7. Lower Limb Orthotics Flashcards
List 6 benefits of orthosis.ππ
- A kinesthetic reminder
- Prevention of contracture
- Correction of deformity
- Control of spastic muscles
- Support/stability
- Augmentation of weak muscles (assist in motion)
- Reduction in pain/comfort (injury, inflammation)
- Unloading of diseased or damaged joints
- Improvement in function
- Limitation of ROM (restriction of motion)
Cuccurollo 4th Edition Chapter 6 P&O pg513
PMR Secrets 3rd Edition Chapter 34 pg278 q5
Line of gravity (weight line) in quite standing. ππ
π‘ While standing, the COG is in the midline and just anterior to the S2 vertebra
- Behind the cervical vertebrae
- Front of the thoracic vertebrae
- Behind the lumbar vertebrae
- Posterior to the hip joint and tends to passively extend the hip joint
- Anterior to the knee joint and tends to passively extend the knee.
- 1 to 2 inches anterior to the ankle joint and tends to dorsiflex the ankle which is resisted by the soleus and gastrocnemius muscles
What is the principle of orthoses in order to control joint motion?
How does an orthosis control joint motion? π Dr. Jamal
-
Three-point pressure system
- Opposing three-point pressure systems
- Multiple three-point pressure systems
- Four-point pressure system
Cuccurollo 4th Edition Chapter 6 P&O pg514
Materials in orthosis. Advantages and Disadvantages.
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STEEL/METAL
- Low cost, fatigue resistant, provides high strength and rigidity.
- Heavy weight, long term erosion (oxidation)
-
ALUMINUM
- Corrosion resistant, provides high strength, lightweight.
- Lower endurance limit under repeated dynamic loading
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TITANIUM
- Strength comparable to steel with only 60% of the density, resistant to corrosion
- Limited availability, high cost
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CARBON FIBER
- Lightweight, high strength
- Very expensive, difficult to shape or modify
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THERMOPLASTIC
- Lightweight, shaped directly to the body without the need for a cast
- Body irritation and allergic reactions
List 8 Uses for AFO. Why we use orthosis for lower limb?
π‘ Muscle (weak or tight)- Ligaments - Bone - Joint - Gait/Function - Protection
- Weak dorsiflexion (drop foot) : stroke - spinal cord injury
- Correct deformity (spasticity - contracture) : cerebral palsy, spina bifida/myelodysplasia
- Healing for ligament injury : ankle sprain
- Healing for bone conditions : fracture - post operative
- Reduce pain from arthritic joint : OA - RA
- Improving gait : hyperextension of the knee or genu recurvatum
- Add stability : Ehlers-Danlos syndrome, Marfan syndrom, hyper-mobility
- Protection from wounds: diabetic foot
Metal AFO. Components - List two indications - How to correct varus and valgus
Components
- Calf Band
- Metal uprights
- Ankle Joint
- Leather straps
- Footplate or other interface between the brace and the shoe
Two indications for metal AFO
- Individual may have grown accustomed to a metal brace and thus despite the advantages of newer types may not want to change.
- Condition may require a stronger stability provided by metal AFO
- Fluctuating lower limb edema
Medial T strap
Apply pressure over the medial malleolus and buckle around the lateral upright.
Lateral T strap
Apply pressure over the lateral malleolus and buckle around the medial upright.
