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Rehabilitation of the stability function of psoas major

Authors:
  • Neuromuscular Rehabilitation Institute

Abstract and Figures

Psoas major is an important stability muscle of the lumbar spine, sacroiliac joint and hip. This is supported through anatomy, biomechanics, and physiology. The reported harmful effects of psoas major are based on myths and observations that we now understood to be false with our greater understanding of muscle function. This paper describes the assessment and rehabilitation of specific motor control rehabilitation for psoas major.
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www.orthodiv.org January/February 2002 - Orthopaedic Division Review 9
Rehabilitation of Psoas Major
Introduction
Psoas major is the largest muscle in
cross section at the lower levels of the
lumbar spine (McGill et al, 1988). A
review of the literature reveals it has
been a poorly investigated muscle and
there is still controversy concerning its
true functional role (Gibbons, 1999).
This may be due to several reasons; its
location within the body, which does
not permit routine access with
myolectric electrodes or a clear visual
with real-time ultrasound imaging, it’s
complex anatomy (Bogduk et al,
1992), and finally, it is not always
considered separately from iliacus
(hence the name ‘iliopsoas’). A better
understanding of the implications of
the function of psoas major on the
stability of the lumbo-pelvic region
may improve clinical management of
related dysfunction. Research was
undertaken to gain an understanding
of the anatomy, physiology and
function of psoas major. This involved
a systematic review of the literature,
dissection studies of psoas major and
the deep myofascial system. From this,
a biomechanical model was
developed. The purpose of this paper
is to briefly highlight this project and
discuss specific strategies for training
psoas major to contribute to lumbo-
pelvic stability.
Summary of Anatomy and
Physiology
Psoas major has fibrous
attachments to the anterior aspect of
all lumbar transverse processes and to
the antero-medial aspect of all the
lumbar discs and adjoining bodies
with the exception of the L5-S1 disc
(Bogduk et al, 1992; Gibbons, 1999).
For their relative positions on the
spine, the attachments on the
transverse processes were named
posterior and those on the discs and
bodies called anterior. These
attachments constitute individual
fascicles. The fascicles of psoas are
about the same length within
specimens and have a unipennate
fibre orientation. The fibre length
within anterior fascicles range from 3
to 8cm and 3 to 5cm in the posterior
fascicles. The fascicles run infero-
laterally to reach a central tendon
where they descend over the pelvic
brim and share a common insertion
with iliacus to the lesser trochanter
(Gibbons, 2001, Gibbons et al, 2001).
Psoas also has significant fascial
relations. The medial arcuate ligament
is a continuation of the superior psoas
fascia. The right and left crus make up
the spinal attachment of the
diaphragm. They attach to the antero-
lateral component of the upper three
vertebrae and bodies. The crus and
their fascia overlap psoas and appear
continuous with psoas until they come
more anterior and blend with the
anterior longitudinal ligament
(Gibbons, 1999). As psoas descends,
its infero-medial fascia becomes thick
at its lower portion and is continuous
with the pelvic floor fascia. This also
forms a link with the conjoint tendon,
transversus abdominus, and the
internal oblique. As psoas passes over
the pelvic brim, the fascia of the
posterior fascicles attaches firmly to
the pelvic brim (McVay and Anson,
1940; Williams et al, 1989; Gibbons,
1999, 2001, Gibbons et al, 2001).).
The nerve supply to psoas is not
reported consistently as most
anatomical texts list 3 different
variations. These are listed under
psoas major, the lumbar plexus and
the femoral nerve. Dissection has
shown that the anterior and posterior
fascicles have a separate nerve supply.
The posterior fascicles are supplied by
the ventral rami of spinal nerves T12
through L4. The anterior fascicles are
supplied by branches of the femoral
nerve from L2, 3 and 4 (Gibbons, 1999,
2001, Gibbons et al, 2001).
Literature Review Summary
A tool was developed to
systematically evaluate literature on
muscle function, which consisted of
critical methodological criteria and
general methodological criteria. It was
divided into sections based on the type
of research project and the methods
used. Each section was given a score
based on the criteria within it. Very
few studies passed the basic
component of the critical
methodological criteria. In addition,
many studies did not consider psoas
separately from iliacus or the method
of assessment was very poor (Gibbons,
1999; Gibbons, 2001).
From the literature review, psoas
major is thought to function as a
stability muscle for the lumbar spine
through axial compression and offers
little, or no contribution to range of
spinal movement. (Bogduk et al,
1992). Andersson et al (1995) state
that psoas major controls spinal lateral
movement eccentrically and their
results indicate that it also contributes
to stabilization of the hip joint and
assists iliacus with hip flexion.
Evidence of Muscle Dysfunction
Based on motor control studies,
Hodges and Richardson (1996, 1997;
see Richardson et al, 1999a)
concluded transversus abdominus was
important for spinal stabilization. They
identified an anticipatory reaction in
transversus abdominus in response to
spinal disturbance produced by limb
movements. In subjects without low
back pain transversus abdominus was
activated prior to limb movements and
spinal disturbance, while activation of
transversus abdominus was
significantly delayed in subjects with
low back pain independent of the
Rehabilitation of the Stability Function of Psoas Major
Sean GT Gibbons, Mark J Comerford and Peter L Emerson
10 January/February 2002 - Orthopaedic Division Review www.orthodiv.org
direction of limb movements and
spinal disturbance. The delayed onset
of contraction of transversus
abdominus indicates a deficit of motor
control and as a result of this the
authors hypothesize there would be
inefficient muscular stabilization of the
spine.
