IMOs/SMOs, Hinged AFOS, KOs & KAFOs Flashcards
(134 cards)
1
Q
What motions are controlled by plastic AFO and HAFOs?
A
- PF
- pronation
- Supination
2
Q
How is PF controlled by plastic AFO & HAFO?
A
- A force directed posterior/inferior originating from the top of the shoe or a calcaneal strap is balanced by an anteriorly directed force originating from the posterior superior portion of the plastic shell and a superiorly directed force from the bottom of the orthotic in the area of the metatarsal heads
3
Q
How is pronation controlled by plastic AFO & HAFO?
A
A laterally directed force originating medially in the area of the talus and navicular is balanced by medially directed forces originating laterally at the lateral superior portion of the plastic shell and lateral portion of the brace/shoe in the area of the 5th metatarsal head
4
Q
How is supination controlled by a plastic AFO & HAFO?
A
A medially directed force originating laterally at the lateral malleolus and talus is balanced by laterally directed forces originating medially at the medial superior portion of the plastic shell and the medial portion of the brace/shoe in the area of the 1st metatarsal head
5
Q
Describe an overlap joint
A
- inexpensive but strong and relatively simple in construction
- drawback to this joint is that it is very wide and if the patient adducts and walks with a narrow BOS, they may trip
6
Q
Describe the Gaffney joint
A
single axis metal joint which is not as durable as some of the other choices
7
Q
Describe the Oklahoma joint
A
- plastic joint but designed and reinforced in a more streamlined manner compared to the overlapping joint
- It is frequently used
8
Q
Describe the tamarack & Gillette hardware
A
- they allow for a simple hinged articulation
- depending on design/shape, may provide the ability to assist with motion at the ankle (typically DF)
- These joints are made of rubber composite and are commonly used
- A spring assist in a joint is contraindicated anytime there is spasticity
9
Q
Describe the wafer joint
A
- metal joints designed to be durable and adjustable into both PF and DF range depending on the assist may be incorporated into either of these joints
- They are more durable than the plastic and rubber joints
- heavier and more expensive than plastic joints
10
Q
What is the function of a PF stop?
A
used to decrease PF
11
Q
When is a PF stop indicated?
A
- whenever there is a lack of active DF or control of DF necessary for adequate swing clearance
- A plantarflexion stop could be set at 0 degrees or varying degrees of plantarflexion.
12
Q
T/F: If any PF is allowed, that motion is not controlled
A
True
13
Q
Where is a check strap typically positioned? What is its function in this position?
A
- posteriorly or laterally
- Used to restrict the amount of DF
14
Q
When is a check strap indicated?
A
patient is demonstrating a flexed gait
15
Q
Why might a hinged AFO be preferred over a SAFO?
A
- allows varying degrees of movement at the ankle providing the opportunity for greater ease and efficiency in functional movements
- It is indicated if the patient has a fair amount of control at the trunk/ hip and at least emerging control at the knee
16
Q
Why might a SAFO be preferred over a hinged AFO?
A
- when trunk/hip/and knee control is compromised but yet upright function may still be the goal
- A solid ankle provides a good deal of stability at the ankle and biases the hip and knee towards a desired position depending on the angle at which the ankle joint is set.
- The SAFO may also be used to maintain alignment
17
Q
If a post is present where is it found? What is it made out of and what is the function?
A
- it is found on the inferior surface of the orthosis
- It may be made out of plastic or foam
- functions to hold the orthosis steady in the shoe
18
Q
T/F: Posting should add height to the orthosis
A
False- It should not
19
Q
what is the difference between SMOs & IMOs in regards to trim lines?
A
Trimlines of the SMOs typically extend up above the malleoli where as IMOs are trimmed below the malleoli
20
Q
What motions might an IMO control?
A
Supination or pronation
21
Q
How is pronation controlled in an IMO?
A
laterally directed force originating medially in the area of the talus/navicular with medially directed forces originating laterally in the area of the calcaneous and the 5th metatarsal head (maybe from the brace if it extends out that far or from the lateral part of the shoe)
22
Q
How is supination controlled?
A
a medially directed force originating laterally in the area of the talus combined with laterally directed forces originating medially in the area of the calcaneous and the 1st metatarsal head (maybe from the orthotic if it extends out that far or from the medial part of the shoe
23
Q
What is the calcaneal relief function?
