is forward
Figure 11. (A) Muscles of the left anterior interior chain and right brachial chain. Copyright—3D4 medical modied with
permission by the Postural Restoration Institute®. (B) A classic example of a Left AIC, right BC paern.
Innovations in Spinal Deformities and Postural Disorders148
and upward, while the psoas pulls the spine forward and downwards. The action of these
two muscle groups encourages an exaggerated lumbar lordosis, reinforced by the lumbar
paraspinals [16] (see Figure 4).
Exaggerated lordosis in the sagial plane precedes a cascade of compensatory muscle and
respiratory activity, as the brain encodes alternative strategies for continuing upright function.
Further sagial plane dysfunction follows, for example, the development of thoracic kyphosis
to rebalance weight distribution over the pelvis. Another common strategy is the development
of thoracic lordosis with reversal of the cervical spine to assist inhalation as cervical respiratory
accessory muscle use increases to support the inecient diaphragm position. According to the
Hueter-Volkmann Law, epiphyseal bony growth is inhibited by compression and facilitated by
tractioning [40]. In a young spine, exaggerated lordosis compressing the posterior vertebral seg-
ments would facilitate the development of relative anterior spinal overgrowth (RASO). This sag-
ial plane aening of the thoracic kyphosis is an acknowledged precursor of scoliosis [41, 42].
Human physiological asymmetry expressed as right-side dominance via the left AIC, right BC pat-
tern, demonstrates biomechanical challenges to maintaining neutrality of the pelvis and ribcage
in the sagial plane. Other factors contributing to loss of neutrality may include prolonged static
positioning, especially siing, hypermobility especially when participating in extreme sports or
dance, and impaired somatosensory input. In the absence of pathology, right stance is a common
default stance position. Respiration and gait will reinforce imbalance once neutrality is lost.
3. PRI tests to evaluate tri-planar musculoskeletal relationship and
function
Taking into account the universal predisposition for human left AIC, right BC paerning, PRI
tests accurately assess structural relationships such as sagial plane position of the hemipel-
vis and ribcage and rotational orientation of the lumbar, thoracic, and cervical spines. Other
palpatory tests reveal the patients’ ability or inability to expand both apical lungs elds and
both posterior mediastinal spaces. Initial testing exposes underlying paerning based on the
left AIC, right BC model. Therefore, patients who exhibit typical ndings for these paerns
are not in a neutral state. It has to be understood that results from any further testing of range
of motion, or strength, including core strength, would be based on their compensatory strate-
gies. Deviation from predictable conguration implicates pathological compensation.
Neutral posture is dened by an alignment of body segments involving minimal amount
of stress and strain and which is conducive to maximal eciency in use of the body. It also
optimizes diaphragmatic respiration. The neutral position of a muscle is equivalent to physi-
ological rest [19]. This equates with musculoskeletal relative balance in a body, which is
physiologically and functionally asymmetric. It is, therefore, imperative to rst restore this
neutrality. Once accomplished, further testing will give accurate information about weak-
nesses or restrictions in joints limiting appropriate frontal plane and transverse plane bal-
ance and function. Only with the restoration of musculoskeletal neutrality can appropriate,
compensatory-free strengthening be initiated.
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Over 25 PRI tests are available for initial assessment and to guide exercise progression as
the patient progresses toward functional strength, respiratory competence, and upright
alternating reciprocal activity. During treatment, the PRI tests are often applied before and
after therapeutic exercise to determine its eectiveness, to reveal weakness or improvements
in strength, and to further guide appropriate exercise progression. Three basic tests are
described below.
3.1. The adduction drop test (ADT)
This is an example of a positional test for hemipelvic position in the sagial plane. This side-
lying test position facilitates a neutral hemipelvic position by exing the hips and knees,
thereby taking potential overstretch o the hamstring muscles. If the hemipelvis is in its neutral
range, the ipsilateral femoral head will align with the acetabular groove allowing the femur to
achieve full passive adduction as it is lowered by the clinician. If the hemipelvis is anteriorly
rotated despite the test position of bent hips and knees, the femoral neck will impinge on the
acetabular rim. The femur will not achieve full passive adduction (see Figure 12).