There is evidence of lumbar
multifidus muscle wasting ipsilateral to
symptoms in patients with acute /
subacute low back pain (Hides et al,
1994; Kader et al, 2001). Hides et al
(1994) used real-time ultrasound to
assess the multifidus muscle. The
paraspinal muscles were scanned in
normal subjects and in patients with
acute unilateral low back pain.
Significant asymmetry of multifidus
cross sectional area (CSA) was noted
in subjects with low back pain.
This decrease in size of multifidus
was seen on the side of the symptoms
with the reduced CSA observed at a
single vertebral level suggesting pain
inhibition (now considered a decrease
in normal low threshold recruitment).
However, while the pain may resolve
the dysfunction may persist. Hides et
al (1996) found that recovery of
multifidus symmetry was not
spontaneous after painful symptoms
resolved. They observed that recovery
of symmetry was more rapid and more
complete in patients who received
specific, localized multifidus retraining
(Hides et al, 1996). Correction of this
asymmetry resulted in a decreased
incidence of recurrence after a three-
year follow up (Hides et al, 2001)
Inamura et al (1983) examined
psoas and sacrospinalis muscle CSA in
relation to sex and age. The results
suggest there is a decrease in psoas
CSA in increasing age for men and
women. Cooper et al (1992) studied
sacrospinalis and psoas CSA in
subjects with recent and chronic low
back pain. They found psoas atrophy
in both groups of subjects with a
greater decrease in CSA in the chronic
group. This was of a similar degree to
that of the paraspinal muscle wasting.
Dangaria and Naesh (1998)
assessed the CSA of psoas major in
unilateral sciatica caused by disc
herniation. There was significant
reduction in the CSA of psoas major at
the level and the site of disc herniation
on the ipsilateral side. In a single case
study, the width was decreased in the
posterior fascicles at the level and
ipsilateral to the site of symptoms in
acute low back pain (Whelan and
Gibbons, submitted). More research is
currently in progress in this area.
This is a similar pattern of inefficient
normal low threshold recruitment
(previously referred to as inhibition) as
seen in the deep segmental fibres of
lumbar multifidus (Hides et al, 1994).
This implicates psoas as having a local
stabilizing role in the lumbar spine
(Gibbons, 1999; Gibbons et al, 2001;
Comerford and Mottram, 2000).
Further motor control studies are in
progress to investigate a possible
anticipatory timing pattern of psoas as
seen in other local stability muscles.
Model of Psoas Major Function
From dissection studies and a
review of the literature, Gibbons
(1999) has presented a model of psoas
major. A common model of lumbar
stability shows the musculature
forming a cylinder. The top of the
cylinder is the diaphragm, the bottom
is the pelvic floor and the wall is
formed by the segmentally attaching
abdominal and posterior spinal
musculature, specifically transversus
abdominus and the segmental fibres of
lumbar multifidus (Morris, 1961;
Bartlink, 1957; Richardson et al,
1999a). Psoas major has intimate
anatomical attachments to the
diaphragm and the pelvic floor. This
unique anatomical disposition allows
psoas to act as a link between the
diaphragm and the pelvic floor that
may help maintain stability of the
lumbar cylinder mechanism. This can
be conceptually visualized as a rod in
the middle of a cylinder.
During inspiration, the diaphragm
increases tension making the cylinder
relatively more stable. During
expiration, the diaphragm relaxes
making the cylinder relatively less
stable. The anticipatory timing pattern
seen in transversus abdominus is
earlier in expiration (Hodges et al,
1997), presumably to compensate for
this decrease in stability (Richardson
et al, 1999a). Richardson et al (1999a)
feel that the motor control of the
stabilising action of transversus
abdominus may be superimposed and
summated to the respiratory action of
the diaphragm. This may occur,
however psoas is ideally located to
assist in a stability role here. Through
its segmental attachments, axial
compression and links to the
diaphragm and pelvic floor, psoas may
play a role in spinal stability and
should now be considered as an
important stabilizer of the lumbar
spine.
Two previous classification systems
of muscle function were combined to
develop a new model (Mottram and
Comerford, 1998; Comerford and
Mottram, 2000; 2001). This divides
muscles into local stabilizers, global
stabilizers and global mobilizers. Psoas
major should be classified as a local
and global stabilizer. The posterior
fascicles are ideally suited to perform a
local stabilizer role while the anterior
fascicles are better suited to have a
global stabilizer role.
Action:
The local stability role of psoas is to
produce axial compression along its
line of pull. This has the effect of
compressing the vertebral bodies to fix
the spine in neutral alignment while
longitudinally pulling the head of the
femur into the acetabulum. This
‘pulling in’ or ‘shortening the leg’
action should be localized to the hip
and pelvis. There should not be any
lateral tilt (‘hitching’), anterior or
posterior tilt, or rotation of the pelvis.
Likewise, any spinal rotation, flexion
or extension should be discouraged.
Bogduk (1997) suggests that psoas
has minimal ability to produce any
significant range of motion at the
lumbar spine. It has segmental
attachments anteriorly to every lumbar
vertebra and disc (except L5/S1). He
states that the primary role of psoas on
the lumbar spine is generating force
along a longitudinal moment to
enhance spinal stability via axial
compression. Psoas contraction
should increase stiffness segmentally
in the lumbar spine and should resist
motion segmentally rather than
produce it (Comerford and Emerson,
1998).
Assessment and Rehabilitation
The assessment and retraining of
the stability role of psoas major is
outlined in the diagram below.
