Tony Wickman, CTPO

It’s been said that America’s favorite color is shiny, and I agree.

Pre-preg is great. Really, it’s a wonderful material—high strength-to-weight ratio, easy to engineer, highly repeatable—but there’s just one problem…it’s ugly! The usual method of using a cloth wick and a breather layer to remove excess resin during the curing process leaves a dull, abrasive finish that just isn’t what we are used to in this industry. Usually, your only options are either to be okay with ugly or do a lot of post-production work to make it pretty. Some people sand the material smooth and spray it with a coating, and some actually laminate over it to achieve a nicer finish. Both of these methods work but require investing a lot of extra time. I was never really satisfied with either of these options, so my team kept working to figure out some way to get a really nice finish on our pre-preg components without having to do any of the crazy, time-consuming things I’ve seen people try to make this stuff acceptable to the consumer. I mean, let’s face it—it can be an amazing material, but if it’s ugly, we can’t sell it. After a lot of trying, we finally got the solution down.

An outer layer of polyethylene is applied over the layup.

The fix actually came from some early problem solving. When we first started to work with this material, everyone said that the water in the plaster molds was a major problem for the pre-preg, so a lot of people suggested using dental plaster, extra hardeners, or all kinds of voodoo fixes that would help maintain the strength of the mold while it was being subjected to the extensive drying cycles. Most of this came from the idea that the experts were using PVA bags as their inner surface! PVA is smooth and easy to apply, but it’s water permeable! If water was the problem, why on earth would we use a permeable barrier? We fixed the problem by using a very thin polyethylene inner layer. It’s cheap, easy to apply, allows us to use the same plaster mold material we use for all our other molds, and no matter how wet the mold is, it never interferes with the pre-preg! One byproduct of this technique was that the inner surfaces of the devices we fabricated were beautiful! Their outsides, however, were not that nice looking. We tried PVA, we tried silicone, and we did have some success, but we just couldn’t get the outside to look like the inside.

The obvious answer was to use a polyethylene layer on the outside as well, but it wasn’t that simple. Pulling an inner layer of polyethylene is easy—you just use a separator (a fabricating hose) to wick the air out—but if we used a fabricating hose between the inner and outer layers, it left a texture on the inside of the outer piece of plastic, which then transferred to the outside of our pre-preg. If we didn’t use a separator, the material cooled in random patterns and wasn’t smooth.

So the trick became pulling a very thin layer of polyethylene over the polyethylene inner layer without using any kind of wicking layer that would leave a pattern on the inside of the outer layer. We tried a few different parting agents until we finally settled on Liquid Wrench® Dry Lubricant with Cerflon. It is designed to go on wet and then dry out, leaving a layer of Cerflon (a combination of PTFE and boron nitride) behind. This effectively stops the layers of plastic from sticking together and still gives a very smooth surface.

The finished layup is shown under vacuum.

At this point, you might be wondering how we made up for the volume of the pre-preg material between the two layers of plastic since we didn’t allow for that in forming the outer layer of plastic. The answer is simple: we didn’t. We just cut the outer layer a few centimeters beyond our intended trim lines, layed up our pre-preg, and then applied the outer layer of plastic over the pre-preg material. By adding a few layers of fabricating hose over the outer layer of plastic and covering that with a PVA bag to act as our vacuum vessel, we could pull an effective amount of vacuum, and as the material ramped up to temperature, it “reformed” to fit the mold.

The process is simple: Modify the mold as standard. Add one layer of fabricating hose and pull a uniform layer of polyethylene over the entire mold. If no liner is to be used, then 1/16 in. is fine; if you plan to use a liner, you can pull a layer consistent with the thickness of liner you will use (1/8 in. liner = 1/8 in. polyethylene, for example). Sand down any seams that may get in the way, spray with the Liquid Wrench dry lubricant, and let it dry. A quick buff of the lubricant, and you’re ready for your next layer of polyethylene. For this layer, 1/16 in. is fine, and feel free to stretch it as thin as you can. Remove the entire outer layer. Trim this outer layer to extend just a few centimeters beyond your desired trim lines and discard the remainder of the second layer.

The finished pre-preg is smooth and shiny, inside and out.

Now, just lay up your pre-preg in the predetermined pattern directly on top of the first layer of plastic and then apply the second layer over that. You still need to be concerned with removing as much excess resin as possible, so apply a few layers of smooth wicking agent to the outside of the entire mold and then apply a PVA bag to the outside of that. Apply vacuum as usual, and the layup will be de-bulked. Use a slightly longer ramping time to ensure that you evacuate as much resin as possible, then give it a short heat cycle to ensure the best curing of the final piece. The result is a component that is strong and attractive, with no postproduction effort required.

