How Finding the Right Prosthetist Made All the Difference to One Above-the-Elbow Amputee

One of the most educational things for us at is to talk to the end-users of bionic devices.

We talk to people who have had great success with those devices because we gain insight into what made them successful.

We talk to people who are disappointed with their bionic limbs so that we can help others avoid the same fate.

And along the way, we’re building a list of prosthetists who always strive to achieve a successful outcome so that we know where to send people when they ask for advice.

This story is about an above-the-elbow amputee who knew only disappointment for her first 13 years as a bionic arm user. She was greatly frustrated and even disillusioned. But she just happened to live near one of only a handful of prosthetists that we have on our recommended list for upper-limb bionics. What happened next is an incredibly important lesson for anyone who is similarly frustrated with their solution and on the verge of giving up.

Meet Tabitha McKinney

Tabitha contacted us in May of 2021. She had been an above-the-elbow amputee (two inches above the elbow) since 2008. Her first bionic prosthesis included an electronic elbow called the Utah Arm, which had been around in one form or another for nearly 40 years. Her version — the Utah Arm 3+ — had just been released.

Tabitha Photo

In Tabitha’s case, the solution was not a good one primarily due to socket problems. It took her 15 minutes just to don her prosthesis. It never worked very well for her so she didn’t use it much.

After losing some weight in 2011, Tabitha got her socket and harness refitted. But with only four days of occupational therapy, the outcome was no better. When her existing device gave out, her prosthetist tried to fit her for a new device, but, after testing, he concluded that her “nerves were dead” and that she lacked the ability to control a myoelectric device.

That wrong conclusion led to her going 8 years without a prosthesis. During that time, she took college courses to become a substitute teacher. When she was ready to apply for work, she wanted to get a new prosthesis so she went to a different prosthetist. After testing, she was told that her nerves were fine but that she lacked the necessary insurance coverage to get the prosthesis that she needed.

Still persistent, she went back to her original prosthetist and did manage to get approved for a new device but the outcome was no better. Despite what Tabitha called a “great fit” at the prosthetist’s office, only small changes in how she donned the prosthesis meant it wouldn’t detect her myoelectric signals and became useless. Changes to her stump size, due mostly to temperature fluctuations, also caused the socket to slip off, often within an hour.

Here is a side view of that setup:

Tabitha Old Prosthesis Side View

And here is a short video showing some of the difficulties that she was experiencing. Keep in mind as you watch this that Tabitha was an experienced, albeit dissatisfied, myoelectric user:

To make matters worse, without an effective prosthesis, overuse of her good hand led to a repetitive-use injury that required surgery. Tabitha’s dream of returning to work was in serious jeopardy. By the time she reached out to us, she was at her low point in what had been a 13-year ordeal.

Meet Tony Gutierrez, Certified Prosthetist and National Clinical Specialist

Back in early 2021, we launched our Clinical Insights Program. We thought, hey, we get lots of information from bionic manufacturers and bionic device users, so let’s get some input from qualified medical personnel to round out our sources of information. To make it easy for participants, we allowed them to essentially publish their comments on any of our articles with minimal effort. As with everything we do, the goal was simply to help educate patients in accordance with our belief that an informed patient is an empowered patient.

Tony Gutierrez was one of the few prosthetists that joined that initiative. And of the prosthetists that did join, he was by far the most prolific, offering his balanced views of both the pros and cons of many bionic devices.

Clinical Insights was ultimately a failure because we couldn’t get enough prosthetists to sign up. This caused us to swing more toward patient-driven stories like this one. But we didn’t forget Tony. We truly appreciate his knowledge, passion, and candor, and quite frankly we wished we had found 100 more like him.

Tony Gutierrez Profile Picture

Naturally, then, when we found out that Tabitha lived near one of Tony’s clinics, we suggested that she contact him. At the same time, we were candid with Tony. We told him that Tabitha had lived through 13 years of disappointment and, to some extent, neglect, and that she might be a challenging patient. He was completely undaunted.

A Quick Look at the Outcome

Tabitha and Tony finally met for the first time in June 2021. As is often the case with bionic limbs, it took time for them to work through the initial assessments and especially the insurance application. But by December, Tabitha was in a brand new prosthesis, which you can see in this picture:

Tabitha New Prosthesis Side View

We are by no means experts in shoulder harnesses, but there is something to be said about quality workmanship in every walk of life, isn’t there?