Stage 1: Instruct Specific Action of
Axial Compression
Psoas should have the ability to
activate in any position of the trunk
and under any load situation. The first
stage must be viewed as only
instruction in the longitudinal action
of psoas. This is so the subject
understands and is aware of the
contraction required. It is not part of
the segmental assessment or
rehabilitation, although information
regarding sensation of effort,
proprioception and substitution
strategies is gained.
Monitoring technique
When assessment is performed in
supine or inclined sitting, it is possible
for the therapist to monitor these with
a simple palpation technique. The
therapist uses the second and third
digits (‘peace sign’) to palpate the
anterior superior iliac spine (ASIS) and
the soft tissue below in the antero-
lateral groin (5cm below the
ASIS)(Figure 3b).
The upper finger assesses for
control of movement of the pelvis and
maintenance of the lumbo-pelvic
neutral position while the lower finger
checks for excessive activity in rectus
femoris and sartorius. As the client
attempts to activate psoas, there
should be no movement of the pelvis
(assessed by monitoring the ASIS).
Any pelvic movement (monitored at
the ASIS) is discouraged. This is
considered a loss of the neutral lumbo-
pelvic position and is thought to be
associated with excessive activity of
quadratus lumborum or iliocostalis.
It is important that the client is
aware of the sensation of shortening
the leg. The therapist should not be
able to palpate radial expansion of
sartorius or rectus femoris under the
lower finger. It is possible for sartorius
and the tensor fascia latae (TFL)/ilio-
tibial band (ITB) to co-contract to
produce shortening of the hip. This
would be associated with noticeable
muscle contraction and significant
resistance to passive rotation of the
femur. Rectus femoris and the
hamstrings may also co-contract to
shorten the hip. This would be
associated with noticeable contraction
and significant resistance to passive
movement of the pelvis.
Step 1
Describe the position of psoas
major on the lumbar spine and hip to
the client. The action is vertical
shortening so that the hip moves closer
to the spine or it ‘shortens the hip into
the acetabulum’. The description that
different individuals relate to will vary
so it is useful to become familiar with
different verbal cues for this action.
When in the starting position, it may be
useful to passively distract the femur
and push it into the acetabulum
www.orthodiv.org January/February 2002 - Orthopaedic Division Review 11
1. Instruct the specific action of axial compression
(low threshold recruitment / low load training)
2. Assessment of segmental stability role
3. Retraining of segmental stability role
4a. Specific local stability muscle retraining
5. Integration of local stability muscle recruitment
into specific function
6. Integration of local & global co-activation into
normal function
4b. Assessment and specific global stability
muscle retraining
+/- movement or load facilitators
Figure 1: Summary of the six stages of psoas major stability rehabilitation.
12 January/February 2002 - Orthopaedic Division Review www.orthodiv.org
several times to give the sensation of
the action required.
Step 2
Starting position: Supine with the
lumbar spine in a neutral position. A
common substitution strategy is to
hitch the hip using quadratus
lumborum or iliocostalis. In this
situation, long sitting would be
preferred instead of supine.
Alternatively, in long sitting a common
substitution strategy is to rotate the
pelvis. In this situation supine would
be preferred. The hip should be in
neutral rotation (a guide is to position
the toes vertically) (Figure 3b). If the
hip is externally rotated at rest, it
should be placed in its mid position
and actively controlled there.
Step 3
Gently distract the femur and then
give an appropriate instruction. The
most common are “pull (or suck) your
hip into the socket” or “shorten your
hip without moving your back”.
Maintain the distraction during the
activation to provide a sensory or
afferent stimulus for the longitudinal
action of psoas. This is the action that
Stage 2 will assess the segmental
efficiency of.
Stage 2: Assessment of Segmental
Stability Role
When the action of psoas has been
correctly been taught the assessment
of the segmental stabilizing role (local
stability) of psoas can start.
The client is prone on the plinth
with one leg firmly extended to help
maintain balance, and the other leg
hanging freely over the edge with the
foot on the floor (Figure 2a). The side
with the leg hanging freely is the side
to be assessed. Gravity will provide a
slight distraction force. The pelvis and
spine are positioned in neutral with the
trunk muscles relaxed. Each lumbar
vertebral level is manually palpated to
assess the relaxed joint play
displacement in the transverse and
anterior directions (Figure 2b).
Psoas is facilitated by instructing the
patient to “pull the hip back into the
socket”, against the minimal
distraction force of gravity, without
moving the spine or pelvis. This gentle
contraction is sustained. Here, the
therapist should check for observable
or palpable co-contraction of the
erector spinae. If present, the therapist
should instruct the client to decrease
the effort until this is eliminated. Each
lumbar vertebral level is re-palpated to
assess the contracted joint play in the
transverse and anterior directions.
Ideally, there should be a significant
palpable increase in resistance to
manual displacement (stiffness) at
each level with psoas activation. The
client should be able to maintain the
contraction (and increased stiffness)
for fifteen seconds with normal
relaxed breathing and without fatigue
or substitution. This response should
be noted at all lumbar segmental
levels.
Segmental psoas dysfunction is
identified at the vertebral level in
which there is no increased resistance
to manual displacement during psoas
activation when compared to adjacent
levels (which do increase resistance to
translation when psoas is activated).
This lack of resistance to manual
displacement indicates a probable loss
of segmental control of the local
stability role of psoas (Comerford and
Emerson, 1998; Comerford and
Mottram, 2000). This assessment may
also be performed in other positions
(prone or side lying) so long as
distraction of the hip is controlled and
there is no over activation of the
paraspinal muscles.
Note: If the client is using facilitation
techniques during the assessment to
activate psoas, the palpation should be
performed with and without the
facilitators for comparison. It is
possible to facilitate other local
stability muscles, which may affect the
palpation component of the
assessment.
