Wheelchairs and Seating. Meg Meinerz, PT DPT Spinal Cord Injury Service VA Puget Sound Health Care System

Transcription

1 Wheelchairs and Seating Meg Meinerz, PT DPT Spinal Cord Injury Service VA Puget Sound Health Care System

2 Learning Objectives Identify different forms of wheeled mobility (PWC, MWC, PAD, sports equipment) Determine which factors of each device are responsible for functional changes Identify objective of different elements of a customized seating system Review principles of equipment that preserve upper extremity function and skin integrity. Review special adaptions to devices to allow for increased access to different environments

3 Prevalence of Wheeled Mobility 2010 US Census indicates that 3.6 million people over age 15 use a wheelchair, up from 2.7 million in Estimates are that this value has increased as general population ages with time, but difficult to measure accurately. As of 2003, it was estimated that globally 30% of people requiring a wheelchair did not have access to one. Of those that did, a large majority did not have an appropriate one

4 A History Of Wheelchairs Earliest record of wheeled seats being used to move the disabled were in 2 nd Century BCE in China Bath chair popularized in 1760s was used throughout Europe and the US Wheelchairs intended to be propelled by their passengers developed shortly thereafter Harry Jennings and Herbert Everest invented the first lightweight MWC in 1933 after Everest was injured in a mining accident

5 Goals of Wheelchair Prescription Maximize independence Maintain posture Minimize risk for safety concerns, trauma Improve comfort Support positive self-image

6 Types of Wheelchairs Power wheelchairs (PWC) Manual wheelchairs (MWC) Power assist device (PAD) Sports/Recreation wheelchairs

7 How To Choose? Patient s goals Physical presentation, comorbid factors, diagnosis and prognosis of related conditions Strength, available range of motion, sensation, muscle tone Cognitive status, history of TBI, relative safety factors Balance and functional abilities Environmental considerations, lifestyle, social history Home, community, work, leisure Cost/Insurance

8 Clinician Responsibility Consider relevant medical diagnoses and prognosis Appropriate evaluation of all physical skills and characteristics that will impact prescription Knowledge of available products Demonstrate/trial equipment as appropriate and available (varies by clinical setting) Generate prescription Fit/adjust equipment as necessary Provide any necessary training to ensure safety and maximal level of independence with equipment

9 Patient/Client Responsibility Identify personal goals Provide meaningful input during selection/evaluation process Active participation in demo and/or trial opportunities Receptive to training (including family/community training as appropriate)

10 PWC Scooters Seat atop a drive platform that is operated with a handlebar or steering wheel style control Power wheelchairs Seat atop a drive platform that is operated with (most commonly) a joystick or other drive interface to control

11 Power Device Types (As defined by Medicare) Group 1: Light Use Group 2: Consumer Rehab Group 3: Complex Rehab Group 4: High-Activity Use Group 5: Pediatric Group 6: Miscellaneous

12 Scooters 3 wheel vs 4 wheel configuration 3 wheel is more compact, smaller turning radius 4 wheel provides increased stability Advantages: Low cost Typically easily disassembled for stowage or travel Disadvantages: Poor customization options Poor stability control Increased footprint (vs PWC) makes accessibility a larger problem Requires greater functional mobility skills

13 PWC Separated by drive wheel Front wheel Mid wheel Rear wheel

14 Front Wheel Drive PWC Good at managing uneven terrain and small obstacles (thresholds, uneven sidewalks, gravel) Challenging steering as pivoting wheels are on the back Drives like a forklift Difficulty with steering and stability at higher speeds

15 Mid Wheel Drive PWC Smallest overall footprint Good indoor maneuverability, small turning radius Generally a good all purpose chair but not able to manage rough outdoor terrain Risk of high centering chair when travelling up/down inclines

16 Rear Wheel Drive PWC Steering is most intuitive, drives like a vehicle Safest at high speeds for this reason Larger turning radius because of wheel position therefore less maneuverable indoors. Very good at navigating outdoor terrain

17 QUESTION Which of the following PWC models is most appropriate for a user who lives in a small mobile home? A. Front wheel drive B. Mid wheel drive C. Rear wheel drive D. None of the above

18 Power Seating Not always present on all PWCs Never an option on scooters Available options include: Recline Tilt Elevate (vertical assist) Power operated leg angle Lateral tilt Latitude system Standing Adds to overall weight of the chair but may improve function, postural control, independence etc.