Also published in the May 2010 edition of the O&P Edge. © 2010 O&P Edge

Update – August 17, 2010

I created a pre-preg PTB brace, utilizing the techniques outlined above. The orthosis was super lightweight with really good axial loading capabilities.

PTB brace utilizing our pre-preg 'should be patented' process.

Tony Wickman, CTPO

I’ve been thinking for the past decade that the technician’s role has been evolving from an entry-level point of ascension into a viable career. In the past, technicians tried to become practitioners and only remained technicians if something got in the way. However, as technology progresses and consumers become more demanding, our role will ultimately call for more knowledge and competence. In fact, it’s now becoming too difficult for one person to serve as both practitioner and technician. The two roles have become distinct and similarly difficult. Each has its own challenges. In short, they’re separate but equal.

Currently, the highest credential the industry affords a technician is ABC registration, which was developed as an entry-level credential for individuals who had attended a technical-education program. It has blossomed into an all-inclusive credential that is available to any technician with a high school diploma, who has graduated from an accredited technical program or has two years experience in each discipline, and has passed the day-long technician exam. This model served well for many years. Registration was valued because most registered technicians earned more than their non-credentialed counterparts, and it indicated that a technician was serious about his or her work. Registered technicians were seen as more of an asset to their employer and were generally rewarded as such.

In 1997, ABC began to require continuing education for registered technicians in a model that basically mirrored the requirements for other credentialed individuals. This move was lauded by most of us involved in the process because we all wanted the same thing: an increase in the stature of the technician’s role. The end of the first MCE cycle revealed something startling: about one-third of previously credentialed individuals failed to meet the new requirements and therefore lost their registration status. Since that time, the number of individuals seeking credentialing has declined; this attrition continues to this day.

Why are technicians no longer seeking this credential? I have asked this of technicians nationwide over the past year. Most technicians don’t understand the importance of credentialing as a career move or as a protective measure for the industry. The remaining technicians simply don’t care because it doesn’t directly impact their job. In my opinion, both of these points have some merit, but both are ultimately wrong.

Credentialing is a gateway to opportunity. If you aren’t credentialed, you have no voice in the field. No one knows you exist, and subsequently you don’t matter. You can’t join most of the industry’s most prestigious organizations, you don’t get on the mailing lists for continuing education, and you don’t get to help steer the ship. Why be a part of an industry that controls you without the opportunity to help shape the direction it goes?

Though some people do their work just to get by, most of us are in this industry because we care about our customers. We want to help people live as actively as technology will afford, and we want the devices we manufacture to afford patients the maximum possible increase in their quality of life. How can we achieve these goals without credentialing and continuing education?

We can’t just blame technicians. The whole landscape of this industry has changed. Providers are paying less, materials are more expensive, paperwork eats more of our time, and regulatory changes make it more difficult to get the available technology to the people who need it. For a lot of people, the expense of credentialing is just too great in time and money, and the return on investment isn’t there. More and more, the act of credentialing and continuing education is becoming altruistic. Most do it simply because they feel a strong desire to climb whatever mountain is put in front of them. That has to change.

We need to make technical credentialing and continuing education less expensive, and we need to make it mandatory. Several ideas have been put forward to meet these needs. The move to an Internet-based exam has been proposed, and I think it’s a good idea. Initially, I wondered how we’d test hand skills over the Internet. In industries as varied as personal exercise training and massage therapy, though, this has been the norm for years. Current technician testing doesn’t include hand-skills testing anyway; at least, it doesn’t include standards for quality or attractiveness—they’re too subjective. We instead test for all the other information and skills required to ensure minimum competency.

I know, I know—mandating credentialing as a component of accreditation is a real can of worms. But think about it—if credentialing was mandatory for accreditation, it would get done. How many times have you not done good things just because you lacked momentum to do them? If you had to do it, you would, and you would benefit from it. Just think about it—that’s all I’m asking.

I realize these ideas will not appeal to everyone, but I hope they will be provocative and spur some of you to develop better solutions, because there is more to do. If you like these ideas or hate them, tell me so we can consider your point of view. If you don’t speak up now, you may not have another chance. This is a fork in the road, not a dead end—we have to go one way or the other.