Stage 3: Retraining of the
Segmental (Local) Stability Role
There are a variety of facilitation
strategies to aid in the rehabilitation of
the segmental stability role of psoas.
Facilitation Strategies:
From the current research evidence
to date, the local stability muscles have
a motor control deficit in the presence
of low back pain that is not related to
weakness or length change. These
deficits are better retrained with
specific low effort exercises (Hides et
al, 1996; Richardson et al, 1999a;
O’Sullivan, 1997). As with other local
stability muscles, subjects respond
differently to various facilitation
strategies. The goal is to achieve
consistent low threshold activation of
psoas major to provide segmental
stiffness when the assessment (Stage 2)
is re-tested. When this can be
achieved, the facilitation techniques
should be discarded and retraining
should be progressed to a more
efficient specific contraction and
integration into function.
The following techniques can help
facilitate psoas:
1 - Active hip external rotation
This should be a slow, low effort,
small range movement. When the
client’s hip is normally positioned in
external rotation, it is useful to apply a
small amount of resistance to the
external rotation so the movement is
not passive (Figure 3). This facilitator
serves three purposes. First, the
external rotation may disadvantage or
Figure 2: A: Starting position for the
assessment of the local stability role
for psoas major. B: Manual palpation
of the spine in the assessment
position.
www.orthodiv.org January/February 2002 - Orthopaedic Division Review 13
inhibit the TFL/ITB, which is a femoral
internal rotator. Second, the external
rotation may recruit the deep hip
intrinsic muscles. These fit the
classification of local stabilizers as
outlined by Comerford and Mottram
(2001). Local stability muscles should
functionally co-activate together
(Richardson et al, 1999a), so activating
the deep hip intrinsic muscles may
facilitate the local stability role of
psoas major. Thirdly, psoas and iliacus
share a common tendon as they insert
into the lesser trochanter and they may
contribute to lateral rotation. In
normal function the local and global
muscles recruit synergistically. Low
threshold activation of the global role
of iliacus and the anterior fascicles of
psoas through lateral rotation may
facilitate the local function in the
posterior fascicles of psoas.
2 - Normal (unforced) end range
expiration
During expiration the diaphragm
ascends and because of the
anatomical relationship that exists
between the diaphragm and psoas,
expiration may create a mechanical
pull on psoas via fascial connections.
However, it is possible that this
relationship may be more
neurophysiological rather than
biomechanical. Abdominal breathing
in supine / crook lying provides the
best excursion of the diaphragm and
will have the best leverage for any
fascial pull on psoas (Williams et al,
1989).
3 - Pelvic floor contraction
There is a strong anatomical
relationship between the pelvic floor
fascia and the inferior psoas fascia.
The pelvic floor contraction should be
a low effort (less than 25% maximum
voluntary contraction) contraction. If
a proprioceptive / sensation of effort
deficit exists, a higher perceived effort
is permissible (Comerford and
Mottram, 2001; Gibbons and
Comerford, 2001) providing the
oblique abdominal muscles do not
dominate the contraction. The
oblique dominance is monitored via
palpation of the antero-lateral
abdominal wall (Figure 4). With a
slow, low effort pelvic floor
contraction, a ‘tensioning’ (transversus
abdominus recruitment) should be felt
and not a ‘bulge’ in the antero-lateral
abdominal wall (Richardson et al,
1999b). It is understood that local
stability muscles should co-activate
(Richardson et al, 1999a). When a
‘bulge’ is palpated, it is non-specific for
transverses abdominus and may not
be specific for posterior psoas major
facilitation.
4 - Resistance to passive anterior
rotation of the innominate
Psoas passes over the pelvic brim
where it becomes tendinous and
continues to the lesser trochanter.
While it does, the fascia of the
posterior fascicles attaches to the
pelvic brim. As psoas generates force,
this orientation creates a posterior
rotation moment on the innominate
relative to the sacrum that can resist an
anterior rotation action. The client is
instructed to use minimal effort to
maintain a neutral spine and hold the
pelvis steady during isometric
resistance to passive anterior rotation
of the innominate.
5 - Side-lying segmental lumbar
facilitation
The client is positioned in side lying
with the dysfunctional psoas
uppermost. The bottom leg is straight
and the top leg bent with the spine and
pelvis in neutral alignment in terms of
tilt and rotation. The top leg is
supported horizontally with the spine,
pelvis and upper trunk all neutral.
Psoas is facilitated by gently distracting
the top leg longitudinally and the
patient is instructed to pull the hip
back into the socket without moving
the spine or pelvis. Facilitation may be
localized to the segmental level of
dysfunction by manually palpating the
dysfunctional spinal level (as
identified in Stage 2 testing). The
therapist or client gently grips the
spinous process and manually
oscillates that vertebrae with a side to
Figure 3: A: Client positioned in hip
external rotation at rest. B: Low
effort resistance to active hip
external rotation during psoas major
facilitation with the hip in neutral
rotation.
Figure 4: Palpation of the lower
abdominal wall to monitor abdominal
activation during a pelvic floor con-
traction. (from the ASIS, palpate
2cm down along the inguinal liga-
ment then 1cm medial).
14 January/February 2002 - Orthopaedic Division Review www.orthodiv.org
side, back and forth motion, while the
psoas activation is sustained. This
provides afferent mechanical
proprioception and feedback. As
function improves with retraining,
there should be reassessment of
symmetry and segmental control with
the assessment (Stage 2).
