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Assessed for Success: Lightweight Wheelchairs and Beyond

A keen understanding of wheelchair types and indications, combined with postdelivery training, helps assure high function for patients.

by Lauren Rosen, PT, MPT, MSMS, ATP/SMS

There are 18 different types of manual wheelchairs according to Medicare Guidelines (Medicare HCPCS Manual Wheelchair Codes). Some are designed for people to be dependent while others are designed for independent propulsion. Understanding the different types of wheelchairs and the proper indications for them is vital for therapists. It is equally important for a therapist to understand the complexity of wheelchairs so that clients can be assured they receive the correct equipment, properly set-up and adjusted to maximize their function. Understanding the importance of postdelivery training is the other essential component therapists will need to assure clients are able to function at their highest.

Wheelchair Assessment
Therapists need to perform a thorough assessment to determine the appropriate equipment for each client. The areas to be assessed will vary based on a client’s current functional needs. There are templates and guides designed to assist in assessing the correct information for each client.1

For therapists who are not knowledgeable in wheelchairs, referral to a wheelchair clinic with well-trained therapists may be necessary. Clinic therapists should have additional knowledge and certifications in wheelchairs such as Assistive Technology Professional (ATP) or Seating and Mobility Specialist (SMS). When a client’s needs are too complex for a treating therapist, these specialists are best equipped to assist the client.

Wheelchair suppliers also can provide assistance if they are knowledgeable. An ATP certification shows an individual has at least a basic amount of knowledge. However, it does not mean that person has the necessary knowledge to assure a client receives the correct equipment. So it is important for therapists to have a good understanding of the equipment they recommend and not rely on anyone else to determine what products best meet a client’s needs.

Basic Wheelchairs
Standard hospital style wheelchairs and similar models (K0001-K0003) are designed for individuals who either cannot or should not be propelling themselves. The sizes available are basic (18w x 18d, 16w x 16d) and generally cannot be customized. The chair generally weighs more than 40 pounds and has heavy wheels without any adjustment in the axle position.

This type of wheelchair is good in a hospital situation. It also works well for someone who will only need a wheelchair for a few weeks post-surgery when they cannot move around in the home. Due to the weight of these chairs and their overall setup options, these models are not appropriate for users to propel them long distances or for long periods of time.

Lightweight Wheelchairs
The name of this category of wheelchairs (K0004) is a bit deceiving. These wheelchairs weigh between 30 and 40 pounds, which is not lightweight by most people’s definition. These chairs generally remain appropriate for the same population who use basic wheelchairs. They are available in more sizes but lack the axle adjustability and customizability that most full-time wheelchair users require to effectively propel. Unfortunately, these chairs are prescribed for many clients because the professionals hear the word “lightweight” and do not understand the actual weight or the lack of adjustability of these wheelchairs.

Ultralight Weight Wheelchairs
Depending on the source, an ultralight weight wheelchair weighs less than 25 to 30 pounds (K0004-K0005). However, many ultralight weight wheelchairs weigh less than 20 pounds. This type of wheelchair is generally recommended for full-time wheelchair users.

Manual wheelchair users experience chronic upper extremity pain.1 This pain results in a lower quality of life and an increased dependence on others.2 The rate of carpal tunnel syndrome and shoulder, elbow, and neck pain increases the longer an individual uses a manual wheelchair.3 Wheelchair users push their handrims 3,500 times a day on average.4 If the wheelchair weighs 5 pounds less than another wheelchair, that is a savings of 17,500 pounds a day that they will have to push. The heavier the weight of a person and the wheelchair, the higher the force that is required to propel it. Additionally, users who had to generate the higher forces during propulsion had poor nerve conduction velocities and they had greater difficulty propelling their wheelchair than those propelling a lighter weight wheelchair.5 The users of ultra lightweight wheelchairs utilize less energy and travel further during an average day.6

There have been many studies on the durability of ultra lightweight wheelchairs. One study showed that these wheelchairs last more than 13 times longer than standard wheelchairs and that the cost is over three times less to operate over the lifespan of the wheelchair.5 When comparing this type of wheelchair to lightweight wheelchairs, it lasted over four times longer and cost two times less to operate.7 Ultralight wheelchairs have the longest survival rate and fewer catastrophic failures than standard and lightweight wheelchairs when tested to failure.8-9

Chair Setup
The design and setup of a wheelchair is as important as any other aspect of the wheelchair chosen. DiGiovine et al discuss the many design and setup options on ultralight weight wheelchairs and why those options matter for propulsion.10 Their position paper is a great synopsis of the important issues.

One of the most confusing measurements for therapists seems to be the width of a wheelchair. Many people were taught that a wheelchair should always be 2 inches wider than the client’s hip width. For most manual wheelchair users, that “rule” is wrong and should be broken. Making a chair too wide can make reaching the handrims difficult. It also can place the shoulder in increased abduction, which can increase the risk of rotator cuff tears and shoulder pain. Additionally, a seat that is too wide will cause the wheelchair users to slide laterally, which decreases their balance and can result in shear injuries. Ideally, the width of the wheelchair should be equal to the person’s hip width in adults.