3.2. The humeral glenoid internal rotation test (HGIR)
This positional test assesses ribcage alignment. The posterior ribcage, as the foundation
for the scapulae, determines scapular position and glenoid orientation, and therefore,
humeral-glenoid mechanics. In the supine, bent knees test position, the humeral head is
abducted to 90°, the elbow is exed to 90°, and the forearm is pronated. Neutral alignment
of the hemiribcage will allow full passive humeral internal rotation within the glenoid
fossa. If the ribs of the anterior ribcage are internally rotated and the intercostals adap-
tively shortened, the apical chest wall will exhibit restriction and limited expansion with
inhalation. The scapula is pulled forward by pectoralis minor and positioned in a state of
upward rotation, abduction, internal rotation, and protraction. Consequently, the humeral
head is now in external rotation relative to the glenoid fossa. Passive internal rotation of
the humerus will result in impingement on the glenoid fossa and the range of motion will
be limited (see Figure 13).
Figure 12. Adduction drop test used with permission from the Postural Restoration Institute®. Copyright 2017, www.
posturalrestoration.com
Innovations in Spinal Deformities and Postural Disorders150
3.3. Trunk rotation test (TRT)
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1
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Figure 14
Figure 13.
Figure 14.
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Findings from this test must be correlated with the ADT for accurate assessment. If the ADT
demonstrates a bilaterally neutral pelvic position, the rotational range to right and left should
be equal. If the ADT reveals left or bilateral anterior pelvic rotation, the legs should have a
greater range of motion to the right. The rationale for this test assumes a right-side dominant
paern unless the ADT demonstrates neutral balance. In a right-side dominant person, the
lumbar spine will be right-oriented; therefore, the legs will appear to turn further to the right.
If the legs move farther to the left, it indicates that the right iliolumbar ligament is compro-
mised and does not maintain lumbopelvic stability.
These few examples give an idea of how the ndings from PRI clinical tests correlate with one
another to give an understanding of the patient’s position and biomechanical function. These
physiological details are otherwise hard to assess and factor into treatment protocols.
4. Exercise progressions for restoration of musculoskeletal balance
Exercises, termed “nonmanual techniques” in PRI, are powerful tools for proprioception and
physiological transformation for patients with scoliosis of all ages. Based on the model of right-
side dominance due to human asymmetry, and taking into consideration the patient’s unique
conguration and function revealed by the evaluation tests, exercises are carefully chosen to most
appropriately meet the tri-planar needs of that patient. Some of the greatest similarities between
the methodology of Schroth Barcelona and PRI are in the application of exercises. Both place
emphasis on exercise position, breath, and stabilization in the corrected tri-planar position [8, 9].
Exercise progression begins in fully supported positions to isolate and recruit underused or
misused muscles. Supported positions are also favored for the introduction of multimuscle
integration. When the patient demonstrates competence in activating correct muscle chain
activity while supported, challenge is intensied by progression to more upright activi-
ties. Repetition of challenging positions, held through multiple breathing cycles, promotes
proprioceptive familiarity with new alignment and stabilization in new muscle paerns.
Increased self-awareness and more precise muscle and breath control enable the patient to
self-correct in activities of daily living. Achieving true alternating, reciprocal movement, as
required in gait, is a nal challenge.
4.1. Repositioning for sagial plane neutrality
The PRI protocols begin with establishing the patient’s ability to achieve sagial plane neutral
position of the pelvis and the ribcage. As previously described, this means that in a position of
rest, their musculoskeletal system is in a state of relative muscle balance following a “reposition-
ing” activity. Sagial plane repositioning is most easily achieved in supported positions. Gravity
is thereby eliminated and underused muscles can be positionally isolated and challenged.
Recruitment of the hamstring muscles is the most common starting point for repositioning
exercises. The hamstring muscles insert proximally on the ischial tuberosity and distally on
the medial tibial condyle and on the head of the bula and the lateral tibial condyle. When
Innovations in Spinal Deformities and Postural Disorders152
the pelvis tilts anteriorly, the ischial tuberosity moves proximally and away from the tibia,
resulting in overlengthening and weakening of the hamstring complex. Consequently, this
powerful muscle group is unable to perform its postural function of stabilizing the pelvis,
especially during stance phase of gait. Assessing ADT or another relevant test, prior to and
following the activity, demonstrates whether that activity was helpful in restoring correct
hamstring length and neutral pelvic alignment. If so, it is useful to ask the patient to stand and
describe their body sensation to assure a denitive, proprioceptive experience of dierence.