Also published in the March 2010 edition of the O&P Edge. © 2010 O&P Edge

Tony Wickman, CTPO

Metal orthoses are simple to fabricate. I once visited a brace shop in Port Au Prince, Haiti, which was staffed entirely by people who were deaf mute. They made crude but very effective orthoses with little more than an anvil, a drill press, and a lot of files. They made their own rivets out of discarded nails, used cold-rolled steel for the bands and bars, and just filed the ends of the bars to create joints. It’s becoming less and less common to see even basic metalworking tools in most facilities these days, so a lot of technicians become frustrated by metal work. Though metal orthoses are simple to fabricate, some specialized tooling is needed to make the job easy and efficient. They also require practice. It’s hard to get really good at something you do twice a year with half the tools you need.

One of the primary reasons metal orthoses are used is that they’re really rugged. Even today, with modern thermoplastics and composites at our disposal, just the phrase “rugged orthosis” conjures images of Mel Gibson in the Mad Max movies wearing his old Pope Klenzack AFO with the joints on backward. This is one Hollywood image that is rooted in reality. These designs have long been favored by hard-working farmers, factory workers, and heavy-equipment operators. However, they can also be made to be quite light. Using lightweight aluminum and thin-gauge bands, you can produce devices whose weight, with the shoe factored in, compares to some thermoplastic designs.

Metal braces also offer a level of torsional rigidity that can’t be matched. When you’re trying to reduce genu varum or genu valgum, that rigidity allows the device to resist medial or lateral loads very well, even when there is a rotational element. If your primary pathological force is in the sagittal plane, such as a knee-flexion contracture or hyperextension, a conventional metal device is a great way to manage those forces. The inherent shape of the mechanical structure is normally a dual parallelogram. This shape allows the device to resist forces in every plane with a very small cross section. That means we get a lot of strength from a fairly small mass, and the patients get a lot of control without a lot of weight.

Metal orthoses usually offer a very small contact surface. This can be a disadvantage in cases with tissue damage or where tissue requires a broad, low-pressure contact force. A lot of people don’t need that, especially in warmer climates! If the patient has good tissue and the forces required for correction can be limited to a small area, then a metal orthosis can work well. Even in cases in which the contact patch has to be increased, this can often be done with a leather lacer. Less contact means less heat build up, less opportunity for impingement, and more comfort.

Metal orthoses are normally attached to a shoe, which presents its own set of pluses and minuses. Frequently, (especially with KAFO patients) the foot may not actually be involved in the pathology. If, for instance, the device is intended simply to correct genu varum, involving the foot could be counter-productive. When a thermoplastic foot cup is used, the patient will lose some ankle motion, inversion/eversion, and proprioception. These are all important mechanisms for normal locomotion. The attachment of the device to a shoe will maintain a lot of these factors as “normal.” Attaching the device to the shoe might limit footwear choices, even when a split stirrup is used, but the use of a plastic foot cup does not imply an unlimited choice of shoe options. Lastly, having a visible stirrup can be perceived as less cosmetically acceptable for some wearers, but for many the increased comfort and function are more than enough to offset this.

Of course, we get to use a lot of different materials in this industry, and just about all of them have a demographic to which they can be appropriately applied. Whether it is the comfort and control of thermoplastics, the low mass and high strength of composites, or the open, rugged designs of conventional metal, there is something for everyone.

Also published in the November 2009 issue of the O&P Edge. © 2009 O&P Edge

Tony Wickman, CTPO

When I started out as an orthotic technician over 25 years ago, I believed you should always flatten the plantar surface of an AFO mold. That’s what I was taught because it was the conventional wisdom of the day. Then I had the opportunity to work with a group of physical therapy students. I felt secure in talking with the students about my techniques, because I thought I was applying the best we had to offer to the science of rehabilitation.

The students toured the lab and remarked that we were doing some amazing stuff, until they saw how we were modifying our molds. One of the students posed a question, “Why do you flatten the bottom of the foot when you modify the mold?” I answered that we were building mechanical devices, and that flat surface was our foundation. Wasn’t it?

After that, I started to question my fundamental beliefs on how to build a quality device. I was fortunate to have spent my first few years as a technician with some visionary orthotists, and what they taught me made sense, but at this point, I started to think we might be overlooking a very important part in the process, the part where modifications are made so that a device will become an extension of the patient. I noticed when we make arch supports, we never flatten the plantar surface. On the contrary, arch supports mirror the plantar surface. So what’s the difference between making an arch support and an AFO? Why would we think an arch support should take advantage of the curvatures of the plantar surface, but the bottom of an AFO or other orthoses should be flat?

