LL 2 questions

what is the formula for stirrup length

(2xankle axis height) + (2x sole thickness) + heel width + 6mm

what is the formula to calculate stirrup length

(2xankle axis height) + (2xsole thickness) + heel width +6mm

normal, passive RoM for the knee in the sagittal plane is:

0-135deg

the angle from the proximal thigh band is___ degrees from a line perpendicular to the mid- sagittal line

15

the width of the walking base during normal gait is approximately

2-4"

the proximal edge of the calf band of the metal AFO should be ___ mm ____ to the neck of the fibula

20, distal

to allow for normal RoM for the free motion mechanical ankle joint to function like the talocrural joint, you would need to allow

20deg DF and 20deg PF

the ideal clearance between the inside surface of the aluminum uprights and the individuals skin is

3-6mm

for correction of the clinical presentation of a flexible genu varum, forces should be applied over the

30mm distal to the perineum, medial aspect of the foot and the head of the femur

what is the minimal clearance needed for the proximal medial edge of the proximal thigh band from the perineum

30mm inferior

for the reciprocating gait pattern, when genu varum is present on a LL KAFO schema, an assessment reference line would connect the mid-perineum mark and the mark at

30mm medial to the ankle

at mid-stance, the hip abductor muscles on the stance side function to provide a mediolateral pelvic stabilization. the force exerted by the hip abductors on the stance side has been estimated to be equal to

3x body wt

clearance for the anatomical ankle joint in a metal double upright AFO system is ___mm medial and ___mm lateral

6, 5

the max knee flexion angle during the swing phase of gait is approximately

60deg

the minimal clearance for a mechanical knee joint on a metal KAFO should be

6mm medially and 5mm laterally

anterior translation of the tibia w/ respect to the femur may result from an injury to which ligament

ACL

the magnitude of anterior deflection of the medial sidebar is determined using which measurements

AP to the medial and lateral malleoli

t/f the lateral femoral condyle is larger than the medial femoral condyle

False

which of the following gait deviations would likely be the result of absent DF

IC w/ the forefoot

a 20 yr old w/ a history significant for post-polio syndrome is seen in clinic. upon evaluation it was discovered that she had weakness at her left hip, knee, and ankle. she also has 15deg genu recurvatum. which orthotic device would you recommend?

KAFO w/ off-set knee joints and ankle control

abduction angulation (genu valgum) of the knee may result from an injury to which ligament

MCL

the width of the calf band is equal to

ML of the calf + 6mm

injury to the unholy triad involves the

MMA, medial meniscus, medial collateral ligament, anterior cruciate ligament

posterior translation of the tibia in respect to the femur may result from an injury to which ligament

PCL

which ligament is best oriented to prevent the femur from sliding off the anterior edge of the tibia and to prevent the tibia from displacing posterior to the femur

PCL

at heel strike, what type of moment is present at the ankle in the sagittal plane

PF

during normal standing, which of the following muscles or groups are most likely to be active

PF

on a KAFO designed to prevent knee recurvatum, 2 of the necessary components would be

a calf band and distal thigh band

what would be the ideal componentry for knee recurvatum and why

a posterior offset knee joint because it accommodates 10deg recurvatum and a solid foot plate with built in PF to discourage excess knee flexion

on a conventional (metal) KAFO used to prevent knee flexion, which components are responsible for the anteriorly directed stabilizing forces

a proximal thigh band and the shoe counter

to control excessive knee flexion during stance phase, the DAAJ of the metal double upright AFO system should be set up with

an anterior pin

the weight line falls just ___ to the ankle joints during static standing in the sagittal plane

anterior

when a DAAJ on a metal AFO are aligned posterior to the anatomical ankle joint, as a pt goes into DF, one could expect the new calf band path to be

anterior and distal to the original path

what is the gait compensation for quad paralysis w/ weak gluteus maximus

anterior trunk bending

the side bars of a KAFO w/ drop locks on the knee joints should lay ____ of the leg in the sagittal plane