Some patients, especially people with hypermobility, have diculty noticing subtle dier-
ences. Others notice new sensations: “I feel lighter, taller, more weight on my heels.”
The skill of sensing, i.e., the ability to focus aention on subtle sensations, is a potent tool for
reshaping one’s alignment from within. These sensations include awareness of the ground, of the
body’s orientation in space, internal structural relationship, and subtle changes in muscle tone.
Most empowering is the ability to achieve expansion of targeted thoracic regions on inhalation.
4.2. Balancing the frontal plane
As the patient becomes stronger and more procient at maintaining sagial plane ribcage
and pelvic alignment via hamstring and lateral abdominal integration, work begins on bal-
ancing muscles of the frontal plane. The pelvis and hips are key components. For example, in
the stance phase of gait, the femur should be internally rotated relative to the acetabulum to
insure stability. The right leg is typically beer positioned to achieve stable stance. The pelvis
is typically oriented right, positioning the right femur in stance and the left femur in swing
phase of gait. Muscle chain activity supporting left stance is weak. Exercise progressions to
recruit, strengthen, and integrate the left nondominant muscle chain are initiated. Target
muscles to promote frontal plane balance include, but are not limited to the left adductor, the
left anterior gluteus medius, the right gluteus maximus, and right serratus anterior.
Frontal plane exercise progressions often begin with sidelying to assist isolation, strengthening,
and neural encoding of underused muscles. More upright positions challenge the patient’s ability
to maintain sagial control with the addition of appropriate abduction and adduction movements.
Exercise complexity and challenge increases as isolated muscles are integrated together in activi-
ties that require frontal plane muscle chain activity. Isolated left nondominant muscles are gradu-
ally integrated together in increasingly complex and challenging exercises in the frontal plane.
Muscle inhibition is another powerful technique utilized by PRI to rebalance paerned systems.
Recruitment of an antagonist to an overactive muscle will neurologically inhibit that muscle’s
ring. Overactive and overused muscles are inhibited by the exercise position as well as by the
action of the exercise.
4.3. Restoring the transverse plane (via the left zone of apposition)
As we see in right-side dominant posture and in almost every patient with scoliosis, irrespec-
tive of curve paern, the left anterior ribcage is prominent and ared. The anterior left lateral
abdominals are lengthened and weak, and the right abdominals are often restricted anteri-
orly. The left diaphragm is maintained in a position of inhalation. Activities to restore and to
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achieve greater left diaphragm respiratory eectiveness require a neutral pelvis and relative
frontal plane balance. Mobilizing muscles to promote left anterior ribcage internal rotation
targets left internal obliques and transverse abdominis. Right and left lower trapezius, left
serratus anterior, and right subscapularis are important muscle chain agonists.
Retraining of alternate, reciprocal, upright gait is the ultimate goal. Balanced asymmetry in
gait requires sagial core strength to maintain neutrality of the pelvis and ribcage, with fron-
tal plane competence to achieve left AFIR in stance phase and right AFER in swing phase, and
the ability of the left diaphragm to fully exhale and the right to fully inhale. This exemplies
normalized function of the nondominant right AIC (see Figure 10). Although not all patients
can achieve full-balanced asymmetry, especially in the presence of structural change, balanc-
ing triplanar muscle activity will enhance functionality, improve respiration, and in most
cases, halt curve progression.
4.4. Examples of exercises
90-90 Hip Lift with Right Arm Reach and Balloon: This is one of the several versions of sagial
plane repositioning activities. In this activity, the patient is able to stabilize the pelvis in a neu-
tral position, via bilateral, isometric hamstring activation, making it easier for many patients
to achieve control. The addition of a balloon in any activity will promote active resistance to
exhalation and concentric contraction of internal obliques and transverse abdominals. Right
reaching in this activity further promotes left abdominal shortening and helps the patient to
sense desired left posterior pelvic rotation (see Figure 15).
All Four Belly Lift Walk: This activity oers greater sensory awareness of position through 4
points of contact with the ground as well as movement against gravity. The patient is asked
to “reach” during synchronized breathing with both hands and heels as they “walk” their
feet forward, keeping knees bent. This promotes improved thoracic positioning through acti-
vation of internal obliques and transverse abdominals as well as diaphragmatic expansion
and elongation of the thorax, while paraspinals are inhibited. Ankle dorsiexion required for
posterior weight shifting is an additional valuable component of this activity (see Figure 16).