19 PWC frame setup Highly adjustable with modular parts Setting dimensions of product based on dimensions of client Width of seat based on hip width Depth of seat based on upper leg length (B) Distance to footrest based on lower leg length (C) Height of backrest based on torso height (F) Position of headrest for head support in tilt or recline (H) Height of armrest based on location of elbow (I) Drive or tilt controls positioned for access by client

20 PWC Drive controls Proportional Hand operated joystick (most common) Chin/mouth operated Foot control Touchpad

21 PWC Drive controls Non Proportional Head Array Proximity Switch Sip N Puff

22 MWC Folding frame Rigid frame Tilt in space or recline Types (as defined by Medicare) Standard, >36#, K0001 Lightweight, <36#, K0003 Ultralightweight, <30#, K0005

23 Folding Frame MWC Folds along longitudinal axis generally by pulling upward on seat upholstery Generally has swing away footrests which allows for ease of putting feet on the floor Depending on material can be very heavy (steel, older chairs sometimes >50#) or relatively lightweight (aluminum, titanium can be in range of 25-35#)

24 Folding Frames cont. Advantages: Easily stored in a tall, slim package that tends to fit in cars, closets, etc. Generally very adjustable Less expensive More appropriate for ambulators or those who stand to transfer as they allow person to put feet on the floor directly below knees from seated position. Disadvantages More moving parts = more play, poorer energy translation into forward motion Moving parts loosen over time, add weight

25 Rigid Frame Wheelchairs L shaped frame that comprises seat and footrest does not collapse May have folding backrest to decrease size of chair Once rear wheels removed, chair has lighter overall package

26 Rigid Frame cont. Advantages: Lighter weight Decreased turning radius, able to have more compact frame Increased energy efficiency, smoother ride Disadvantages: More expensive Less adjustability (as person adapts, chair cannot be modified to their body/abilities) Takes up a more specific volume for storage

27 Tilt in Space + Recline Generally for those more dependent persons Moving parts allow for position change via tilting chair back (seat + backrest together) or reclining back. Rear wheels tend to be set far behind client for stability when weight moves backward so not ergonomically set for independent propulsion Can be outfitted with power tilting mechanism Without power tilt and made of lightweight aluminum can weigh <50# but with power option likely >75#

28 Tilt In Space + Recline cont. Advantages: Allows for caregivers to perform simple pressure redistribution and increase comfort Materials lighter than PWC so may maintain some forms of transit as chair can be disassembled and put in standard vehicle Disadvantages: Provides seating surface but little mobility for the client Recline produces risk for skin shearing on seating surfaces

29 MWC Set-Up Diagram

30 MWC setup considerations Distribution of weight inside of frame for balance and function Placement of wheel for ideal propulsion Ideally should have center axle equal to position of arm hanging at side, at rest Top of rim should involve some shoulder extension, some elbow flexion, ~30

31 Materials used in wheelchairs Steel Aluminum Titanium Magnesium Carbon Fiber

32 QUESTION A smaller front caster on a manual wheelchair can improve which of the following functional mobility skills? A. Ability to propel across carpeting. B. Ease of pushing uphill C. Ability to perform a wheelie D. Maneuverability in a small space

33 QUESTION What is the most appropriate style of manual wheelchair frame choice for a client with hemiplegia and extensor tone who performs stand pivot transfers? A. Rigid frame with low backrest height, COG set at 3 B. Rigid frame with tall backrest height, COG set at 0 C. Folding frame, swing away leg rests, seat dump of 3 D. Folding frame, swing away leg rests, seat dump of 0

34 Power Assist Devices (PAD) Generally added to manual chairs Removable with varying degrees of ease Provide power assistance for navigation of environment that the individual cannot manage due to grade, terrain, etc. May limit ease of travel with chair given weight of device to transport as well as complexity of attachment to MWC.

