Muscles of the CoreLumbo-Pelvic-Hip
Complex
Core Muscles
• The term core refers to the Lumbo-PelvicHip Complex (LPH)
• It is the center of the body and the
beginning point for movement
• Comprised of about 29 muscles that
attach to the spine and/or pelvis
• Involves structures of the lumbar, thoracic,
and cervical spine, the pelvic girdle and
the hip joint.
Lumbo-Pelvic-Hip Complex
• The lumbo-pelvic-hip complex
(core) functions primarily to
maintain dynamic postural control
by keeping the center of gravity
over our base of support during
dynamic movements
Core Muscles
• Abdominals (Deep to Superficial)
– Transverse Abdominis
– Internal and External Oblique
– Rectus Abdominis
• Spinal Muscles (Deep to Superficial)
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Rotatores
Semispinalis
Mulitifidus
Quadratus Lumborum
Erector Spinae
Latissimus Dorsi
Core Muscles
• Hip Extensors: Gluteus Maximus, Hamstrings
• Hip Abductors: Gluteus Medius, Gluteus
Minimus, Tensor Fascia Lata, Iliopsoas, and
Sartorius
• Hip flexors: Iliopsoas, Rectus Femoris, Tensor
Fascia Lata and Pectineus
• Hip Adductors: Gracilis, Adductor Magnus,
Adductor Longus, Adductor Brevis, and
Pectineus
Transverse Abdominis
• The most important abdominal muscle
• Contracted first before any other muscle
Transverse Abdominis
• The deepest layer of abdominal muscles
• It wraps around the trunk from front to back and from
the ribs to the pelvis
• The muscle fibers run horizontally, similar to a corset
or a weight belt
• It does not move the spine or pelvis
O: Thoracolumbar Fascia, Iliac Crest, Costal Cartilages
of Ribs #7-12
I: Linea Alba, Pubic Crest
A: Facilitates forceful expiration of air from the lungs
• Stabilizes the spine
• Compression of abdominal contents
Integrated Function of Transverse
Abdominis
• Works synergistically with the internal oblique,
multifidus, and erector spinae to stabilize the
lumbo-pelvic-hip complex
Transverse Abdominis Exercises
•
Draw In (supine, quadruped, prone, seated,
kneeling or standing)
•
Attempt to pull the bellybutton through the
spine
Or imagine trying to zip up the world’s tightest
pair of pants
Attempt each position for five reps held for five
to 10 seconds
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•
Internal and External Abdominal
Oblique Muscles
Internal Abdominal Oblique
• Deep to external oblique and lies just
above transverse abdominis
O: Inguinal Ligament, Iliac Crest, and
Thoracolumbar Aponeurosis
I: Last three ribs (10-12), Pubic Crest, Linea Alba
A:
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•
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Flexion of Trunk
Lateral Flexion of Trunk
Contralateral Rotation of the Trunk
Compression of Abdominal Contents
Integrated Function of Internal
Oblique
• Assists in eccentric deceleration of trunk
extension
• Assists in eccentric deceleration of trunk
rotation
• Works synergistically with the transverse
abdominis, multifidus, and erector spinae
to stabilize the lumbo-pelvic-hip complex
External Abdominal Oblique
• Located externally in the abdomen with
diagonal fibers
• Lateral to the rectus abdominis
• “Pocket Muscles” (put your hand into a
coat pocket and your fingers would be
pointing along the direction of the fibers)
• It’s fibers meet latissimus dorsi at ribs #
10-12
External Oblique
O: Lower 8 ribs (# 5-12)
I: Anterior Iliac Crest of Pelvis and
Abdominal Aponeurosis
A:
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•
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Flexion of the Trunk
Lateral Flexion of the Trunk
Contralateral Rotation of the Trunk
Compression of Abdominal Contents
Integrated Function of External
Obliques
• Assists in eccentric deceleration of trunk
extension
• Assists in eccentric deceleration of trunk
rotation
• Assists in dynamic stabilization of the
lumbo-pelvic-hip complex
External and Internal Obliques
• Force Couple:
–Two separate muscle groups on
opposing sides of the body work
together to achieve the same movement
goal.
–One movement will have two agonists
on opposite sides of the body.