The appropriate positioning of the axle in all planes is necessary to assure appropriate placement of the wheels so that a person can effectively propel the wheelchair. The K0004 (High Strength, Lightweight Wheelchair) and lower wheelchairs do not provide the amount of axle adjustability that the K0005 wheelchair does. Because body proportions differ, it is important to configure the wheels individually for each client.

The center of gravity of the rear wheel and the vertical position of the wheel are two very important adjustments. The further forward the wheel, the easier the wheels roll so the chair is easier to propel. A good starting point is to have the axle directly below the middle finger when a client’s arms drop down. However, if the wheel is too far forward for the client, the chair can become too tippy and unstable. Wheels too far back can cause excessive shoulder extension and elbow flexion.

Similarly, if the vertical position of the wheel is not properly adjusted, propulsion can be difficult. Clients should have a small amount of elbow flexion at the initiation of propulsion on top of the handrim. If their elbows are too flexed, they can injure themselves. If their elbows are too far extended, they cannot generate strength to propel the wheelchair.

Wheelchair Adjustment and Training
The therapist should be an active participant in the delivery and adjustment of the wheelchair. Some small “tweaking” is usually necessary at delivery to assure the client is comfortable and can propel the best they can. This may be completed at the initial delivery or the client may need further assistance with adjustments after becoming used to the wheelchair and can handle a more advanced wheelchair setup.

Once the wheelchair is properly adjusted, the next step is discussing propulsion technique and method. Boninger et al looked at propulsion technique and found that a semicircular propulsion pattern is generally best to decrease forces and risk of injuries.11 Working with the client to practice this technique is important. Not all clients will be effective with this technique, but knowing that there is a recommended “gold standard” technique may help them consider changing their propulsion and improving it over time.

As a therapist who works with clients who use wheelchairs, assuring those clients receive the correct equipment requires the right evaluation, right wheelchair choice, right adjustment, and right training. If any of these pieces is omitted, outcomes are limited and our clients cannot accomplish all that is possible. RM

Lauren Rosen, PT, MPT, MSMS, ATP/SMS, is a Physical Therapist and Seating and Mobility Specialist at St. Joseph’s Children’s Hospital in Tampa, Fla. She is the Program Coordinator for the Motion Analysis Center, where she also runs a pediatric and adult seating and positioning clinic. She is on the Board of Directors of the Rehabilitation Engineering and Assistive Technology Society of North America. For more information, contact RehabEditor@nullallied360.com.

 

References

1. Arledge S, Armstrong W, Babinec M, et al. The RESNA Wheelchair Service Provision Guide. Approved January 26, 2011.
2. Subbarao JV, Klopfstein J, Turpin R. Prevalence and impact of wrist and shoulder pain in patients with spinal cord injury. J Spinal Cord Med. 1995;18:9-13.
3. Dalyan M, Cardenas D, Gerard B. Upper extremity pain after spinal cord injury. Spinal Cord. 1999;37:191-95.
4. Gellman H, Chandler DR, Petrasek J, Sie I, Adkins R, Walters RL. Carpal tunnel syndrome in paraplegic patients. J Bone Joint Surg Am. 1998;70:517-519.
5. Boninger ML, Dicianno BE, Cooper RA, Towers JD, Koontz AM, Souza AL. Shoulder magnetic resonance imaging abnormalities, wheelchair propulsion and gender. Arch Phys Med Rehabil. 2003;85. 1141-1145.
6. Boninger ML, Cooper RA, Baldwin MA, Shimada SD, Koontz A. Wheelchair pushrim kinetics: body weight and median nerve function. Arch Phys Med Rehabil. 1999;80(8):910-5.
7. Cooper RA, Robertson RN, Lawrence B, et al. Life-cycle analysis of depot versus rehabilitation manual wheelchairs. J Rehabil Res Dev. 1996;33:45-55.
8. Cooper RA, Gonzalez J, Lawrence B, Renschler A, Boninger ML, VanSickle DP. Performance of selected lightweight wheelchairs on ANSI/RESNA tests. American National Standards Institute-Rehabilitation Engineering and Assistive Technology Society of North America. Arch Phys Med Rehabil. 1997;78:1138-44.
9. Fitzgerald SG, Cooper RA, Boninger ML, Rentschler AJ. Comparison of fatigue life for 3 types of manual wheelchairs. Arch Phys Med Rehabil. 2001;82(10):1484-1488.
10. Digiovine C, Rosen L, Berner T, Betz K, Roesler T, Schmeler M. RESNA Position on the Application of Ultralight Wheelchairs. Approved March 27, 2012.
11. Boninger ML, Souza AL, Cooper RA, Fitzgerald SG, Koontz AM, Fay BT. Propulsion patterns and pushrim biomechanics in manual wheelchair propulsion. Arch Phys Med Rehabil. 2002;83:718-23.