Wheelchair and power mobility

Author(s): Phil Chen, MD, and Gianna Rodriguez MD

Originally published:10/22/2013

Last updated:3/23/2017

1. OVERVIEW AND DESCRIPTION

Background:

An estimated 3.6 million people, or 1.5% of the United States population aged 15 and older, uses a wheelchair for mobility. The percentage increases to 5.2% in those greater than 65 years old.1  Independent mobility allows people to participate in work, education, basic and instrumental activities of daily living, access to health care, and to actively contribute to the world around them. Disabled individuals without independent mobility are more likely to develop secondary health complications and be financially dependent. An effective wheelchair prescription tailored to an individual’s needs requires an interdisciplinary wheelchair assessment team, which typically includes the patient, rehabilitation engineer, occupational therapist, physical therapist, rehabilitation technology supplier, and rehabilitation physician.2

Types of wheelchairs7:

Manual Wheelchairs:

Manual wheelchairs are propelled either by the user or an attendant. They are lighter weight, easier to transport without special equipment, and require less maintenance than power wheelchairs and scooters.

  1. Standard (40-65 lbs): limited capacity for adjustment or additional options. They are most appropriate for short-term use.
  2. Lightweight (28-36 lbs): offers slightly more adjustability, but lacks rear axle adjustability. Not suitable for everyday active users.
  3. Ultra-lightweight (20-30 lbs): Made of aluminum, titanium or composite materials. Offers partial to full frame adjustability.  Reduces risk of repetitive strain shoulder injuries, and is more durable than the other manual wheelchair categories.
  4. Hemi-height: lower seat-to-floor height to allow feet to assist with propulsion. Often with swing away footrests, and may have one-arm drive option.

Power Wheelchairs:

Power wheelchairs or scooters are indicated for those who cannot manually propel a wheelchair and who have the cognitive ability and coordination needed to safely propel a power device.  May be appropriate for patients with upper limb weakness, cardiopulmonary disease, poor trunk stability, upper limb pain, limited endurance, or obesity.

  1. Power-assist manual wheelchairs: motors mounted into wheel hub or as an add-on unit to wheel or axle. Augments self-propulsion in manual wheelchair. Decreased upper limb strain and force required.  Requires a battery system and increases weight, making transportation more difficult (examples: Xtender, E-motion, SmartDrive, Twion).
  2. Power scooters: typically three or four wheels, Captain style seating and a tiller for steering. Three-wheel scooters are more maneuverable, but less stable than four-wheel scooters.  Requires ability to independently transfer to device, good trunk control, and good upper limb function to drive and steer.  Generally lighter weight, less costly, and easier to transport than power wheelchairs.  Larger turning radius makes indoor use challenging.  Works well for those who have trouble ambulating long distances, primarily outside the home.
  3. Power wheelchairs: indicated for individuals with tetraplegia, poor upper limb coordination, or severe range of motion restrictions. Typically heavier and do not disassemble so transportation is more challenging.
    1. Group 1 – basic configuration and seating. No special seating or controls.  No power seating options.
    2. Group 2 – limited seating and specialty controls.
    3. Group 3 – complex seating and specialty controls, multiple seat functions.
    4. Group 4 – larger motors, suspension, larger battery capacity for active outdoor use.

How wheelchair prescription applies for different levels of acuity:

Wheelchairs used in the acute setting are designed for short-term use and do not offer postural support or pressure relief. Temporarily disabled individuals can benefit from a rental chair. Individuals with chronic ambulatory deficits benefit from using a wheelchair tailored to their specific bodies and functional needs.

Personalized fit options2,7:

  • Frame type and composition: rigid vs folding
  • Adjustable rear axle: horizontally and vertically. Axles placed more posteriorly are more stable, but less maneuverable. More anteriorly placed axles are more “tippy,” but have better positioning for wheel propulsion, performing “wheelies,” and tighter turns.
  • A range of seat widths, depths, and dump adjustment
  • Armrest length, height, and design; fixed vs removable
  • Footrests: fixed, elevating, swing-away
  • Wheels: Mag, spoke, composite material
  • Tires: air vs airless, various treads
  • Handrim shape and material
  • Back support: sling, solid, custom; range of heights
  • Various cushion types to balance pressure relief, moisture management, comfort, stability.
  • Optional postural supports
  • Power input devices: joystick, breath control, head array, switches
  • Seating functions:
    • Recline: positioning for ADLs, orthostasis, rest; can cause shear forces
    • Tilt-in-space: pressure relief, positioning, orthostasis, rest
    • Seat elevators: assist with transfers, access higher surfaces, overhead tasks; adds height to chair
    • Standing: pressure relief, weight bearing, access higher surfaces; won’t work with contractures, reduced bone density
    • Elevating legrests: orthopedic issues, edema, tone; adds length, may make transfers more difficult

