Lab 2: Shoes and AFOs Flashcards
What is a lift?
Used to accommodate a leg length discrepancy or when asymmetry exists to promote greater ease in swing on the contralateral side
What biomechanical effect would there be if a lift was only added to the heel of a shoe?
It would put the ankle into plantarflexion
How much lift can be accommodated within the shoe?
1/2”
What is the function of a cushioned heel?
Absorb shock during heel strike
When is a cushioned heel indicated?
Heel pain or when an individual is using a solid AFO so that it can assist with forward weight shift
What is the function of a rocker sole, metatarsal bar, and rocker bar?
Decrease weight bearing through the metatarsal heads to allow for an easier and more comfortable transition from heel strike to push off
What is a rocker sole?
Extends the length of the sole of the shoe
What is a metatarsal bar?
Strip of leather or rubber placed just posterior to the metatarsal heads
What is a rocker bar?
Strip of leather or rubber placed just posterior to the metatarsal heads but is beveled at the ends and resembles the rocker base of a rocker chair
What are the four styles of rocker bottoms?
Rocker sole, double rocker, toe rocker, heel rocker
What type of rocker is shown in the image?
Rocker sole
What type of rocker is shown in the image?
Double rocker
What type of rocker is shown in the image?
Toe rocker
What type of rocker is shown in the image?
Heel rocker
What is the purpose of a flare?
Increase the M-L surface area of the bottom of the shoe. Can be placed either medially or laterally
What is a wedge?
External modification that is thicker on one side and tips the shoe in a desired direction
What is the purpose of a heel wedge?
Directly influences the calcaneal position to correct a flexible deformity or support a rigid deformity
Where is a sole wedge located?
Originates distal to the heel, bisects the midline of the sole, and extends to the anterior midline of the footwear
What effect does a medial sole wedge have?
Inversion
What effect does a lateral sole wedge have?
Eversion
What is the function of a flare?
Increase BOS and prevents inversion or eversion injuries
What is the function of a wedge?
Help to correct a flexible deformities or support rigid deformities
If a pt presents with a flexible pronation deformity, what type of wedge or flare could be recommended?
Wedge: medial heel, will push calcaneus superior to to redistribute weight laterally
Flare: lateral, will encourage weight shift to lateral side of foot
If a pt presents with a rigid pronation deformity, what type of wedge or flare could be recommended?
Wedge: lateral hindfoot will support the everted position and redistribute the weight to the medial side
Flare: medial can increased BOS for loading, not practical though because it will be required bilaterally
If a pt presents with a flexible supination deformity, what type of wedge or flare could be recommended?
Wedge: lateral hindfoot will push calcaneus inferior to redistribute weight medially
Flare: medial may encourage weight shirt, but would be required bilaterally
If a pt presents with a rigid supination deformity, what type of wedge or flare could be recommended?
Wedge: medial hindfoot will support inverted hindfoot and redistribute weight laterally
Flare: lateral may help to improve balance by increasing BOS where foot is loaded
What is a Thomas heel?
An extension of the front edge of the heel anteriorly on the medial side
When is a Thomas heel used?
Increase stability of the sole of the shoe when there is pronation
What is a Reverse Thomas heel?
Breast of the heel is extended anteriorly on the lateral side
When is a Reverse Thomas heel used?
Increase stability of the sole when there is supination
Describe a dorsiflexion assist elastic strap type orthosis
Added to the shoe near the laces with a strap around the distal leg
What is a scaphoid pad?
Convex pad used within the shoe to support the longitudinal arch
What is the proper positioning of a scaphoid pad?
Placed under the longitudinal arch – apex of the pad should be positioned between the sustentaculum tali and navicular tuberosity
What is a metatarsal pad?
Soft domed shape pad that supports the metatarsal arch and relieved pressure from the metatarsal heads by shifting pressure to the metatarsal shafts
What is the proper positioning for a metatarsal pad?
Just posterior to the metatarsal heads and anterior to the cuneiforms
Describe the structure and general function of a heel spur insert
Anteriorly sloped to redistribute weight with a calcaneal relief to minimize pressure
What type of shoe modifications tend to be more effective, internal or external?
