RGO, HKAFO, and KAFO Flashcards
1
Q
Benefits of complex neurologic orthoses
A
- Facilitate upright posture
- Prevention of osteoporosis
- Improved bowel function and urinary drainage
- Improved peripheral circulation
- Stimulation of leg growth in young children
- Improved interaction with peers and the environment
- Improved body image and greater self respect
2
Q
Challenges of complex neurologic orthoses
A
- Transfers become complex and demanding motor tasks
- Additional constraints on dynamic anticipatory and reactionary postural responses
- Need for additional stabilization from assistive device
- Increased energy expenditure, poor efficiency
- Difficult to don and doff independently
- Any of these factors may lead to an individual abandoning the use of the orthosis. All of these should be considered when the cost of fitting, fabrication, and training for KAFO use is factored in
3
Q
What does a hip guided and reciprocal orthoses allow
A
- Allow for hip motion in the sagittal plane
- Allow for pt to avoid the 2 point swing through gait pattern
- HGO (pediatric) and Parawalker (adults) use gravity to assist the swing leg
- RGO uses a reciprocal link to facilitate a reciprocal gait pattern : Flexing one hip extends the other
- Bottom Line: Hip joints are connected
4
Q
Pros of a reciprocating orthoses
A
- Will not allow both hips to flex simultaneously
- Can use orthoses as exercise equipment 3x/week for 2 hrs
5
Q
Cons of a reciprocating orthoses
A
- Discontinue rate 61-90% in children with myelomeningocele & 46-54% in adults with SCI
- Oxygen cost 1.0mL/kg/m at gait speeds of 0.2 – 0.3 m/sec, compared to 0.176 mL/kg/m at 1.28 m/s for non disabled
- Clinical tip: Use 2lb ankle weights to simulate the weight of the orthosis
- There needs to be some (>2/5) hip strength to advance limb in swing
6
Q
Describe a HKAFO
A
- Similar to Reciprocal Orthoses, except nothing fancy to facilitate gait pattern: Pelvic band/corset and Unilateral (rare) or bilateral application
- Control sagittal and frontal plane motions well
- Poor control of transverse plan motions
- Solid/fixed AFO distally is placed in slight DF to assist with standing posture in the “tripod” position
7
Q
Describe the HKAFO training implications
A
- To effectively use HKAFOs, hip and knee joints of the lower extremity must be flexible enough to be positioned in extension.
- Although exaggerated lumbar lordosis may compensate for mild hip flexion contracture in achieving upright position, over time and with repeated forceful loading of swing through gait, this lordosis will likely contribute to development of disabling low back pain.
- For stability in standing, the individual typically stands in a tripod position, with crutch tips diagonally 12 to 18 inches forward and a slightly exaggerated lumbar lordosis. This position ensures that the individual’s center of gravity (weight line) falls posterior to the hip joint, creating an extension moment at the hip, achieving stability by alignment.
8
Q
What is ReWalk
A
- A wearable robotic exoskeleton that provides powered hip & knee motion to enable individuals with SCI to stand upright, walk, turn, & climb and descend stairs
9
Q
Indications for a ReWalk
A
- Hands & shoulders can support crutches or a walker
- Healthy bone density
- Skeleton does not suffer from any fractures
- Able to stand using a device such as EasyStand
- In general good health
- Height is b/w 160cm and 190cm (5’3”-6’2”)
- Weight does not exceed 100kg (220lbs)
10
Q
Contraindications for a ReWalk
A
- History of severe neurological injuries other than SCI (MS, CP, ALS, TBI etc)
- Severe concurrent medical diseases: infections, circulatory, heart or lung, pressure sores
- Severe spasticity (Ashworth 4)
- Unstable spine or unhealed limbs or pelvic fractures
- Heterotrophic ossification
- Significant contractures
- Psychiatric or cognitive situations that may interfere with proper operation of the device
- Pregnancy
11
Q
Clinical application of KAFOs
A
- KAFOs are only used when stability during stance cannot be effectively provided by one of the AFO options.
- KAFOs are prescribed when there is: Impaired ankle control, Hypertextension or recurvatum that jeopardizes structural integrity of the knee, Abnormal/excessive valgus angulation in weight bearing during stance
- KAFOs were initially developed during the Polio epidemic
- Craig Scott orthosis development in the 1970’s made the KAFO more common, but still poor compliance with use due to energy cost and slowness of gait speed
- Current KAFOs are built on stance control technology, but are expensive
12
Q
Describe the ground reaction force vector with a KAFO
A
- Early stance = GRF through ankle, posterior to knee, through hip = external flexion moment at the knee
- Quadriceps will contract to prevent the knee from collapsing into further flexion, hamstrings and hip abd stabilize hip, gastroc/soleus controls fwd progression of the tibia: This combo of muscle patterns created internal extension moment
- Neurological or musculoskeletal injury disrupts this balance: The magnitude of the deficit determines AFO or KAFO
13
Q
What are the different types of KAFOs
A
- Conventional
- Thermoplastic
- Carbon Composite
14
Q
Describe a conventional KAFO
A
- Indications: Max strength and durability are required, Obese patient, Fluctuating edema
- Pros: Strong, durable, easily adjusted
- Cons: Heavy, fewer contact points, less cosmetic; Shoe insert or attachment to shoe
- Terminology: Scott-Craig orthosis
15
Q
Describe a thermoplastic KAFO
A
- Indications: Intimate/total contact fit = maximal limb control; When energy expenditure makes weight of the orthosis an issue; When more control is needed
- Pros: Lightweight, interchangeability of shoes, can wear under clothes
- Cons: Hot to wear
- Terminology: Hybrid Thermoplastic orthosis
