Week 8 Flashcards
What is the most common means of assessing spinal curvature
Cobb angle
Normal curvature of the thoracic spine
20-50 degrees
Normal curvature of the lumbar spine
20-70 degrees
What is the stability of the spinal column provided by
extrinsic and intrinsic structures and factors
what are the 3 functional components of the intervertebral conjunction
transverse & spinous processes apophyseal joint interbody joint(intervertebral disc)
What are the transverse and spinous processes used for
they are levers that increase mechanical leverage of muscles and ligaments
What does the intervertebral joint do
absorbs and distributes loads
adhesion between vertebrae
what happens to the spine as we age
Intervertebral disc dehydrates & undergoes fibroses
- alters spinal load in the body
facet joints undergoes OA changes
ligaments / capsules & muscles also age
what is spinal coupling
movement in one plane associated with an automatic movement in another
e.g. Rotation and translation (at the same time)
Thoracic spine
most mechanically stable portion of the vertebral column (excluding SIJ)
When determining Lx ROM, need to consider
lumbopelvic rhythm
impact of pelvic tilt
sitting posture
what is lumbopelvic rhythm
Trunk flexion - bending forward, knees straight
combo of approx. 40 degrees Lx flexion and 70 degr hip flexion
extension from full flexion, knees straight
What is the SIJ joint
transition between caudal end of skeleton + lower appendicular skeleton
Form closure SIJ
anatomic features
closely fitting joint surfaces - create friction to reduce shear
ideally no external force needed
results in minimal movement
Force closure SIJ
muscles and ligaments
compression of joint surfaces
prevents shear
nutation & counternutation important
primary ligamnts of the SIJ
anterior sacroiliac ligament
short and long posterior sacroiliac ligaments
interosseous ligaments
iliolumbar ligaments
secondary ligaments of the SIJ
sacrotuberous
sacrospinous
what is nutation
anterior tilt of sacral base (top) relative to the ilium
ischial tuberosities move apart
What is counternutation
posterior tilt of the sacral base relative to the ilium
ischial tuberosities move together
When does nutation and countenutation
can occur by sacral on iliac rotation, iliac on sacral rotation or combination
what is optimal posture
position that minimises stress applied to each joint
requires least muscular support
minimises loads on supporting ligaments and muscles
What may sub optimal posture do
place undue stress on joints and ligaments
Positional, non structural causes of bad posture
excess weight shape of spinal curves poor habitual static posture decreased muscle strength connective tissue extensibility position and magnitude of external loads pain
Anatomical factors that influence spinal curve shape (5)
wedge shaped vertebral bodies
wedge shaped intervertebral discs (eg lx and Cx discs slightly thicker anteriorly)
ligament tension
muscle stiffness
disease causes of bad posture
osteoporosis ankylosing spondylosis orthopaedic conditions MSK condition muscular dystrophy
how to correct poor posture
strengthen weak muscles stretching tight structures increasing joint mobility postural re education movement strategies balance