Cuccurollo 4th Edition Chapter 6 P&O pg515
How to differentiate between plastic AFO? when to use each one? ππ
POSTERIOR LEAF SPRING/FLEXIBLE
- Trim line is behind the ankle
- Flaccid foot drop
- Allow to push-off/plantar flexion phase
- Dorsiflexion assist during the swing phase
SEMI-RIGID
- Trim line is behind the malleoli
- Foot drop with some extensor tone
- Provides increased ML stability of the ankle
- Patient cannot easily propel during push-off
RIGID
- Trim line at the malleoli or anterior to the malleoli with
- Highest levels of spasticity/tone, contracture or post op
- No motion allowed at the tibiotalar or subtalar joint
- Postoperative immobilization of the foot or ankle
Cuccurollo 4th Edition Chapter 6 P&O pg515
Posterior Leaf Spring (PLS) AFO. Advantages & Disadvantages ππ
Specs
- Trim line is behind the ankle
- Dorsiflexion assist during the swing phase
Uses
- Flaccid foot drop
Advantages
- Lightweight
- Cosmetic appeal
- Increased comfort with foot inside a shoe
- Can fit into a shoe with relative ease
- Lack of attachment to the shoe
Disadvantages
- No ML Support
- Do not offer as much control of inversion/eversion or of varus/valgus mal-alignment
Rigid (solid) plastic AFO. Uses & Disadvantages ππ
Specs
- Trim line at the malleoli or anterior to the malleoli
- No motion allowed at the tibiotalar or subtalar joint
Uses
- Spasticity
- Contracture
- Stabelization (post operation or injury)
- Early to moderate Charcot joint
Disadvantages
- Bulky, limiting options for shoes
- Cosmetically unacceptable to many
- More difficulties in walking (no rockets), patient may not accustom to it
- Require a greater energy expenditure
- Excessive pressure on or presence of skin breakdown
Prefabricated braces may be preferable by the patient for many reasons. Mention 4.
- Brace will be needed for only a limited time period
- You need a brace today
- Cheaper than custom made braces
- Itβs what you have available
- You want to use it as an assessment tool prior to fabrication
Identify
Double-action metal ankle joint with solid stirrup
Braddom 6th Edition Chapter 12 LL Orthotics pg34
AFO with hinged ankle joint. List 2 benefits & 2 types.
BENEFITS/INDICATIONS
- Reduce the energy cost of ambulation
- Paralysis of dorsiflexion, plantar flexion, foot inversion, foot eversion
- Prevention and correction of deformities
SINGLE POSTERIOR CHANNEL
- Spring for dorsiflexion assist, after planterflexion it will spring back to dorsiflexion
- Steel pin for plantar flexion stop
- Inserting both a pin and a spring for dorsiflexion assist and plantar flexion stop
DUAL POSTERIOR & ANTERIOR CHANNEL
- Additional option of an adjustable steel pin
- Lock the joint in a fixed position
- Block the forward progression of the tibia at midstance (dorsiflexion stop) (Quadriceps muscle is weak will cause non-stop dorsiflexion and buckling)
- Anterior spring help in planterflexion βpush-offβ thus getting up easier from a chair
Cuccurollo 4th Edition Chapter 6 P&O pg516
Knee hyperflexion and hyperextension. Explain the mechanism and the Tx AFO of choice.
KNEE HYPERFLEXION
- During foot strike, the direction of GRF fall behind the knee, and in this case the GRF will tend to encourage flexion of the knee. If the GRF falls in front of the knee (by improving planterflexion), then knee extension is assisted.
- Dorsiflexion assis in knee flexion and collapse (GFR posterior to knee)
Use: Ground reaction force AFO
KNEE HYPEREXTENSION
- Plantarflexion stop can be adjusted to keep the ankle more dorsiflexed. This adjustment will move the GRF posterior to the knee joint and encourage more flexion and discourage the hyperextension of the knee that was occurring previously.
- Plantarflexion assist in knee extension (GFR afterior to knee)
Use: Solid AFO
Explain why patient c/o aches in thighs after using AFO.
Most AFOs hold the ankle in slight dorsiflexion, moving the tibia forward and causing a flexor moment at the knee. This flexor moment must be controlled by the quadriceps.
This increased activity of the quadriceps may cause a sense of fatigue and aching in the thighs especially if the quadriceps are a bit weak.
Why patient c/o Knee instability after wearing AFO.
Why patient c/o aches in thighs after using AFO.
Mention 2 orthotic fixes and 2 shoe modifications.
Explain
- AFO creates a flexor moment at the knee: If quadriceps are not strong enough to provide an opposing extensor moment, the knee will be unstable and collapse into flexion.
