LE Oral Questions Flashcards
How do you determine stirrup length?
2 x height of distal tip of medial malleolus + width of heel + 6 mm
How do you determine band length?
1/2 circumference + 1.5”
What are the minimum clearances for ankle joints and knee joints?
Ankle: 6mm medial/5mm lateral
Knee: 6mm medial/3mm lateral
In a conventional KAFO what changes could you use to reduce recurvatum?
Shallow bands
Move calf band up and distal thigh down (move closer)
Increase heel height
What problems could you encounter in moving the bands of a KAFO?
Peroneal nerve impingement
Limited knee flexion
How much PF would you allow a patient who has suffered a CVA?
Neutral
How do you determine if a patient requires locks on his KAFO vs free knee?
Hip/knee extensor weakness
What do you recommend for a patient who exhibits foot slap at heel strike?
AFO with PF stop
What is Legg-Calve-Perthes disease?
Avascular necrosis of the femoral head
Usually boys 9-14
Femoral head will return to normal if the leg is abducted and internally rotated
Name 3 orthoses used for LCP.
Scottish Rite
Toronto
Newington
Name 3 orthoses for the treatment of hip dysplasia.
Pavlik
Rhino
Ilfeld Splint
Frejka pillow
What is tibial torsion?
Difference between knee and ankle joint axes as viewed in the transverse plane
How is tibial torsion measured?
KF 90*
Measure apex of each malleolus to a surface behind the leg
What types of functional devices can be used for excessive pronation of the foot?
FO
UCBL
A UCBL is used for more control of what part of the foot?
hindfoot
subtalar joint
What is the cause of Charcot joints in the feet/ankle?
Any neuropathic disease can have Charcot joints
diabetes, herpes, syphilis
Evaluation of a patient with a gunshot wound to the hip reveals weak hip flexors. What peripheral nerve is injured?
femoral N.
What is your orthotic recommendation for pt w/ weak hip flexors?
cane on contralateral side?
Describe chondromalacia.
softness of the articular cartilage usually involving the patellofemoral joint
What is your orthotic recommendation for chondromalacia?
Palumbo orthosis or other patellar stabilizing orthosis
A patient’s KAFO has free motion knee, but the mechanical joint is 1” distal to the anatomical joint. In flexion, the resulting pressures will be…
Proximal posterior thigh
Distal anterior thigh
Orthosis migrates proximally
Toe drag is a bigger problem in what phase of gait? Why?
Initial swing - if the toe does not clear the floor, the patient takes short steps and may trip
Why do diabetics get foot ulcers?
loss of sensation
What is the advantage of an offset knee joint for treating recurvatum?
puts the weight bearing line anterior to the knee joint, making it unnecessary to lock the knee
Describe Guillain-Barre and its effects on the patient.
infectious polyneuritis with progressive muscular weakness, distal to proximal, may lead to paralysis
prognosis usually full recovery
Describe Charcot-Marie-Tooth.
inherited progressive neuromuscular atrophy characterized by progressive weakness of the distal muscles of arms and feet
usually develops in childhood
When would you recommend a bail lock on a KAFO instead of drop locks?
only one functional hand
When canes/crutches are used with bilateral KAFOs
Name two contraindications for plastic AFOs.
uncontrolled edema
sensitive skin
Name two methods of minimizing knee flexion torque at initial contact in a lower extremity orthosis.
beveled heel
undercut heel
SACH heel
What implications do weak hip flexors have in your design of a KAFO?
a lightweight design could encourage hip flexion at swing phase
For which diagnoses would you recommend a rocker bottom shoe?
diabetes
arthritis
ankle fusion
What is the rx rationale for a rocker bottom shoe?
simulate normal foot biomechanics and promote even wt bearing distribution in a pt w/ limited or no ankle motion
A polio patient has a flail ankle, good knee muscles, good hip muscles, and full ROM at knee w/ recurvatum of 25*. Knee buckles when tired. What orthosis do you recommend? Describe the mechanical principles.
Lightweight KAFO, offset or drop lock knee, solid plastic AFO section w/ rocker bottom shoe or a DAAJ.
Solid ankle for AFO section
Six weeks post ACL repair, how do you cast? What two mechanical principles do you want?
cast in slight flexion
prevent hyperextension and control rotation
Name 2 reasons why you might not use pretibial AFOs for a patient who walks w/ crouch gait.
hip flexion contracture
lack of ankle ROM
inability to don
Give 4 contraindications for RGOs.
obesity hip flexion contracture >20* spasticity non-plantigrade foot hip dislocation
Name 3 clinical signs of charcot joints at ankle mortise.
swelling instability excessive joint mobility pain anesthetic foot visual deformity
Name 3 mechanical principles for treatment of Charcot joints.
immobilize in total contact AFO
minimal weight bearing
rocker bottom
Name 3 signs in evaluation of heel spur pain
valgus foot
pes planus
localized pain at loading
Name 2 mechanical principles for treating heel spurs.
distribute and reduce pressure in arch support
UBC for hindfoot and/or forefoot control
Where should you place the mechanical hip joint?
1/2” anterior and 1” superior to GT
How would elevating the shoe heel affect a solid ankle AFO?
increased KFM at heel strike
What effect would posterior placement of knee joints have on a KAFO?
migrates proximally with pressure on anterior calf cuff
What modifications can you make to a plastic KAFO to reduce recurvatum?
trim proximal and distal sections closer to the knee
pad shells
shallow shells
Why would you choose a metal AFO over plastic for a patient with Charcot joints?
prevent skin breakdown due to insensate foot
What are the stance phases of gait and what is the hip position through each?
IC: 30* flexion LR: 25-30* flexion Midstance: 20* flexion to 5* extension Heel off: 10* extension Push off: 10* extension
How can you prevent a knee orthosis from migrating down?
supracondylar wedge
suprapatellar strap
attach to foot plate
lightweight belt