How Obliques Cause Trunk
Movement
Trunk Flexion
• Right and Left sides of Internal and External
Obliques
Lateral Trunk Flexion
• Lateral flexion right : Right External Oblique
and Right Internal Oblique
•
Lateral flexion left: Left External Oblique and
Left Internal Oblique
How Obliques Cause Trunk
Movement
Trunk Rotation
• Rotation Right : Left External
Oblique and Right Internal
Oblique
• Rotation left : Right External
Oblique and Left Internal
Oblique
Rectus Abdominis-Anatomy
• The Rectus
Abdominis is a
superficial muscle
bisected by tendinous
inscriptions that is
covered by the rectus
sheath which is
formed by
aponeurosis.
The Rectus Abdominis is a superficial
muscle bisected by tendinous inscriptions
that is covered by the rectus sheath which
is made up of aponeurosis
• Tendinous
Inscriptions
–Three fibrous
bands that
transect and
divide the rectus
abdominis.
The Rectus Abdominis is a superficial muscle
bisected by tendinous inscriptions that is covered
by the rectus sheath which is made up of
aponeurosis
• Rectus Sheath
– Sheath (protective
covering)
– Anterior and posterior
sections
– Lays under and over RA
The Rectus Abdominis is a superficial muscle
bisected by tendinous inscriptions that is covered
by the rectus sheath which is made up of
aponeurosis
• Aponeurosis
– Flattened tendons with a
shiny, whitish-silvery
color.
– Sparingly supplied with
blood vessels and
nerves.
– When dissected, are
papery, and peel off by
Rectus Abdominis
• The two rectus sheaths (left and right) meet in
the midline of the abdomen and form the linea
alba
• Linea Alba: The tendinous band along the
midline of the rectus abdominis muscle.
Rectus Abdominis
• Rectus means straight
O: Pubic crest
I: Xiphoid process of sternum
and costal cartilages of 5th,
6th and 7th ribs
A: Trunk Flexion
• Compression of Abdominal
Contents (expiration,
vomiting, expulsion of feces
from the intestines and
urine from the bladder)
• Posterior Tilt of the Pelvis
Integrated Function of Rectus
Abdominis
• Assists in eccentric deceleration of trunk
extension
• Assists in eccentric deceleration of anterior
pelvic tilt
• Assists in dynamic stabilization of the lumbopelvic-hip complex
Rectus Abdominis Exercises
Common Mistakes Made:
• Pulling the head with the hands
(risking injury to the cervical vertebrae)
• Not pressing back to the floor
• Flexing the torso to a fully seated
position
– When straight leg raises or full sit-ups are
done, the movement is not trunk flexion
but hip flexion.
Multifidus
• A deep muscle located
along the back of the
spine very close to the
midline.
• The deep fibers are short
and span single vertebral
segments.
• Functions together with
transverse abdominis &
pelvic floor muscles to
stabilize the low back
and pelvis BEFORE
movement of the arms
and/or legs occurs
Multifidus
• Important stabilizer of the back
• Studies have shown people who
had low-back pain also had
wasting of the multifidus muscle on
the side of the back that matched
the painful side. The studies also
showed that over time back pain
did improve.
Multifidus
O: Sacrum, lumbar, and
cervical transverse
processes
I: Spinous Processes of all
Vertebrae
A: Extension of Trunk and
Neck
• Lateral Flexion of Trunk
and Neck
• Contralateral Rotation of
Trunk and Neck
Integrated Function of Multifidus
• Assists in eccentric deceleration of trunk
flexion
• Assists in eccentric deceleration of trunk
rotation
• Assists in dynamic stabilization of the lumbar
spine
• Provides proprioception (awareness or
sense of where the body is in space-up,
down, left, right…) during dynamic
movements which enhance neuromuscular
efficiency
Multifidus
• There are lots of exercises that
strengthen the multifidus as well as the
other back extensor muscles. The only
problem is all the extensor muscles will
contract with traditional back exercises
• The multifidus must first be isolated and
re-activated through specific isometric
exercises then followed up with
functional exercises to further
strengthen the muscles of the lowerback.