- Most AFOs hold the ankle in slight dorsiflexion, moving the tibia forward and causing a flexor moment at the knee. This flexor moment must be controlled by the quadriceps.
- This increased activity of the quadriceps may cause a sense of fatigue and aching in the thighs especially if the quadriceps are a bit weak.
Orthotic Fixes
- Can modify it into GRF AFO
- If quadriceps muscle strength of grade 3 or less, consider KAFO.
Shoe modifications
- More plantar flexion (but more difficulty clearing the foot during swing)
- Shorter heel with cushion: higher or firmer heel will cause an increased flexor moment at the knee and does not allow free plantar flexion.
Presence of knee hyperextension in a pt wearing an AFO List 5 reasons. What are two ways of correcting? ππ
CAUSES
- plantarflexion contracture
- quadriceps spastic
- weak flexors
- soft heel
- low heel
CORRECTION
- Limit ankle planterflexion, enhance dorsiflexion
- KAFO
List 4 reasons for knee buckling in a pt with an AFO ππ
Give 2 shoe causes of increased knee flexion in an articulated AFO
List 3 Ways for limiting knee instability/buckling ππ
CAUSES
- Weak quadriceps grade <3/5 (Polio, Paraplegic SCI)
- Knee flexion contracture
- Hamstring spasticity (Stroke, CP)
- Ligament injury (ACL)
- Excessive dorsiflexion
- High heel
- Hard heel
CORRECTION
- Increase plantar flexion
- Lower heel height
- Softer heel
How does AFO reduce energy cost of hemiparetic ambulation? ππ MOCK
- Prevent foot drop in swing phase
- Easy to negotiate stairs
- Reduce energy cost
- Increase walking speed
PMR Secrets 3rd Edition Chapter 11 pg113 Q11
Identify (1) mention 2 uses, 2 advantages and 2 disadvantages
Name
Carbon fiber AFO
Indications
- Foot drop with associated flaccidity
- Partial foot amputations
Advantages
- Light weight
- Low profile
Disadvantages
- No ML support
- Lack adjustability (ready made)
Identify (2) and mention key deference
Ground reaction ankle-foot orthosis (AFO) used for knee hyperflexion.
Braddom 6th Edition Chapter 12 LL Orthotics pg233
Identify (1), describe, mention its usage, one advantage and disadvantage
Name
- Carbon fiber GRF AFO
- Energy storage AFO
- Intrepid dynamic exoskeletal orthosis (IDEO)
Posterior dynamic element (PDE)
- Carbon fiber composite spring system, provides energy return.
- Plantar and dorsiflexion resistance
Use
Off load damaged foot/ankle while still providing high performance ability (i.e. running).
Advantage
Helps to reduce pain and facilitate running for those with limb salvage
Disadvantage
Features that enhance running make walking more difficult.
Identify (2) and mention key deference
Neuro Swing AFO
Single ankle joint to facilitate the gait in individuals with neurologic disorders.
Identify (2) and indication
Name
Controlled ankle movement (CAM) walker boots
Use
Extensive injuries such as fractures, sprains, and tendon tears.
Identify (3) description and function.
Charcot Restraint Orthotic Walker (CROW)
Description
- Rigid AFO
- Plastic clamshell design
- Soft interior
- Rocker bottom of rubber
Function
Provides total contact for weight redistribution
Need lift on other side to manage height difference
Electrical Stimulation Devices, how they work and the uses.
Work
Electrical stimulus to nerves and muscles during gait cycle to activate dorsiflexors to prevent the foot drop
Uses (UMN cases)
Stroke, incomplete SCI, traumatic brain injury, and multiple sclerosis
With intact periphral nerve
List 6 Clinical Indications for Knee Orthoses
π‘ Knee Anatomy: Patella, Ligaments, Meniscus, Joint, Muscles, Bones
- Patellar support and control of patellofemoral tracking
- Anterior or posterior knee instability (ACL or PCL strain)
- Medial or lateral knee instability (MCL or LCL strain)
- Prophylactic bracing to reduce the risk of ligamentous injury
- Off-loading (Medial or lateral compartment in OA)
- Motion restricion
- Postoperative stabilization
Braddom 6th Edition Chapter 12 Box 12.1
List planes of motions affected by knee orthosis. 3 marks.