Figure 15. 90–90 hip lift with right arm reach and balloon used with permission from the Postural Restoration Institute®.
Copyright 2017, www.posturalrestoration.com
Innovations in Spinal Deformities and Postural Disorders154
Left Sidelying, Left Flexed Femoral Acetabular Adduction with Right Lowered Extended Femoral
Acetabular Abduction: This frontal plane sidelying exercise is a progression following the acqui-
sition of sagial plane neutral pelvic position. The sidelying position oers support and sen-
sory reference to help the patient nd and recruit the proper muscles. Activation of the left hip
adductor helps to maintain sagial plane neutral pelvic position. The left lateral abdominals are
concomitantly activated with a right lower extremity reach to correct the left lumbar scoliosis in
the frontal plane. The sidelying position oers gravitational resistance to right hip abduction,
strengthening the right gluteus medius and maximus in the corrected position (see Figure 17).
Right Sidelying Right Apical Expansion with Left Femoral Acetabular Internal Rotation (AFIR): A
higher-level challenge for control of a right thoracic curvature is presented in this activity. The
loaded right arm facilitates right scapular depression and retraction of the thoracic promi-
nence toward the midline with benecial elongation of the right lumbar spine. The left reach
promotes right trunk rotation and left posterior mediastinal expansion. The pelvic position
further encourages the corrective left lateral abdominals, left acetabular femoral adduction,
and internal rotation (AFIR) with right acetabular femoral abduction and external rotation
(AFER). Without sucient right thoracic control, this activity can result in patients “dropping
into” their thoracic curve, making this an advanced activity (see Figure 18).
Figure 16. All four belly lift walk used with permission from the Postural Restoration Institute®. Copyright 2017, www.
posturalrestoration.com
Figure 17. Left sidelying, left exed femoral acetabular adduction with right lowered extended femoral acetabular abduction used
with permission from the Postural Restoration Institute®. Copyright 2017, www.posturalrestoration.com
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Standing Supported Left Acetabular Femoral Internal Rotation (AFIR) with Right Femoral Acetabular
Abduction: This frontal plane, upright, supported activity is a natural progression of a left
sidelying program. For patients with left lumbar scoliosis, activation of left internal obliques
and transverse abdominals creates a stabilizing triplanar force on the lumbar spine, a region
clinically associated with instability in these patients. Frontal plane control of the pelvis is
highlighted as the patient aempts to abduct their right leg and maintain triplanar pelvic
corrections. Bringing this familiar frontal plane challenge to the upright position allows the
patient to carry over sensations and control established in left sidelying to a more functional
integration of postural correction (see Figure 19).
Four Point Gait with Mediastinum Expansion: Ecient gait requires the pelvis to move over the
stance limb with the trunk counterrotating. Patients with scoliosis are commonly challenged
during left stance due to limited left pelvic rotation and right trunk counterrotation. The use
of walking poles is an eective method to achieve “all 4” sensory awareness of the ground
when upright. The patient is guided into a movement paern for left pelvic orientation over
the left stance limb as they simultaneously expand the left posterior mediastinum via left arm
reach as they advance the left pole, promoting right trunk counterrotation (see Figure 20).
Figure 18. Right Sidelying Right Apical Expansion with Left Femoral Acetabular Internal Rotation (AFIR) used with permission
from the Postural Restoration Institute®. Copyright 2017, www.posturalrestoration.com
Figure 19. Standing supported left acetabular femoral internal rotation (AFIR) with right femoral used with permission from the
Postural Restoration Institute®. Copyright 2017, www.posturalrestoration.com
Innovations in Spinal Deformities and Postural Disorders156
Seated, Supported Left Acetabular Femoral Internal Rotation (AFIR) with Right Psoas and Iliacus
and Right Femoral Acetabular External Rotation (AFER): In scoliosis, spinal compression is
problematic because it increases spinal torsion. Siing is likely the most common posture
associated with increased spinal compression. Eective seated postural corrections are,
therefore, an important skill requiring advanced, tri-planar control of the pelvis and thorax.
