711 Flashcards
Def: Kinematics
the study of movement related to displacement, v, and a
Def: kinetics
the study of movement related to forces
Types of Forces:
Gravity - vertically down
Shear - coplanar, opposite
Tensile - colinear, opposite
Compressive - colinear, same
Newton’s Laws
1) Inertia
2) Acceleration
3) Action/Reaction
Def: Moment/Torque
the application of force at a distance from the point of pivot that cause rotation around a stationary point
force x distance
Levers
First Class - fulcrum in center
Second Class - load in center
Third class - Effort in center
Connective tissue function
connect, protect, support
Viscoelastic material properties of conn tiss
time dependent - longer load, greater deform
rate dependent - better quickly resisted
hysteresis/elastic
function of corticoal/compact bone
resists torsion and bending
function of cancellous/spongy bone
metabolic activity, highly vascular
Wolff’s Law
bone is laid down in areas of high stress and resorbed in areas of low stress
stim for bone
loading along axis of bone
stim for cartilage
compression/decompression
stim for lig/ten
tensile stress in line of fiber orientation
Type I mus fibers
slow, oxidative one joint arthrokin first to atrophy prone to weakness
type IIa mus fibers
fast oxidative glycolitic
type IIb fibers
fast glycolitic 2 joint osteokin prone to tightness dominate
size principle in muscle fibers
I > IIa > IIb in regards to what is used first
when is a greater force produced in concentric contraction
slow
when is greater force achieved in eccentric contraction
fast
what length is optimal for muscles force production to be max? why?
120%
max cross-bridge interactions
active insufficiency
concentric
the inability of a 2 joint mus to perform a concentric contraction over one joint when it is shortened over another
passive insufficiency
eccentric
the inability of a 2 joint mus to lengthen over one joint when it is already lengthened over another
quad body weight ratio
males 100% @ 60deg / sec
females 80% @ 60deg / sec
ham body weight ratio
70% at 60deg / sec
Synarthrosis Joint
Non-synovial
allows for slight to no movement
fibrous and cartilaginous
Diathrodial Joints
Synovial
allows for mod to extensive movement
uniaxial, bi, and tri/multi
Types of uniaxial joints
hinge, pivot
types of biaxial joints
saddle, condyloid
types of tri/multiaxial joints
plane, spheroidal
hip arthro
opposite
Lower extremity pronation hip
shortens limb:
hip IR and flex
Lower extremity supination hip
lengthens limb: hip ER and ext
normal angle of inclination
125deg
coxa valgum angle
> 125
coxa valgum effects
less mechanical advantage
decreased hip stability
increase risk of dislocation and OA
coxa varum angle
coxa varum effects
longer moment arm for the hip (decreased joint reaction forces)
greater risk for fx
normal angle of torsion
8-15
excessive anteversion
> 15
retroversion
tibia is ER’ing
CAM impingement
caused by femoral neck
Pincer impingment
caused by shape of acetabulum
Anterior tilt effect on hip and back
Hip: flexion
Lumbar spine: extension
Posterior tilt effect on hip and back
Hip: extension
Lumbar spine: flexion
why use cane on contralateral side?
substantially less total joint force compared to ips side
LE Closed Chain Pronation
Femoral: IR Knee: flexion Tibia: IR Talus: PF and add Calc: eversion *shortens limb
LE Closed Chain Supination
Femur: ER Knee: ext tibia: ER Talus: DF and abd calc: inversion
Screw-Home Mechanism
Open Chain: 10 deg of ER of tibia in last 30deg ext
Closed: 10deg of IR of femur in last 30deg ext
what is the screw home mechanism driven by?
shape of medial femoral condyle
passive tension of ACL
lateral pull of quads
MCL fxn
resists valgus and extension forces
clip injury
LCL fxn
resists varus and extension forces
ACL fxn
stability–extension mainly
proprioception
arthrokinematics
OC: prevents ant translation of tibia on femur
CC: prevents post translation of femur on tibia
PCL fxn
arthro
resists flexion
OC: prevents post translation of tibia on femur
CC: prevents ant translation of femur on tibia
Meniscus fxn
stability, shock absorption, lubricate, guide arthro
Medial men
c-shaped
more attached
Lateral men
o-shaped
ankle fxns
stability - base of support, rigid lever for push off
flexibility - adapt to terrain, shock absorption
Ankle Supination
stability: rigid lever for pushoff
Ankle Pronation
flexibility: shock absorption
Windlass mechanism
extension of great toe causes tightening of plantar aponeuroiss (makes stable)
4 Points of Normalcy
- Tibia is verticle
- Calcaneus is in line with tibia
- metatarsals are in a plane perpendicular with calcaneus
- metatarsals are in the same plane
Forefoot Varus Open Chain
forefoot inverted (plane of metatarsals is more dorsal on medial side) STJ neutral and Calv vertical
Forefoot varus closed chain
forefoot flat
STJ pronated
Calc everted
*pronated too long
rearfoot varus open chain
forefoot inverted
STJ neutral
calc inverted
rearfoot varus closed chain
forefoot flat
STJ pronated
Calc verticle
*pronates too much
forefoot valgus open chain
forefoot everted (metatarsals more dorsal on lateral side)
stj neut
calc verticle
forefoot valgus closed chain
forefoot flat
stj: supinated
calc: inverted
* supinates too soon
most common ankle sprain
inversion, pf, rotation
Grade I: ant talofib, tibiofib
Grade II: + calcaneofib
Grade III: + post talofib
Acute Phase of Healing
Inflammatory: red, swollen, warm, painful
3-7/10 days
pain at rest and with motion
wbc coagulation
acute phase goals
rest, relieve, protect
subacute phase
migratory and proliferative phase 10days - 6weeks pain with motion limited ROM capillary growth, granulation tissue formation, fibroblast proliferation increased macrophage activity
subacute goals
optimal stim, protect, gain motion
chronic phase
remodeling/maturation
6weeks-1year+
scar tissue formation/tensile strength
pain maybe after activity
chronic goals
increase tissue stress
full motion
strengthen
return to pain-free function
muscles of hip flexion
iliopsoas, rect fem, sart, TFL, pect, adductors, ant glut med
motions for sartorius
hip flexion, abduction, ER
muscles of hip extension
glut max and hams
how do you isolate glut max in MMT of hip ext?
bend knee to active insufficiency rect fem
hip er’s
gogo’s, glut max