More important, here is a video of Tabitha performing some basic functions with her new prosthesis. As you watch this, keep in mind that this is only her second day with her new device, which uses a completely different control system, and she’s a bit nervous. Nonetheless, she is already far more proficient with this setup than she was with her prior solution:

Frankly, we were amazed to see her already exhibiting such great control over a device that she had just started using. We were even more amazed to see the change in her attitude, going from someone who had in many ways lost hope that she’d ever find a successful prosthesis to someone who seemed genuinely excited about her new solution.

Naturally, we wanted to know why there was such a difference in outcomes. What were the technical problems that made Tabitha’s situation so challenging, and what were the solutions to those problems?

As always, Tony was completely open with us. The following section is entirely in his words.

The Technical Factors Behind Tabitha’s New Bionic Arm Solution

Socket Design

“Tabitha’s previous socket design used a traditional trans-humeral approach. This is general global compression of the limb tissue with large stabilization trim lines across the chest and back. This results in a lack of control of the humerus during limb motion. Why is this important? A lack of control equates to a lack of translation from the skeletal motion to prosthetic motion. This results in loss of range of motion in both flexion (inward motion) and abduction (outward motion) of the humerus. With this socket design, Tabitha was only able to achieve 20 degrees of shoulder flexion and 45 degrees of shoulder abduction. If she attempted more than this, it would cause her socket to shift, which resulted in a loss of myoelectric signal detection and thus a loss of control over her prosthesis. For those who like technical terms, this design is similar to the ischial containment socket system.

“For the new socket design, I used a Biodesigns High Fidelity skeletal capture system. This provides targeted compression around the humerus.”

Simulated Skeletal Capture with HiFi

“This technique has been shown to significantly improve the translation of humeral motion to prosthetic motion. By better controlling the humerus, I was able to lower the chest and shoulder trim lines to increase the range of motion. This allowed Tabitha to successfully obtain about 45 degrees of shoulder flexion and 80 degrees of should abduction.”


“Skin suction was utilized for both solutions. This is the gold standard for limb control as well as electrode contact. As an auxiliary suspension, her previous prosthesis used a chest strap and shoulder saddle suspension. This was utilized with dacron straps (rigid strapping) and foam padding.

“I utilized a shoulder rotator cuff brace that I get from Amazon. This has flexible strapping and nice cosmetic finishing. I am able to use this suspension because of the greater control afforded by the Biodesigns HiFi system.”

Control Scheme

“Tabitha’s previous control scheme was a two-electrode system with a linear transducer. The electrodes on the biceps and triceps group controlled hand function. The linear transducer controlled elbow flexion and extension. The linear transducer was attached to the rigid harness system. This is an electrode that is controlled by the harness similar to a body-powered control.

“Shoulder flexion resulted in electrode activation. By flexing the shoulder, the electrode was activated and the elbow would flex, then a quick activation of the electrode would extend the elbow until the shoulder was flexed again to set the elbow position. After the utilization of the linear transducer, she would often begin to lose the suspension of her prosthesis.

“Her new control system is a coapt signal processing system. This system utilizes 8 pairs of electrodes arranged all over the limb. The goal of this control system is to read all of the muscular activity in the limb and directly correlate it to the desired motion. The system allows the user to repeatedly re-program these readings or add layers of data to an existing program.”

Coapt Gen2 Pattern Recognition Signals
Coapt Gen2 Pattern Recognition Signals

“This is beneficial mainly because inconsistent donning can and does take place, resulting in inconsistent electrode placement. When Tabitha uses her arm in any position beyond resting position, she is activating muscles to move the arm, which creates muscle signals. With a traditional myoelectric system, this muscle activity can only be filtered by increasing thresholds to detect the desired activation of the prosthesis. It is, in effect, a one-trick pony.

“With the new Coapt system, users can train their systems to use different activation patterns for different arm positions. This ensures proper myoelectric control for a much wider range of motion.”

