Clinically Speaking

Open CRT for ALS: A Demonstration

Whether you are a clinician, manufacturer or supplier, the future of complex rehab will ultimately depend on our ability to demonstrate that complex rehab technology (CRT) makes a difference. Simply put, it’s about getting successful outcomes.

In my June column, I wrote that successful outcomes require accurate understanding of the person, their problems, products and effective configurations. While each area of expertise tends to be associated with the clinician, manufacturer or supplier, we cannot simply “stay in our lanes” and assume we will get the outcome we want. Effective solutions require us to stay actively engaged, validate our assumptions, and critically analyze the problem from as many perspectives as possible.

Every day, clinicians and suppliers do just that for clients who need CRT. They accrue “practice-based evidence” every time they critically assess how well a given product, provided in a specific configuration, met the needs of its intended user. What most of us don’t do often enough is share that information with others.

Open Complex Rehab applies “open innovation” and “open development” to CRT. It is based on the premise that sharing practice-based evidence is necessary to improve the effectiveness of CRT for specific populations. I’ll demonstrate how Open CRT can benefit users with amyotrophic lateral sclerosis (ALS).

How ALS Challenges CRT Provision

ALS is a progressive neurodegenerative disorder affecting motor neurons in the motor cortex, brainstem and spinal cord. The diagnosis of ALS implies evidence of degeneration in three of four neurological regions (bulbar, cervical, thoracic and lumbosacral). Weakness usually develops in an extremity or in bulbar muscles that control oral motor function, and spreads to other regions. We won’t know for certain what the next region will be, but eventually no region will remain untouched.

Some individuals have “functional variants” of ALS characterized by very distinct patterns of weakness. Perhaps the most challenging of these variants for seating/wheeled mobility professionals is “flail arm syndrome.” These individuals will lose function in their upper extremities, but retain fairly good function elsewhere. Approximately 10-15 percent of the veterans I see have this functional variant. Since they are usually unable to use a conventional joystick, they require complex configurations capable of taking advantage of function they have elsewhere.

Regardless of the region of onset or functional variant, there eventually is extensive loss of motor neurons in all regions. In time, most individuals will lose the ability to control the muscles responsible for movement, breathing, swallowing and talking. The result is extensive paralysis. Those who don’t die due to secondary complications will become “locked in.”

We do know that progression of weakness in a given individual will be fairly linear, but the rate of progression among individuals varies significantly. Those who have rapid onset of symptoms tend to progress rapidly; those with more insidious onset tend to live longer. This creates a significant variation in life expectancy. In the majority of cases, death from respiratory complications will occur in three to five years, but some individuals die within months, while others live 10 years or longer.

ALS poses challenges because we do not know the next symptom or how quickly it will appear. We know we will need at some point to address changes in function, but we will not know what changes we need to make. We know some individuals will use their chairs for years, while others will die before they receive a power chair that needs to be ordered. They may benefit from an existing power chair, but reconfiguring a previously used chair so it effectively meets the needs of a new user can be labor intensive if it was specifically configured to meet the needs of its previous user using our conventional “snowflake” approach.

While we don’t know exactly what is in store for a given user, we can utilize practice-based evidence to identify predictable issues and incorporate solutions into the configuration of an ALS power chair so many of these issues may be addressed before they are even identified as problems.

Solutions that Anticipate Future Needs

Many predictable manifestations of ALS that we can address through a power chair’s configuration are directly related to the influence of gravity. As such, we should account for gravity in every context in which an ALS power chair is likely to be used.

Movements that can appear to be effortless in one plane may become quite difficult in another. Consequently, we need to know about the user’s strength and active range of motion when they are sitting upright and when they are tilted. Eventually, the weight of the affected body part will exceed the muscle’s capacity to overcome the force of gravity in a given plane.

ALS power chairs should be configured to be operated by a user who has 3/5 strength (full range of motion against gravity, but unable to tolerate resistance). The amount of anti-gravity movement to operate the chair should be minimized, and we should provide a base of proximal support where antigravity movements take place. Since weakened muscles will be very susceptible to fatigue, the need to sustain efforts should also be minimized. Demonstrating CRT component positioningHere’s a “low, level and inline” joystick configuration (right):
(a) Joystick inline and roughly level to the surface of the arm pad with a neutral wrist and forearm.
(b) Proximal stability with even distribution of pressure along length of arm pad.
(c) Armrest parallel to seat rail at back angle needed for breathing and stability.
(d) Elbow stop only makes contact when tilted.
(e) Armrest height provides glenohumeral support without restricting elbow movement.

Gravity also has a detrimental effect on posture during upright sitting. Progressive postural rounding and a forward migration of the head are inevitable. The further the head moves away from the body, the greater the rounding becomes, and the more severe the implications will be for the user’s quality of life.

Here, we need to be more proactive in our approach. Users with ALS should be encouraged to frequently tilt their seating systems in the early stages of the disease to counter the adverse effects of gravity. Tilting may not prevent postural rounding or a forward migration of the head, but it may be the most effective tool we give them to mitigate the rate of progression.

We also need to recognize that as axial weakness causes head and trunk control to deteriorate, these individuals will lose the ability to “sit perfectly.” Excessive posterior pelvic tilt becomes the norm, not the exception, and they will sit slightly differently every time they use their chair.

When they tilt, their entire body will migrate toward the back of the seating system, the position of their head relative to the body will change, and their distance away from the headrest will change by inches. We need to recognize these changes when we position joysticks, provide remote switch access or configure systems for head-controlled driving.

Practice-based evidence can also be used to develop modular assemblies or more specialized configurations and to allow us to address many less frequent, but very challenging issues we can expect to encounter in a subset of users. The ability to easily implement technology and replicate solutions in the future can recoup the investment of time and effort needed to develop them.

Lastly, there are times when practice-based evidence makes it evident that innovation is necessary to meet unmet needs.

CRT HeadrestHeadrests that provide comfort, headrests that provide positioning, and head arrays are widely considered to be three distinctly different products. Many individuals would benefit from characteristics of all three.

ALS affects function in every part of the body, yet today’s alternative driving system configurations are designed to be operated using just one body part. Versatile systems that take advantage of function wherever it exists are needed.

Why haven’t manufacturers developed products to address these unmet needs? Maybe we haven’t shared practice-based evidence to identify these needs and propose innovative solutions. I’ll have specific examples in my next column.

Editor’s Note: Steve Mitchell works at the Cleveland VA Medical Center. His opinions do not represent official policy or positions of the Department of Veterans Affairs.

This article originally appeared in the August 2016 issue of Mobility Management.

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