Problem solving tips - watch for and
eliminate substitution:
1 - Dominant or excessive
activation of rectus femoris
Use less effort and a slower
contraction. A pillow may be used to
put the knee in slight flexion to
disadvantage rectus femoris
2 - Dominant or excessive
activation of TFL/ITB
Use less effort and a slower
contraction. Ensure the hip external
rotation is active rather than passive
and slightly more effort may be used
during the external rotation
contraction. The hip may be placed in
slight abduction to disadvantage
TFL/ITB.
3 - Dominant or excessive
of quadratus lumborum
Ensure the spine is in neutral. Use
less effort and a slower contraction.
Change position to long sitting.
4 - Dominant or excessive
activation of iliocostalis
There is excessive anterior tilt and
spinal extension. Ensure the spine is in
neutral. Use less effort and a slower
contraction.
5 - Dominant or excessive
activation of proximal trunk
muscles
Significant resistance to passive
rotation of the pelvis identifies this.
Use less effort and a slower
contraction. Ensure low effort activity
by the facilitators.
6 - Loss of neutral spine
Ensure the spine is in neutral
actively rather than passively after it is
achieved. Use less effort and a slower
contraction.
Movement and load facilitators
In situations where psoas is
dysfunctional or there is a lack of
proprioception by the client, it can be
useful to use movement and load
facilitators. A dysfunction identified in
psoas is a decrease in normal low
threshold recruitment. Under higher
load situations psoas will be activated.
These can be used to facilitate psoas
and then the client can return to the
normal low load facilitators.
Some techniques are listed below:
1 - Side-lying rotation to neutral
(psoas co-activation with
multifidus)
(Adapted Grieve)
The client is positioned in side lying
with the dysfunctional side of psoas
uppermost. The bottom leg is straight
and the top leg bent with the spine and
pelvis in neutral alignment in terms of
tilt and rotation. The uppermost leg is
allowed to drop towards the plinth
causing the trunk and pelvis to rotate
forwards. Psoas is facilitated by gently
distracting the top leg longitudinally
and the patient is instructed to pull the
hip back into the socket until the trunk
and pelvis rotates back to the neutral
position. The segmental or oblique
fibres of multifidus are co-activated by
the direct rotational movement. The
technique can be segmentally
localized by manual fixation at the
level above the dysfunction. The same
facilitators as before may be used here.
Hip external rotation is achieved when
the client gently pushes the top heel
downwards. The breathing, pelvic
floor contraction or resistance anterior
rotation of the innominate can follow.
2 - Sitting - leaning back
(eccentric hip flexors)
The client sits with the spine and
pelvis in neutral and the feet on the
floor. Keeping the spine and pelvis
neutral the patient is instructed to
slowly lean backwards by only moving
at the hips (rock from the ischium).
This requires that the deep hip flexors
eccentrically lower the trunk
backwards. Ensure that the lumbo-
pelvic neutral alignment is maintained.
There should be no substitution
dominance from the hip flexor
mobilisers (anterior tilt of the pelvis) or
the abdominals (palpable bulge in the
antero-lateral abdominal wall; trunk
flexion and posterior pelvic tilt), and
there should be no fatigue. The client
can lean backwards as far as can be
controlled and then leans forward to
return to neutral (if the forward lean
continues beyond 90° hip flexion the
bias shifts to multifidus and gluteals to
eccentrically control the movement).
3 - Hand - knee diagonal push
Lie in crook lying with the spine
supported in neutral. Slowly lift one
knee towards the opposite hand and
push them isometrically against each
other on a diagonal line (watch for
substitution e.g. do not stabilise with
the opposite foot or allow posterior
pelvic tilt). Ensure that the neutral
spine position is maintained. Psoas
strongly co-activates multifidus in this
procedure. This technique uses
significant more global stabilizer co-
contraction than many of the others.
This may be appropriate when
significant inhibition is present (e.g.
post surgery or inflammatory trauma).
Progression of Psoas Retraining
Once the correct activation can be
accomplished, psoas recruitment
retraining is performed in a variety of
different positions. Clinically, it may
be best to start in a position where the
client is confident they can achieve a
correct activation, rather than what the
therapist feels is the best activation.
For the majority of patients, recumbent
postures, such as supine lying, incline
sitting or side lying, are the positions
where it is easiest to facilitate and
teach the correct activation of psoas.
From this, other positions are trained.
As a general guide, the psoas
contraction should be maintained for
ten seconds and for ten repetitions,
during relaxed breathing. Two or
three sets a day are reasonable,
depending on the client. The
segmental stability of psoas should be
reassessed (Stage 2) regularly to
ensure appropriate progression.
Stage 4 A and B
Assessment of Global Stability
The global stability role of psoas
(anterior fascicles) is functionally
combined with iliacus. This may be
considered efficient when the
stabilizer can move the limb through
the available passive range of 120° hip
flexion. In sitting with the lumbar
spine in neutral, the hip is actively
flexed through the full range of motion
(ideally 120°). There should be no loss
of lumbo-pelvic neutral or co-
contraction of TFL / ITB and sartorius,
or the hamstrings. This can be
www.orthodiv.org January/February 2002 - Orthopaedic Division Review 15
identified as significant resistance to
passive rotation of the hip when it is
flexed. In optimum function, this
position should be maintained for ten
seconds and ten repetitions (it is
recognized that there may be other
reasons why there is a loss of a neutral
spine during this test).