Internal because they are closed and in close contact with the foot
What is the proper positioning for the posterior superior trimline of a plastic SAFO?
3 fingers below the popliteal fossa
What is the proper location for the lateral superior trimline of a plastic SAFO?
2 fingers below the fibular head
How far should the medial and lateral trimlines extends on a plastic SAFO?
Just anterior to the malleoli
What motions are controlled by a SAFO?
Plantarflexion, dorsiflexion, pronation, supination
Describe the force system to control plantarflexion with a SAFO
Primary: originates anterior and superior at the calcaneal strap and is directed posterior and inferior
Secondary: originates at the posterior superior trimline and is directed anterior
Secondary: originates from the inferior portion of the orthosis at the area of the metatarsal heads and is directed superior
Describe the force system to control dorsiflexion with a SAFO
Primary: originates posterior and inferior at the heel cup and is directed anterior and superior
Secondary: originates anterior at the superior leg strap and is directed posterior
Secondary: originates superior at the shoe and is directed inferior at the area of the toe box
Describe the force system to control pronation with a SAFO?
Primary: originates medially at the area of the orthosis at the talus and navicular and is directed lateral
Secondary: originates lateral at the lateral superior trim line and is directed medial
Secondary: originates lateral at the orthosis at the area of the 5th metatarsal head and is directed medially
Describe the force system to control supination with a SAFO?
Primary: originates laterally at the orthosis at the lateral malleolus and is directed medially
Secondary: originates at the medial superior trimline and is directed laterally
Secondary: originates at the medial portion of the orthotic at the area of the 1st metatarsal head and is directed laterally
What 4 views do you need to consider when evaluating alignment of a SAFO?
Posterior, lateral, superior, anterior
What are you looking for from a posterior view when evaluating alignment of a SAFO?
If the heel cup is vertical or in slight varus
What are you looking for from a lateral view when evaluating alignment of a SAFO?
If the hindfoot, midfoot, and forefoot is is neutral
What are you looking for from a superior view when evaluating alignment of a SAFO?
Is the forefoot neutral – if you bisect the heel, a line should pass between the second and third metatarsal heads
What are you looking for from an anterior view when evaluating alignment of a SAFO?
If the metatarsal heads are level
Why would a SAFO be made with the ankle in slight dorsiflexion if there is no rigid deformity, and when is this indicated?
Creates a flexion moment at the knee and hip. Indicated when there is excessive hyperextension at the knee
Why would a SAFO be made with the ankle in slight plantarflexion if there is no rigid deformity, and when is this indicated?
GRF passes anterior to the knee causing an extension moment. Indicated for a crouched gait
What functional activities are more difficult when wearing a SAFO?
Ambulation, sit-to-stand, squatting etc. because there is no motion allowed
What effect would the addition of an elastic anterior leg strap have on the motions controlled in a SAFO?
The elastic strap would allow for some degree of anterior translation of the tibia over the talus, so it would allow forward weight shift for functional transitions
What would the purpose be of adding a calcaneal relief to a SAFO?
Provides greater stability of the subtalar joint by saddling the calcaneous
What would the purpose be of adding a metatarsal head relief and shelf to a SAFO?
Inhibit toes for hyperextending or clawing to inhibit tone
What is the function of a medial flange?
Assists in distributing the primary force utilized to control pronation by preventing IR of the tibia on the talus
Is the addition of a flange considered to be a fourth force of the pressure system?
No
What is the function of a lateral flange?
Disperse the primary force necessary to control supination by preventing ER of the tibia on the talus
How distal does a partial footplate extend?
Just proximal to or at the metatarsal heads
How distal does a full footplate extend?
Just past the toes
When is a partial footplate indicated?
Pt has active toe extension and is able to active motion through swing phase for adequate clearance
When is a full flexible footplate indicated?
Pt will be ambulating but lacks active toe extension to adequate clearance during swing phase OR excessive toe clawing and contact with the brace inhibits it
Why would a full footplate be indicated for a pediatric patient?