- Sagittal plane: Limits hyperextension of the knee (genu recurvatum)
- Axial rotation: Provides ML and axial control
- Coronal plane: Theoretically mimics anatomic knee joint function
Cuccurollo 4th Edition Chapter 6 P&O pg517-518
Knee Orthosis. Mention one method to decreased rotational instability / increase stabelity
Adding a footplate to a knee immobilizer decreases the rotational instability of the knee.
Cuccurollo 4th Edition Chapter 6 P&O pg518
Patient with genu recurvatum, give 4 mechanical causes. ππ
- Quadriceps weakness
- Quadriceps contracture, spasticity
- Hamstring weakness or spasticity
- Planterflexion contracture
- Leg length discrepancy
Mention how can you prevent excessive extension or flexion in patient with polio. Prescribe orthosis for hyper-flexion and extension.
LIMIT EXTENSION
- One band placed posterior to the knee joint in the popliteal area
- Two bands placed anterior to the knee axis (one superior and one inferior to the knee)
- Example: SWEDISH KNEE CAGE
LIMIT FLEXION
- Anteriorly directed force on posterior proximal thigh
- Posteriorly directed force on anterior surface of the knee
- Anteriorly directed force on posterior aspect of the calf
Cuccurollo 4th Edition Chapter 6 P&O pg518
Your opinion on flexible knee orthosis / knee sleeves π
- Psychologic comfort for patients with osteoarthritis, minor knee sprains, and mild edema.
- Minimal mechanical support
- Proprioceptive feedback/kinesthetic reminder
- Can retain body heat
- Theoretically stabilizes patellar tracking with patellofemoral dysfunction
Cuccurollo 4th Edition Chapter 6 P&O pg518
Orthosis of choice post ACL injury. π
Lenox hill derotation orthosis
- Control of knee axial rotation
- Anterior-posterior control
- Medial-lateral control
Cuccurollo 4th Edition Chapter 6 pg518
Orthosis of choice post operative.
- Total knee immobilizers
- Hinge for restricted ROM
Patient with OA. Prescribe orthosis.
Off-loading KOs
π‘ Effectiveness of these KOs remains debatable
Knee orthosis with three-point distribution for unloading of the medial or lateral knee compartments.
Patellofemoral Syndrome Hx PEx Orthosis
Knee orthosis with patellofemoral joint support
Components of KAFO π
- AFO
- Two Uprights
- Knee Joint
- Knee Joint (3)
- Knee Lock (8)
- Thigh Band
List 4 Clinical Indications for a (K)AFO ππ
π‘ Knee Too Much: Anterior, Posterior, Mediolateral, Aligment
CONDITIONS
- Too much flexion: Weak knee extensors & flexors β buckling and risk of fall
- Knee flexion spasticity
- Too much extension: Hyperextension of the knee (genu recurvatum), stroke or polio
- Knee instability
- Genu varum and valgum
CLINICAL INDICATIONS
- UMN lower extremity weakness: Stroke, ABI, SCI
- LMN lower extremity weakness: polio, peripheral neuropathy, myopathy
- Lower extremity weakness and any of these associated conditions:
- Knee hyperextension
- Spasticity
- Varus or valgus knee deformity
- Intrinsic knee joint instability
- Knee pain
- Sensory impairment
Braddom 6th Edition Chapter 12 LL Orthotics pg240 Box 12.4
List 3 Types of knee joints in KAFO π
List Types of knee locks in KAFO π
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DROP LOCK
- Ring drop either by gravity or with assistance from the patient
- Locking knee in 0 degree extension position
- Pros: Simple to use, Lightweight and durable
- Cons: Required hand dexterity, No locking mechanism until full knee extension
-
VARILOC POSITIONING JOINT
- Rotary joint that allow rotatory locking with ease of operation.