This advanced, integrated activity positions the pelvis in left rotation with counterrotation
of the thoracic spine into right trunk rotation. The lengthened right psoas is shortened and
strengthened in its role as a hip exor (see Figure 21).
Figure 20. Four-point gait with mediastinum expansion used with permission from the Postural Restoration Institute®.
Copyright 2017, www.posturalrestoration.com
Figure 21. Seated, supported left acetabular femoral internal rotation (AFIR) with right Psoas and iliacus and right femoral
acetabular external rotation (AFER) used with permission from the Postural Restoration Institute®. Copyright 2017, www.
posturalrestoration.com
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5. Case studies
5.1. Case 1
History: MD is a very active, extremely exible, 9-year-old girl. She is passionate about bal-
let. She reports right hip pain and limited motion with some dance moves. Her shoulders
occasionally “pop out of joint.” Her mother reports numerous falls. MD was diagnosed
with left thoracolumbar scoliosis at age 8, with a Cobb angle of 13°. Her doctor recom-
mended to “wait and see.” One year later, at age 9, the Cobb angle had increased to 27°.
Again, her doctor recommended to “wait and see.” MD’s mother decided to seek conserva-
tive treatment.
Initial evaluation ndings: Observation—general laxity, swayback, forward head posture,
restless, constantly moving into dierent end-range extension positioning. Standing pos-
ture—stands on left leg, left knee hyperextension, left hip shifted to left, left pelvis posi-
tioned in swing phase (AFER), right knee bent, minimal right weight bearing. Unilateral
stance—left leg 20 s, right leg 6 s. Bilateral stance (equal weight bearing)—10 s, then reverts
to left stance. Forward bend—¼ range of motion, no lumbar reversal, states “my back
will break.” Seated hip rotation—internal: right 59°, left 45°, external: right 45°, left 45°.
Spirometry (FEV)—average of three trials 1173 cc (age norm 1550 cc), weak exhale. Gait—
extreme lumbar lordosis, bilateral Trendelenburg. Unable to maintain test position for ADT
due to restlessness.
5.1.1. Clinical reasoning and treatment progression
MD being hypermobile demonstrated the common nding of decreased proprioception. In
her physiological aempts to feel stable, she resorted to end-range positioning via hyperex-
tension. In the sagial plane, this lordotic posturing caused anterior pelvic rotation and ante-
rior ribcage elevation. Chronic anterior ribcage elevation decreased diaphragmatic eciency
and resulted in the diaphragm acting as a postural extensor muscle. Due to chronic pelvic
anterior rotation and overuse of her right leg, especially in dance class, right hip impingement
developed. MD shifted o the right leg to avoid impingement pain. This became a strong
paern, and she could no longer maintain bilateral stance. To balance her left-sided shift, her
spine migrated right. She remained in hyperextension.
Treatment began with a practice of bilateral and right stance. This was pain-free, but very
challenging. Sagial plane: repositioning was introduced at the second visit via the All Four’s
Belly Lift Walk (see Figure 16). This activity inhibited the tight paraspinals while shortening
and strengthening lateral abdominals. Over the next few visits 90/90 Hip Lift activities were
added to inhibit the paraspinal muscles in a supported position while isolating the hamstring
muscles to establish pelvic neutrality. A balloon blow was added to 90/90 Hip Lift to increase
recruitment of lateral abdominals while in a pelvic neutral position (see Figure 15). A siing
exercise with back supported, balloon blow, and left arm reach was added to challenge her in
a more upright position. MD also practiced siing in a chair blowing out through a straw to
help her learn how to breathe diaphragmatically.
Innovations in Spinal Deformities and Postural Disorders158
Frontal plane: Left AFIR was introduced with a hip hinge standing activity that simultaneously
facilitated left posterior mediastinal (concavity) expansion.
The lateral spinal curve was eliminated in ve physical therapy sessions of 1 hour each, over
a 3-month period by addressing sagial plane and respiratory dysfunction. MD’s mother
helped her with daily exercises. Due to her extreme hypermobility, MD is continuing physical
therapy check-ins at 3–6-month intervals to maintain alignment, to stabilize, and strengthen
her structure and to assure a neutral baseline. Scoliosis has not recurred. She continues her
intensive ballet.
