Spinal Stability and the Msucles of the trunk and pelvis

6.  Traditional anatomy descriptions of the
spinal muscles have only taken a look at
the posterior view or from the back.
 Muscles are typically studied or viewed
as straight line cables.

7. A more current understanding of muscle
anatomy involves how movement is created
and joints are stabilized.

8.  Many anatomy books describe the function of
the rotatores as small rotator muscles of the
spine. The intertransversarii as lateral flexors of
the spine.
 According to McGill (2002), these muscles
are very tiny and do not create movement.
• However, they may function as vertebral
position sensors at every thoracic and lumbar
joint.

10.  Extensors of the Vertebral Column
Multifidi
Semispinalis
Longissimus
Iliocostalis
Spinalis
 Quadratus Lumborum

13.  The major extensors of the thoracic and lumbar spine.
 The role of these muscles is different in the two areas
of the spine.
• Thoracic:
 These muscles attach to the ribs and the thoracic vertebrae
with long tendons that run parallel to the spine and attach
at the sacrum and iliac crests.
 The thoracic extensors run just under the fascia over the
lumbar spine.
 These extensors have the greatest moment or torque.

14.  According to a study from the American
Journal of Neuroradiology 2005, the
development of extreme thoracic kyphosis
might contribute to excess biomechanical
stress in the spine and may identify a
population at risk for future vertebral
compression fracture at the thoracolumbar
junction.

15.  These muscles originate over
the posterior sacrum and go
at an angle and deeply
attach to the lumbar
vertebrae.
 Injury or load to the lumbar
spine increase when there is
flexion of the spine. These
muscles lose their angled
attachment with spinal
flexion increasing the load or
force to the spine.
 The extensors of the lumbar
spine create a shearing force
in flexion.
 This is, unfortunately, the
way most people bend over
to pick something up.
Therefore, increasing risk of
injury to the spine and
muscle tissue.

18. During lifting, muscles and ligaments significantly
increase loads to the spine.
In weak spines, a spinal load of 7,000N or 1,560lbs
begin to damage the spine. Think of how many
times you bend over during the day to pick
something up!
In young healthy spines, 12-15n or approximately
2,600-3,360 lbs begin to load the spine.
In weight lifters with ideal mechanics, the load can
increase to 4,480lbs.

19.  One avoids injury to the back when you
flex at the hips, therefore reducing or
minimizing tissue tension.
 If you are flexed at the hips and not the
spine, there is a increase in thoracic
extensors and the lumbar extensors do
not increase the load to the spine.
 The abdominal muscles are activated by
creating a “corseting” effect stabilizing
the spine through abdominal bracing.

21.  According to Callaghan, Gunning and McGill
(1998), to have safe therapeutic muscle
activation for the lumbar extensors, one must
activate one side of the spine at a time.
 As discussed previously, there are four sections
of the extensors. Right and left thoracic and
right and left lumbar.

22.  Increases the load to
the spine to 6,000N or
over 1,300 lbs.
 It certainly does
activate all 4 sections
but with injury to the
spine.

28.  These muscles only span a few joints or
vertebrae and the force they apply is
very localized.
 The multifidus does play a role in
stabilizing but cannot be isolated.

29.  The “lats” are involved in lumbar extension
and spinal stabilization.
 The latissimus is active during pulling and
lifting.
 Activated in Bird Dog with arm and opposite
leg activated, rows and pull downs.

32.  Trunk flexor.
 Why is it segmented instead of one long
muscle?
• Possibly to facilitate flexion/extension of the
torso and to assist with abdominal distension
or contraction as volume changes ( M.
Belanger, 1996).

33.  Functional point of
view
• Work together and
independently.
• The oblique's create
a twisting and lateral
bend and enhance
flexion.
• Rectus primarily
creates flexion.
 Upper and lower
Abdominal Wall
• According to Leman
and McGill, 2001,
there is no separation
of upper and lower ab
wall.

34.  The oblique's and the transverse abdominus
form a hoop around the entire torso
creating stability or stiffness for improved
spinal stability.

36.  Attaches to T12 and to all
the lumbar vertebrae and
to the femur.
 The psoas is a hip flexor
and not a spine stabilizer
Juker, McGill and Kopf,
(1998). This is because it
attaches to the lumbar
vertebrae, creating a
stiffening of the spine
only when the hip is flexed
(McGill 2005).

38.  Attaches to each of
the lumbar vertebrae,
pelvis and rib cage.

39.  The quadratus lumborum, or QL, is a common source of lower
back pain.
 The QL is capable of extending the lower back when contracting
bilaterally, the two QLs of the low back pick up the slack, as it
were, when the lower fibers of the erector spinae are weak or
inhibited (as they often are in the case of habitual seated
computer use and/or the use of a lower back support in a chair).
 There is a mechanical disadvantage created by constant
contraction while seated which can overuse the QLs, resulting in
muscle fatigue.
 A constantly contracted QL, like any other muscle will experience
decreased blood flow, and will create muscle spasms over time.

41.  True spine stability is accomplished by a balanced
“stiffening” from the entire musculature of the torso.
 This includes the abdominal wall, quadratus
lumborum, latissimus dorsi and the back extensors of
longissimus, iliocostalis and the multifidus.
 There is not a single muscle that is responsible for
spinal stability like the transversus or multifidus. Very
few individuals can singularly activate these muscles.
By attempting to recruit these muscles by drawing in
ones ab wall, one creates instability when they are
attempting to increase spinal stability by “hollowing”
(McGill 2009).

42.  The core muscles differ from the arm and leg muscles in
that the muscles co-contract stiffening or corseting the
trunk so that all the muscles work together synergistically.
Therefore, training the muscles of the core is different than
training the muscles of the limbs.
 The core generally functions to prevent motion rather than
initiate it. Activities of daily living need power to come
from the hips and transmit to a stable torso. Pushing,
pulling, lifting, carrying and efforts of the torso are
compromised by the spine bending or what are called
“energy leaks”. These energy leaks over time can
accumulate and create an injury to the spine.

43.  What are Energy Leaks?
 Energy leaks are caused when weaker joints
are forced into eccentric contraction by
stronger joints.
 Energy leaks are points at which energy is lost
during the transfer of force from the ground.
Energy leaks are a result of the inability of the
body to stabilize a particular joint.

44.  Sitting with a rounded
back.
 Squats with rounded
back or knees that cave
in.
 Lifting a child, lifting
groceries with a rounded
back poor posture.
 Walking or running with
with hips that have a
great deal of
movement.
 Energy Leaks create
injury.

45.  Standing on an unstable surface.
 Sit ups.
 Stretches that emphasize knee to chest
or toe touches.
 Using a physioball does not create
spinal stability. To use seated with
rounded posture is a significant “energy
leak”.

49. The “Bug”

50. Basic Quadruped

51. Bird Dog : Do not add leg extension and arms until basic
Quadruped is mastered

52. Bird Dog with Sweep

53. Off set load with hand to the side

54. Basic Side Bridge

55. Feet can be either stacked or in front for different
muscle recruitment

56. Stir the Ball

58.  Examples of what can lead to an injury
further up or down the kinetic link.
Old Shoes
Over Pronation, Under Pronation, High Arches
Back Pain
Gluteal amnesia
Shortened hamstrings
Shortened hip flexors
Psoas
Quadriceps: Rectus Femoris

59.  Lateral hip pain, knee and foot injuries
Gluteus medius
Trochanteric bursitis
IT Band Syndrome
Meniscal Injuries
ACL injuries
Plantar fasciitis

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