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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5830_Библиотеки_им_академика_М_И_Перельмана.pdf
INTERNAL OBLIQUE (IO) AND TRANSVERSUS ABDOMINIS (TrA)
An inability to isolate the TrA demonstrated by a simultaneous
contraction of the oblique abdominals, or RA, may result in inappropriate (excessive) force closure of the pelvis, lumbar spine and
thorax (Lee 2004). The resulting ultrasound image will demonstrate a concurrent, phasic, increase in depth and decrease in length
of both the TrA and IO (Fig. 3.7a). This simultaneous contraction
TABLE 3.1 OBSERVATIONAL CONSIDERATIONS DURING PREFERENTIAL ACTIVATION
OF TRANSVERSUS ABDOMINIS
PHASE CONSIDERATION POTENTIAL IMPLICATION
Resting Position of the spine (neutral, fl exed, Resting superfi cial muscle tone
position extended)
Location and symmetr y of breathing Degree of abdominal laxity, increased
pattern (apical, lateral costal, abdominal) thoracic elasticity (joint dysfunction,
muscle hypertonicity, disease process)
Presence of creases or rib clamping Resting superfi cial muscle tone
Expiratory activity of the oblique Underlying breathing dysfunction
abdominals
Hernia Bias towards the use of a high IAP
strategy
61
Diastasis, stretch marks Laxity in the myofascial system
Scars Adhesions between muscle layers
During Movement of the spine (thoracolumbar Superfi cial muscle activity
contraction fl exion, posterior pelvic tilt, thoracic
rotation)
Movement of the rib cage (expansion, Superfi cial muscle activity
clamping down, gripping)
Visible contraction of the abdominal Super fi cial muscle activity
muscles
Upward, downward or outward motion Superfi cial muscle activity, or
of the umbilicus increased IAP (outward)
Inward motion of the umbilicus Potential TrA isolation
Alteration in breathing pattern Superfi cial muscle activity, underlying
(holding, valsalva, bearing down) breathing dysfunction
Speed of contraction (phasic vs. tonic) Type of muscle activated (phasic =
superfi cial)
During Inability to fully relax the abdomen Hypertonicity
relaxation
Speed and coordination of relaxation State of motor control
Movement of the spine Relaxation of superfi cial muscle
activity
62
3 Image interpretation: qualitative
will fail to demonstrate the independent sliding (shortening) of the
TrA under the IO that is responsible for increasing the tension in
the anterior TrA fascia (linea semilunaris). Consequently, a characteristic protrusion of the anterior reach of IO into this fascia will
be seen (Fig. 3.7a). Additionally, outward pressure of the abdomi-
nal wall may be detected through the ultrasound probe and either
depression of the rib cage towards the pelvis (thoracolumbar fl exion)
TABLE 3.2 PALPATORY CONSIDERATIONS DURING PREFERENTIAL ACTIVATION OF
TRANSVERSUS ABDOMINIS
PHASE CONSIDERATION POTENTIAL IMPLICATION
Resting Quality of resting muscle tone Possible superfi cial muscle tone
position (abdominals, erector spinae etc.)
Location and symmetr y of breathing Amount of abdominal laxity, increase
pattern (apical, lateral costal, abdominal) thoracic elasticity (joint dysfunction,
muscle hypertonicity, disease process)
Freedom of the rib cage to disassociate Degree of resting muscle tone
from the pelvis (resistance to rib cage
wiggle)
During Quality of the tension developed with the Isolated contraction of the TrA
contraction contraction (drawing in of the fi ngers
until a lightly tensioned trampoline
sensation is felt)
Quality of the tension developed with Oblique abdominal ac tivity and/or
the contraction (fi ngers being pushed increase in IAP
out of the lower abdominal wall)
Movement of the rib cage (feel for rigidity Superfi cial muscle activity
or bracing)
Movement of the thoracolumbar junction Superfi cial muscle activity
or rib cage
Movement of the pelvis (feel for posterior Superfi cial muscle activity
tilt)
Palpable co-contraction of the lumbar Local system co-contraction
multifi dus
Co-contraction of the erector spinae, Superfi cial muscle activity
external rotators of the hip etc.