Not long after that encounter with the physical therapy student, I had the opportunity to work with another visionary, a physical therapist and author, who was teaching a class on Neuro-Developmental Treatment (NDT) at that same physical therapy school. She had a test subject for the NDT class and needed a volunteer to fabricate an AFO. Naturally, our lab was offered and I worked one on one with her, and she helped me understand the intricacies of the foot: its bones, nerves, tendons and vascular structures, and how each of these components have their own set of needs. After working with her, I was convinced that technicians must see the foot as the foundation of an orthoses, not the floor! I knew I had to learn more about pedorthics, tone inhibition and neuro-developmental techniques if I wanted to create bio-mechanical devices, devices that fit properly, as well as focus on the specific pathology without causing any collateral damage.

This level of knowledge is beyond the standard education for technicians, but if I am modifying a mold, it’s my responsibility to know about physiology, neurology, and pressure mapping. Every patient who needs a brace has a pathology. Seldom are those pathologies purely orthopedic, there are typically underlying vascular or neuropathic disorders as well. There is no orthopedic solution for a neurological problem.

Technicians need to be aware of this when building a device, and practitioners need to be aware of this when taking a cast. If the cast is taken weight bearing, on a flat surface, much of the plantar data disappears. When a cast can be taken on a foam block, semi weight bearing, or even hand manipulated, that cast takes on a whole new level of function. The surfaces of the foot become much more natural and the load pressures can be more accurately distributed. Neurological inputs can be reduced and deep-tissue weight-bearing techniques can be utilized, and the brace can better fit the patient. One of the issues with casting a patient on a flat surface or flattening the bottom of a mold is that the device created from that mold can cause collateral damage, by creating excessive pressure on at risk tissue, or exacerbating existing problems and putting the surrounding tissues at risk.

No matter the casting technique, I can make a device, but it may not function properly, and it will certainly be less comfortable for the patient. I see these issues most frequently with neuropathic (CROW) walkers and pediatric devices. I’ve worked with many practitioners to help them change their casting technique for these devices, and by doing so, they are seeing better results with their patients.

I believe a technician’s role is to understand and interpret the orthotist’s vision for the patient and make that vision a reality. I also believe the practitioner and technician should work together as a team to make a device that will assist the patient in the best manner possible. If I don’t have an understanding of the nerve structures on the foot, then it’s probable that I won’t make a properly functioning device. Orthoses are not “widgets” that come off an assembly line, they are custom-made bio-mechanical devices that help improve the quality of life for the people who use them.

In order to increase the overall caliber of the rehab team, I suggest that you learn as much as you can about pedorthics, tone inhibition, and neuro-developmental technique. The manipulation of the surfaces of the foot is the foundation of a good lower limb orthosis and these specialized disciplines will give you a good foundation upon which to build your skills.

Tony Wickman, CTPO

I discovered that a couple of techs had little stops or V-shaped blocks, but for the most part, these devices were kind of sloppy holding fixtures. I was pretty sure that with a little ingenuity we could do better.

I knew we wanted to hold the molds rigidly, and ideally, to bolt them down. The problems were that (1) each mold is a little different, and (2) we’d have to embed a nut in the mold. Anything with a nut in it would need a holding fixture to keep the nuts flat and square—otherwise, they’d break the mold when we tightened them. And the nut would have to be submerged below the actual surface of the mold so we could flatten the mold’s bottom without hitting the nut.

Basically, we needed an adjustable holding fixture that would allow us to drop the nuts into the wet plaster cast and hold them in the correct alignment. It would have to be easy to make because we’d need a lot of them.

What we came up with was a flat piece of band stock that was 1.5 in. by 14 in. long (long enough to span a bio-foam box), with slots milled down the center for adjusting the spacing of two nuts. We used ¼-20 zinc T-nuts (they’re cheap and really bite into the plaster) with small plastic standoffs through which the bolts could pass to allow us to actually submerge the T-nuts.

How to Do It

Pass a ¼-20 zinc bolt through the metal plate, drop a plastic standoff onto the bolt, then secure the T-nut to the bolt. When you snug the T-nut down, it pinches the standoff and the plate together and holds everything tight (figure 1). Set one nut dead center into the deepest part of the heel and one in the met heads, then snug them down.

Prepare the mold as usual, then pour wet plaster into it. While the plaster slurry is still wet, drop the jig (nut-side down) into it and let it harden (figure 2). Once it hardens, spin out the bolts and use pliers to pull out the standoffs.

