Orthotics Flashcards
What is orthotics?
The science that deals with the use of specialised mechanical devices to support or supplement weakened or abnormal joints or limbs
What is an orthosis?
An externally applied device (may also be called a brace, splint or orthotic)
Who is an orthotist?
A registered health care professiona who specialises in the assessment of the whole body for biomechanical problems and if appropriate may prescribe, measure, fit or review an orthosis
List the 6 types of lower limb orthotic
Foot orthosis Footwear AFO - Ankle Foot Orthosis KO - Knee Orthosis KAFO - Knee Ankle Foot Orthosis HKAFO - Hip Knee Ankle Foot Orthosis
What is a valgus deformity?
Everted position in the frontal plane
What is a varus deformity?
Inverted position in the frontal plane
What is an equinus deformity?
Plantarflexed position in sagittal plane
What is a foot orthosis?
A moulded walking base used inside footwear (insoles and heel cups)
What can foot orthoses be used for?
Re-distribution and reduction of plantar pressure Relieve pain Improve function Prevent structural deformity Correct mobile deformity Accommodate fixed deformity Limit or prevent joint motion
What is a mobile foot deformity?
The foot can be manipulated into a ‘normal’ alignment
What is a fixed foot deformity?
The foot cannot be manipulated into a ‘normal’ alignment
How does the use of foot orthoses differ in mobile or fixed deformity?
Mobile = foot orthosis to CORRECT deformity Fixed = foot orthosis to ACCOMMODATE deformity
What is involved in the physical assessment before prescribing an orthotic?
ROM Muscle Powers Sensation Proprioception Circulation Muscle tone
How does a foot orthosis correct a valgus deformity?
Manipulate corrected position and hold foot by applying 3 point forces - MEDIAL wedge on insole or footwear
How does a foot orthosis accommodate a valgus deformity?
Accept foot position and accommodate to achieve greater stability - LATERAL wedge on insole or footwear
How does a foot orthosis correct a varus deformity?
Manipulate corrected position and hold foot by applying 3 point forces - LATERAL wedge on insole or footwear
How does a foot orthosis accommodate a varus deformity?
Accept foot position and accommodate to achieve greater stability - MEDIAL wedge on insole or footwear
What is an equinus deformity?
Plantarflexed position in the sagittal plane
How is an equinus deformity corrected with foot orthoses?
Manipulate corrected position and hold foot by applying 3 point forces
Is equinus normally a fixed or mobile deformity?
Fixed
What is it important to ensure when fixing an equinus deformity with a foot orthossi?
Ensure knee is not made unstable (can cause hyperextension)
How is an equinus deformity accomodated with foor orthoses?
Heel raise - following the contour of the foot and ensurring the knee is nto made unstable
What can happen if the equinus is not adequately accomodated?
Knee hyperextension
What additional treatment may be required alongside equinus foot orthosis?
Compensatory heel raise in contralateral shoe
What footwear design features are good for an insensate foot?
Soft leather upper Few internal seams Padded tongues and cuffs Lace/velcro fastening Wide and deep toe box Rocker soles
Name 4 ways in which footwear can be adapted
Raises
Wedges
Flares
Rocker soles
What is the purpose of a shoe/heel raise?
To accommodate fixed equinus foot or leg length discrepancy
What are the purposes of shoe wedges?
Correct mobile or accommodaye fixed varus/valgus foot
How can shoe wedges be fitted?
Can be added externally or internally in the heel and sole
What is the purpose of a shoe flare?
To increase stability from a varus/valgus foot
What effects does a rocker sole have on footwear?
Increase stiffness of sole
Increase toe spring
Ground reaction point shifted posteriorly
What is an AFO?
Externally applied device which extends from just below the knee, around the ankle and across the sole of the foot
What is an AFO used for?
Used for support and/or correction of foot/ankle deformities (can also have effect on knee)
What are the functional potential of an AFO?
Correction of the MSK system Maintenance of position Assist motion about a joint Resist motion about a joint Protection Improve walking speed and cadence Reduce energy expenditure
What are the 4 types of AFO?
Solid AFO
Posterior leaf spring AFO (PLS)
Varus/Valgus control AFO Jointed AFO
How is an AFO produced?