Summary: At age 9, when MD began PT, no spinal structural changes were evident, and there
was no countertilt. However, her curve had progressed over a year, at Risser 0, from 13° to 27°
with a rapid growth period ahead of her. Without intervention, structural change and curve
progression were inevitable. This case highlights the importance of early detection and treat-
ment. In the US, the current medical approach to juvenile and adolescent scoliosis is “wait and
see.” Once exaggerated curvatures in sagial or frontal planes progress to structural change,
rehabilitation is signicantly more challenging and often less successful.
5.2. Case 2
History: RM is a 12-year-old female who was diagnosed with scoliosis at age 11. Her X-rays
showed a right thoracic, left lumbar PRI nonpatho curve paern, measuring 28° from T6–T12,
and 21° curve from T12–L4. Her sagial view lm showed 52.4° of lumbar lordosis and 42° of
thoracic kyphosis. She was told by her physician to “wait and see” and return 6 months later.
New X-rays revealed progression to 38° from T6–T12 and 26° from T12–L4. She was still a
Risser 0 and had not yet started menses. She was ed for a Boston Brace, which she wore for
16–20 hours a day, for about 2½ years weaning to nights only at the beginning of her freshman
year of high school and continuing. RM is an athlete playing basketball, tennis, and ultimate
frisbee and more recently, doing yoga. She spends the summers at a 6-week sleep-away camp
and travels internationally with her family.
Initial evaluation ndings: Her starting height was 5′3″. It is speculated that she had a growth
spurt from time of diagnosis over the 6-month period in which her curve progressed by
roughly 10°. Standing posture—anterior pelvis, knee hyperextension left greater than right,
the right medial border of scapula more prominent with the right scapula being rounded
forward, protracted, and slightly elevated, her right hip is higher and shifted slightly to
the right. In the sagial view, her weight is shifted anteriorly toward her toes. Gait—arm
swing was greater on the left than right, right shoulder is higher, and she lacks knee ex-
ion at the loading response bilaterally. Her upper body stays sti and her pelvis moves
in the frontal plane more than in the transverse plane. Forward bend—visible left lumbar
curve with slightly elevated right rib cage. Spirometry (FEV)—2200 cc, (age norm – 2150
cc.) Scoliometer—5° rotation to the right in mid-thoracic spine, 4° rotation to the left in mid-
lumbar spine.
Clinical testing: PRI testing—ADT indicated left anterior hemipelvis rotation, right hemipel-
vis neutral position (see Figure 12). HGIR indicated bilateral ribcage elevation and external
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rotation, left greater than right (see Figure 13). TRT—knees go farther to the left, indicating
suspected iliolumbar ligament laxity (see Figure 14). Both Right Apical Chest Wall Expansion
and Left Posterior Mediastinum (left thoracic concavity) Expansion were limited. Single limb stance
for 60 s—more stable in right stance, and trunk is more symmetrical in right stance than left
stance. In left stance, her hip and pelvis are shifted anteriorly. Her favorite position is to stand
on her right leg with her left leg crossed in front, her right hip out to the side with her right
hand propping on her right hip. She was pain-free.
5.2.1. Treatment progression and clinical reasoning
Postural awareness and behavior changed during activities of daily living—she lightened her
backpack and began to use a waist strap to redistribute weight to her pelvis from her spine.
We encouraged her to sense her heels and improve standing posture. We incorporated spinal
precautions (hip hinge instead of spinal exion) due to relative anterior spinal overgrowth
(RASO) and encouraged corrective postures for studying and lounging (i.e., avoiding prone
on elbows and siing in her curve paern).
Sagial plane: Supported supine activities to reposition pelvis were initiated by concomitant
strengthening of hamstrings and lateral abdominals focusing on exhalation to bring her rib
cage down anteriorly, restoring her respiratory zone of apposition. A left hip shift bias was
used to help anchor her left femoral-pelvic position with her left lateral abdominals as in the
90/90 Hip Lift with Right Arm Reach and Balloon (see Figure 15). Improved sagial plane posi-
tion was maintained throughout her program while addressing other planes of correction and
progressing positional challenges against gravity.