Specific Retraining of the Local
and Global Muscle Role Through
Range
Global Supported Hip Flexion
The global role is best started in
supine or inclined sitting. Here, the
local role of psoas is combined with
the global role. ‘Shortening the hip’
activates psoas, and then while
maintaining this action, slow heel
slides are started. The heel actively
slides up beside the opposite leg
towards the buttock (as far as the
contralateral knee). The heel should
slide only as far as the client
confidently feels that the hip is still
‘shortened’. This position is held for
ten seconds. The eccentric return
(straightening of the leg) should be
controlled and performed at the same
slow pace as the concentric
component. The client should be
taught to monitor tibial external
rotation, hip internal rotation and hip
adduction (signs of TFL / ITB
dominating hip flexion) and lateral hip
rotation (a sign of sartorius dominating
hip flexion). The therapist should also
check for co - contraction rigidity at
the point the hip is held. Once the heel
slide can be coordinated and reach
the opposite knee, the foot can be
lifted 2cm and held. The exercises can
then be progressed to standing, and
sitting unsupported control exercises.
Global Unsupported Hip Flexion
Because the client often
experiences difficulty performing this
without substitution, the global
retraining may start without the local
role. This can start in standing with
some individuals. Others will have to
start in supine or long sitting. In
standing, hip flexion can start at 70°,
and progresses to 80° and 90°. This
can start supported on the wall with a
neutral spine and then unsupported
standing. This is progressed to sitting
hip flexion from 90° to 120°.
Global Spinal Stability Role -
Eccentric Control
Psoas also has an eccentric role in
spinal stability. This can be started in
sitting during a lean backwards and
then in standing. Standing and side
bending of the trunk is also controlled
by psoas and is best started supported
at a wall with the spine in neutral and
then progressed to unsupported
standing.
Rothstein has suggested that to
integrate an activity or skill into
normal, automatic or unconscious
function, many repetitions must be
performed under diverse functional
situations. To do this, some form of
reminder is needed. He has proposed
that small ‘red dots’ are placed so that
they are frequently seen and will act as
a visual reminder (e.g. on wristwatch,
clock, telephone, mirror etc.) for the
subject to perform a specific task each
time they are observed. This process
lends itself well to training of the local
stability system.
Stage 5: Integration of Local
Stability Muscle Recruitment into
Specific Function
When the psoas becomes efficient
and is easily activated it can be readily
integrated into functional activities. It
is easier to start with static activities
such as standing or sitting. When this
becomes easier, it can be incorporated
into dynamic movements such as
bending and walking.
Stage 6: Integration of Local and
Global Co-Activation into Normal
Function
Since the local role of psoas is
usually rehabilitated before the global
role, integration of the local retraining
into function starts earlier. As the
global role becomes more efficient, it
can also be incorporated into function.
This can include the hip flexion
component of the stairs, moving while
sitting or driving, and standing.
It is important the client continue
their functional activity when
retraining psoas into function, and not
‘stop’ and then activate. This may
hinder incorporation of psoas into
function. The retraining is progressed
into activities of daily living, and then
work or sport related activities.
Conclusion
A review of the literature to date
reveals that psoas major has been a
poorly investigated muscle. It
functions as a lumbar and hip
stabilizer through axial compression
and vertical shortening, respectively.
Research suggests psoas may have a
local stability role in the lumbar spine.
A model has been proposed in which
the posterior fascicles play a local
stability role while the anterior
fascicles are a global stability role.
Specific exercises and facilitation
strategies have been developed for the
rehabilitation of psoas major.
Although not discussed here, this
model has implications for retraining
of pelvic floor dysfunction. As well,
psoas may be considered a local
stabilizer for the hip and components
of the above regime may be used in
hip rehabilitation. Current research
includes validation of the exercises
and monitoring technique with real-
time ultrasound, and deep needle
electromyography. This will aid in the
further understanding of psoas, which
may lead to improved assessment and
rehabilitation strategies.
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... The fiber length within anterior fascicles range from 3 to 8cm and 3 to 5cm in the posterior fascicles. The fascicles run infero-laterally to reach a central tendon where they descend over the pelvic brim and share a common insertion with iliacus to the lesser trochanter (Gibbons, 2001). Psoas also has significant fascial relations. ...
... This also forms a link with the conjoint tendon, transversus abdominus, and the internal oblique. As psoas passes over the pelvic brim, the fascia of the posterior fascicles attaches firmly to the pelvic brim (McVay and Anson, 1940; Williams et al, 1989; Gibbons, 1999, 2001). The nerve supply to psoas is not reported consistently because most anatomical texts list three different variations. ...
... The posterior fascicles are supplied by the ventral rami of spinal nerves T12 through L4. The anterior fascicles are supplied by branches of the femoral nerve from L2, 3 and 4 (Gibbons, 1999, 2001). Literature review summary A tool was developed to systematically evaluate literature on muscle function. ...
... Mechanisms of respiration, continence, and lumbar stability are intertwined. The pelvic floor muscles and the diaphragm not only play an important role in continence and breathing, but, together with the transversus abdominis, the deep fibers of lumbar multifidus and possibly the psoas major form the deep lumbar cylinder, responsible for providing lumbopelvic stability through correct intra-abdominal pressure [122][123][124]. These common symptom presentations seen in obese subjects would lead to believe that the deep lumbar cylinder is often insufficient and the longer and more superficial trunk muscles dominate in their attempt to compensate. ...
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In the last two decades, whole-body vibration training (WBVT), involving exercising on a vibrating platform, emerged as an alternative exercise modality for the treatment of obesity. In this chapter, the possible clinical use of WBVT in obese individuals is addressed, involving its effect on body composition, muscle strength, and cardiovascular function.