Allows for length changes over time, a full foot plate would transition to a partial as they grow
When is a semi-rigid or flexible footplate indicated?
When the pt will be ambulating
What does a semi-rigid or flexible footplate allow for?
Metatarsal break
When is a rigid footplate indicated?
If braces are only being worn for positioning or standing, partial foot amputation
If you are ambulating with a rigid footplate, what compensatory motion is happening at the hip?
ER
What does PLSO stand for?
Posterior Leaf Spring Orthosis
Why are PLSO’s typically a stock orthosis?
Trimlines are narrow medially and laterally so there is little need for a custom fit
Compare the trimlines of a PLSO to a SAFO in relation to the malleoli
PLSO trimlines are well behind the malleoli when compared to a SAFO
What motions are controlled with with a PLSO?
No motions are controlled, but some plantarflexion may be limited during swing phase
Why does a PLSO not control supination or pronation?
There is not medial or lateral support
What is the primary purpose of a PLSO?
Dorsiflexion assist – as the pt plantarflexes at pushoff, the posterior portion of the shell is compressed
Is a PLSO designed to correct a flexible deformity or support a rigid deformity?
Typically does not because there is little brace contact with the foot
When would a PLSO be indicated?
Inadequate foot clearance through swing phase
When would a PLSO be contraindicated?
If there is spasticity in the involved LE
What does HAFO stand for?
Hinged Ankle Foot Orthosis
When would a metal upright be indicated?
If the individual is or slight build and there is little to no spasticity
When would a metal HAFO with a double metal upright be indicated?
Where a fair amount of force is necessary to control motion, it would provide greater stability and control
Why should the calf band not extend over the fibular head?
The avoid pressure on the peroneal nerve
Why must a steel shank be incorporated into the shoe design of a metal HAFO?
Add reinforcement to the bottom of the shoe and serve as an anchor for the metal uprights
Why would a split stirrup be used over a steel shank for a metal HAFO?
Split stirrup with allow each side of the shoe to detach, so easier for donning and doffing. However, it is less durable and heavier than a solid
What is the purpose of a medial T-strap?
Correct pronation
What is the purpose of a lateral T-strap?
Correct supination
Describe the force system of a medial T-strap
Controls pronation
Primary: originates medially at the T-strap and is directed laterally
Secondary: originates laterally at the lateral portion of the calf band and is directed medially
Secondary: originates laterally at the shoe at the area of the 5th metatarsal head and is directed medially
Describe the force system of a lateral T-strap
Controls supination
Primary: originates laterally at the T-strap and is directed medially
Secondary: originates medially at the medial portion of the calf band and is directed laterally
Secondary: originates medially at the shoe at the area of the 1st metatarsal head and is directed laterally
When would a free ankle joint design be indicated?
Rarely, possibly as part of a KAFO or HKAFO for a polio patient with intact ankle musculature but compromised knee or hip control
What motion does a posterior stop limit?
Plantarflexion
What motion does an anterior stop limit?
Dorsiflexion
When is a posterior stop indicated?
If the pt drags their foot through swing phase
When is an anterior stop indicated?
If the pt has a crouched gait
What is the advantage of a molded shoe insert AFO with bilateral uprights compared to a conventional metal design?
Molded shoe insert by provide better correction of foot alignment because it is closer to the foot
What are advantages of a metal AFO compared to a plastic AFO?
Metal AFO’s can accommodate changes in girth, is a cooler temperature, prior metal device, remote areas where plastic materials are not readily available
Name the SAFO part labeled 1
Superior anterior leg strap
Name the SAFO part labeled 2
Lateral trim line
Name the SAFO part labeled 3
Calcaneal strap
Name the SAFO part labeled 4
Footplate
Name the SAFO part labeled 5
Heel cup
Name the SAFO part labeled 6
Medial trim line
Name the SAFO part labeled 7
Superior trim line
Name the HAFO part labeled 1
Calf band
Name the HAFO part labeled 2
T-Strap
Name the HAFO part labeled 3
Ankle joint
Name the HAFO part labeled 4
Stirrup
Name the HAFO part labeled 5
Upright
