Seating Flashcards
Why its important
Can be closely related to fit and function of prosthetic/orthotic devices
Ex. Amputee may require modifications to footrests to accommodate prosthesis
Children with reciprocating gait orthosis will have moveable pelvic laterals which can easily be adjusted to change in pelvic width
General Principles
Comfort
-enable person to sit in upright position for several hours at a time
Function
- allows person to participate in home/school/work related activities
Practical
- provides easy access to home, toilets, car, and environment
Physiologicial
- decrease progress of deformity and dislocation, prevent trauma
- improved respiration, bowel, and bladder function, upper extremity control
Mobile- maximize independence
Cosmesis
Mobility Devices
Stroller
Manual Wheelchairs
Midrange chairs
Ultra lights and Sports chairs
Electric Wheelchairs
Scooters
Headrests
Different types and combinations
Most common is flat headrest mounted to backrest to prevent injuries in transit
Tilting can also help maintain head on headrest
Can be difficult component to fit, often fitted last once the trunk is stabilized
Henzinger Collar
Foam roll structure which fit around neck with 2 extensions which rest on the chest wall to support the chin
Can be mounted on plate so it can be attached to backrest
Good for children with moderate head control
Ottobock Contoured Headrest with Forehead support
Occipital Support and Lateral wings combined into headrest
Forehead support has a metal structure covered in soft rubberized foam
Straps attach the two together and prevent head from falling forward and reduce neck hyperextension
Backrests
Help maintain trunk in a upright position over the pelvis and prevent any lateral leaning
Also serve to remind person to return the trunk to upright/midline position and can be used to help distribute any forces evenly over bony locations
Contoured backs
Most common
Has slight concave bend to it so that it wraps around persons chest wall and provides moderate support
More complex backs can accommodate spinal deformities, custom molded from cast of person
Low tone children will require more support
Bean bag vacuum method
Air is evacuated out of the bag the rubber bladder can be pulled and shaped to target areas of required support
Afterwards cast of the bladder is made and cushions can be created from this
Often method used for custom seat cushions
Seats
Provide stable base of support
Help distribute total body weight over broader area
Help reduce risk of pressure sores
Style and construction dependent on person’s ability to detect, adjust to any discomfort after prolonged sitting
Most fabric slung seats not suitable for prolonged sitting
Replacement with flat rigid base to support seat cushion helps person feel more stable and secure
Custom seats also take into account contractures and deformities that might be difficult to fit with off the shelf seats
Cushions
Gel, air and foam cushions useful in prevention and management of pressure sores
Total contact nature of cushion re-distributes forces away from the sacrum and ischial tuberosities
ROHO high profile dual compartment cushion
4 inch (10cm) interconnected air cells provide exceptional therapeutic properties
Dual compartments can be adjusted independently to increase positioning and stability for either side to side or front to back
JAY cushions
Provide floatation effect by splitting up the bladder into 3 compartments
Left and right thigh sections and 1 in the sacral area
Prevents fluid (clay and oil mix) from being driven out of one location and increasing the risk of a pressure sore
Foot Rests
Properly supported legs prevent pelvis from being pulled out of the seat and reduce any pressure along anterior edge of seat
Foot rests can also be used by some children as aid to transferring to and from ground
Important they they area set at right angle and elevation for the legs
Elevating leg rests must also be able to accommodate for changes in leg length as it moves from flexed to extended
Individual foot pods pods can help control foot and leg position and use foot straps helps to secure the foot in stable position while operating the chair
Strollers
Often first mobility device that child uses
Light and simple to transport
Easy for parents to use
Accepts a seating insert
Adult models available
Manual Wheelchair, standard/institutional wheelchair
Very sturdy
Heavy steel tubing 30-40lb
Simple in design
Limited adjustable features
Gets you from A to B
Rental units
Midrange Chair
Alloy tubing for lighter frames
Different wheel assemblies and sizes
Precision wheel bearings
Better seat and back support
Removable armrests
Various Footrest angles and plates
Requires more maintenance
Ultra Lights and Sports
Very light and maneuverable
Custom designed for sport application
Not normally used as primary chair
Very high maintenance
Increased camber on wheels help align wheels with arms and provide more stability
Anti-tipper wheels prevent flipping chair backwards
Electric Wheelchairs
For patients who lack physical strength or endurance to propel a manual wheelchair
Available sizes
Children 12x12
Adult 36x20
Options include
- tilt and recline mechanisms
- zero shear backs
- elevating leg rests
- elevating seats
- light packages
Scooters
Easy access to mobility that is only used for distances that person could otherwise not walk
Average speed 5-12mph
3-4 wheel models carries up to 300lbs
25-30 km range on a full charge
Options can be added
Custom seats
Insert specifically tailored to fit individual needs of the patient
Can be comprised of many types of materials
Most commonly foam and plywood, foam and plastic
Foam in Place
Pour A B foam into plastic bag which the person is sitting on
Fast method of cushion fabrication which can be done at patients home or facility with minimal tools
Doubled up flannel shit protects patient from heat of expanding foam, also acts as spacer which is latter replaced with layer of soft foam
Seat and back would be 2 separate pours
Foam is hard, should be covered with soft layers of foam in high pressure areas
Pros
Static sitters who have severely deformed backs or pelvic deformities
Cons
Require several experienced hands to do
Not good for dynamic sitters as they move within confines of cushion and create areas of high pressure = pressure sores and discomfort
Foam Injected
Impression of patients back or seat is taken with beanbag and vacuum pump
Bean bag shape can be altered before cast is taken
Soft foam cushion is produced from the cast
Can be sent to cushion manufacturer (Ottobock, Pin-Dot)