... Mechanisms of respiration, continence, and lumbar stability are intertwined. The pelvic floor muscles and the diaphragm not only play an important role in continence and breathing, but, together with the transversus abdominis, the deep fibers of lumbar multifidus and possibly the psoas major form the deep lumbar cylinder, responsible for providing lumbopelvic stability through correct intra-abdominal pressure [122][123][124]. These common symptom presentations seen in obese subjects would lead to believe that the deep lumbar cylinder is often insufficient and the longer and more superficial trunk muscles dominate in their attempt to compensate. ...
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The aim of this chapter is to present a practical overview of the most common equipment for patient handling and rehabilitation technologies for a clinical setting, focusing the attention on devices suited for obese individuals. In details, the equipment, devices, aids, and resources designed as alternative to manual handling are described. We have reviewed the equipment related to lifting, transferring, repositioning, moving, and mobilizing of obese patients ensuring that patients are cared for safely preventing consequences of immobility, while maintaining a safe work environment for employees.
... Information is available elsewhere relating to specific translation control exercises for the hip (Gibbons et al 2002, Gibbons 2007c, muscle imbalance (Page et al. 2010, Grimaldi 2011) and movement pattern control (Sahrmann 2002, Lewis and Sahrmann 2006, Sahrmann and Associates 2011. Some common clinical tests for translation control are described in table 14. ...
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Yoga, as both a science and art, elicits neurochemical response mediated by neurophysiological mechanisms, and when used in rehabilitation, can honor both its cultural philosophy while evolving as an evidence-based therapy. The central theme of this chapter is to provide a foundation for a novel yogic model of rehabilitation practice using proposed common psychotherapeutic and physiological factors that affect patient outcomes. This model is guided by Ten Precepts that can guide the use of yoga in rehabilitation as a medical, therapeutic, yoga, in order to foster evidence-based practice, which is representative of best practice techniques in rehabilitation. The 10 Precepts include guidelines on optimization of patient assessment and intervention, education, respiratory function as a first-line psychophysiological intervention, fostering stability and safety through six evidence-based neurophysiological principles, inclusion of Ayurveda and other yogic tools, and non-dogmatic yoga practice in rehabilitation.
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Yoga, as both a science and art, elicits neurochemical response mediated by neurophysiological mechanisms, and when used in rehabilitation, can honor both its cultural philosophy while evolving as an evidencebased therapy. The central theme of this chapter is to provide a foundation for a novel yogic model of rehabilitation practice using proposed common psychotherapeutic and physiological factors that affect patient outcomes. This model is guided by Ten Precepts that can guide the use of yoga in rehabilitation as a medical, therapeutic, yoga, in order to foster evidence-based practice, which is representative of best practice techniques in rehabilitation. The 10 Precepts include guidelines on optimization of patient assessment and intervention, education, respiratory function as a first-line psychophysiological intervention, fostering stability and safety through six evidence-based neurophysiological principles, inclusion of Ayurveda and other yogic tools, and non-dogmatic yoga practice in rehabilitation.
Article
Der M. psoas major als der größte Muskel im unteren LWS-Bereich trägt zur körperlichen Stabilität bei. Die vorliegende Arbeit stellt das klinische Assessment und die Rehabilitationsstrategien zur stabilisierenden Funktion des M. psoas major dar. Ein besseres Verständnis dieser Funktion kann die klinische Behandlung von damit im Zusammenhang stehenden Dysfunktionen verbessern.
Article
Study Design: The contribution of transversus abdominis to spinal stabilization was evaluated indirectly in people with and without low back pain using an experimental model identifying the coordination of trunk muscles in response to a disturbance to the spine produced by arm movement. Objectives: To evaluate the temporal sequence of trunk muscle activity associated with arm movement, and to determine if dysfunction of this parameter was present in patients with low back pain. Summary of Background Data: Few studies have evaluated the motor control of trunk muscles or the potential for dysfunction of this system in patients with low back pain. Evaluation of the response of trunk muscles to limb movement provides a suitable model to evaluate this system. Recent evidence indicates that this evaluation should include transversus abdominis. Methods: While standing, 15 patients with low back pain and 15 matched control subjects performed rapid shoulder flexion, abduction, and extension in response to a visual stimulus. Electromyographic activity of the abdominal muscles, lumbar multifidus, and the contralateral deltoid was evaluated using fine‐wire and surface electrodes. Results: Movement in each direction resulted in contraction of trunk muscles before or shortly after the deltoid in control subjects. The transversus abdominis was invariably the first muscle active and was not influenced by movement direction, supporting the hypothesized role of this muscle in spinal stiffness generation. Contraction of transversus abdominis was significantly delayed in patients with low back pain with all movements. Isolated differences were noted in the other muscles. Conclusions: The delayed onset of contraction of transversus abdominis indicates a deficit of motor control and is hypothesized to result in inefficient muscular stabilization of the spine.