at midline

a knee joint mechanism which will prevent drop locks from inadvertently engaging is/are

ball bearing retainers

the medial mechanical ankle joint impinges on the medial malleolus during ambulation. this is due to a valgus condition of the pts calcaneus and a pronated hind- and mid-foot. describe the modification/ adjustment you could do to metal AFO

correct: add t-strap to anterior- medial shoe accommodate: add more space on medial by re-countouring the stirrup and re-squaring the ankle DAAJ

the goal in management of a flexible pathomechanical deformity is

correction

clinically, the location of the mechanical ankle axis for a metal AFO should be at the

distal tip of the medial malleolus

when assessing toe-out and tibial torsion for a metal double upright AFO, it is critical to

ensure perpendicular alignment of the knee axis relative to the line of progression

the advantage of a posterior offset, free motion knee joint vs a standard free motion knee joint is the

extension moment it induces during early stance phase

it is necessary to reverse the schema for metal AFO fabrication because

fabrication will be oriented from the posterior view of the leg

a primary advantage of a bail lock mechanical knee joint on a KAFO is it can

facilitate operation of the mechanical lock when there is upper limb involvement

what is one functional deficit that is indicated for pins in both chambers of DAAJ

fair/poor anterior and posterior muscle compartments of the lower leg

as the anatomical knee is going toward extension, the screw home mechanism of the knee consists of the

femur internally rotating on the tibia in an open kinematic chain

which height measurement is required for fabrication of a double upright AFO

fib neck, distal tip of medial malleolus

how do you determine the placement if the distal thigh band

find the distance from mechanical knee to the proximal trimline of AFO. this distance is applied from knee center superior to place distal thigh band

when the right foot is 1 1/2 sizes shorter than the left, it is better to

fit two mis-mate shoes

during normal standing, which muscles or groups are most likely to demonstrate EMG activity

gastroc

during mid-stance, which of the following combos of muscles or muscle groups is/are active on the stance side

hip extensors, hip abductors, PF

at the time of loading response during gait, which of the following muscles or groups are active

hip extensors, quads and DF

arthrodesis of the talocrural, subtalar calcaneocuboid and talonavicular joints will tend to cause

hyperextension of the knee on the ipsilateral side bw mid-stance heel off, a reduced step length on the contralateral side, increased knee flexion on the ipsilateral side bw heel strike and foot flat

during a cycle of gait, the limbs undergo axial or length rotations about their long axes. during which of the following parts of the cycle will the lower limb be internally rotating

initial contact

according to the 1975 study by Lehman and Warren, which is not an acceptable knee control design for ambulatory KAFOs

knee cap strap

during the period of acceleration, which of the following muscles or groups undergo a lengthening (eccentric) contraction

knee extension

if an individual utilizing a metal double sidebar AFO w/ free motion ankle joints presented w/ a flexible subtalar varus deformity, to what side of the shoe would you attach/ sew the corrective strap

lateral

w/ what type of ankle joint setting in a DAAJ metal AFO might you use both a cushioned heel and a rocker bottom shoe modification

limited/ restrained DF and PF

during the stance phase of gait, the max knee flexion angle is usually reached at

loading response

ecess DF in an AFO w/ DAAJ can be reduces by

loosening the posterior and tightening the anterior set screw

the schema for a metal KAFO should indicate the knee and ankle joint axes both to be

perpendicular to the mid-sagittal line

which knee joint best simulates normal knee joint motion

polycentric

a pin in the ___ compartment of DAAJ would help limit genu recurvatum

posterior

a spring placed in the ___ channel of DAAJ will assist DF

posterior

at the time of terminal stance during gait, the floor reaction force is

posterior and medial to hip

when DAAJ AFO are aligned distal to the anatomical ankle joint, one could expect the new calf band to track ___ to the original path while moving into PF

posterior and proximal

when DAAJ are aligned anterior to the anatomical ankle joint, one could expect the new calf band path to track ___ to the original path while moving into DF

