Trunk Flashcards
(44 cards)
Briefly describe the structure of the sacrum:
fusion of 5 sacral vertebrae into an inverted triangular, concave shape. The bone has a base, apex and four articular surfaces
Why are the articular facets of C1 so large compared with those of other vertebrae?
There is no vertebral body in C1, so the large articular facets transfer forces from the occicpital facets to the vertebral body of C2
How many intervertebral discs are there?
23
What is the pars interarticularis? Explain the mechanism causing a pars interarticularis defect.
Under compression an extension weight can be transferred through the inferior articular processes to the laminar, causing a pars interarticularis fracture (collar fracture)
The suboccipital muscles move the head on C1 OR move the head & C1 on C2.
What movements occur at C0/1?
What movements occur at C1/2?
What bony features of C1 C2 provide increased moment arms?
• C1:
• C2:
What movements occur at C0/1? Head flexion and extension
What movements occur at C1/2? Head flexion and rotation
What bony features of C1 & C2 provide increased moment arms?
• C1: Anterior arch
• C2: Odontoid Process
Due to their small size and moment arm interspinous produce insufficient force to produce movement.
What is their function?
Proprioceptive
Explain the movements of the head and neck when the sternocleidomastoid contracts concentrically;
(i) Bilaterally:
(ii) Unilaterally
Explain the movements of the head and neck when the sternocleidomastoid contracts concentrically;
(i) Bilaterally:
Upper cervical extension & lower cervical flexion
Explanation:
The line of action of SCM has a vertical component that crosses posterior to the upper cervical spine (= ext) and anterior to the lower cervical spine (= flexion).
(ii) Unilaterally
Ipsilateral lateral flexion & contralateral axial rotation
Identify the diaphragm and briefly describe its structure.
Dome superiorly with central tendon,
attaches inferiorly to L1-3, costal cartilages 6-12, & lower ribs
Identify the three major structures that pass through or behind the diaphragm:
- inferior vena cava @ T8
- oesophagus @ T10
- descending aorta @ T12
Explain how can the diaphragm contribute to postural stability?
Contraction increases intra-thoracic volume. If the abdominal muscles are also contracted, the intra-abdominal pressure also increases. Increased pressure makes it more difficult to move the joint and thus increases stability
How does respiratory drive affect the postural activity of the diaphragm?
Respiratory drive will cause contraction, but not the accompanying increase stability, as the focus is on oxygen consumption
Identify the pelvic diaphragm and its two major components:
- levator ani
* coccygeus
Identify two structures that pass through the pelvic diaphragm:
- anal canal
* urethra
How does activity in the pelvic floor muscles relate to trunk / spinal stability?
Increases IAP to increase stability and stiffness of the spine
Is the TLF different to the erector spinae aponeurosis
They are different structures, but do have some blending
Considering all the muscles of the abdominal wall:
Which are the most powerful flexors of the thoracolumbar spine?
Justify your answer:
Which are the most powerful rotators of the thoracolumbar spine?
Justify your answer.
Which are the most powerful flexors of the thoracolumbar spine?
Justify your answer: Rectus abdominis, it has the largest flexion moment arm and PSCA
Which are the most powerful rotators of the thoracolumbar spine?
Justify your answer. Internal and external obliques, they have the greatest moment arm the greatest PSCA
Define:
Spondylolysis:
Spondylolisthesis:
At which vertebral levels are they most commonly found?
Spondylolysis: a stress fracture of the pars interticularis
Spondylolisthesis: a fractured pars interticularis shifts/ slips forward on the vertebra directly below it
At which vertebral levels are they most commonly found?
L5
What are uncovertebral joints?
Found bilaterally between adjacent cervical vertebrae, identified by the cat ear shaped uncinate processes of the C3-7 vertebrae
How does the intervertebral disc height: vertebral body height affect range of motion?
How does it differ in the vertebral column regions?
How does the intervertebral disc height: vertebral body height affect range of motion?
Greater disc height allows greater range of motion
How does it differ in the vertebral column regions?
The cervical and lumbar regions have a greater disc height
Is the vertebral endplate more firmly attached to the vertebra or the intervertebral disc?
Intervertebral disc
Which of the 4 suboccipital muscles is best aligned to produce rotation of the head & C1 on C2?
Obliquus capitus inferior
Which muscles are the primary cervical spine o extensors o flexors = o lateral flexors = o rotators:
o extensors = semispinalis capitis and semispinalis cervicis
o flexors = longus capitus and longus cervicis
o lateral flexors = scalenes,
o rotators: R rotation = L SCM + R splenius
Which muscles are the primary thoracolumbar o extensors o flexors o lateral flexors o rotators
o extensors = longissimus thoracics pars thorarcic and par lumborum
o flexors = psoas major and rectus abdominis
o lateral flexors = quadratus lumborum
o rotators = obliques
What action(s) does the external oblique perform?
Unilateral: Trunk contralateral lateral flexion and rotation
Bilateral: Trunk flexion and increases IAP
