Ch 12 - Wheelchairs Flashcards
What is a major contributing factor to increased deformity and pressure ulcer development?
Inaccurate measurements during WC seating system measurements
How should seat width be measured?
Measure across the widest point of the hips (with clothing and any braces or orthoses)
What should the seat width be for manual WC users?
Same as max hip width or up to 1 inch greater than the patient’s measured hip width
What should the seat width be for power WC users?
Up to 1 inch wider than their hip width but utilize hip guides to ensure maximum alignment is maintained in the pelvis with scoliosis
What are complications of too narrow WC seat widths?
Transfers will be more difficult
Inc risk of pressure ulcer on the greater trochanters
What are complications of too wide WC seat widths?
Trunk support is compromised l/t scoliosis, back pain, and difficulty with WC propulsion
How is seat depth measured?
Dorsal buttocks to the popliteal fossa, and subtract 1/2 inch from this measurement
Subtract backrest cushion measurement
How are seat depth measurements changed for patients propelling WC with feet?
1 to 2 inches subtracted
Cushion is beveled back to allow the knee adequate flexion to propel the wheelchair.
What are complications of too shallow WC seat depths?
Dec distribution throughout the femurs, resulting in Inc pressure on the ischial tuberosities
How is seat height measured?
Lower leg length from the bottom of the heel of the shoe to the posterior thigh. Subtract the height of the “compressed” seat cushion from the measurement, and then add 3 to 4 inches to allow for adequate leg rest clearance
How are seat height measurements changed for foot drive or hemiplegic height WC?
Seat closer to the floor, to allow the unaffected leg to propel the chair
Where should WC back rest be in patient’s who use their arms for propulsion?
Inferior angle of the scapula
Where should WC back rest be in patient’s who has no UE strength and poor trunk control?
Spine of scapula
How is head support for WC measured?
Bottom of the buttocks to the top of the cranium, add the height of the “compressed” seat cushion and adjust down by 2 to 4 inches depending on the patient’s support preference
How are armrests for WC measured?
Bottom of the patient’s bent elbow at 90° and add the height of the compressed seat cushion
What is the MC prescribed armrest?
Removable desk length armrest Of ~10”
How are footrests for WC measured?
Distance from the heel of a patient’s shoe to the posterior surface of the thigh at the popliteal fossa
Footrest at least 2 inch clearance from floor
What is the most important reason for tilt and recline seating systems?
Provide patient or caregiver ability to perform adequate weight shift for pressure redistribution to minimize the risk of pressure ulcer and to provide a patient with postural support from gravity for upright
What degrees of reclining can be added to a WC?
Semi: 120°
Full: 180°
What does a tilt-in space system allow for?
Pressure to be redistributed from the seating surface to the back support
What degree of tilt should a tilt-in space system allow to redistribute sufficient pressure?
Tilt at least 45°
Most systems provide 45° to 60° of posterior tilt
What are advantages of a tilt-in space system?
– Independent pressure relief – Postural support from gravity – Pain relief – Assist in orthostatic episodes – Minimizes shear – Diminishes effects of spasticity during position changes – Maintains seating position during weight shifts – Helps mobilize secretions – Smaller turning radius
What are the standard size WC wheels?
3-to 8-inch (diameter) front caster wheels
24-inch (diameter) rear wheels
When is a fixed axle appropriate?
Someone who is not using the wheelchair as a primary means of mobility
How can an adjustable axle be moved?
Moved forward to position the center of gravity underneath the client to allow for improved rear wheel access and more efficient wheelchair propulsion
What does a forward axle position facilitate?
“Wheelies” to transition up/down curbs
What does a posterior axle position facilitate?
Inc WC stability to compensate for the change in the location of the COG
When is a posterior axle position essential?
Absence of legs in a bilateral amputee patient and with a reclining back or tilt-in-space WC
What happens with more posterior rear wheels?
– Inc rolling resistance – Inc energy required for propulsion – Inc turning radius – More stable the chair – More extension needed at GH joint, which can inc stress/injuries at the shoulder
What happens with more anterior rear wheels?
– Dec rolling resistance
– Dec energy required to propel
– Smaller turning radius
– Less stable chair
– More maneuverable (easier to perform a “wheelie”)
– Relieve shoulder pain during manual propulsion
What is the best tire for carpet?
Pneumatic tires are best because carpeting increases the rolling resistance by a factor of 4
What does WC camber with lower wheel further out than top of wheel allow for?
Better biomechanical location to the shoulder joint
Easier to propel (especially at higher speeds)
Inc stability
Easier to turn
What is the camber of everyday WC uses?
2° to 5°
Which patients use one-hand-drive WC?
Plexus injury
Upper extremity amputation
Hemiplegia
What does a smaller caster allow for?
Smaller turning radius but performs poorly on outdoor surfaces and on carpets because it can get stuck in cracks on sidewalks and in uneven contours of an uneven surface
What is the standard castor size?
8-inch diameter on a basic WC
What castor size allows for the best overall indoor and outdoor performance?
5 or 6-inch diameter
What does moving the castor more posteriorly cause?
Dec turning radius
Inc maneuverability
Dec stability
What are the types of WC cushions?
Viscous fluid Air Gel Viscoelastic foam Foam
Describe the controls of a sip and puff WC.
Hard puff: forward
Soft puff: right
Soft sip: left
Hard sip: stop, once the WC is stopped, it can also be a reverse command