Tony’s Explanation to the Insurance Company

In order to assist other patients in need of similar solutions, Tony has graciously agreed to share with us how he documented the medical necessity of the HiFi socket design and the Coapt pattern recognition compared to Tabitha’s current traditional system. We hope this helps anyone out there in similar situation who is struggling to obtain insurance approval. Here is the description that Tony put in the application:

“Tabitha McKinney is a 43-year-old female with a left trans-humeral amputation. Her traumatic amputation was a result of a motor vehicle accident that occurred over 12 years ago. Since her amputation, she has utilized a full myoelectric prosthesis with a powered elbow and hand. She has always struggled with traditional control of her prosthetic limb due to her short limb length. This has complicated her independent use of the prosthesis. She currently utilizes a linear transducer to control elbow flexion and extension, and a myoelectric site to control hand open and close, as well as switching to other available hand grips. She has not had success gaining full integration of the prosthesis into daily use.

“Tabitha currently lives at home with her husband and is looking to return to work full time. She has daily complications and can no longer independently do the things he used to do such as cooking, cleaning, buying groceries, getting dressed, and doing laundry.  She has debilitating levels of pain in her sound limb due to overuse.

“In the past year, since receiving her current prosthesis, the fit and function have never been appropriate. Her prosthesis fit is no longer optimal. After 10-20 minutes of use the prosthesis slides off her limb and she loses suction suspension. Her soft tissue has low muscle tone and the socket design is not supportive enough to stabilize her tissue around her humerus to ensure proper suspension and limb control. When she moves her arm to control the prosthesis, it will sometimes completely slide off. Her suspension harness and shoulder saddle are properly designed and have adequate tightness, but they are unable to support the socket system for her. Operation of the linear transducer for the elbow for her is also causing back and shoulder pain as it requires a violent movement to induce elbow extension.

“Tabitha is very motivated to utilize a trans-humeral prosthesis in order to regain her independence and resume her normal routine.  She would like to return to work and significantly reduce her sound hand, wrist, elbow, shoulder, neck, and back pain.

“Alternative socket design necessity:

“Tabitha has had consistent fit issues over the past 12 years due to poor fitting sockets that have limited her use and adaptation of her prosthesis. She will benefit from a humeral lock modification socket system, which will result in increased skeletal capture and control. Tabitha will enjoy many benefits from this including greater energy efficiency and less fatigue, increased comfort, greater range of motion, improved rotational control, increased and faster prosthesis and component responsiveness, and much greater stability and safety in prosthesis use. This will give Tabitha the ability to wear her prosthesis for longer each day because of the increased comfort, performance, and energy savings. This will be an important factor for her returning to her prior level of function.

“Benefits of Pattern recognition control:

“Tabitha’s prosthetic use history has limited her independence due to lack of control and poor fit. Pattern recognition control offers the ability to control multiple movements in a seamless manner without switching. Pattern recognition prosthetic control can help Tabitha utilize her prosthesis more naturally, giving intuitive control over her terminal devices. Pattern recognition usage is shown in multiple studies to provide users with a more intuitive way to select and use the various grips available to them.

“Tabitha was trialed in a HiFi (Humeral lock system) with pattern recognition control. She was able to successfully use this system to control the prosthesis without the prosthesis falling off of her limb. Due to her complex case, this is the only option for her to be a fully successful prosthetic user at this time. This design will assist Tabitha in completing everyday tasks such as shaking hands, holding a broom, and using utensils.  It also will assist her in completing more complex tasks for work and ADL.”

Tony then went on to include the technical factors described earlier.

Our Q & A Session with Tony

Q. Tabitha experienced a great deal of disappointment and frustration for 12 to13 years before we introduced her to you. Yet, you seemed to have resolved everything in less than six months, with most of that likely waiting for approvals. How were you able to succeed when multiple attempts before you failed?

I know that this is going to sound over-simplified, but a good solution starts with listening — truly listening — to a patient’s challenges, wants, needs, goals, and expectations. There are technical elements to all of this, of course, but all the parameters are set by understanding the patient. Only then can you apply your technical skills.

Even when you do this, sometimes compromises have to be made to balance function, weight, cosmetic appeal, and usability. That’s not an easy conversation to have with someone because I sometimes feel terrible explaining that this is the best tech we can provide. But that communication has to occur, too, because it’s the only way that you can truly form a team with a patient, i.e. to understand what that person wants and for them to understand what’s available so that you can choose the best possible solution together.