2. RELEVANCE TO CLINICAL PRACTICE

Goals for seating and mobility:

  • Provide postural support
  • Maximize function
  • Ensure skin integrity with appropriate pressure relief
  • Meet consumer’s lifestyle and environmental factors
  • Meet consumer’s aesthetics needs

Pre-wheelchair evaluation:

While wheelchair use does not change the natural history of any disorder, an appropriate wheelchair can give an individual functional independence, minimize disability, and contribute to quality of life and social integration. A well-fitted wheelchair can also minimize or prevent complications that might occur if the wheelchair prescription was inappropriate, such as progression of postural deformities or pressure ulcers. Co-morbid or associated conditions that may interfere with the use of a wheelchair (or require modifications to the wheelchair prescription) include cognitive deficits, vision and hearing deficits, spacial neglect, and obesity. While there are few absolute contraindications to wheelchair use, the patient’s ability to safely utilize a wheelchair must be evaluated. This becomes especially important when prescribing power mobility.

Contraindications to power mobility include:

  • visual deficits
  • uncontrolled seizures
  • impaired cognition and judgment

Contraindications to manual wheelchairs include:

  • inability to utilize the arms for propulsion (assuming this is a goal, rather than having the caregiver propel the patient)
  • need for features that can be utilized independently by the patient, such as power tilt, recline, and seat elevation
  • cardiopulmonary impairments may limit propulsion of a manual wheelchair, as upper extremity propulsion can increase diastolic blood pressure response and cardiac afterload, as well as requiring elevation in cardiac output

Wheelchair evaluation:

Historical features to consider when determining whether wheelchair mobility is appropriate include ability to ambulate, history of falls, and activities that the proposed wheelchair will help the user to perform. Once it has been determined that wheelchair or power mobility is indicated, the rehabilitation team can assess the patient to formulate an appropriate wheelchair prescription.2,7

Factors to consider when writing a wheelchair prescription:

  • diagnosis and prognosis
  • age
  • cognitive function
  • physical ability
  • transfer ability
  • body weight
  • leisure interest
  • environment in which the wheelchair will be used
  • time spent in wheelchair daily
  • level of independence in activities of daily living
  • transportation outside the home
  • insurance coverage
  • medical issues such as incontinence, skin breakdown, and spasticity

Physical examination should document:

  • weight
  • basic vision and visual field testing
  • heart and lung exam in those with cardiopulmonary disease
  • circulatory function
  • joint swelling and deformity, such as kyphosis, scoliosis, limb contractures
  • strength
  • upper and lower limb range of motion
  • coordination
  • tone
  • skin condition, particularly at common pressure-sensitive regions and bony prominences (e.g., elbows, wrists, buttocks, greater trochanters, calves, and heels)

All wheelchair seating assessments require accurate measurements of the patient’s dimensions in a sitting position7:

  • seat width: width at widest point of hips (add 0-1 inch)
  • seat depth: length from buttocks to popliteal fossa (minus 2 inches)
  • seat and footrest height: popliteal fossa to bottom of feet (add 2-4 inches)
  • height of back: bottom of buttocks to shoulders or bottom of scapula, depending on expectations for self-propulsion
  • armrest height: elbow-to-buttocks distance

Posture should also be assessed:

  • sitting posture and balance
  • spinal alignment (scoliosis, kyphosis)
  • pelvic tilt/rotation/obliquity
  • shoulder symmetry and posture
  • head position
  • x-rays may help delineate bony abnormalities such as heterotopic ossification, and help differentiate fixed from flexible deformities of the spine, pelvis, and extremities

Functional assessment should include:

  • ability to transfer
  • ability to self-propel or operate the controls of a power mobility device

Other factors in the wheelchair prescription process:

Complications of wheelchair use:

Undesirable effects and injuries associated with wheelchair use are often related to improper fit or components that do not match the needs of the user. Examples include inadequate cushioning leading to pressure ulcers; unstable wheelchairs tipping, leading to injury; improper positioning of pushrims leading to upper extremity injuries; inadequate trunk support leading to pain, pressure ulcers, or further deformity. Especially pressure-sensitive areas include the elbow and wrist, greater trochanter, ischial tuberosity and buttock, popliteal fossa, and heel.