posterior and proximal

what is the gait compensation for hip extensor weakness

posterior trunk lean

if a pt utilizing a double upright AFO system w/ free motion ankle joints has a fixed subtalar varus deformity, to what side of the shoe would you attach the accommodative t-strap

posterior- lateral

the outline drawing of the patients leg and associated schema are reversed so that they can be veiwed

posteriorly

during swing phase of gait, the quads function to

prepare the limb for wt acceptance

in class and from your readings, we discussed many indications for using KAFOs to control mal-alignment of the knee instead of an AFO to influence mal-alignment of the knee. list 2 indications for the use of KAFO to control knee mal-alignment

quad weakness, knee instability

low levels of stress on the foot (in the range of 2-5lbs per square inch) will more likely cause damage to the soft tissues of the foot when

repetitive stresses are applied

which disease affecting the foot respond to mechanical management

rheumatoid, reiters, gout

in anatomical position, 3 principle reference planes define different views of the body as well as its movement. The sagittal plane divides the body into

right and left halves

what special adaption should be incorporated in KAFOs for children

segmental length adjustments

in a KAFO, recurvatum may be controlled by

shallowing the distal thigh band

what is the gait compensation for zero grade PF

shortened stride length

what is the effect in gait with a solid metal AFO system

stance: no toe off for terminal stance, knee flexion during loading response swing: toe clearance w/ flat foot IC

KNOW THE FORMULA FOR STIRRUP LENGTH!!!!!

stirrups only come in 1/2" increments -can go 1/2 size up for pediatric

a lateral heel wedge is used for which pathology

talipes equinovarus, flexible pes varus, fixed pes valgus

during normal gait, the ankle joint is subjected to its DF moment (torque)

terminal stance

during normal gait, the ankle joint is subjected to its greatest greatest dorsiflexion moment (torque)

terminal stance

during normal gait, the knee is subjected to the greatest extension moment (torque) at

terminal stance

the vertical component of the GRF is said to exceed the body wt at 2 distinct intervals during stance

terminal stance and loading response

in regards to normal human locomotion, the greatest amount of hip flexion is expected during___ while the greatest amount of hip extension can be seen during ____

terminal swing, terminal stance

an individual wearing a metal double upright AFO system is displaying an excessive amount of knee flexion at IC. what may be the cause

the AFO is locked in a position of 5deg of DF

what landmarks are used to locate the anatomical knee axis clinically

the adductor tubercle and the medial tibial plateau

name 2 areas which anterior deflection of sidebars should not occur

the insertion area to the DAAJ and where calf band is attached

the definition which best describes toe in/out is the relationship of

the long axis of the foot to the line of progression

when would you deflect the side bar

the side bar of the AFO section is deflected to midline when the knee joint is used

as the cadence of gait increases beyond 120 steps/minute

the step length increases

a pt reports excessive anterior pressure from the calf strap and pad while going into DF w/ their DAAJ. which is a cause

the stirrup tongue is too long, the shoe shank is too stiff or long, the anterior pin is too long

during normal standing, w/ the wt equally distributed on both feet, the body wt normally passes

through and posterior to the hip medial and anterior to the knee medial to the subtalar and anterior to the ankle

lateral sole wedges on the shoe may cause the foot to

toe out

what is the three point pressure system for a KAFO addressing unilateral knee recurvatum

two posteriorly placed and anteriorly directed corrective forces, one at the calf band and the other at the distal thigh band. two anteriorly places and posteriorly directed stabilizing forces, one at the shoe and the other at the proximal thigh band

a torn collateral ligament of the knee would create a ___ moment and a tendency for the knee to move ___

valgum/ medially

what is the gait compensation that makes the involved limb relatively longer

vaulting

what biomechanical condition happens when running

vertical forces increase and stance phase shortens

what is the most important condition that should be met in order to ensure static equilibrium (balance)

weight line should pass through the base of support

when would a DF assist ankle joint be indicated for a metal AFO recommendation

when the individual presents w/ anterior muscle compartment failure