A
greater stability of the subtalar joint by “saddling” the calcaneous in the heel cup
24
Q
What function may metatarsal relief be used for?
A
It may be tone inhibiting
25
Why may a toe shelf be incorporated into the footplate?
Toes should be horizontal (not hyperextended or clawed)
26
What is the difference between reliefs & buildups?
- Reliefs allow those areas to “sink into” or “drop into” the orthosis by saddling of the calcaneous
- Build ups are raised and support the corresponding anatomy in those areas
27
What is the difference between use of IMO vs shoe modifications?
- With an IMO, the corrections made are closer anatomically to the foot and may have greater impact
- The IMO may be more cosmetically acceptable and occasionally can be interchanged in different shoes.
- When a shoe is modified it typically can accommodate changes in foot volume to a greater degree
28
What motions might a SMO control?
- Supination
- Pronation
- possible PF
29
How might a SMO control supination?
medially directed force originating laterally from the orthosis in the area of the lateral malleolus/talus and laterally directed forces originating medially from the orthosis in the area of the medial malleoli/superior trimline of the orthotic and the 1st metatarsal head(maybe from the orthosis if it extends out that far or from the medial part of the shoe)
30
How does a SMO control pronation?
a laterally directed force originating medially from the orthosis in the area of thetalus/navicular and medially directed forces originating laterally from the orthosis in the areaof the lateral malleoli/superior trimline and the 5th metatarsal head (maybe from the orthotic ifit extends out that far or from the lateral part of the shoe)
31
How might a SMO control PF?
diagonal force directed inferiorly and posteriorly originating from the calcaneal (ankle) strap or the top of the shoe, a superiorly directed force originating from the base of the orthosis near the metatarsal heads, and an anteriorly directed force originating from the superior posterior trimline of the brace.
32
When comparing an IMO vs SMO which would demonstrate a greater triplanar (supination/pronation) control?
SMO because with the increased vertical construction/dimension there is greater leverage to control supination/pronation
33
Which would demonstrate PF control an IMO or SMO? Why?
SMO because high poster trimline is essential to set up a 3 point pressure system to control PF
34
How does height of posterior trimline affect PF control?
- one of the counterbalancing forces.
- The longer (higher) the posterior trimline (lever arm), the greater the leverage to control PF
35
When would you recommend an SMO over an IMO?
- SMO would be recommended when medial and lateral control is not adequately obtained using an IMO
- An SMO is also warranted when there is a need for PF control
36
How do you know if an SMO is designed to correct a flexible deformity or support a rigid one?
- If the orthosis is aligned to neutral, then the orthosis was used to correct a flexible deformity
- If the orthosis is not aligned to neutral; then most likely the orthosis was used to support a rigid deformity.
37
Which movement are controlled by a supracondylar shell KAFO or a Floor Reaction Orthosis (FRO)?
- At the knee, hyperextension, valgus, and varus
- Some amount of control is provided at the foot and ankle for PF, DF, supination and pronation.
38
How is hyperextension controlled by supracondylar shell KAFO or a Floor Reaction Orthosis (FRO)?
an anterior directed force originating at the posterior/superior margin of the orthosis is balanced by posterior directed forces originating at the anterior superior and inferior portions of the orthosis.
39
How is valgus controlled by the Supracondylar Shell KAFO or Floor Reaction Orthosis (FRO)?
a laterally directed force originating from the central portion of the medial aspect of the orthosis near the knee is balanced by medially directed forces originating from the superior and inferior lateral aspect of the orthosis.
40
How is varus controlled by a supracondylar shell KAFO or Floor Reaction Orthosis (FRO)?
a medially directed force originating from the central portion of the lateral aspect of the orthosis near the knee is balanced by laterally directed forces originating from the superior and inferior medial aspect of the orthosis
41
How is PF controlled by a supracondylar shell KAFO or Floor Reaction Orthosis (FRO)?
an inferior/posterior directed force originating at the anterior inferior trimline of the orthosis (on the dorsum of the foot) is balanced by a superior directed force from the bottom of the shoe and an anterior directed force from the posterior superior margin of the orthosis
42
How is DF controlled by a supracondylar shell KAFO or Floor Reaction Orthosis (FRO)?
