week 4- biomechanics and spinal biomechanics Flashcards
name the 5 components of biomechanics
motion-movement of body or an object through space
force- push/pull causing object to speed/slow/stop/change direction
momentum -product of a weight and its velocity when moved
levers- arms and legs act as levers
balance- alignment of body centre of gravity over the base of support
in flexion, are facet joints of the spine close together or far apart
far apart
when the spine bends backwards, what happens to the invertebratal disc
it moves anteriorly as facet joints move closer together.
in lateral rotation (right) what happens to the spine.
right facet joint moves inferiorly, posteriorly and laterally, joining the facet joint inferior
left facet joint extends superiorly and medially. ‘interior superior glide’
if a person laterally rotates right, which direction is the spinous process
spinous process moves left
does the atlas have a spinous process
no
in cervical flexion, describe what occurs
-anterior surface gets smaller
-posterior surface gets larger.
-spinous processes seperate from one another
-tension is put on posterior ligaments
-anterior longtiduidal ligament has some laxity in it
what occurs to the facet joints in cervical flexion
upsloping.
superior vertebra glides superiorly and anteriorly.
‘veratbra above glides superior and anteriorly relative to the vertebra below’
What is the fulcrum
The joint, or contact point with surface
What is the load/resistance
Mass of object the lever is moving
What is the effort
Force being applied to lever system
What is the lever arm
The bone/ muscles which apply the effort
State the types of levers
1st order lever
2nd order lever
3rd order lever
Describe 1st order lever
Fulcrum is halfway between load and effort
E.g. flecion of head/neck. Load is head. Effort is muscles of the neck. Spine is fulcrum
Describe second order lever
Load is halfway between fulcrum and effort
E.g. calf raise. Fulcrum is contact point with ground, load is body weight, effort is Achilles tendon from calf to heel
Describe 3rd order lever
Effort is halfway between fulcrum or load
E.g. fulcrum is joint, load is dumber,, effort is central between. Bicep curl. Effort is muscle
Describe how the spine is a 1st class lever and Chiros role
Spine is fulcrum of upright vertebral body and 2 facet joints
Load is weight of our body and weight if anything we carry
Effort is required contraction of spinal muscles on the opposite side of the fulcrum to keep the spine balanced
If first class lever is altered, increased effective mechanical load born by the fulcrum
Give an example of eversion
Turning foot outwards , allowed because of ankle
An example of inversion
Pointing ankles together at an angle, angled from medial inferior of foot
Give an example of elevation and depression
Lifting the shoulders and putting them back
Lost spinal specific ROMS
neutral
Flexion
Extension
Exhale extension
Axial rotation
Lateral flexion
Why must the spine be rigid and flexible
Protect the spinal chord
Transfer weight
To allow bending movements of upper body to pelvis
To absorb shock
To allow the head to pivot
Why is the vertebral column curved
To have more resistance to forces, balance can occur