Overuse injuries of the upper extremities are common. Many manual wheelchair users have incomplete acquisition of wheelchair skills, which is associated with lower satisfaction and community participation, more shoulder pathology and shoulder pain, and places the patient at higher risk of injury.8 Wheelchair skills training programs have been shown to be effective.

Wheelchairs frequently need repairs. Repairs and adverse consequences are more common in power wheelchairs compared to manual wheelchairs.  The most frequent repairs are wheels/casters on manual wheelchairs and electrical/power/control systems on power wheelchairs.9

Meeting patient needs:

The success of a wheelchair prescription is the full adoption of the prescribed wheelchair in a way that meets the goals for its prescription, with few or no detrimental outcomes. While few formal outcome tools exist, discussion with the patient and family often best lets the prescribing clinicians know they have been successful. Other factors that may influence clinical decision-making include choosing a wheelchair that will integrate into the patient’s social roles. Often the wheelchair user considers the wheelchair an extension of their own person, and thus chooses elements of the wheelchair to fit with the image they want to project. Wheelchairs can be customized in a variety of ways, including varying color choices and finish patterns (for example, camouflage or an American flag pattern), custom spoke guards, and badges sewn into the upholstery.

Transportation:

While it is optimal to provide patients means of transporting their wheelchairs that is ideal for the user/chair, sometimes cost constraints limit these options and may dictate a different choice of equipment. As an example, if the patient does not own a car that can transport a larger power scooter, another option would be a lighter weight scooter that can be taken apart and put in the trunk of the car. The trade-off may be more frequent provision of a replacement scooter, due to decreased life expectancy of the lighter weight components.

  • Manual wheelchairs: easily folded or disassembled and transported by car. Trunk lift or hitch attachment can also be used. May also consider modified vehicle with ramp and tie-down system.
  • Scooter: may be disassembled and transported by car, though heavier than a manual wheelchair. Rear mounts can also be used.
  • Power wheelchair: usually requires a modified van, with lift or ramp, and a tie-down system.
  • Airlines: depending on size, manual wheelchairs can be boarded and then checked, or checked at the gate. Power wheelchairs are placed in cargo compartment and batteries need to be approved.  Airlines may require or recommend advance notice and written instructions on how to transport or disassemble the wheelchair.  It is recommended to remove and store separately any parts that are easily damaged or lost, such as control modules and electronics.7

Cost and insurance coverage:

Cost may dictate the wheelchair prescription to some extent. Documentation of deficits and needs for the mobility device can be very specific. Insurance companies may require a detailed letter of medical necessity, including line-item justification for each of the recommended components, and how the wheelchair will help facilitate basic and instrumental ADLs. Often insurance policies dictate other things, including the length of time between wheelchairs or the type of wheelchair approved. For example, some insurers will not pay for both a manual and a power wheelchair, so patients with a progressive disease may have to choose something based more on future functional expectations rather than current needs.  Given this complexity, evaluation by a multidisciplinary specialty seating and wheelchair clinic is recommended.

The importance of cost and insurance is highlighted by research showing a disparity in providing the appropriate manual wheelchair in SCI patients, which is a lightweight and customizable wheelchair.10  Minorities and those with low income, Medicare/Medicaid insurance or low education were more likely to receive a standard wheelchair instead of a customizable wheelchair.

Medicare has specific guidelines that apply to the prescription of manual and power mobility, which are considered Mobility Assistive Equipment (MAE), and are covered under the Medicare Part B DME benefit. See the “National Coverage Determination for Mobility Assistive Equipment” at CMS.gov for details (https://www.cms.gov/medicare-coverage-database/details/ncd-details.aspx?NCDId=219&ncdver=2&NCAId=143&ver=25&NcaName=Mobility+Assistive+Equipment&bc=BEAAAAAAEAAA&).

According to CMS, the improper payment rate for power mobility devices was 81.8% in 2013, projected at $329 million of improper payments.11  The most common reasons for improper payments were insufficient documentation and medical necessity errors.

Under Medicare, to qualify for a manual wheelchair, the patient must meet criteria A-E, and F or G.

  1. Has a mobility limitation that significantly impairs his/her ability to participate in 1 or more mobility-related activities of daily living (MRADL) such as toileting, feeding, dressing, grooming, and bathing in customary locations in the home. A “mobility limitation” includes being unable to perform the MRADL entirely, within a reasonable time frame, or places the patient at higher risk of morbidity or mortality to attempt MRADLs.
  2. Cannot be resolved with a cane or walker.
  3. Patient’s home has adequate access and maneuverability.
  4. Use of chair will improve MRADLs and patient will use on a regular basis.
  5. Patient has not expressed unwillingness to use chair.
  6. Patient has sufficient capabilities to self-propel the chair during a typical day (for example, adequate cognition, vision, and upper extremity function).
  7. Patient has caregiver who is willing and able to assist with chair.