an anterior/superior force originating from the heel portion of the shoe is balanced by an inferior directed force originating from the anterior inferior trimline of the orthosis (on the dorsum of the foot) and a posterior directed force originating from the superior anterior portion of the orthosis
43
How is supination controlled by a supracondylar shell KAFO or Floor Reaction Orthosis (FRO)?
a medially directed force originating laterally in the area of the lateral malleoli and talus is balanced by laterally directed forces from the anterior medial distal portion of the orthosis and the shoe in the area of the 1st metatarsal head and the medial superior portion of the orthosis
44
How is pronation controlled by a supracondylar shell KAFO or Floor Reaction Orthosis (FRO)?
a laterally directed force originating medially in the area of the talus and navicular is balanced by medially directed forces originating from the anterior lateral distal portion of the orthosis and the shoe in the area of the 5th metatarsal head and the lateral superior portion of the orthosis
45
T/F: A supracondylar shell KAFO is unique because the ankle joint is set in DF
False- Ankle joint is set in PF
46
How does the Supracondylar joint KAFO being set in PF influence biomechanics alignment?
With the ankle set and then supported in PF, the weight is shifted anteriorly towards the ball of the foot
- This shifts the ground reaction force more anteriorly as well
- The knee is biased towards extension and the hip towards flexion
47
What are the advantages of the supracondylar KAFO being set into PF?
This orthosis biases the knee toward extension without having to extend the orthosis much higher than the femoral epicondyles
48
What are the disadvantages of the supracondylar KAFO being set into PF?
- The patient prescribed this orthosis must have adequate hip extensor strength to control and overcome forces biasing it towards flexion
- For this reason, many have felt that this orthosis may actually be destabilizing
- Cosmetically, when the patient sits with this orthosis it extends up past the knee and for this reason may be awkward when wearing pants
49
What are the typical indications for supracondylar shell KAFO?
patient demonstrates a crouched (flexed) gait pattern
50
Describe the general guidelines to assess optimal fit of a double metal upright KAFO
- Superiorly brace extends to the upper third of the thigh with adequate clearance 3-4” in the groin area.
- Superior, lateral portion of the brace should fall below greater trochanter.
- Knee and ankle joints should correspond anatomically to the knee and ankle respectively.
- Condylar pads should be positioned over the condyles
- shoe should be comfortable in weightbearing and non- weightbearing positions
- Calf band should be placed 2-3” below popliteal fossa posteriorly and lie inferior to the fibular head
51
Which motions are restricted by a double metal upright KAFO?
When the knee joint is locked in the orthosis: knee hyperextension, flexion, valves & varus are controlled
52
How is hyperextension controlled in a double upright metal KAFO?
a combined anterior directed force originating posteriorly from a combination of the inferior thigh band and the calf band (work together as primary force) is balanced by posterior directed forces originating anteriorly from the thigh strap and the inferior leg strap
53
How is flexion controlled by a double upright metal KAFO?
a posterior directed force originating anteriorly from the knee pad (or a combined force from the supra and infra patellar straps) is balanced with anterior directed forces originating posteriorly from the superior thigh band and the calf band
54
How is valgus controlled by a double upright metal KAFO?
a laterally directed force originating from the medial condylar pad is balanced by medially directed forces originating from the superior and inferior portion of the lateral bar
55
How is varus controlled by a double upright metal KAFO?
a medially directed force originating from the lateral condylar pad is balanced by laterally directed forces originating from the superior and inferior portion of the medial bar
56
What is an adjustable or fan design knee joint?
allows the knee joint to be locked even though the patient may not possess full knee extension as is required for either the single axis or offset knee joints
57
If a patient has a single knee joint, do they need to be able to achieve full extension?
Yes
58
What are the advantages and disadvantages of a drop lock?
- is inexpensive and simple in its design requiring little maintenance and chance of breakdown
- It is difficult to manipulate and release from the standing position
59
Describe a spring loaded pull rod?
- is added to a ring or drop lock, it is easier to release lock from standing as it decreases the distance the individual needs to reach to release the locking mechanism
60
Why is common to order a combination of a drop lock and a spring loaded pull rod?
- That is to say that a medial drop lock may be indicated and released first.
- A lateral spring loaded pull rod would then maintain the locked position of the knee until the individual was safely ready to transition back to sitting
61
When may a single lock (typically on the lateral side) be suitable?