Next, flatten the bottom of the mold; you’ll hold on to the nuts with another jig. Take a 24-in.-long piece of ½-in. by 1½-in. aluminum and mill two slots into it. Match these slots to those in the pouring jig exactly so you can line them up. Then mill the holding jig down so you can slide it into the pipe mandrels you use to hold other molds. To give yourself more options, flatten the jig’s sides so the jig can be held in a vice, and drill mounting holes in case you decide to mount it permanently to a bench. Buy some ¼-20 knobs that you can tighten by hand to allow for quick connection of the mold to the jig (figure 3).

This process is fast, simple, and highly effective. With a small investment in time and tooling, you can turn one of the more difficult, time-consuming tasks in your production line into a positive revenue generator that meshes well with the rest of your production, and you have a cool new tool!

This article was originally published in the September 2009 issue of the O&P Edge © 2009 O&P Edge

Tony Wickman, CTPO

Knowing the cost of O&P processes will put the industry on top for the economic rebound.

It feels like the global economic crisis is parked at our front door. The good news is O&P is still a strong industry and when we have been confronted with issues like this before we have emerged stronger, more organized and more efficient than ever.

To ensure that O&P rebounds on top, we have to ask certain questions. How are we going to raise the bar? How are we, as an industry, going to provide our customers with a more accurate, effective and efficient product?

To do this we are going to have to think about what we do every day. We are going to have to be more thoughtful in our approach to process and production. The first step to meet these goals is to develop metrics, or numerical guidelines to ensure that we are always improving upon our processes.

Cost of labor

One of the most important figures you can extrapolate is your labor cost per hour. Simply put, how much do you really pay for each hour of labor that you or your employees work? It is easy to think about how much you pay each employee or how much you take home, as the cost of labor, but in most companies that rate is a fraction of the actual cost of labor. You will need to dig deep into the actual numbers. If you have never done this exercise, or if you have not done it in some time, you may be surprised at best or shocked at worst.

To get to the real number you will have to add up some figures.Take the aforementioned labor rate (the actual hourly wage) then add in the employers portion of Social Security and Medicare, the cost of vacation and sick time actually used, the cost of benefits including insurance, bonuses, continuing education, licensing, workers’ compensation insurance, unemployment insurance and any other perks or benefits derived from the enterprise, for each employee.

I like to annualize these numbers by using the actual cost per year. Once you have the annual total you can divide it by the actual number of hours each person works. This will give you a good approximation of what it actually costs for an hour’s worth of work. This is the number you will use to counterbalance all of the figures we will discuss in the rest of the article.

Labor hours billed

Without understanding all of the numbers, none of them made sense. Then I found a number that could give real power to our technical staff. It is a number I call the labor hours billed. In reality what we are looking for is the actual amount of time each person spends during the day making money.

Now before we get too far into this I should point out that not everyone in your facility is actively involved in making money so this metric is really only effective for technical staff and in some cases clinical staff. It is also important to realize that it is unrealistic to shoot for 100% billable hours from your entire staff. Instead you need to pick a number with which you are comfortable, usually somewhere between 75% and 90%. The actual number is not that critical because what you really want to track is not the number, but the trend.

To develop this number you need to do some homework. In our facility, what we have done is taken the wholesale price for which we sell each of our end products then we back out the material costs. We take what is left over and divide it by our labor cost. What this should leave you with is the labor hours it should take to complete a given task. It is not that important to get to the number to the seventh decimal place, you just want an estimate.

In short, if you have a part that sells for $100 and you have $10 in materials, you have $90 in labor. If your labor cost is $90 per hour then you have to be able to complete this task in 1 hour. If you can do it in 45 minutes – great. If you have already chosen 90% as your target labor hours per day then each of your producers will have to make 7.2 of these units per day. Remember this process starts with an arbitrary assumption so do not become frustrated if you do not meet your goals right away.

Share information

Now here is the really important part and one that most managers overlook. Knowledge is power for everyone. Most people who work for a living, like their job and want to do it as well as they possibly can. If you can give employees an honest metric that they can use to improve the job they do, they will use it to their advantage and step up their game.

Share this number with them every day. It does not have to be a fancy display. A flip chart with the days marked out and the goals indicated will do. Post the number daily so that they know how well or poorly they did the previous day. We go one step further and track it on a second chart that shows the monthly average. If you want to, you can easily put the numbers into a quick spreadsheet and graph it on an ongoing basis.

Now that everyone can see this number, discuss it with your technical staff. Ask questions. What did we do yesterday that caused the number to jump? Why did we work hard all day yesterday only to see terrible numbers today? All of these questions should be presented in the spirit of discovery. This process should be about you helping each other do a better job. If it becomes a method for you to criticize or condemn no one will follow your lead.

This article was originally published in the May 2009 issue of the O&P Business News © 2009 O&P Business News