During Inability to relax the abdomen, status of Hypertonicity
relaxation the resting muscle tone
Speed and coordination of relaxation State of motor control
Movement of the spine Relaxation of superfi cial muscle
activity
Movement of the pelvis Relaxation of superfi cial muscle
activity
MIDLINE ABDOMINAL FASCIA
or posterior tilting of the pelvis (lumbosacral fl exion) may be
observed (Fig. 3.7b).
When USI is used to assess the behaviour of a muscle there is a
tendency to focus entirely on the display screen. It is critical that
the therapist keep in mind that USI is only an adjunct to the
examination process and not to abandon other tools such as observation and palpation. It is critical that the patient is observed and
TrA is palpated throughout the ultrasound assessment (Fig. 3.8).
Tab l es 3.1 and 3.2 summarize common observation and palpation
considerations and their potential implications.
63
Figure 3.8 Palpation site for TrA (medial and inferior to the ASIS).
MIDLINE ABDOMINAL FASCIA
The integrity of the fascia that extends from, and envelops, the
muscles that delineate the boundaries of the abdominal cavity (TrA,
the PFM, diaphragm and dMF) is crucial for their function. Anteriorly the transmission of forces produced by TrA will diminish if
there is either an increase in width or a loss of structural integrity
of the linea alba or abdominal fascia. An increase in width can
result from repetitive use of high IAP strategies (either for lumbopelvic postural control or straining with bowel evacuation etc.),
obesity or pregnancy, while a loss of fascial integrity is most commonly seen with either diastasis or an abdominal hernia. Clinically,
there are two goals associated with USI of the midline abdominal
fascia (linea alba). The fi rst is related to resting state, and the second
considers the impact of either increasing IAP pressure or muscle
activation upon the fascia:
64
3 Image interpretation: qualitative
1. Speculate on the resting state, tissue quality and integrity of
2.
Determine if the width of the midline abdominal fascia either
Resting state
The integrity of the midline abdominal fascia can be easily established with USI (van Uchelen et al 2001, Whittaker 2004b). Once
an appropriate image (Fig. 2.5a, b) has been generated, the resting
architecture and relationship of the two heads of RA, as well as
the intervening fascia, are considered. Attention is paid to the
clarity of the muscle contours, as well as the delineation of the
layers of the midline fascia. In addition, the echogenicity of the RA
with respect to a reference muscle (e.g. if the probe is drawn laterally IO can be brought into the fi eld of view), at a set gain level,
can be commented upon. As we will see below, in reference to
multifi dus, greater echogenicity of a muscle may be associated with
an increase in fatty and fi brous content, which can occur with
ageing, chronic disuse (Tsubahara et al 1995, Campbell et al 2005)
or denervation as a result of an injury (Andary et al 1998). Although
there are no references with respect to fatty infi ltration of RA in
the literature, increases in echogenicity have been seen clinically.
However, when interpreting the ultrasound image it is important
to note that the midline abdominal region is a common site for
adipose tissue and consequently it is possible to see a great deal of
scatter (Fig. 1.5a) which may change the appearance of the ultrasound image (e.g. increase the echogenicity) and lead to false conclusions regarding tissue quality.
the RA and midline abdominal fascia (linea alba).
decreases (may suggest effi cient transmission of tension),
increases or is not affected (may suggest ineffi cient transmission
of tension) by activities that result in either activation of the
muscles that attach into it (RA, EO, IO and TrA) and/or
produce an increase in IAP (head lift, straining, cough, sneeze,
active straight or modifi ed leg raise).
Response to load
After the integrity, clarity and echogenicity of R A and midline
fascia has been established the patient is asked to perform a task
that results in activation of the muscles that attach into the fascia
(RA, EO, IO and TrA) and/or produce an increase in IAP (head
lift, straining, cough, sneeze, active straight or modifi ed leg raise).
Clinical experience suggests that a normal response is one in which
the tension in the fascia is increased, and the bellies of R A are
drawn together (Fig. 3.9a, b). Conversely, an abnormal response
MIDLINE ABDOMINAL FASCIA
RA RA
65
a
b
Figure 3.9 USI of the midline abdominal fascia (linea alba) – rectus abdominis
(RA) contraction. a. Resting transverse ultrasound image of the midline
abdominal fascia (bracket). b. Transverse image of the midline abdominal fascia
at the heig
midline fascia as the two heads of the rectus abdominis are brought together, as
well as the increase (dotted arrows) in RA depth as they contract.
ht of a RA (head lift) contraction. Note the decrease in width of the
66
3 Image interpretation: qualitative
is one in which there is either no change or an increase in the distance between the medial edges of RA. A qualitative judgment
regarding the movement of the RA bellies with respect to each
other or, the change in the width of the midline abdominal fascia
(increased, decreased or remained the same) during these events can
be made. Beyond this, the width of the fascia can be measured (see
Chapter 4) at rest and then again at the height of the event.