Individual is fairly slender with limited spasticity
62
If a dual locking mechanism on both the medial and lateral side is indicated then what lock system may be the best choice?
Bale release attached to a pawl lock
63
How does a bale release attached to a pawl lock work?
- this allows for simultaneous release of both the medial and lateral locks and is triggered by pushing up on the bale. (This is fairly simple and canbe easily facilitated by using the back of a chair.)
- The bale release because it extends out posteriorly may be released unexpectedly by knocking up against something or someone in the environment
64
What are the typical indications for a KAFO?
- when there is compromised motor control at the foot, ankle, knee, and hip
- Trunk control may also be impaired
- This type of orthosis is used most often for patients with spinal cord injury, spina bifida, polio or post-polio syndrome
- It may occasionally be indicated for a patient with stroke or CP
65
In some KAFOs the ankle joint may be set in approximately 10o of DF. How does thisinfluence alignment at the knee? at the hip?
- When the ankle is set in DF it biases the hip and knee towards flexion because the ground reaction force is positioned posterior to the knee and anterior to the hip
66
In some KAFO the ankle joint may be set to 10 degree DF and the knee is locked into extension. How does this influence the hip?
If the ankle is positioned in DF and the knee is mechanically locked the line of gravity passes posterior to the hip and biases this joint towards mechanical extension
67
What patient would benefit from a KAFO with the ankle joint set in DF and the knee locked into extension?
- This is important particularly for a patient with spinal cord injury where there may be little to no active hip extension
- The patient is able to maintain the hip in extension by “resting” on the Y ligament
- Alignment using these principles affords the individual the opportunity to ambulate without extending the brace past the knee
68
Name a specific orthosis designed metal KAFO in which the ankle joint is set 10 degree of DF?
Craig- Scott orthosis
69
Describe the optimal fit guideline for a custom molded plastic KAFO
- Thigh shell should extend to the upper third of the thigh but medially to approximately 3-4” from the groin
- Superior, lateral trimline of the brace should fall below greater trochanter
- Posterior inferior trimline of thigh shell should be a minimum of 1.5” from popliteal crease
- Knee joint and condylar pads should correspond with anatomical counterparts.
70
What motions are controlled by a plastic KAFO?
Knee hyper extension, flexion, valgus, varus and pronation & supination
71
How does a plastic KAFO control hyperextension?
a combined anterior directed force originating posteriorly from the inferior portion of the thigh shell and superior portion of the AFO shell is balanced by posterior directed forces originating anteriorly from the thigh strap and the inferior leg strap (or calcaneal strap)
72
How does a plastic KAFO control flexion?
a combined posterior directed force originating anteriorly from the supra and infra patellar straps is balanced with anterior directed forces or originating from the posterior portion of the thigh shell and the posterior inferior portion of the AFO shell (heel cup)
73
How does a plastic KAFO control valgus?
a combined laterally directed force originating from the inferior medial potion of the thigh shell and the superior medial portion of the AFO shell (or a single force from the medial condylar pad) is balanced by medially directed forces originating from the lateral superior portion of the thigh shell and the inferior lateral portion of the AFO shell
74
How does a plastic KAFO control varus?
a combined medially directed force originating from the inferior lateral potion of the thigh shell and the superior lateral portion of the AFO shell (or a single force from the lateral condylar pad) is balanced by laterally directed forces originating from the medial superior portion of the thigh shell and the inferior medial portion of the AFO shell
75
How is a metal KAFO and a plastic KAFO similar?
- Both the plastic and the metal KAFOs assist with upright function by controlling the knee and ankle as well as indirectly influencing hip position
- For this reason they are often indicated for the same types of patient populations.
76
How are metal and plastic KAFO different?
- Metal KAFOs are cooler and can more easily accommodate to changes in girth and length
- Plastic KAFOs are lightweight and cosmetically more acceptable as they can be worn underclothes.
- plastic KAFOs are in closer contact with the LE surface and are thought for this reason to provide better control
77
Which type of KAFO (metal or plastic) are thought to provide better control?
plastic KAFOs are in closer contact with the LE surface and are thought for this reason to provide better control
78
What component parts from the metal & plastic KAFO are combined to construct a hybrid version??
