Biomechanics 2 - TF Flashcards
whatre we concerned about –> M/L alignment
stabilizing RL in the socket
stabilizing hip joint/pelvis in frontal plane
M/L stability
single leg stance
gait
midstance
stabalization
stabilization –> gait
socket/RL interface
muscle stabilization
pelvis falls to unsupported side
socket/RL interface –> stabilization
prevent movement b/w them
pelvis falls to unsupported side –> stabilization
eccentric ABDs
M/L normal BoS
2-4”
support point –> ML
weight bearing point
ischial containment
G max/ischial tub
support line –> ML
weight line
from support point to ground
inset/neutral/outset
inset foot –> ML
normal ML alignment
normal BoS
what should we look at –> ML alignment
pressures in socket
stabilization of ABD (pelvis)
socket pressures –> inset
proximal medial
distal lateral (cut end of femur)
socket pressures –> outlet
distal medial (ADDs)
proximal lateral (greater trochanter, pressure sensitive)
ABD stabilization –> MS
lateral socket stabilizes ABDs
prevents pelvis from dropping on unsupported side
ischial containment socket –> socket design
pressure system/pelvic lock
3 point pressure system
what does the ischial containment socket prevent
shifting of tibial tuberosity
what does the ischial containment socket stabilize
the pelvis
ischial containment socket has
narrow M/L
curve of lateral femur
pelvic lock
pelvic lock –> ischial containment socket
ischial tuberosity locked
minimizes movement
minimize socket pressure
minimize socket pressure –> ischial containment
minimize distal lateral pressure
foot alignment –> ML
b/c femur is well stabilized
what is the femur well stabilized w/ –> foot alignment
start at inset
move out laterally if there is lateral pain
ABD stabilization has
narrow ML
curve of lateral socket along the shape of femur
pelvic lock
stabilizes ABDs
socket position –> ABD stabilization
neutral
not adducted
subischial socket has no
lock of ischial tuberosity
ischial tuberosity slides w/ muscle contraction
subischial socket provides
poor stabilization of the ABDs
w/ a subischial socket
get gait deviation
lateral trunk bend
ABD stabilization result –> socket position
in ADD
puts ABDs on stretch
ischial containment –> foot position
start at inset
ischial containment –> socket position
neutral b/w ABD and ADD
subischial –> socket position
socket position
AP stabilization
socket position
knee/TKA line
what muscle is most important at HS –> AP stabilization –> ischial containment socket
G max
what does the socket wall do–> AP stabilization –> ischial containment socket
stabilizes distal attachment
lock on the pelvis
good G max stabilization
socket position –> AP stabilization –> ischial containment socket
neutral
subischial socket –> AP
poor stabilization of the G max
put G max on stretch
AP socket position is flexed
knee alignment/TKA line is
independent of socket type
TKA line
trochanter/knee/ankle
for AP alignment we look at
knee in relation to TKA line
alignment terms
involuntary alignment
voluntary alignment
neutral alignment
involuntary alignment
pt doesnt work to knee stable
aligned for stability
voluntary alignment
pt has to work to keep knee stable
aligned for mobility
neutral alignment
balanced b/w involuntary and voluntary
balanced b/w stability and mobility
knee position
in relation to TKA line
anterior to TKA –> knee position
flexion moment
posterior to TKA –> knee position
extension moment
in line w/ TKA –> knee position
balance b/w
involuntary alignment –> knee and TKA
knee posterior to TKA
flexing the knee –> involuntary
harder to do
involuntary alignment is
more stable
less mobile
how is involuntary alignment controlled
by alignment
voluntary alignment –> knee/TKA
knee is anterior to TKA
flexing the knee –> voluntary
easier
voluntary alignment is
less stable
more mobile
voluntary alignment –> control
pt controlled
neutral –> TKA/knee
knee in line w/ TKA
neutral alignment is
balanced
there is a balance b/w –> neutral
mobility and stability
neutral control
some alignment control
some pt control
what should we always consider
alignment
fxnal level of pt
characteristics of the components
any control from component
friction, computerized, hydraulic
more aggressive alignment
voluntary
less aggressive alignment
involuntary
AP alignment –> ischial containment –> socket position
neutral
AP alignment –> ischial containment –> knee/TKA position
pt and component dependent
AP alignment –> subischial containment –> socket position
flexed
AP alignment –> subischial containment –> knee/TKA position
pt and component dependent