Rath et al (1996) studied the width of the linea alba in 40
fresh cadavers, using computerized tomography, in an attempt to
establish criteria for the defi nition of diastasis in two age groups
(<45 y rs and >45 yrs). In the younger group a separation >1 cm
above the umbilicus, 2.7 cm at the level of the umbilicus and 0.9 cm
below became the benchmark, while in the older group the corresponding values were 1.5 cm, 2.7 cm and 1.4 cm. Based on clinical
observation Sapsford et al (1998) state that above the umbilicus the
width of the linea alba should be between 1 and 2 cm, while below
it tends to be narrower.
The linea alba of a nulliparous, non-obese female is seen in the
ultrasound image in Fig. 3.10a. The medial edges of the RA
muscle come together and resemble ‘cat eyes’ and the layers of the
midline fascia are discernible (refer back to Fig. 2.5b). This is in
contrast to the linea alba of a multiparous, non-obese female (Fig.
3.10b) in which there is an obvious increase in width, and slight
loss of fascial delineation. These two images represent the range of
diversity that can be found in individuals whose myofascial system
is capable of generating and distributing tension in a functional
manner. Abnormalities include either structural (loss of fascial
architecture which allows for a separation >2 cm between the
medial edges of the RA) (Fig. 3.10b) and/or functional (either an
increase or no change in length of the midline fascia with an
increase in IAP or muscle activation) factors which point to poor
transmission of the tension developed within the muscular
system.
If an increase in width or a loss of structural integrity is identi-
fi ed, it is important to consider that clinical management must initially be aimed at improving (use of external support such as a
sacroiliac belt or binder) or restoring this structural defi cit. Although
there has been some indication that rehabilitation may play a role
in closing a diastasis (Sheppard 1996), the degree of architectural
loss, and the need for a multi-professional (surgical) approach must
be considered (Toranto 1990).
LUMBAR MULTIFIDUS
Clinically, there are three main goals associated with imaging of
lumbar multifi dus. The fi rst is related to resting state, the next
LUMBAR MULTIFIDUS
67
RA
RA
a
RA
RA
b
Figure 3.10 USI of the midline abdominal fascia (linea alba). a. Tra nsver s e
ultrasound image of the midline (arrow) abdominal fascia of a non-obese,
nulliparous middle-aged female. b. Ultrasound image demonstrating an
increase in length of the midline (arrow) abdominal fascia in a non-obese,
multiparous middle-aged female. Note the increase in distance (parenthesis)
between the two heads of RA due to an increase in length of the intervening
fascia, as well as the increase in echogenicity of the muscle itself.
68
3 Image interpretation: qualitative
considers automatic activation, and the third is dependent upon
voluntary effort.
1.
Speculate on the resting state (tissue quality), shape and sym-
2. Determine if the lumbar multifi dus demonstrates sustained
3. Determine if the segmental fi bres of lumbar multifi dus (dMF)
Both the sagittal and transverse imaging techniques outlined in
Chapter 2 will be employed to gather this information. The specifi c
indications and limitations for each are outlined below.
metry in size of the lumbar multifi dus within the medial compartment of the lumbar fascia.
tonic activity during a task that loads the spine and pelvis, such
as a side or prone leg lift, and then fully relaxes after the
challenge.
can be preferentially activated. Specifi cally, contracted in relative isolation from the superfi cial fi bres and maintained as an
isometric, low-intensity contraction which results in fascial tensioning and co-contraction of other local system muscles (PFM,
diaphragm and TrA).