Multifidus Exercises
Prone Trunk Extension with Rotation
1. Begin in a prone position
2. Rest your forehead on your hands
3. Retract your scapula
4. Extend the lumbar spine and rotate
the upper torso
5. Keep scapula retracted
Quadratus Lumborum
• This muscle is shaped like a square located in the
back
• Anterior to quadratus lumborum are the colon, kidney,
and diaphragm
O: Posterior Iliac Crest
I: 12th Rib and Transverse Process of L1-L4
A:
•
•
•
Elevation of Pelvis
Lateral Trunk Flexion
Extension of Trunk
Depression of 12th Rib
Integrated Function of
Quadratus Lumborum
• Assists in eccentric deceleration of
lateral trunk flexion
• Works synergistically with the hip
abductors and adductors as the primary
frontal plane stabilizers
Quadratus Lumborum
• The quadratus lumborum can elevate
the pelvis sometimes called “hip
hiking”.
• Do not confuse this with flexing the
femur
• To feel how the pelvis moves using
the quadratus lumborum stand with
feet apart and weight equal on both
feet. Shift your weight from side to
side while lifting up your toe on the
side that you are shifting away from.
Quadratus Lumborum
• Pulls
rib inferiorly causing
thoracic cavity to expand
which creates more space for
the lungs to expand
th
12
Quadratus Lumborum Exercises
• Horizontal isometric side bridge which can
be done from a knee supporting position
on the floor or a more challenging version
which utilizes a feet supported version.
Erecter Spinae
• Makes the spine
erect
• Divided into three
longitudinal columns
• From lateral to
medial they are:
–Iliocostalis
–Longissimus
–Spinalis
Erector Spinae
Iliocostalis:
O: Sacrum, Iliac Crest,
and Ribs 3-12
I: Ribs 1-12 and
Transverse Process
of C4-C7
Erector Spinae
Longissimus
O:Sacrum, Iliac Crest and
Transverse Process of
T1-T5
I: Ribs 4-12, Transverse
Process of T1-T12 and
Mastoid Process of
Temporal Bone in Skull
(behind ear)
Erector Spinae
Spinalis
O: Spinous
Process of T11L2 and C7
I: Spinous Process
of T5-T12 and
C2
Erector Spinae
Actions:
• Extension of Trunk, Neck and Head
• Lateral Flexion of Trunk, Neck and
Head
• Rotation of Trunk, Neck and Head
• Anterior Tilt of Pelvis
Integrated Function of Erector
Spinae
• Assists in eccentric deceleration of trunk flexion
• Assists in eccentric deceleration of trunk
rotation
• Assists in eccentric deceleration of lateral trunk
flexion
• Assists in dynamic stabilization of the lumbar
spine during dynamic movements
Exercises for Trunk Extensors
• Isometric Trunk Extensions on Floor
• Trunk Extensions on a SB
• Trunk Extensions on a Bench
Exercises
Trunk Extensions
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•
Muscles Worked: Erector Spinae, Multifidus, and
Semispinalis
Common Mistakes Made: “hyperextending” the back
past a horizontal position, flexing the spine, and
performing the reps too fast.
Exercises
Trunk Extensions
• Possible Risks:
– By flexing (rounding your back) and
hyperextending your spine during this exercise
you allow your vertebrae to separate from each
other. Through repeated repetition, there is a large
possibility of slipping a disk through the vertebrae.
• To Perform Correctly
– Slowly bend forward at the waist as far as you can
while keeping your back neutral. Do not round
your back. Slowly raise your torso until your legs
and upper body are in a straight line again. Do
NOT arch your back past a straight line!
Belts and Wraps
• Using Belts (knee and/or ankle wraps) For
Every Exercise:
• Common Mistakes Made: Dependence of
the weight belt for every exercise.
• Negative Effect: Weak abdominals and
lower back muscles
• Solution: Avoid wearing the belt and lower
your weight so the muscles you weakened
due to belt use can recover. Most people
use belts only for squats and power
exercises. Even this is excessive, unless
you are doing maximal weight loads
Belts and Wraps
• Knee and elbow wraps should
generally not be used. If you have
an injury you should not be lifting, or
should reduce the load.
• Belts can be important at certain
times, such as when you are lifting
heavy loads with which you can only
do a few reps, and when you are
learning form on power exercises.