Frontal plane: Exercises focusing on balancing left lumbar curve were implemented in left side-
lying with a right leg reach, and by PRI left-side plank activities to lengthen her right lateral
abdominals and shorten/strengthen the left. Her right thoracic curve was addressed with left
sidelying activities to allow gravity to assist with centralization, as well as with positioning
and muscle activation to direct air for right apical and left thoracic concavity expansion. Right
upper extremity retraction/shoulder extension in external rotation was implemented to help
activate her right low and middle trapezius to help reposition her right scapula toward the
midline. Position was progressed from sidelying to siing to standing. Examples of these
PRI nonmanual techniques are the Left Sidelying Left Flexed Femoral Acetabular Adduction with
Right Lowered Extended Femoral Acetabular Abduction (see Figure 17), and the Standing Supported
Left Acetabular Femoral Internal Rotation (AFIR) with Right Femoral Acetabular Abduction (see
Figure 19).
Transverse plane: Once the left respiratory zone of apposition was achieved to anchor left ante-
rior rib are, activities to strengthen right low trapezius and triceps were used to assist with
thoracic spine derotation and rib cage balancing. Likewise, right iliacus and psoas were used
for lumbar spine derotation in siing and standing. The left serratus anterior and low tra-
pezius were activated concomitantly to bring the left rib cage posteriorly (to expand the left
thoracic concavity). Exercises were progressed from supine to seated to supported standing
to freestanding, followed by the addition of resistance (dynamic stabilization) in standing for
strengthening and maintenance of this correction.
Innovations in Spinal Deformities and Postural Disorders160
Final Clinical Findings: Height—5′6 & 5/8″ (2½ years later, almost 4″ of growth), X-rays - right
thoracic: T5–T12 = 35°, left lumbar: T12–L4 = 29.1°, Risser 4. Menses began summer of 2016. Her
growth has stabilized, and we are hopeful to prevent progression requiring surgical correc-
tion/xation. Spirometry (FEV)—2700 cc, which is age-appropriate. Single limb stance—more
symmetrical and balanced on each leg with good observable pelvofemoral position bilaterally.
Summary: Working with teenagers can be challenging as well as rewarding due their very busy
lives and neurodevelopmental immaturity to realize consequences. When trying to prevent
curve progression, over a long period of time during growth, the process can become repetitive
and laborious and it is easy for an adolescent to lose belief and/or motivation in the process.
School and extracurricular activities can override exercise programs, especially if the patient
has no pain. However, RM was diligent with her program and was able to implement concepts
of correction and to perform challenging exercises while away at summer camp. Her case is
an excellent example of the possibility to hold a curve that began to rapidly progress (10° in 6
months), with a starting point >25°, during a period of growth. She was able to avoid the need
for surgical correction and now has a “tool bag” of exercises and positions she can use to thwart
potential discomfort, as well as to maintain balanced asymmetry, throughout her lifetime. At
recent follow-up, she proudly oered that she has less pain than her peers and teammates fol-
lowing exercise classes and games “because I now know how to take care of my spine!”
5.3. Case 3
History: JP is a 66-year-old female with primary complaint of loss of upright function for the
past 10 years due to debilitating left leg sciatica. JP was able to stand and/or walk for only 10
min at a time, and this was greatly aecting her ability to participate in her choir practice and
in her ability to play actively with her grandson. The patient was diagnosed with scoliosis
as a teenager but was not oered any intervention. X-rays reveal right thoracic convexity
between T2 and T11 (apex T8) with a Cobb angle of 26°. There is a larger, left lumbar con-
vexity between T11 and L4 (apex L2) with a Cobb angle of 51° and clear evidence of rotary
instability with moderate lateral listhesis of L4 on L5.
5.3.1. Initial evaluation ndings
Standing posture—anterior translation of the pelvis. There is a notable, xed left thoracolumbar
kyphosis deformity and an associated left trunk imbalance with a right pelvic orientation in
the frontal and transverse planes. JP is noted to have a at thoracic spine and anterior rib ares
bilaterally. Gait—elevated thorax with no appreciable right arm swing, the pelvis remains right-
oriented throughout right and left stance phases. Clinical tests—ADT (see Figure 12) reveals
the right hemipelvis is in neutral position and the left hemipelvis in anterior rotation. HGIR
(see Figure 13) reveals restriction of right glenoid-humeral internal rotation due to restrictions
of right apical chest expansion with elevation and external rotation of the left anterior ribcage.
