On Outcomes and Testing

Because of the potential impact of orthoses and prostheses on the quality of your life, you require information specific to the orthotic and prosthetic needs and wants of individuals with lower limb physical limitations.

Since 1996, I have collaborated with my DynamicBracingSolutions™ Network colleagues to design products and balance training techniques designed to make individuals walk better with high performance graphite orthoses or prostheses. As part of the design process, we also developed computerized measuring technologies to monitor performance by demonstrating the mechanical outcome that is pertinent to walking better.

Our purpose is to inform you about these potentials as you should be aware of the quality and function of your lower limb orthoses or prosthesis through an understanding of what outcome measurements are all about.

Many products can be evaluated and tested individually with resulting statistical outcomes. For example, testing a new toaster or television set will yield outcome data that is statistically relevant for all the toasters and television sets of a specific style and brand.

Testing an orthosis or a prosthesis for functional outcomes however, is somewhat like testing the performance of a new automobile: the outcome will vary according to the training and experience of the driver. Outcome measurements for orthotic and prosthetic must therefore be specific to the device, the individual, and the training. These measurements can then be compared to accepted standards of gait and to other devices.

Jean-Paul Nielsen, The DynamicBracingSolutions™ Network

Performance

Satisfaction with a product or service is not an outcome measurement; it is simply your personal subjective reaction to the performance of a product or service, especially when benchmarked with similar products or services. Performance is the way in which someone or something functions. Performance implies outcomes or results. To bring about satisfactory results or outcome measurements today from the use of a lower limb orthosis (orthopedic brace) or prosthesis (artificial limb) makes more demands of an orthotic or prosthetic clinician.

Yet, many insurance companies, including many managed care companies and Medicare in the United States, do not require outcome measurements for these complex products. Therefore, without knowing what these products should do in any given instance and whether or not they do what they are intended to do, the value is undetermined. Cost becomes a matter of negotiation over the wrong issues.

What is an outcome?

An outcome is a result. But more strongly than a result, it implies finality and may suggest the operation of a cause over a relatively long period. ⁽¹⁾

An outcome is what you pay for. How good the outcome is determines the value of the product and/or service that you require and, ultimately, your satisfaction. This is true of any product or service including an orthosis (brace) or a prosthesis (artificial limb).

You should always inquire and receive outcome information about an orthotic or prosthetic product/service. This should be standard practice when purchasing such a product, whether you are paying for it personally or a third party such as an insurance company is paying for it. Following an initial evaluation, and certainly following a diagnostic fitting, your clinician should be ready to discuss with you what will be the mechanical structural outcome and indicate what should be the functional outcome.

Are outcome measurements possible in lower limb orthotics and prosthetics?

Yes. Outcome is not just a "buzzword". It is sometimes implied that orthotics and prosthetics is a service profession and not a product business. However it is not possible to remove the product from the outcome process. In our collected clinical experience at DynamicBracingSolutions™, we find that a mechanical and functional outcome is possible in almost all cases and that it is possible primarily because of the product.

Most products create an effect; they do something when used as intended. How well they do what it is they are intended to do can usually be measured and compared. It is therefore normal and reasonable to assume that the use of an orthosis (brace) or a prosthesis (artificial limb) should result in a measurable cause and effect relationship.

But, an orthosis or a prosthesis cannot be viewed strictly by itself as a product. As such, it is only a crafted product composed of various materials such as plastic or metal and has a limited value.

An orthosis or a prosthesis can only be viewed when combined with a human body "...to form a mechanical system that obeys mechanical laws and achieves mechanical effects." Smith and Juvinal, Orthotics Etcetera ⁽²⁾

Thus the interaction between the orthosis or prosthesis and the user, is critical. The design and construction of the device as well as fit, alignment, and pressure distribution must relate to structural correction, load (weight) transfer, and to the balance of the trunk, head, and arms, both when standing and when walking.

In other words, the device should at the very least correct and/or prevent deformity. Or, when there is a lower limb loss, it should transfer your body weight to the ground. But it should do more.

