Vertebal Column Flashcards
Interdependence of curves of the spine
Curves are dynamically interdependent= change in position of one segment results automatically in change of position for adjacent segments- like a gear moving other gears as they move
Flexion / extension of the vertebral column
In the sagittal plane
About a medial- lateral axis of rotation
Flexion: bending over to touch toes
Extension: back bend
Lateral flexion of the vertebral column
In the frontal plane
About an anterior posterior axis of rotation
Trunk bending to the left and the right
Axial rotation of the vertebral column
In the horizontal plane
About a vertical axis of rotation
Twisting trunk to the right and to the left
2 main articulations of the vertebral column
Apophyseal (facet joints) = synovial
Interview joints= cartilaginous
A joint’s range of motion is determined by the __________ and the _________.
Surface area of articular cartilage
Orientation of articular cartilage
Apophyseal/facet vs inter body joints
Apophyseal/ facet joints= formed by articulation of opposing facet surfaces, synovial (designed for movements)
Interbody joints= formed by the connections between the intervertebral disc and adjacent vertebral bodies (for shock absorption)
Structure of intervertebral joint
Central nucleus pulposus surrounded by an annulus fibrosus bordered superiorly and inferiority by vertebral plates
Nucleus pulposus
Pulp like gel (mostly water) within an intervertebral disc
Very high GAG content
Annulus fibrous
10-20 layers of collagen fibers that trap water based nucleus pulposus
Function of IV disc
compression raises the pressure within the nucleus pulposus (jelly within donut wants to get out)
Pressure is directed outward into the annulus fibers, which resists displacement (the donut keeping the jelly inside)
Pressure of the nucleus is then exerted on the vertebral end plates, distributed to the next vertebral body
Amount of pressure generated in a disc - amount of displacement of nucleus pulposus
The most pressure occurs from activities required forward bending, axial rotation, and vigorous trunk muscle contraction (ex: Picking something up from the ground)
3 important points of disc pressure
Disc pressures are larger when one holds a load in front of the body
———- The farther you hold an object from your body, the more force required of your trunk extensors
Lifting a load with the knees straight causes greater pressure than lifting with your knees bent
———— Straight knees requires bending your vertebral column (bad)
Sitting in a forward slouched posture produces greater pressure than when sitting up
A fusion of C1 and C2 would result in limitation of what motion?
Axial rotation
Anterior pelvic tilt
Force couple between hip flexors and back extensor muscles
muscles
Results in increased lordosis and lumbar extension
Posterior pelvic tilt
Force couple between hip extensors
Results in decreased lordosis and lumbar spine flexion
The primary muscle controlling forward bending of the trunk is:
Erector spinae! Using eccentric control
Erector spinae muscles:
Bilateral concentric activation?
Bilateral eccentric activation?
Unilateral activation?
Bilateral concentric activation: extends the spine
Bilateral eccentric activation: controls the descent of the trunk into flexion (when bending over)
Unilateral activation: ipsilateral lateral flexion and axial rotation
Transversospinalis
Bilateral concentric activation?
Bilateral eccentric activation?
Unilateral activation?
Bilateral concentric: extends the spine
Bilateral eccentric: controls the descent of the spine into flexion
Unilateral activation: contralateral axial rotation
Abdominal muscles
Bilateral activation?
Unilateral activation?
Bilateral activation: flex the thoracic and lumbar spine, posterior lay tilting the pelvis (like in a crunch)
Unilateral activation: lateral flexion
Muscles produce an __________ amount of force on proximal and distal ends.
Equal
Quadratics Lumborum:
Bilateral activation?
Unilateral activation?
Bilateral activation causes extension
Unilateral activation causes ipsilateral lateral flexion
If a patient had a right CVA with left hemiplegia (paralysis of the left side), in which direction would the trunk of the patient lean?
Patient would lean to the RIGHT
Unilateral activation causes lateral flexion
In an attempt to restore normal posture, you would stretch the trunk to the LEFT to try to activate the left erector spinae muscles
In what ways can you reduce force demands while lifting?
Reduce the weight of external load
Or reduce the length of the external moment arm- bring the load closer to your body
Sternocleidomastoid :
Unilateral activation?
Bilateral activation?
Unilateral activation: ipsilateral flexion and contralateral rotation
Ex: Torticollis
Bilateral activation: flexion of the cervical spine and extension of the head
Ex: protraction