Assessment of patients functional loss Observation of gait Biomechanical assessment of gait deviations Identify functions required of orthosis Plaster wrap cast of patient's lower leg
Mechanically, how can the characteristics of an AFO be altered?
Increasing/decreasing medial/lateral trimlines Increasing/decreasing material thickness Changing cross-sec shape Adding reinforcements/stiffeners Material choice
What is the trimline of an AFO?
Border of the orthosis
Why must heel height be assessed?
Altering the heel height of shoes will influence the GRF around the knee and can increase or decrease stability
What is a knee orthosis?
Externally applied device worn on the leg extending from mid -thigh to mid-calf
What are the functional potentials of knee orthoses?
Relieve pain Improve function Prevent structural deformity Correct mobile deformity Limit or prevent joint motion
What motions can be controlled by a knee orthosis?
Flexion Hyperextension Anterior/Posterior instability Medial/Lateral instability Rotation
List 4 common reasons for fitting a knee orthosis
OA
Post-surgical
Ligament injury
Mild instability
How many forces are required for knee orthosis use?
3
Why do knee orthoses only work for mild correctable deformities?
Due to the short lever arms on a knee orthosis
What is a KAFO (Knee Ankle Foot Orthosis) commonly referred to as?
A ‘calliper’
What is a KAFO?
Custom made externally applied device worn on the leg extending from thigh to foot - used for support and/or correction of knee/ankle/foot deformities
What are the functional potentials of a KAFO?
Correction of the MSK system Maintenance of position Assist motion about a joint/joints Resist motion about a joint/joints Protection Improve walking speed and cadence Reduce energy expenditure
What factors should be considered when choosing what type of KAFO?
Patient age, weight, activity level General health Occupation Lower limb function Goals and expectations Upper limb function
What is a conventional KAFO made from? What are the pros/cons?
‘Calliper’ typically made from metal and leather
Heavy in weight
Hard wearing
What is a cosmetic KAFO made from? Why are these good?
Typically made from thermoplastic
Light in weight
Durable
Improved cosmesis
What 2 materials can side bars be made from?
Steel
- hard material
- heavy
- hard weaing
Dural
- aluminium alloy
- softer material
- light weight
What is a drop locked knee brace?
When the knee is in extension, gravity causes a ring to drop and joint to lock
What is a manual drop lock knee brace?
When knee is in extension, a ring needs to be moved by hand to lock
What is a semi automatic lock knee brace?
When knee is in extension, the spring activates a ring to lock
What is a bale lock knee brace?
Bar or cord activated ring lock joint
What is a polycentric knee lock brace?
More than one joint centre
What is a spline lock knee brace?
Incremented joint to allow fixed setting - can be used in contracture management
Describe weight bearing in a KAFO?
KAFO requires to take body weight through the side bars, reducing weight through the leg
What is a quad top?
Ischial tuberosity rests on a ledge outside the socket
What is ischial containment?
Ischial tuberosity rests within socket
What is a HKAFO (Hip Knee Ankle Foot Orthosis)?
Basically a KAFO with the addition of a hip joint and pelvic band (provides control to selected hip motions as well as the leg)
What is the advantage of a HKAFO over a KAFO?
Can reduce or minimise the risk of the hip moving out of proper position or dislocating
What is the aim of HKAFO?
To stabilise the hip and lower spine in cases where the patient is weak or paralysed
Describe an example of a HKAFO
Hip guidance orthosis (HGO)
HGO consist of bilateral KAFOs linked via specially designed low friction hip joint
Used in conjunction with crutches the HGO allows reciprocal ambulation
What can be used alongside a HKAFO when greater trunk stability is required?
Spinal support instead of a simple pelvic band
Which is more common, upper or lower limb orthotics?
Lower limb
Name 6 examples of upper limb orthotics
Finger orthosis Hand orthosis WHO - Wrist Hand Orthosis Elbow Orthosis EWHO - Elbow Wrist Hand Orthosis Should Orthosis
Describe an upper limb static orthosis
Typically a WHO
Holds wrist/hand in static position
Prevents movement at specific joints
Used to prevent contracture development
Describe an upper limb dynamic orthosis
Has springs and moving components
Holds arm in corrected position while allowing active movement at specific joints
Aids rehab