It should incorporate design elements and materials that can assist to potentially function better when walking as the correct training is introduced.

Some deformities or physical limitations are so complex that measurable improvements may not be possible and preventing further deformity may be the only goal. These represent a small percentage of all individuals with physical limitations. In most instances, a mechanical outcome is possible.

What kind of mechanical effects or outcomes are possible with a lower limb orthosis or prosthesis?

When combined with a human body with a physical limitation, the use of an orthosis or prosthesis should at least result in the following measurement differences:

1. Measurable joint angulation differences.
2. Measurable translation differences, if applicable.
3. Measurable symmetry ratios such as the stance to swing ratio (the amount of time a limb spends on the ground compared to the amount of time it spends swinging).
4. Measurable stride length and duration comparisons.
5. Measurable rate of walking comparisons.
6. and if applicable, measurable pressure differences.
   

Are these measurable differences important?

Yes. An improvement in those measurements usually will result in an improved gait when using an orthosis or a prosthesis.

The intended result of the use of a lower limb orthosis or prosthesis may be to permit an individual to perform such functions as basic ambulation or transferring. There is, however, a significant difference between basic ambulation and normal walking, both in terms of the functional speed of walking as well as the way one looks when walking. It is relevant to question an orthotic/prosthetic clinician about products and services such as:

How well does the device assist me in performing basic functions?

Does the device assist me to achieve normal walking?
If it does not assist me to achieve normal walking, how close (or off) is it to normal walking? How does it benchmark against the norm?

Normal parameters exist for comparative purposes and a clinician should be able to provide such comparative or outcome information.

One always wants to function as normally as possible. While there may be factors that prevent normal walking, the use of a lower limb orthosis or prosthesis should bring about a positive measurable improvement.

Angulation measurements should improve.

Body symmetry measurements should improve.

The walking speed should improve.

DynamicBracingSolutions™ Outcomes

DynamicBracingSolutions™' clinicians are trained to create a positive outcome from the interaction between an individual with a physical limitation and an orthotic or prosthetic device. As structural alignment is the mechanical foundation for achieving a normal gait, our clinicians assure all our clients a particular structural outcome following a clinical and computerized evaluation. Without an improvement in structural alignment, our goals for functional outcomes are, as a rule, not possible.

How does DynamicBracingSolutions™ bring about positive outcomes?

DynamicBracingSolutions™ basic clinical goal for an individual with a physical limitation affecting the lower limbs is to create a stable symmetrical gait with a walking speed that can be sustained.

A normal body moving in one direction creates a force capable of sustaining movement from one step sequence to the next with relatively little energy.

But when a physical limitation or deformity exists, however, sustaining this motion is often difficult and, sometimes, not possible at all. Sometimes, after every single step you take, the effort necessary to advance forward must begin all over again. It is not at all unusual for fatigue to set in quickly because deformities and abnormal body movements create abnormal forces that detract from the potential net force necessary to sustain normal motion.

DynamicBracingSolutions™ clinicians are trained to identify and inventory all deformity, all abnormal deviations, and all abnormal compensatory movements that can have an effect on the walking speed. With computer assistance, all of these are measured statically and dynamically and an initial baseline report, complete with explanatory graphics and measurements is published and discussed with you and with your physician.

Following an initial diagnostic fitting of an orthosis or a prosthesis, functional goals are discussed and refined. The final design of the product reflects both the input of the clinician and of our database for a specific problem. During this period, balance training is initiated.

Following the fitting of the final orthosis or prosthesis, an outcome report is published that compares the new measurements to the measurements taken at the initial evaluation. The new measurements will also be compared against any old or existing device. This report is necessary to monitor continuing improvement over a six month period.

After six months of use and balance training, a final structural and functional outcome report is printed.

References
¹. American Heritage Dictionary, Houghton, Mifflin, Company, 1992.
². Smith and Juvinal, Mechanics of Orthotics, Orthotics Etcetera, Williams and Wilkins, 1986, p. 21