- medial and lateral metal uprights
- plastic thigh cuff/ attached to shoe or metal thigh bands/plastic
- SAFO shell, superior/inferior thigh straps, anterior leg strap
79
What is the benefit of a plastic metal hybrid KAFO?
- Flexibility in brace length
- Can be worn under clothes
- More cosmetically acceptable
- Lightweight
80
How are Knee orthoses classified?
As either flexible, semi-rigid or rigid
81
What is the function of an elastic knee orthosis?
- compressive design retains heat in the area, may reduce edema, provide proprioceptive feedback.
82
What are the typical indications of an elastic knee orthosis?
Indicated with arthritis in the knee, for edema & minor knee sprains
83
Is an elastic knee orthosis with medial lateral support flexible, semi-rigid or rigid?
Semi - rigid
84
Are any motions restricted by an elastic knee orthosis with medial & lateral support? Does a true 3-point pressure exist?
- Valgus and varus may be somewhat limited with this orthosis because of the medial and lateral vertical bars (depending on the stability/material of the bars)
- a true three point pressure system with utilizing rigid bars and bands does not exist
85
What is the function of the elastic knee orthosis with M-L supports?
- the same as the elastic KO.
- compressive design retains heat in the area, may reduce edema, and provide proprioceptive feedback
86
What is the typical indication for an elastic KO with medial lateral support?
Indicated for patients with arthritis in the knee, for edema & minor knee sprains
87
Is a knee immobilizer flexible, semi-rigid or rigid?
semi- rigid
88
Describe the most optimal fit of the knee immobilizer
- this orthosis should extend superiorly to the upper third of the thigh and inferiorly to approximately 1-1.5” above the malleoli
- Anterior cut out should be positioned over the patella
89
Are any motions restricted by a knee immobilizer?
- This orthosis may provide tactile input increasing kinesthetic awareness and thus decreasing movement at the knee
- Full restriction/control of movement is questionable however because of its semi-rigid design
- Some resources do describe 3 point pressure systems to control knee flexion and extension, varus and valgus
90
What is the function of a knee immobilizer?
This orthosis may be used to decrease movement at the knee post surgically or post trauma; or assist with upright postural control when there is weakness at the knee (ex-stroke)
91
What are the typical indications for a knee immobilizer?
This brace may be indicated for a patient with a TKR, acute knee trauma, or weakness at the knee (secondary to stroke, MS, Guillian Barre, or other NM pathology)
92
What are the advantage to a knee immobilizer over just an elastic KO?
Longer leverage and verticalbars (stays) in this orthosis may provide greater support to the knee.
93
Is the adjustable knee immobilizer flexible, semi-rigid or rigid?
Semi- rigid
94
Describe the most optimal fit for adjustable knee immobilizer
- The longer the orthosis, the greater the leverage to effectively maintain or increase ROM at the knee
- This orthosis should extend superiorly to the upper third of the thigh and inferiorly to approximately 1-1.5” above the malleoli
- Knee joint should correspond with anatomical knee joint
95
Are any motions controlled by an adjustable knee orthosis?
- this orthosis will provide tactile cues/increased kinesthetic awareness which may decrease all motions at the knee
- the ability of this orthosis to fully control motion is questionable due to the semi-rigid design
96
If this orthosis (adjustable knee immobilizer) were able to truly restrict or control motions, what component parts must be present?
In order to truly control motion, horizontal bands should be present
97
What is the function of the adjustable knee joint?
Varying degrees of range may be limited to minimize post-surgical trauma to the operative site
98
What are the typical indications for an adjustable knee immobilizer?
Typically, this KO is recommended acutely for post operative or post-traumatic management of the knee
99
What are the advantage of an adjustable knee immobilizer over the elastic KO and/or elastic KO with medial lateral support?
This KO is more restrictive than previous KOs described because of increased length (leverage) and rigid construction (although horizontal bands are not present)
100
Describe the position for the most optimal fit a resting or positional splints for the knee
- the longer the brace, the greater the leverage to effectively maintain or increase ROM at the knee
- This orthosis should extend superiorly to the upper 1/3rd of the thigh and inferiorly to approximately 1-1.5”” above the malleoli
- The knee joint if present should correspond with anatomical knee joint
101
Are any motion controlled by the resting knee orthosis?