Resting state
The literature suggests that the cross-sectional area (transverse
plane) of lumbar multifi dus in normal young adults should be symmetrical bilaterally at a given segmental level, characteristically oval
in shape (Hides et al 1992, 1994), and increase in bulk progressively
from L2 caudally to S1 (Amonoo-Kuofi 1983). Stokes et al (2005)
investigated these qualities in a large and diverse cohort and confi rmed the expectation of symmetry of size within a segment. They
identifi ed that although there is individual variation in the transverse plane resting shape of the lumbar multifi dus it can generally
be categorized as round, oval, or triangular. Furthermore, they
speculated that it is the increasing bulk of the muscle that determines this shape. Specifi cally, as the muscle increases in size it
transforms from a round, to oval, to triangular shape, due to the
fact that both the medial and anterior confi nes of the muscle are
bony (spinous process and lamina respectively) leaving only the
superolateral direction for hypertrophy (which results in a characteristic triangular shape).
Hides et al (1994) employed USI to identify both an alteration
in shape (rounder), and decrease in size, of lumbar multifi dus ipsilateral and at the level of symptoms in individuals with acute and
subacute LBP. They speculated that the rounder shape may have
been indicative of hypertonicity; however, this was never formally
investigated. The wasting identifi ed by these investigators was
LUMBAR MULTIFIDUS
detected through cross-sectional area, depth and width measurements of the medial compartment of the lumbar fascia from still
transverse plane images (Fig. 2.9a, b). The specifi cs for establishing accurate measurements of this muscle will be considered in
greater detail in Chapter 4; however, as the wasting did not spontaneously recover with the resolution of pain, that is, it did not
correlate with symptoms (e.g. wasting can be present without
pain), there is a basis for contemplating and comparing both the
symmetr y in size and shape of lumbar multifi dus (in a transverse
plane) (Figs 2.8, 2.9a, b) in a resting state, at various segmental
levels prior to further testing.
After commenting on the resting shape and symmetry of multifi dus the quality of the muscle tissue should be considered. It is
accepted that a decrease in water content in conjunction with an
increase in fatty and fi brous content, which can occur with ageing,
chronic dysfunction (Tsubahara et al 1995, Campbell et al 2005)
and denervation as a result of injury (Andary et al 1998), will
result in greater echogenicity of a muscle (that is it will appear
more ‘white’) (Kader et al 2000, Strobel et al 2005). This has been
reported in the fi ndings of Stokes et al (2005) who identifi ed an
increase in the echoic nature of the multifi dus in some of their
older subjects. Strobel et al (2005) prospectively evaluated the
accuracy of USI in depicting fatty atrophy of the supraspinatus and
infraspinatus muscles, with magnetic resonance imaging (MRI) as
a reference standard. They proposed a qualitative evaluation tool
based upon both the degree of demarcation of architectural characteristics (visibility of muscle contour, pennate pattern, the central
tendon), and muscle echogenicity at a set level of gain. On the
basis of their fi ndings they concluded that USI is moderately accurate in the detection of signifi cant levels of fatty atrophy in these
muscles. Specifi cally, a three-point scale was used to evaluate the
visibility of muscle contours, pennate pattern (architecture of the
muscle fi bres) and the central tendon (0 = clearly visible muscle
contours, fi bres and central tendon, 1 = partially visible structures,
2 = structures no longer visible), while a second scale was used to
evaluate the echogenicity of the muscle (0 = iso- or hypoechoic
in comparison with a reference muscle, 1 = slightly more echoic
than a reference muscle, 2 = markedly more echoic than a reference muscle). The reference muscle used was the deltoid, and the
diagnosis of fatty atrophy was made with a score of 2 on at least
one of the two scales. In keeping with this proposed qualitative
analysis the above factors (employing a transverse view which will
bring longissimus into the fi eld of view so that it can be used as
a reference) can be considered, and commented upon (while maintaining a standard gain setting), while appraising the resting state
of multifi dus (or for that matter TrA, IO, EO or rectus
abdominis).
69
70
3 Image interpretation: qualitative
Tonic activity with spinal loading
After considering the side-to-side symmetry in shape and size of
the lumbar multifi dus, the patient is asked to perform a task that
loads the spine such as an arm or leg lift (prone or side lie) (Fig.
3.11a, b). Although there has been some recent disparity regarding
locomotion (Saunders et al 2004), current evidence suggests that
the deeper segmental fi bres of lumbar multifi dus (dMF) should
contract prior to their more superfi cial fi bres and the thoracolumbar
a
Figure 3.11 Ultrasound probe placement to monitor the lumbar multifi dus
during a. a prone leg lif t.