Lecture #8 (Spine, Thorax, and Posture) Flashcards
What do the IVDs permit?
Compression in any direction and some torsion…they’re good shock absorbers (made of fibrocartilage)
What types of stress is the annulous fibrosus not good for?
Not good for shear and twisting forces (good for compression though)
What is the normal lordotic curve of the c-spine?
30 degrees
What is the gross ROM (all the vertebrae) in the C-spine? (x4)
Flexion= 35-50 degrees Extension= 45-70 degrees Rotation= 90-120 degrees Sidebending= 40 to 50 degrees
What occurs in the upper and lower C-spines during chin tucks? Forward head?
Chin tuck= upper flexion, lower extension
Forward head= upper extensionn, lower flexion
What are some interesting features of the atlas?
No body, no spinous process, large transverse processes and superior facets (to articulate with occipital condyles)
What is the main motion that occurs between the occipital condyles and C1? How much (degrees) happens here? What plane?
Flexion/extension
20-30 degrees (occurs in sagital plane)
What is interesting about the axis (C2)?
The anterior portion extends superiorly as the dens for C1 to rotate around
What is the main motion occuring at C1-C2? How much occurs here? What is the other motion that occurs here? How much?
Rotation (about 50 degrees)
Secondary motion- flexion/extension…about 15 degrees)
How much of C-spine rotation occurs at C1-C2?
50%
What is the facet orientation of the cervical spine? What motions does this favor?
About 45 degrees…favors rotation and lateral flexion
How many degrees of rotation occur per level from C2 down the rest of the C-spine?
4-8 degrees of rotation
What is the coupled motion of the c-spine?
Lateral side bending is associated with ispilateral rotation of the vertebrae…for example, with LSB to the left, the vertebrae rotates to the left because the spinous process moves to the right with rotation)
Why is the coupled motion of the C-spine important?
Protects the arteries (think vertebral artery) and helps to prevent strokes
What is the orientation of the facet joints of the thoracic spine?
More vertical than c-spine…approaches 75 degrees
What are the degrees for each t-spine motion? (x4)
Flexion= 30-40 degrees
Extension= 20-25 degrees
Rotation= 60 degrees
Side bend=50 total
What is the coupled motions occuring in the upper and lower t-spine?
Upper= lateral side bend with ispilateral rotation Lower= lateral side bend with contralateral rotation
How is scoliosis named?
For the same side as the convexity is found (the same side of the rib hump)
With someone with scoliosis, where would a disc herniation typically occur?
On the opposite side of the convexity because it “follows the path of least resistance”
What is the orientation of the lumbar facets?
Facing inward and slightly backward…making those “hooks” because they’re so vertical-but can lead to spondys. They permit flexion and hyperextension (they’re locked out of rotation)
What are the coupled motion of the lumbar spine?
Flexion= ipsilateral rotation Extension= contralateral rotation
How much does flexion of the lumbar spine increase the diameter of the IVD? Where does this increase occur? What about with extension?
Flexion= 19% posteriorly (work for disc herniation) Extension= 11% anteriorly (helps put disc back in...think of cobra exercise)
How many layers make up the thoracolumbar fascia? What does each do?
Three:
- posterior= strongest, superficial to erector spinae
- middle= seperates erector spinae from quadratus lumborum
- anterior (“quadratus layer”)= thin but strong layer that covers the entire QL annd forms the lumbocostal arch
What is the hydraulic amplifier effect of the thoracolumbar fascia?
This fascia surrounds the back muscles and helps to increase their strength by 30% because it works like a retinaculum to help brace and support these muscles. (think of valsalva)
What core muscle activates first before any movement?
Transverse abdominis
Describe lumbopelvic rhythm…
In closed chain, in order for flexion and extension of the trunk to occur, the pelvis must first move on the femurs. If the pelvis doesn’t want to move normally, then the lumbar spine must move more to finish the flexion/extension movement. And vice versa
What muscles work to flex the c-spine? (x3)
SCM, anterior scalenes, and prevertebral muscles (such as platysma)
What muscles work to extend/hyperextend the c-spine? (x7)
Splenius capitus, splenius cervicis, erector spinae (capitis and cervicis), semispinalis, deep posterior spinal muscles, and suboccipital muscles
What muscles work to side bend the c-spine? (x6)
Splenius capitis & cervicis, erector spinae, semispinalis, scalenes, and SCM
What muscles work to rotate the c-spine? (x5)
SCM, deep posterior spinal muscles, splenius, erector spinae, and occipitalis
What muscles work to flex the thoracic and lumbar spine?
Abdominals
What muscles work to extend/hyperextend the thoracic and lumbar spine? (x3)
Erector spinae, seimspinalis thoracics, deep posterior spinal muscles
What muscles work to side bend the thoracic and lumbar spines? (x3)
Erector spinae, oblique abdominals, quadratus lumborum
What muscles work to rotate the thoracic and lumbar spines?
Ipsilateral internal oblique and erector spinae
Contralateral external oblique, semispinalis thoracicis, and other deep posterior spinal muscles
What do the cartilagenous articulations of the thorax (i.e. sternocostal, costochondral, interchondral, and intersternal) allow for? Are they synovial joints?
They are not synovial joints…they only allow for bending
When we breath, in what three directions does our rib cage expand?
Transversely, anterioposteriorly, and vertically
What are the four stages of respiration?
1-pre-inspiration (static that preceeds intake of air)
2-inspiration (expanding thorax and breathing in)
3-pre-expiration (static phase that follows inspiration)
4-expiration (outflow of air and decrease in thoracic volume)
True or false
Quiet breathing involves using the muscles to breath both in and out.
False…quiet breathing only requires muscular action for inspiration, expiration is instead a relaxation of these muscles.
What muscles are active during inspiration? Forced inspiration and expiration?
Inspiration= diaphragm, scalenes, intercostals
Forced inspiration= SCM, serattus posterior superior, levatores costarum, QL, erector spinae, and pec major and minor
Forced expiration= abdominals, erector spinae, transverse thoracic, intercostals
What are some effects of improper posture?
- -Elongation and weakness of muscles that have been under tension
- -Elongation and weakening of ligaments
- -Strains to muscles that have to help postural muscles in staying upright
True or false
The thoracic spine, in terms of posture, tends to follow the c-spine.
True…this is why it may be possible to help fix scoliosis by fixing the forward head posture.
What is the name of the hump that often occurs to little old ladies as they age?
Douger’s hump
What is a “sway back posture”? What could it lead to?
The increased lordotic curve so the butt sticks out…could lead to spondys
What is often the cause of improper posture?
Muscle imbalances
True or false:
We adjust our posture all the time.
True…we do so dynamically because we need to accept forces, accelerate our body, change our base, change direction, etc.
What is the key for dynamic posture?
The relationship between COG, center of pressure, and momentum.
What are the two types of postural adjustments that occur when trying to dynamically control our posture?
Anticipatory (feed forward–think of tensing up before a hit)
Proprioceptive (feed back–think of falling?)
