Final Flashcards
Plumb line
Start from calcaneocuboid joint
Pass through: an axis of knee, slight post to center of hip jt, sacralpromontory, bodies of lumbar vertebrae, odontoid process of axis, external auditory meatus, slight post to apex of coronal suture
Lordotic/Kyphotic
excess convexity of thoracic spine, extended lumbar spine
anterior pelvic tilt
hip flexion, tight iliopsoas
Sway back
thoracic spine posterior to plumb line posterior pelvic tilt hip extension flexed lumbar spine low abs weak
Flat back
Flat thoracic spine posterior pelvic tilt hip extension lumbar spine has no curvature (relatively flexed) Hamstrings tight
Handedness Pattern
On dominant side:
Shoulder girdle is lower
iliac crest is higher
Moment
torque about an axis, varies depending on length of moment arm
M=FA/RA
1st class lever
Force, Axis, Resistance (FAR)
pull, Fulcrum, weight
2nd class lever
Force, Resistance, Axis (FRA)
Pull, Weight, fulcrum
3rd class lever
Resistance, Force, Axis
Weight, pull, Fulcrum
Force couple
parallel force system, forces equal in magnitude but opposite in direction
Creates pure rotation
Force couples in the body are imperfect
Shoulder winging, shrugging, or impingement can occur if motion is not coupled
Connective tissue
functions to connect, protect, distribute tension and transport
surrounds muscle & vessels, limit mobility of jt (stability)
Collage type 1
most common, resists tensile stress
ligaments & tendons
Collagen type 2
thin, interwoven fibers for support
resists compressive stress
cartilage
Bone
resists compressive forces. Optimal simulus for these structures are graded tensile of compressive force in the line of function
Optimal stimulus for regeneration
Cartilage: intermittent compression & decompression
Tendon: graded tensile force in line of function (also ligament)
Bone: mechanical stress??
Stress/Strain curve
Stress = force applied
strain = deformation (ligg)
Toe region: just enough stress to create straight form
Elastic region: linear elongation, deforms and can go back to original shape
Yield point: right before plastic region, will have damage if pass this point
Plastic region: microtearing of tissue, permanent deformation
Failure point: where tissue gives & breaks
Joints
synarthrosis-fibrous
amphiarthrosis- cartilaginous
Diarthrosis: synovial
Type 1 Skeletal muscle fiber
slow oxidative
slow twitch, red, high myoglobin, low glycogen, small motor units, slow fatigue
Arthrokinematic, one joint
slow twitch aerobic, easily recruited
Type IIa
fast oxidative-glycolytic
fast wtich, red/white, intermediate myoglobin, glycogen, fatigue and motor units, anaerobic
Type IIx
fast twitch, white, low myoglobin, high glybogen, high fatigue, large motor units, anaerobic
One joint muscles
Type 1 fibers
arthrokinematic- control the roll and glide
O/I close to joint surface, first to atrophy
Two joint muscles
Type IIa/IIx
osteokinematic (gross movement of bones)
Prone to tightness
Active Insufficiency
Inability of 2 joint mm to perform a concentric contraction over one joint when it is shortened over another joint
Agonist unable to contract any more
Passive insufficiency
length insufficiency
non contractile elements, connective tissue resist stretch
antagonist too short
inability of 2 joint muscle to lengthen over one joint when is is already lengthened over another joint
if a muscle is already lengthed, it will be harder for other mm to lengthen at that joint
Force/Velocity relationship
inverse relationship for concentric motions
direct relationship with eccentric motion
force decreases as muscle shortens
eccentric produces more force than concentric
As velocity increases, force decreases
Length/Tension curve
Eccentric motions create greatest tension with active and passive elements
Max tension:eccentric>isometric>concentric
Passive tension: tension due to stretching of passive elastic components, as stretch applied, tension increases slowly at first then more rapidly as failure occurs
Active tension: reflects the isometric force for a given muscle length
EMG
measures neural activation of motor units
Concentric motion requires more MU firing, eccentric requires least MU firing
Concentric contraction are more metabolically demanding and are a weaker contraction type
With fatigue, MU firing increases until you fatigue out
Determinants of gait
decrease energy output & increase efficiency Pelvic rotation in transverse plane Lateral Pelvic tilt lateral shift knee flexion ankle dorsiflexion heel rise
Stance phase
60% total cycle
40% since support: midstance & terminal stance
20% double support: IC, loading response & pre swing
Swing phase
40% of total cycle
All single support.
Initial swing, mid swing, terminal swing
External moment IC
Hip: Flexion
Knee: extension
Ankle: plantarlexion
External moment LR
Hip: flexion
Knee: flexion
Ankle: plantarflexion to neutral
External Moment Midstance
Hip: Flexion to neutral
Knee: Flexion
Ankle: neutral to dorsiflexion
External moment terminal stance
Hip: extension
Knee: extension
Ankle: neutral to dorsiflexion
External moment preswing
hip: flexion
knee: flexion
Ankle: dorsiflexion