- Disengaged by a push-button mechanism, allowing the joint to rotate
-
BAIL LOCK
- Automatically engages the lock when the joint reaches full extension (i.e. standing).
- Lifting the posterior bail unlocks the knee to allow flexion.
- Cons: Bulky and can be accidentally released if it hits a rigid object.
-
TRIGGER LOCK
- Locks by patient extending the knee, either actively or passively, pull trigger to unlock
- Pros: Prevent knee buckling
- Contraindicated in patients with knee contracture.
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DIAL LOCK
- Adjustable lock with pins allowing certain degree of knee flexion and extension
- Uses: Knee buckling, prevent progression or gradual reduction of a flexion contracture
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STANCE CONTROL / LOAD RESPONCE +/- SPRING
- Allows 20Β° of unresisted knee flexion during the stance phase
- Can be equipped with a spring that provides for shock absorption
- Uses: Weak quadriceps
-
RATCHET LOCK
- Locks every 5 to 10 degrees from 90 degrees of flexion to full extension
- Unlocking by release the lever
- Use: Stretch out knee flexion contractures.
-
GXL-Knee
- Designed to provide extension assist, but doesnβt prevent knee flexion.
- Allow option of locking at full extension for use as a locked knee joint.
Cuccurollo 4th Edition Chapter 6 P&O pg516
Compensatory mechanism(s) in gait for locked knee in extension. ππ
Full extension = long limb, same in long prosthesis
- Hip hiking ipsilateral side
- Vaulting contralateral side
- Circumduction ipsilateral side
SCI L1 patient. List 2 methods for ambulation & Possibility of standing. ππ
1. Scott-Craig Orthosis (KAFO)
Bilateral KAFOs designed for standing and ambulation in adults with paraplegia.
Complete neurological level at L1 or lower to initiate hip flexion
2. Ambulation Aids & Gait Pattern
Crutches or walker using a swing-to or swing-through gait pattern.
3. Unsupported standing
Leaning the trunk backward so that the COG of the trunk rests posterior to the hip joint, resulting in tightening of the anterior hip capsule and the iliofemoral ligament.
Orthotics of choice for correction of Genu Recurvatum.
AFO
- Grade 3/5 Quads
- <30 degree hyperextension
KAFO
- Grade <3/5 Quads
- >30 degree hyperextension
List 4 conditions benefit from HKAFO. Gait pattern in RGO. How it works? ππ
Biomechanics
As step is initiated and hip flexion takes place on one side, the cable coupling induces hip extension on the opposite side, producing a reciprocal walking pattern.
Using two crutches and an RGO, paraplegics can ambulate with a four-point gait.
A walker may also be used.
Conditions βMost imp pediatric topics: CP, SB, DMD .. add any otherβ
- Paraplegia due to SCI
- Spina bifida
- Cerebral Palsy
- Muscular dystrophy
- Poliomyelitis
Indications (Weakness in All ROM)
- Complete paralysis of the leg (sufficient hip flexion motor power)
- Hip flexion/extension instability
- Hip adduction/abduction weakness
- Hip internal rotation/external rotation instability
Cuccurollo 4th Edition Chapter 6 P&O pg517
Braddom 6th Edition Chapter 12 LL Orthotics pg241 Box12.5
Most patients who require a HKAFO abandon use of the brace due to π
- Cost
- Maintenance
- Weight of the brace
- High energy requirements form ambulate
- Restriction of ROM imposed by the brace
Patient came with POLIO, what is the best orthosis for him ππ EXAM 2020
Reciprocal gate orthosis (HKAFO)
Diagnosis and 2 orthotic options
Mention the gait abnormality and prescribe suitable orthosis.ππ EXAM
Bilateral hip dysplasia β Pavlic Harness
Scissoring gait β SWASH