Main Idea
What happens to the cervical spine because of forward head?
What happens to the thoracic spine?
What happens to the lordotic spine?
increased cervical lordosis- tight back of neck, weak deep cervical flexors
Increase thoracic kyphosis- tight chest, front delts, weak back
decrease lordotic curve- tight abbs, weak low back
Anterior concave curves
kyphotic curve
compensation will increase what and decrease what?
Compensation will decrease efficiency and may
increase stress on structures.
Anterior convex curves
Lordotic curve
What structure has greatest influence on the
vertebral column, especially the lumbar
spine.
The Pelvis
Lateral curve
Scoliosis (with rotation component)
Neutral spine/pelvis is....
What is level with the horizontal plane?
What two structures are in the same frontal plane?
When the pelvis is in neutral the lumbar spine has what kind of curve?
Iliac crests level within horizontal plane
ASIS and pubic symphysis are in the same
frontal plane
When pelvis is in neutral position ->
lumbar spine has normal lordotic curve
sway back
Increased L/S curves
What happens to the L/S curve during posterior tilt of pelvis
What happens to the chain?
decreased lumbar lordosis
ASIS posterior to pubic symphysis
Flat back
Decreased L/S curves
What happens to the L/S curve during anterior tilt of pelvis?
What happens to the chain?
increase lumbar lordosis
ASIS anterior to pubic symphysis
Primary curve
At birth, the entire vertebral column is
concave anteriorly. This concave curve
is called the primary curve
The force couple of what muscles create a lateral pelvic tilt?
glute medius, Quadratus lumborum
Secondary curves
Anteriorly convex curves of the C/S and
L/S are secondary curves that develop
as the child grows
The force couple of what muscles create a posterior pelvic tilt
hamstrings , abbs
Neutral pelvis is........
Neutral lumbar lordosis
The force couple of what muscles create a anterior pelvic tilt
low back, hip flexors
LATERAL PELVIC TILT
What's tight? What's weak?
Pelvis dips during what phases of gait?
Controlled by?
During gait:
Pelvis dips from side to side as weight is shifted from stance to swing phase
Controlled by
• Hip abductors:
• Gluteus Medius and Gluteus Minimus
Trun lateral benders: Erector spina, quarts lumborum
What is the plum line test?
From side view:
Where does the line pass slightly anterior?
Where does line pass slightly posterior?
Where does it pass completely through?
From the lateral position, the plumb line should line
up:
• Slightly anterior to the lateral malleolus
• Slightly posterior to patella
• Through greater trochanter of hip
• Level at pelvis
• Through vertebral bodies of L/S
• Anterior to T/S vertebral bodies
• Through tip of acromion process at shoulder
• Through earlobe of head
Anterior-posterior motion of the upright
body caused by motion occurring
primarily at the ankles
Result of constant displacement and
correction of the COG within the BOS
Small BOS with high COG => increased
postural sway
POSTURAL SWAY
WHY IS DISK pressure different in sitting vs standing?
sitting we have lengthening of of some muscles in the back
in standing these muscles are in neutral
SITTING POSTURE
T/F: Takes pressure off the vertebral disks
Disk pressure _______ by almost __% in sitting
compared to the disk pressure of standing
Will disk pressure increase or decrease if leaning forward.
What about when you pick something up?
• Can place A GREAT DEAL of pressure
on the intervertebral disks!!!
• Studies by Dr. Nachemson have
shown that disk pressure
increases by almost 50% in sitting
compared to the disk pressure of
standing
• As person leans forward, disk
pressure increases even more
• As person reaches and/or picks up
a weight/object, disk pressure
further increases as the weight
and/or lever arm increases