Pathophysiology

Mobility is the ability to move oneself from one place to another. The need to move oneself at will is as basic as breathing. Persons with physical disabilities that impede functional mobility often require a wheelchair to augment or replace the function of walking. The National Center for Health Statistics reports that more than 1.3 million people in the United States use manual wheelchairs, with more than 160,000 using powered devices such as powered wheelchairs and scooters.¹⁷ When a person has a physical disability that impedes or prevents walking, a variety of methods, including orthotics, walkers, and crutches, can be used to augment or facilitate mobility. Wheelchairs are considered for a variety of patients, including persons who are unable to walk other than very short distances, whose physical abilities change from day to day or week to week, or who are unable to be mobile without the use of a wheelchair. The first two categories (can walk sometimes and under some circumstances) pose the most challenges to wheelchair evaluation in terms of when to and when not to recommend wheelchairs. Remember that the purpose of mobility is to move from one place to another in the most efficient manner possible. Mobility is not the same as exercise; the person with inefficient mobility should be able to move about at will and still have the energy to accomplish tasks once he or she arrives at the destination. The choice to use a wheelchair need not negate aided or unaided walking. The mobility method should fit the activity.³⁰ For example, walking around the house or classroom may be functional, but grocery shopping or playing on the playground might require wheeled mobility.

Historical perspective

Historically, the ability to apply appropriate powered and manual wheelchair technology is young. The first folding manual wheelchair was produced in the United States by Herbert Everest and Harry Jennings in 1933.³³ This relatively heavy, steel, chromed wheelchair remained the basic style of the manual wheelchair until the late 1970s. The turmoil of the late 1960s and early 1970s produced the disability right’s movements and independent living centers around the country. People with increasingly serious disabilities, including congenital problems such as spina bifida and acquired conditions such as traumatic brain injuries and spinal cord injuries, were surviving when before they had not. Because of consumer demand in the late 1970s and early 1980s, manual wheelchairs were designed and manufactured that provided choices and custom fitting with individual needs and preferences in mind. Marilyn Hamilton, who has paraplegia as the result of a hang gliding accident, led the way in the development of these types of manual wheelchairs.³³ Crude powered wheelchairs initially produced in the 1950s required good upper extremity skills to operate them. During the Vietnam war era, research was performed to develop access to powered wheelchairs for those who did not have upper extremity movement.³³ It was not until the flexibility of electronics that resulted from the development of microcomputers that access and control of powered wheelchairs became possible for clients with very severe physical disabilities. Twenty-five years later, health professionals are able to accommodate a variety of physical and functional needs.

Current issues

Twenty-five to thirty years ago, the variety of wheelchair technology available to assist persons with physical disabilities was limited. Today, a plethora of powered and manual wheelchair technology is available. The challenge for clinicians and wheelchair suppliers is matching client need to specific wheelchair technologies and components. This requires knowledge of clients’ diagnoses and the implications of those diagnoses, their functional and activities of daily living (ADL) needs, and the environments in which they need to function.

Current research

Much of the current research involves manual wheelchair technology, how it should be applied, and factors that contribute to overuse injuries in adults. One of the factors that provided the impetus for some of this research is the large population of adults who are aging with an acquired disability. Studies have primarily retrospectively looked at individuals with spinal cord injury. A conclusion common to these studies is that upper extremity pain is a significant problem that potentially interferes with ADLs, and that manual wheelchair propulsion is one of the culprits. Pentland and Twomey ^23,²⁴ demonstrated an association between duration of injury, not necessarily chronological age, and shoulder pain. Waters and Sie³² found that 46% of persons with tetraplegia and 36% of persons with paraplegia experience shoulder pain. They point out that even a small amount of pain and loss of shoulder range of motion can have a profound impact on a person’s ability to carry out ADLs. Curtis et al.¹¹ noted that one of the most painful activities reported was wheeling up hills.

These and other studies performed in the last decade encouraged researchers take a critical look at the contribution of manual wheelchairs and how they are set up to an individual’s upper extremity problems. A growing body of research assesses the relationship of the location of the rear wheel, forces at the hand rim, and how these forces translate through the wrist, elbow, and shoulder. For example, Boninger et al.³ evaluated the effect of an appropriately set forward axle on 40 wheelchair users. They found lower peak forces, less rapid loading of the push rim, and fewer strokes necessary to get to the same speed as wheelchairs that did not have a forward axle.³

Some studies focus on quality of life, that is, they review the impact of mobility on clients’ lives. In one such study, Davies et al.¹² studied 51 individuals in the United Kingdom (North West London) who had just been provided with powered wheelchairs. Diagnoses for this group included multiple sclerosis, muscular dystrophy, cerebral palsy, spinal cord injury, and cerebrovascular accident. The researchers found that mobility and perceived quality of life improved, and pain and discomfort were reduced.¹²

Treatment recommendations

Evaluation for manual and powered mobility

Although the development of manual and powered wheelchair technologies has seen rapid advances, the focus must be on the consumers and their needs and abilities. A poor match between consumer and technology at best will lead to abandonment of the technology and at worst will cause harm. For example, a manual wheelchair that is too difficult to disassemble for transport may not be used. A powered wheelchair prescribed to someone who is unable to safely operate it could result in a dangerous accident. As with any other clinical intervention, prescription of a powered or manual wheelchair begins with an evaluation. Specific areas must be evaluated and considered. Interwoven with the individual’s needs and wants is medical necessity.¹⁸ Most manual and powered wheelchairs are prescriptive devices, paid for by third-party payers. What will be approved through each payer (public or private insurers) varies as to what is considered medically necessary.

The accepted clinical team for a manual or powered mobility evaluation generally consists of a clinician and a rehabilitation technology supplier.²² It is the responsibility of the evaluators to obtain and coordinate all medical, therapeutic, and other information relevant to the client’s needs and abilities. It is taken for granted that the mobility evaluation will be performed once a seating evaluation has been completed. Only when the client’s seated positioning needs are understood can an evaluation for wheeled mobility can take place. This is true whether the evaluation is for dependent or independent mobility. Dependent mobility involves caregivers moving the client in the wheelchair; independent mobility involves the client primarily moving himself or herself. Overall, the wheelchair mobility evaluation process comprises evaluation, trial of equipment, specific recommendations, funding process, and training (of the client and caregiver). Although no validated evaluations are available for wheelchair mobility, certain factors and areas must be considered⁴: physical considerations, cognitive and perceptual motor considerations, ADL and functional skills, environmental and transportation needs, and technology tolerance.