Palpation reveals limited expansion for both the right Apical Chest Expansion Test and the left
Posterior Mediastinum Expansion Test. Spirometry (FEV) measures were 2100 cc, 1800 cc, and
1800 cc, respectively, over three trials consistent with hyperination and likely reduced FEV for
age and gender (norms for 65-year-old woman, 2160 cc). Functional outcome measure—Roland
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Morris Self-Report Low Back Pain Disability Questionnaire (RMDQ) was 9/24 or 37.5% self-
report disability.
5.3.2. Treatment progression and clinical reasoning
Sagial: Treatment began with sagial plane control of pelvis and thorax to improve critical
respiratory core muscle control. JP started in hooklying and supine 90–90 postures to begin
activities like supine 90–90 with balloon blowing versions (see Figure 15). Once postural test-
ing indicated adequate sagial plane control, she moved to a left sidelying program.
Frontal: For this patient, the left sidelying position was felt to be best to help her begin to
control frontal and transverse plane forces particularly in the region of her left lower lumbar
spine, which were the most likely source of her debilitating sciatica. As JP gained control of
the left abdominal wall in left sidelying and to obtain a ZOA, she began to integrate that con-
trol with combined muscular eorts culminating in left acetabular femoral internal rotation as
with Left Sidelying Left Flexed Femoral Acetabular Adduction with Right Lowered Extended Femoral
Acetabular Abduction (see Figure 17). JP was severely challenged with kinesthetic awareness
of muscle activation and “carry over” to alternative postures. In her case, it was very helpful
to have her stand up after a left sidelying activity to try to reproduce the same movement
paern in upright—her most challenging posture. Adding activities like Standing Supported
Left Acetabular Femoral Internal Rotation with Right Femoral Acetabular Abduction (see Figure 19)
were, therefore, quite a good challenge for improved upright control.
Transverse and alternating, reciprocating movement: As JP demonstrated further capacity for
trunk control with left acetabular femoral internal rotation, we added challenges to coordi-
nate with right trunk rotation as with gait. The use of walking poles was tremendously help-
ful for this patient to help with her balance, core muscle activation, kinesthetic sense of the
ground and weight shifting, as well as to oer additional support for spinal elongation, a criti-
cal element in scoliosis treatment. Activities depicted like Four Point Gait with Mediastinal
Expansion were further developed (see Figure 20).
Summary: Over the course of her last few visits (21 visits total), JP was consistently report-
ing dramatic and steady improvement in her function. She was playing with her grandson
more than 2 hours at a time and able to stand through 3-hour choir rehearsals. Her walking
progression was up to 34 min. The last RMDQ score was 3/24 or 12.5% self-report disability.
All physical therapy goals were met. She was highly compliant and motivated throughout the
course of her care, which no doubt, contributed to her strong outcomes.
6. Conclusion
The theoretical framework of PRI and its model of innate human asymmetry provides the
clinician valuable insight into the development and progression of scoliosis and other spinal
dysfunctions. This framework has the potential to redene how clinicians evaluate and treat
these conditions.
Innovations in Spinal Deformities and Postural Disorders162
It is our experience that early detection and treatment of scoliosis and other postural disorders
makes a signicant dierence to the success of intervention. For instance, a functional disorder
resulting from an asymmetrical dominant paern can more easily be rebalanced than one that
has evolved into structural pathology. In the US, the medical approach to juvenile and adoles-
cent scoliosis is commonly “wait and see.” The PRI model recommends simple tests of balance
and respiration in young people to identify those at risk. Early introduction of exercises to rees-
tablish balanced asymmetry may eectively reduce the need for long-term rehab or surgery.
Patients of all ages and magnitude of spinal deformity can benet from the PRI approach.
Reestablishing neutrality, learning to balance tri-planar muscle activity, and optimizing res-
piration are among the life-long benets of working on these exercises. Self-awareness engen-
dered in this process is additionally empowering for many patients.
Clinical results of the application of PRI methodology have been compelling. We would like
to encourage research on the many aspects of this new, innovative framework.
Acknowledgement
We are grateful to Ron Hruska MPA, PT, executive director of the Postural Restoration
Institute, who formulated these concepts, developed this framework and continues to share
his evolving insights.
Author details
Susan Henning*, Lisa C. Mangino and Jean Massé
*Address all correspondence to: myadvancephysicaltherapy@gmail.com
Advance Physical Therapy, Chapel Hill, NC, USA
PRI certied and Schroth Barcelona certied
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