Article
The purpose of this study was to add to the growing database of cross-sectional areas and moment arm lengths of trunk musculature using the methods of computerized tomographic scanning. An attempt was also made to estimate muscle force and moment generating capacity under various reported values of muscle force per unit cross-sectional area. The data were obtained on 13 active men 40.5 +/- 11.9 years of age, 173.8 +/- 5.9 cm tall and 89.1 +/- 11.7 kg body mass. Transverse CT scans were taken at the level of the L4/L5 disc with the subjects supine. Muscle cross-sectional areas were measured from 35 mm slides of the scans using a planimeter and moment arm length in the transverse plane were taken from the centroid of the L4/L5 disc to the centroid of the muscle section. Prior to estimating force and moment generating capacity, areas were corrected, where necessary, for fibre pennation angle to produce a physiological cross-sectional area. The physiological cross-sectional areas (cm2) for one side of the body were (mean +/- S.D.): sacrospinalis (SS) 15.9 +/- 2.5; multifidus (Mu) 4.2 +/- 0.7; psoas (Ps) 17.6 +/- 4.0; rectus abdominis (RA) 7.9 +/- 2.5; external oblique (EO) 9.4 +/- 2.7; internal oblique (IO) 8.1 +/- 2.3; transverse abdominus (TA) 2.9 +/- 1.3. The anterior posterior moment arm lengths were: erector mass (SS and Mu combined) 5.90 +/- 0.52; Ps 0.58 +/- 0.40; R.A. 10.28 +/- 2.07; E.O. (anterior portion) 5.94 +/- 1.39; E.O. (posterior portion) 2.08 +/- 1.39; I.O. (anterior portion) 6.92 +/- 1.63; I.O. (posterior portion) 3.85 +/- 1.54. The corresponding lateral moment arm lengths were: 3.26 +/- 0.36; 4.88 +/- 0.36; 4.35 +/- 1.31; 12.86 +/- 1.93; 13.95 +/- 1.16; 10.77 +/- 2.02; 12.52 +/- 1.26. The maximum force per unit cross-section that human muscles are capable of generating is not well defined. However, assuming an intermediate value of 50 N cm-2 of physiological cross-section, the erector musculature observed at the L4/L5 level should be capable of generating an extensor moment of about 118 N.m. At a muscle stress of 30 or 90 N cm-2, values also reported on human muscle, the moment would be 71 and 213 Nm, respectively. It must be remembered, however, that muscles not observable at the L4/L5 level can create moments around that center of rotation.(ABSTRACT TRUNCATED AT 400 WORDS)
Article
Recent advances in muscle biology have greatly expanded our knowledge of how muscle functions in health and disease and how muscle adapts to a variety of stimuli. The purpose of this review is to consider how this information can be applied to the practice of physical therapy. The opinions and ideas represent those of a clinician who is also involved in research on the functional performance of muscle and how performance relates to basic biological mechanisms. The review examines selected aspects of muscle physiology, muscle mutability, and problems that arise when basic research material must be generalized for clinical practice.
Article
The activation patterns of the psoas and iliacus muscles were investigated in 7 healthy adult subjects (4 men and 3 women) during a variety of motor tasks in standing, sitting and lying. Myoelectric activity was recorded simultaneously from the 2 muscles using thin wire electrodes inserted under guidance of high-resolution ultrasound. In general, both muscles were coactivated, albeit to different relative levels, particularly when hip flexor torque was required. Selective activation of the iliacus could, however, be seen to stabilize the pelvis in contralateral hip extension during standing. Psoas was found to be selectively involved in sitting with a straight back and in contralateral loading situations requiring stabilization of the spine in the frontal plane. During training exercises from a supine position, such as sit-ups, the contribution of the psoas and iliacus muscles could be varied by changing the range of motion as well as the position and support for the legs. Thus, the 2 anatomically different muscles of the iliopsoas complex were shown to have individual and task-specific activation patterns depending on the particular demands for stability and movement at the lumbar spine, pelvis and hip.
Article
Magnetic resonance images from fifteen physically active and asymptomatic male volunteers were collected to present morphometric parameters on the psoas and its moment arms, which are important in the study of spinal mechanics and models for the investigation of low back pain. The mean age of the subjects was 21.5 +/- 1.8 years. Data were obtained from nine vertebral and/or intervertebral levels (L2, L2/L3, L3, L3/L4, L4, L4/L5, L5, L5/S1, S1). In general, the psoas increased in size as it descended the trunk, moving anteriorly and slightly laterally in relation to the vertebral column. Maximum cross-sectional areas for the psoas (M = 16.3cm2) were observed at the L4/L5 level. Right-left symmetry was apparent in the aforementioned dimension, but not with respect to the mediolateral (X) diameter of the muscle. The length of the X moment arm was significantly (p < .05) greater for the right versus the left psoas from L3 to S1, with the length increasing as the psoas descended the trunk. However, this trend was not noted for the anteroposterior (Y) moment arm where observed values remained relatively small throughout the course of the muscle. These results will contribute to the study of low back pain onset and the design of appropriate rehabilitation interventions by providing accurate morphometric parameters for biomechanical models to predict of the loading conditions of the spine in vivo.
Article
The effect of low back pain on the size of the lumbar multifidus muscle was examined using real-time ultrasound imaging. Bilateral scans were performed in 26 patients with acute unilateral low back pain (LBP) symptoms (aged 17-46 years) and 51 normal subjects (aged 19-32 years). In all patients, multifidus cross-sectional area (CSA) was measured from the 2nd to the 5th lumbar vertebrae (L2-5) and in six patients, that of S1 was also measured. In all normal subjects, CSA was measured at L4 and in 10 subjects measurements were made from L2-5. Marked asymmetry of multifidus CSA was seen in patients with the smaller muscle being on the side ipsilateral to symptoms (between-side difference 31 +/- 8%), but this was confined to one vertebral level. Above and below this level of wasting, mean CSA differences were < 6%. In normal subjects, the mean differences were < 5% at all vertebral levels. The site of wasting in patients corresponded to the clinically determined level of symptoms in 24 of the 26 patients, but there was no correlation between the degree of asymmetry and severity of symptoms. Patients had rounder muscles than normal subjects (measured by a shape ratio index), perhaps indicating muscle spasm. Linear measurements of multifidus cross-section were highly correlated with CSA in normal muscles but less so in wasted muscles, so CSA measurements are more accurate than linear dimensions. The fact that reduced CSA, i.e., wasting, was unilateral and isolated to one level suggests that the mechanism of wasting was not generalized disuse atrophy or spinal reflex inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)