All motions are typically controlled in this type of KO [flexion, extension, valgus, varus) due to the total contact provided by the orthosis
102
How is hyperextension controlled by a resting knee orthosis?
an anterior directed force originating at the posterior medial portion of the orthosis is balance by posterior directed forces originating at the anterior superior & inferior portions of the orthosis
103
How is flexion controlled by a resting knee orthosis?
a combined posterior directed force originating anteriorly from the supra and infra patellar straps is balanced by anterior directed forces originating at the posteriorly at the superior and inferior margins of the orthosis
104
How is valgus controlled in a resting knee orthosis?
a laterally directed force originating from the central portion of the medial aspect of theorthosis is balanced by medially directed forces originating from the superior and inferior lateral aspect of the orthosis
105
How is varus controlled by a resting knee orthosis?
a medially directed force orig inating from the central portion of the lateral aspect of theorthosis is balanced by laterally directed forces originating from the super ior and inferior medialaspect of the orthosis
106
What is the function of the resting knee orthosis?
- maintain or to increase ROM at the knee
- This orthosis may be intended for use only at night in an attempt to gain ROM while not restricting LE function during the day
- A similar design may also be utilized at the elbow to serve the same function
107
What are typical indication for this style of KO?
Any pathology which might cause knee flexion contractures
108
Is the knee orthosis with hyperextension control (Swedish Knee Cage) flexible, semi-rigid or rigid?
Rigid
109
How is hyperextension controlled by the Knee Orthosis with Hyperextension Control (Swedish Knee Cage)?
an anterior directed force originating posteriorly at the popliteal strap is balanced by posterior directed forces originating anteriorly at the thigh and leg straps
110
What is the typical indication for a Knee Orthosis with Hyperextension Control (Swedish Knee Cage)?
Intended for a patient with mild hyperextension at the knee and may be suited for patients with arthritis, stroke, hypotonia etc
111
What is the disadvantage of Knee Orthosis with Hyperextension Control (Swedish Knee Cage)?
- Cosmesis is poor as orthosis is bulky
- Tends to protrude vertically in sitting
112
Is Knee Orthosis with Hyperextension, Medial - Lateral Control (Three Way Knee Stabilizer) flexible, semi-rigid or rigid?
Rigid
113
What motions are controlled by Knee Orthosis with Hyperextension, Medial - Lateral (Three way Knee Stabilizer)?
Hyperextension, valgus & varus
114
How is hyperextension controlled by the Knee Orthosis with Hyperextension, Medial - Lateral Control (Three Way Knee Stabilizer)?
an anterior directed force originating posteriorly at the popliteal band is balanced by posterior directed forces originating anteriorly at the anterior thigh and leg bands
115
How is valgus controlled by the Knee Orthosis with Hyperextension, Medial - Lateral Control (Three Way Knee Stabilizer)?
a laterally directed force originating from the central portion of the medial bar balanced by medially directed forces originating from the superior and inferior portion of the lateral bar
116
How is varus controlled by the Knee Orthosis with Hyperextension, Medial - Lateral Control (Three Way Knee Stabilizer)?
medially directed force originating from the central portion of the lateral bar balanced by laterally directed forces originating from the superior and inferior portion of the medial bar
117
What are the typical indications of Knee Orthosis with Hyperextension, Medial - Lateral Control (Three Way Knee Stabilizer)?
- For mild hyperextension, valgus, or varus at the knee
- May be suited for patients with arthritis, stroke or hypotonia
118
Why might a Knee Orthosis with Hyperextension, Medial - Lateral Control (Three Way Knee Stabilizer) be preferred over the Swedish Knee Cage?
Orthosis is more cosmetically acceptable & additionally controls medial/lateral motion
119
Is Knee Orthosis with Hyperextension, Medial - Lateral Control (Molded Plastic Solid Knee Orthosis) flexible, semi-rigid or rigid?
rigid
120
What motions are controlled by Knee Orthosis with Hyperextension, Medial - Lateral Control (Molded Plastic Solid Knee Orthosis)?