35 PAD: Pushrim Drive Attach to chair via replacement of regular rear wheel Can t change while in the chair. Handrim push-sensor activates motor imbedded in hub of wheel Battery life is easily full day, requires overnight charging Different models vary in weight from 15-25# per wheel Vary in cost from $4-8K

36 PAD: Camber Drive SmartDrive Attaches to MWC at camber tube with simple bracket Easily removed and attached, device weighs about 15#, controlled with bluetooth smartwatch Works well on level, smooth surfaces or sidewalks, not ideal for grass, gravel or other outdoor surfaces Continue to propel MWC as you would with own handrims/wheels Smart Drive

37 PAD: Camber Drive Spinergy ZX1 Attaches to camber tube by clamping to the chair and physically lifting it from the ground. Drives with joystick attached to armrest Weight of device is 80#, awkward to maneuver by lifting Battery life of full day, lithium upgrade available Most similar to PWC function/operation Spinergy ZX1

38 PAD: Front Attachment Attaches to front of chair via lifting casters from the ground Drives like a scooter Significantly increases weight and turning radius of chair; marketed towards people who want to get out in the community more Battery life of approximately one day Firefly

39 Other Non-power MWC Devices Magic Wheels: 2-geared wheels for reduced efforts on hills Wijit Wheels: lever drive RoWheels: reverse propulsion Freewheel: increase front caster clearance, elongated frame footprint

40 QUESTION What is the most appropriate style of chair for a very thin, older gentleman with ALS and limited trunk and arm control who cannot propel himself using his arms? He needs to regularly be taken to medical appointments by family in a station wagon. Lower extremity strength sufficient for moderate assist transfers into vehicle. A. Folding frame MWC with padded arm and backrests B. Rigid frame MWC with padded arm and backrests C. Tilt in space MWC with padded arm, head, backrests D. Mid wheel drive PWC with padded arm, head, backrests, driven by family member.

41 Sports/Recreational Chairs

42 MWC Propulsion Techniques Recommended pattern is semicircular, ranging from 11 o clock -3 o clock on handrim Provides fluid motion, long stroke that covers maximal distance per stroke. Muscle activation cycle Push: bicep + anterior delt + tricep + FCU + ECR + pecs + trunk flexors (abs, ilipsoas) Recovery: posterior delt, tricep, rhomboids, middle trap

43 Interesting concept Reverse propulsion wheels RoWheels REV1

44 Rolling Resistance (RR) RR = combined drag created by points of contact with the ground and their respective bearings. Major factor in energy requirement for propulsion. Remains constant regardless of speed of MWC Inversely proportional to tire diameter RR over flat, hard, smooth surfaces RR over rough, uneven or compliant surfaces (grass, gravel, sand, carpeting)

45 Shoulder Protection Strategies Primary problem with MWC is imbalance between anterior and posterior musculature; anterior performs most of the active movement which contributes to negative postural alignment Combined with overhead reaching, major source of shoulder dysfunction in full-time MWC users.

46 Shoulder Protection Strategies Possible solutions to this chronic problem Conservative PT to manage posture and muscular balance Powered devices to reduce overall wear/tear from propulsion and overhead reaching Customize equipment as much as possible to improve fit and efficiency of use Lightest possible equipment!

47 Cost + Reimbursement Scooter: $700-$2,000 PWC: $1000-$45,000 Standard/lightweight MWC: $200-$1,000 Ultralightweight MWC: $800-$9,000

48 Wheelchair Cushions Operate via one of two principles: IMMERSION OFFLOADING

49 Immersion Air, gel, foam, plastic polymers All bony prominences are fully immersed in the cushion materials Cost varies from $100-$800, estimated lifespan of 1-5 years.

50 Offloading Custom molded (generally) Extended lifespan, can be 10+ years $600-$1500, can be combined with custom backrests, arm/foot protection

51 A little inspiration Wheelchair stunts Murderball Wheelchair basketball

52 References Beekman, C.E., Miller-Porter, L., Schoneberger, M. Energy Costs of Propulsion in Standard & Ultralight Wheelchairs in People with Spinal Cord Injuries. Physical Therapy. February (2): Boninger, M.L. et al. Wheelchair Pushrim Kinetics: Body Weight & Median Nerve Function. Archives of Physical Medicine & Rehabilitation. August : Bronzino, J. The Biomedical Engineering Handbook. Springer Science and Business Media, Kulig, K. et al. The Effect of level of Spinal Cord Injury on Shoulder Joint Kinetics During Manual Wheelchair Propulsion. Clinical Biomechanics : Waters, R.L. Lunsford, B.R. Energy Cost of Paraplegic Locomotion. Journal of Bone & Joint Surgery. October A(8): Watanabe, Laurie. Clash of the Titans: Aluminum vs. Titanium. Mobility Management

53 Thank you! Meg Meinerz