To qualify for a power mobility device (PMD, includes scooter or power wheelchair), the patient must meet all the below (11):

  • Has a mobility limitation that significantly impairs his/her ability to participate in 1 or more mobility-related activities of daily living (MRADLs).
  • Cannot be resolved with a cane or walker.
  • Does not have sufficient upper extremity function (due to pain, deformity, absence of limbs, limited strength, endurance, range of motion or coordination) to self-propel a manual wheelchair in the home to perform MRADLs.

To qualify for a scooter, additional criteria:

  • Must be able to safely transfer to/from scooter, operate the tiller, and maintain postural stability.
  • Has mental and physical capability for safe use in the home
  • Weight within the weight capacity of the scooter
  • Home has adequate access, maneuvering space, and surfaces for operation
  • Using a scooter will significantly improve ability to perform MRADLs
  • Not expressed an unwillingness to use the PMD

To qualify for a power wheelchair, additional criteria:

  • Does not meet criteria for a scooter
  • Has mental and physical capability for safe use in the home, or caregiver is available and willing to operate
  • Weight within the weight capacity of the power wheelchair
  • Home has adequate access, maneuvering space, and surfaces for operation
  • Using a power wheelchair will significantly improve ability to perform MRADLs
  • Not expressed an unwillingness to use the PMD

Additionally, the provider must conduct a face-to-face examination, specifically described as a “mobility examination,” and document the examination, before writing the prescription (known as the 7-element order).  The report and order should go to the supplier within 45 days of the examination.  The device must be delivered within 120 days of the examination.12

The face-to-face examination report should address the following:

  • History of condition relevant to mobility needs
  • Physical examination relevant to mobility limitations (weight/height, musculoskeletal exam, neurological exam)
  • Address the above criteria for recommended device
  • Document the decision to prescribe a PMD
  • For more detailed guidelines – https://www.cms.gov/Research-Statistics-Data-and-Systems/Monitoring-Programs/Medicare-FFS-Compliance-Programs/CERT/Downloads/SE1112PowerMobilityDeviceFaceToFaceExaminationChecklist.pdf

The written prescription (7-element order) requires:

  1. Patient’s name
  2. Date of patient’s face-to-face examination
  3. Pertinent diagnoses/conditions that relate to the need for device
  4. Description of item ordered
  5. Length of need
  6. Treating physician’s signature
  7. Date of physician’s signature

3. CUTTING EDGE/UNIQUE CONCEPTS/EMERGING ISSUES

Recent advances and future directions:

Many recent and proposed innovations in wheelchair design revolve around advances in technology.  These innovations are incredibly varied in scope, design, and effectiveness, but all attempt to improve on the many challenges that wheelchair users still find in daily use.  Many users still find wheelchairs difficult or impossible to use for daily activities and 40% report difficulty or impossibility with steering or maneuvering tasks.  Many people are unable to control a power wheelchair by conventional methods, including those with vision impairments, cognitive impairments, tremors, deformities, and impaired upper body and head control.18  Safety remains a concern, with more than 100,000 wheelchair related injuries treated in US emergency departments in 2003.17  Injuries commonly occur during transfers or are related to loss of traction or loss of stability, since wheelchairs are primarily designed for indoor use.16

Examples of recent advances:

  • Improving safety and mobility – development of robotic wheelchairs that have selectable drive wheel location (rear/mid/front), self-leveling, curb climbing, traction control, two-wheel balance, and/or a wheelchair mounted robotic assisted transfer device.16,17
  • Expanding control devices – gaze-driven maneuverability; wearable orthotic control interface as opposed to a wheelchair mounted control device; voice control; facial expression or body gesture control.13,14
  • “Smart” wheelchair – incorporating multiple functions or technologies on one device. New devices and functions may include laser range finders, infrared or ultrasonic sensors, and GPS/navigation controllers for mapping, localization, obstacle detection and cliff sensors; line or wall following; door passage; path planning, semi-autonomous or autonomous control; camera for telehealth, communication with family and health care providers, or medical alert system; integrated controllers for household appliances and computer access.14,15,18

Recent legislation issues:

As of November 2014, CMS announced it would be using information from the Medicare Competitive Bid Program to adjust the fee schedule for competitively bid items, including wheelchair accessories.  The bid information was drawn largely from standard wheelchair accessories and will be used to reduce payments on complex rehab wheelchair accessories, even though these accessories are vastly different in purpose and actual costs.  This policy would drastically underestimate the costs for complex rehab technology, and thereby limit access of this equipment to the vulnerable population that requires it.  This policy is expected to go into effect January 1, 2017.