Hyperextension, valgus & varus
121
How is hyperextension controlled by Knee Orthosis with Hyperextension, Medial - Lateral Control (Molded Plastic Solid Knee Orthosis)?
an anterior directed force originating at the posterior/superior margin of the brace in the popliteal area is balanced by posterior directed forces originating at the anterior superior and inferior portions of the brace
122
How is valgus controlled by Knee Orthosis with Hyperextension, Medial - Lateral Control (Molded Plastic Solid Knee Orthosis)?
a laterally directed force originating from the central portion of the medial aspect of the brace is balanced by medially directed forces originating from the superior and inferior lateral aspect of the brace
123
How is varus controlled by Knee Orthosis with Hyperextension, Medial - Lateral Control (Molded Plastic Solid Knee Orthosis)?
a medially directed force originating from the central portion of the lateral aspect of the brace is balanced by laterally directed forces originating from the superior and inferior medial aspect of the brace
124
What are the typical indication for use of Knee Orthosis with Hyperextension, Medial - Lateral Control (Molded Plastic Solid Knee Orthosis)?
- Mild to moderate hyperextension, valgus, or varus at the the knee
- Suited for patients with arthritis, stroke or hypotonia
125
Compare and contrast Knee Orthosis with Hyperextension, Medial - Lateral Control (Molded Plastic Solid Knee Orthosis) with 3 way knee stabilizer and the Swedish Knee Cage
T- his orthosis controls the same motions as the three way knee stabilizer (hyperextension,valgus, and varus) and the Swedish knee cage (hyperextension).
- Because it is custom fabricated it fits more intimately and therefore may be more restrictive
- it is cosmetically more acceptable than the other options
- Conversely, it is more costly and does not accommodate changes in girth
126
Is a Knee Orthosis with Hyperextension, Medial - Lateral (Varus/Valgus), and Rotary/Anterior Posterior Translation Control flexible, semi-rigid or rigid?
Rigid
127
What is the optimal fit of Knee Orthosis with Hyperextension, Medial - Lateral (Varus/Valgus), and Rotary/Anterior Posterior Translation Control?
This orthosis extends to the middle third of the thigh superiorly and the middle third of the lower leg inferiorly. Knee joint should correspond to anatomical knee joint. Condylar pads should be positioned over the condyles
128
What motions are controlled by Knee Orthosis with Hyperextension, Medial - Lateral (Varus/Valgus), and Rotary/Anterior Posterior Translation Control?
Knee flexion is not controlled in this orthosis. All other motions can be controlled by thisorthosis. IN this orthosis as translation and rotation occur together, by controlling translation there could be control of rotation
129
How is hyperextension controlled by Knee Orthosis with Hyperextension, Medial - Lateral (Varus/Valgus), and Rotary/Anterior Posterior Translation Control?
an anterior directed force originating posteriorly from the thigh (or supra popliteal) band is balanced by posterior directed forces originating anteriorly at the thigh strap (or band) and lower leg strap (or band)
130
How is valgus controlled by Knee Orthosis with Hyperextension, Medial - Lateral (Varus/Valgus), and Rotary/Anterior Posterior Translation Control?
a laterally directed force originating from the central portion of the medial bar (or condylar pad) is balanced by medially directed forces originating from the superior and inferior portion of the lateral bar.
131
How is varus controlled by Knee Orthosis with Hyperextension, Medial - Lateral (Varus/Valgus), and Rotary/Anterior Posterior Translation Control?
medially directed force originating from the central portion of the lateral bar (or condylar pad) is balanced by laterally directed forces originating from the superior and inferior portion of the medial bar.
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How is rotation controlled by Knee Orthosis with Hyperextension, Medial - Lateral (Varus/Valgus), and Rotary/Anterior Posterior Translation Control?
The forces come from a posterior directed force originating anteriorly from the thigh band (or strap) and an anterior directed force from the supra popliteal strap (or band) are balanced by a posterior directed force originating anteriorly from the infra patellar strap (or orthosis near tibial tuberosity), and an anterior directed force originating posteriorly from leg strap or calf band (depending on design)
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What is the difference between a polycentric and single axis knee joint?
The polycentric knee joint allows for flexion and extension around an instantaneous axis of rotation which more closely mimics the instantaneous axis of rotation of the knee
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What is the typical indication for Knee Orthosis with Hyperextension, Medial - Lateral (Varus/Valgus), and Rotary/Anterior Posterior Translation Control?
- This type of orthosis is typically indicated when there is significant damage to the ligamentous structure of the knee (compromised stability) and the individual still wishes to stay active at work or recreationally.
- It is also commonly used in the post-surgical patient in the sub-acute or long term phase of rehab to provide additional stability at the knee