Pros
Good for static sitters
Moderate movers who have severely deformed backs and or pelvic deformities
Can be modified more easily than foam in place style cushion
Cons
Can be bulky/chunky
Limited colours of covers
Difficult to attach straps to
Can’t put any slots in cushions for straps as this is difficult to clean
May have difficulty fitting into chairs with armrests
Have to use interface which comes iwth manufactures cushion
Insert is quite chunky lookin
OTS (Off The Shelf)
Several large manufactures offer complete seating systems using modular components
Can be easily assembled with limited tools
Pros
Easy to obtain
Easy to assemble
Easy to adjust
Cons
No seating system is acceptable in all situations
Have to know when to amalgamate different components to create most optimal seating system
Price is not that far off cost of custom fabricated seat
CP goals to consider 1
Influencing muscle tone
Decrease tone by positioning feet 90 degrees
Knees 90 degrees
Hips 90 degrees
Helps break extensor pattern in some CP children
CP goals to consider 2
Facilitating motor control by selectively controlling degrees of freedom at various joints
Progressively decreasing degree of external support as control develops
CP goals to consider 3
Facilitating skeletal development through appropriate weight bearing and balancing of muscle forces
CP preventing contracture
Preventing contractures through promotion of neutral alignment and counteracting the force of gravity
CP goals to consider 5
Preventing pressure sore development by distribution of weight through support surfaces and use of materials allowing heat dissipation and moisture absorption
CP goals to consider 6
Preventing of cardiorespiratory comlications
CP goals to consider 7
Facilitating perceptual, cognitive, and social development through provision of opportunities for environmental interaction
CP Low Tone
Child requires full control seating system which totally supports the main trunk and extremities
Head control difficult and tilting the insert 10 to 15 degrees will help
CP High Tone
Strong extensor pattern present and difficult to obtain a normal seating position
Will require strong seating system (aluminum and foam)
Use of belt restraints to maintain the trunk and legs in the desired position
Hands free sitter
Can sit for long periods of time without using hands for support
Requires a firm foam cushion for a stable base of support
Simple back with minimal trunk support
Able to transfer from chair independently
Hands dependent sitter
Because of severe functional or structural deformity
Unable to sit without major modifications to allow for pelvic, trunk and sometimes head and neck support
Benefits form the use of a tray to support the trunk with their hands
Spina bifida, goals to consider
Stable, “hands free” sitting posture
Patient comfort
Ease of transfer = transfer foot rests with convenient hand grips
Avoid pressure sores = ROHO or Jay cushions
Esthetic acceptability
Accommodation for RGO or standing frame assembly
Spina bifida children
Generally start with caster cart
Then progress to manual wheelchair
As activity level decreases, children grow in circumference rather than length, accommodation for pelvic width is always a concern
Power wheelchair is final means of transportation with transfers being done by some type of lifting mechanism
Insensitive skin always at risk and should be supported with proper pressure relief cushion
Spinal deformities
Scoliosis, kyphosis, combined with pelvic obliquity may result in uneven pressure distribution and localized areas of increased pressure over the ischial tuberosities, greater trochanter, or coccyx
May lead to decibitus ulcers
Patient with severe kyphosis are prone to skin breakdown over the apex of the kyphos
Pocket in the back cushion to accommodate the kyphos and decrease the pressure and transfer the pressure to other areas around the kyphos
Spinal cord injuries
SCI patient seating requirements will depend upon their level of injury and the remaining function
Higher level quads (C1-C4) will need more seating intervention in the way of power chair with tilt and recline and a completely supportive seating system
Pressure sores are #1 problem
Use of low back manual chair to allow better upper trunk function
Tend to be sacral sitters, beneift from chest restraints
Pelvic Rotation deformity
Caused by
- asymmetrical tone in hip adductors
- asymmetrical tone in trunk rotators
Solutions
- pelvic “y” strap in mild cases
- pelvic blocks placed below the anterior superior spine on the side of the pelvis which is rotated forward (used in combination with a firm back)
- appropriate accommodation of leg length discrpancy
Pelvic Obliquity
Causes
- spasticity of trunk side flexors
- unilateral hip extensor spasticity
- hammock seat
Solutions
- firm seat
- lateral pelvic supports
- pelvic y strap
- pelvic positioners
3 types of sitters
Hands free sitter- don’t use hands, can sit without trunk support
Hands dependent sitter- hands or trunk support
Prop sitters- cannot sit unless supported with trunk support
4 seating principles
- stable base of support
- friction prevents slipping
- managing pressure distribution
- torso over base of support
Main Goals
Pressure distribution
Accommodation of deformities
Managing tone
Pelvis as stable base of support
Thigh length
back of sacrum to popliteal area
Tibal length
1 inch below popliteal area
Plantar surface of the foot
Arm length
Top of shoulder to the elbow
Forearm Length
Olecranon to wrist (more distal if required)
Length of the chest laterals
Base of the seat to 1 inch below axilla
Headrest heaight
Top of shoulder to top of the head
Foot length
Heel to toe
Shoes on shoes off
Pelvis Width
GT to GT
Chest Width
Edge to edge of the rib cage 1 inch below axilla
Other important widths
Width of head
Width of the thigh
Pommel Width
Distance between medial tibial condyles
Ways to prevent IT pressure
Distribute pressure on the thighs by wedging cushion anteriorly
TIlt of the sit matches thigh angle- accommodates hip contractures
Pressure underneath the thighs, foot is taking weight as well- not excessive space under the thighs though, or excessive pressure, balance
Pelvis is supported in an accommodated position
Ways to prevent patient from sliding out of a chair
Seat belt
Posterior wedge the seat (beware of excessive IT pressure)
Posteriorly tilt the chair
Prevents positions that increase tone
Ideal position in a chair
90 flexed at the hip
90 flexed at the knee
90 flexed at the ankle
Pelvis is level
Back is supported