Legislation has been introduced in the House of Representatives and Senate to clarify the distinction between complex rehab technology and standard wheelchairs.  For more information, visit:

Access2CRT.org: www.access2crt.org/

Protect My Mobility: www.protectmymobility.org

4. GAPS IN KNOWLEDGE/EVIDENCE BASE

REFERENCES

  1. Americans with Disabilities 2010, U.S. Census Bureau, http://www.census.gov/prod/2012pubs/p70-131.pdf
  2. Wilson PE. Seating Evaluation and Wheelchair Prescription. http://emedicine.medscape.com/article/318092-overview
  3. Di Marco A, Russell,M, Masters M. Standards for wheelchair prescription. Australian Occupational Therapy Journal. 2003;50:30-39.
  4. Sabol TP, Heley ES. Wheelchair evaluation for the older adult. Clin Geriatr Emd. 2006; 22:355-375.
  5. Ding D, Leister E, Cooper RA, et.al. Usage of tilt-in space, recline and elevation seating functions in the natural environment of wheelchair users. J Rehabil Res Dev. 2008;45:973-984.
  6. Position Papers and Guides. http://www.resna.org/resources/position_papers.dot
  7. Dicianno BE, Schmeler M, Liu BY. “Wheelchairs/Adaptive Mobility Equipment and Seating.” Spinal Cord Medicine, 2nd Ed. Kirschblum S, Campagnolo DI. Philadelphia: Lippincott Williams & Wilkins, 2011. 341-358.
  8. Worobey LA, Kirby RL, Heinemann AW, Krobot EA, Dyson-Hudson TA, Cowan RE, Pedersen JP, Shea M, Boninger ML. Effectiveness of Group Wheelchair Skills Training for People With Spinal Cord Injury: A Randomized Controlled Trial. Arch Phys Med Rehabil. 2016 Oct;97(10):1777-1784.e3.
  9. Worobey L, Oyster M, Nemunaitis G, Cooper R, Boninger ML. Increases in wheelchair breakdowns, repairs, and adverse consequences for people with traumatic spinal cord injury. Am J Phys Med Rehabil. 2012 Jun;91(6):463-9.
  10. Hunt PC, Boninger ML, Cooper RA, Zafonte RD, Fitzgerald SG, Schmeler MR. Demographic and socioeconomic factors associated with disparity in wheelchair customizability among people with traumatic spinal cord injury. Arch Phys Med Rehabil. 2004 Nov; 85(11):1859-64.
  11. Power Mobility Devices: Complying with Documentation & Coverage Requirements. Department of Health and Human Services, Centers for Medicare & Medicaid Services. April 2015. https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNProducts/downloads/pmd_DocCvg_FactSheet_ICN905063.pdf
  12. Power Mobility Device Face-to-Face Examination Checklist. Department of Health and Human Services, Centers for Medicare & Medicaid Services. 2010. https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNMattersArticles/downloads/se1112.pdf
  13. Winkler SL, Romero S, Prather E, Ramroop M, Slaibe E, Christensen M. Innovative Power Wheelchair Control Interface: A Proof-of-Concept Study. Am J Occup Ther. 2016 Mar-Apr;70(2)
  14. Wästlund E, Sponseller K, Pettersson O, Bared A. Evaluating gaze-driven power wheelchair with navigation support for persons with disabilities. J Rehabil Res Dev. 2015;52(7):815-26
  15. Padir T. Towards personalized smart wheelchairs: Lessons learned from discovery interviews. Conf Proc IEEE Eng Med Biol Soc. 2015;2015:5016-9.
  16. Daveler B, Salatin B, Grindle GG, Candiotti J, Wang H, Cooper RA. Participatory design and validation of mobility enhancement robotic wheelchair. J Rehabil Res Dev. 2015;52(6):739-50.
  17. Grindle GG, Wang H, Jeannis H, Teodorski E, Cooper RA. Design and user evaluation of a wheelchair mounted robotic assisted transfer device. Biomed Res Int. 2015;2015:198476
  18. Madigan EA, Newman WS. What do users want from “smart” wheelchairs? NI 2012 Jun 23;2012:263.

Original Version of the Topic

Susan V. Garstang, MD, Rana Rand, DO. Wheelchair and power mobility. 10/22/2013.

Author Disclosure

Phil Chen, MD
Nothing to Disclose

Gianna Rodriguez MD
Nothing to Disclose

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