Joints & Movements of the Vertebral Column #2 Flashcards
What is the ant. longitudinal lig.?
- strong band extending along surfaces of vert bodies + attached to occipital bone extending as far as upper part of sacrum
- starts from foramen magnum
What is ant. long. lig. made up of?
long. fibres firmly fixed to intervert disc + margins of vert bodies
Where are the diff fibres of ant. long. lig. located?
- deep: extends from 1 vert to next
- superficial: extend over several vert
What is function of ligamentum flavum?
permits sep of lamina during flexion but at same time puts brake on it so limits not reached too quickly + so helps to prevent disc from injury
What is strucutre of ligamentum flavum?
- mainly elastic tissue
- connects lamina of adj vert extending from art capsules to place where lamina joins spine with only a small gap between lig. of each side
How fibres differ in post. long. lig?
- fibres near bone are shorter
- deeper into vert canal
What happens to ant. long. lig. + joints in flexion and sig of this?
- slack
- joints further apart so less stable
What happens to ant. long. lig. + joints in extension and sig of this?
- stretched
- more stable pos as spinous processes closer together
What happens to post. long. lig. + joints in flexion and sig of this?
- stretched
- joints further apart so less stable
What happens to post. long. lig. + joints in extension and sig of this?
- slack
- more stable pos as spinous processes closer together
How does lig. flavum control rate of movement and why?
- elastic fibres
- so don’t get sudden movement and control how far/apart synovial joints become as its between synovial joints
Besides lig. flavum, which other movements control flexion + prevent overflexion?
- interspinous lig.
- supraspinous lig.
Where is interspinous lig. found?
between spinous processes
What are extrinsic muscles?
attached to another region as well as vert
Which muscle of the trunk is extrinsic?
latissumus dorsi
Which muscle of the trunk is intrinsic?
erector spinae
What is function of latissimus dorsi?
- allow lat. flexion
What is function of erector spinae and how does it do this?
allows you to sit + stand, keeps you upright
slow to fatigue
Where does psoas major attach and is function?
- from vert column + goes underneath inguinal lig. + attaches to lesser trochanter of femur
- move limb + trunk
List the phasic muscles
- rectus abdominis
- transversus abdominis
- int. oblique
- ext. oblique
List the post. trunk muscles in the thoracic region and which are extrinsic, intrinsic and deep
- extrinsic:
- trapezius
- lat dorsi
- serratus post.
- intrinsic:
- erector spinae
- deep:
- transvero-spinalis
What is trapezius attached to + when is it a muscle of the trunk?
- scapula, clavicle + base of skull, shoulder
- to all vert
- if fix limbs
What is lat dorsi attached to and its origin?
- arises from lat. part of back + attached to humerus, scapula
- thoracolumbar fascia
List the 3 parts of erector spinae + their attachments
- Ilio-costalis - ilium to ribs
- longissimus - fibres stretch over long no. of segments
- spinalis - attached to spinous process
Where does transversospinalis attach + what is its function?
- from TP to TP + SP to SP
- proprioreceptor fibres feedback on what pos back is in + fine-tuning of back
What is function of trapezius?
shrug shoulders
Where is thoracolumbar fascia attached and its function?
- around ilium, sacrum + spinous processes
- stabilises pelvis + support lower back
Where is erector spinae found + what is its function?
- inside thoracolumbar fascia
- as it contracts, pushes against + tenses fascia
Which muscles are in contact with thoracolumbar fascia and their effects on it?
- TA
- IO
- gluteus maximus
- lat dorsi
- inc tension of fascia as they contract
Which muscles are encased by the fascia + what are their effects on it?
- erector spinae
- multifidus
- have pushing effect on fascia as contraction broadens belly of muscles + inc tension within sheath
What also inc tension of fascia?
movements of limbs + back
Where is intertransversarius found?
- between TP
- only in lumbar region
Where does quadratus lumborum attach + what is its function?
- to iliac crest
- allows platform for contraction of diaphragm in resp
- lat. flexor of trunk
- stabilises 12th rib
List the lat. trunk muscles
- QL
- PM
How is psoas major important for movement?
- lat. flexion
- contralat. rotation
- inc curv of lumbar vert (lumbar lordosis)
How is quadratus lumborum important for movement?
as it contracts, lat. flexes trunk
What are the fibres in PM like?
vert + oblique - from rib + ilium to TP
What are phasic muscles?
not used all the time but intermittently
What happens as RA relaxes?
body falls forwards
How do fibres in IO run?
superiomedially
What is function of TA?
ensures tone of region
How do fibres of EO run?
inferomedially
How do the fibres of IO + EO interact?
criss-cross into shape of parabolic curve - important to withstand forces