As for the technical part of a solution, there are no shortcuts. As with every other profession, you have to do your homework.

Q. This is the second time that we’ve interacted with you where a patient previously received conflicting information about what is or isn’t covered by insurance. And we know from our participation in online forums that this occurs frequently. What is causing this confusion?

Understanding payer sources policies is tough work. The key is to understand what their coverage criteria are and if your patient is a candidate based on these criteria. Additionally, the key concept here is understanding the medical technology of the device you are prescribing and how it applies to your patient’s unmet medical needs.

These are the summary of the key principles I documented on the medical necessity of coapt pattern recognition and HiFi socket design for Tabitha compared to her previous system.

As I said, you have to do your homework.

Q. Speaking of doing your homework or, should we say, due diligence, we often tell people that contact us that properly fitting a bionic arm or hand requires a lot of knowledge, and that right now, when the total quantity of these devices is still relatively small for the population, there aren’t really a lot of prosthetists with the expertise to do it properly. Do you agree with this statement and, if so, what would you do as a patient to try to identify a prosthetist who truly has that knowlege?

I have a two-pronged answer to this question: 

As for devices — most of the devices out there operate on the same principles. You have standard myoelectric or pattern recognition control available. You have elbows that flex or extend with some power assist. And you have hands/hooks that either open/close or have a multi-grip option. Across all manufacturers they are very similar in function.

Where the difference comes in is in two areas: Prosthetic socket design and the Prosthetist/Rehab team teaching device utilization. 

Up until a few years ago I was a terrible upper limb prosthetist and I still do not think I am that good, but I am willing to learn and try new techniques and talk to everyone to learn how to become better. I have a motto in my clinical care that I have already learned all of the wrong ways to do things, and this is my current best approach. Experience is key, but not the most important factor. I urge all patients to find a prosthetist who is going to partner with them in their care and help them set goals and work towards them. These are the best prosthetists that you can work with

Our Q & A Session with Tabitha

Q. Tabitha, from our standpoint, you seemed to have had great difficulty with your various prostheses over a very long time — 13 years! At different points, you were told that your nerves were dead and that you didn’t have the necessary insurance to get the solution that you needed. How did you fight through all that, and what advice would you give anyone else out there who may be at a low point in their prosthetic journey and about to give up?


Q. We have our own belief about what makes a great prosthetist. But since you’ve experienced a few, what do you think it is about Tony that allowed him to help you? Put another way, if you were talking to an amputee just starting out, what advice would you give that person about finding the right prosthetist?


Q. Finally, Tabitha, it seems to us that for a long time your voice wasn’t properly heard re: the difficulties that you were experiencing. We want to make sure it is heard. Is there anything else that you want to say about your journey to this point?


Tony’s Contact Information

Before we get to Tony’s contact information, we’d like to address an issue that we know will be raised by some.

This is not some kind of crafty infomercial. As a strictly volunteer group, does not accept any form of payment from anyone in the bionics industry including any manufacturers, distributors, resellers, insurance companies, clinics, prosthetists, etc. Ours is a 100 % patient-centric, philanthropic mission.

As part of that mission, we try to make potential end-users aware of all bionic devices, background technologies, and research that might affect their choices now and in the future. More recently, we’ve begun covering more patient stories, both good and bad, so that patients can learn from each other, which is the same motivation for our fledgling User Satisfaction Surveys/Reports.

When we happen upon a good prosthetist, which means someone who has proven his/her knowledge and dedication to excellent patient care, we’ve decided to publish that information, too. We do this on a general level through our Clinic Locator. If you visit that page and run a country-wide search (Location = Chicago, Search Radius = 10,000 km), you will see that we list only 11 clinics out of thousands in the U.S. Why only 11? Because they are the only ones that we know for certain, i.e. based on trusted sources and/or our experience referring patients to them, that will provide exceptional care.

All of which brings us back to Tony. He not only works at 2 of those 11 clinics. He’s currently our #1 most trusted prosthetist in the country. Here is his contact information:

Tony Gutierrez CP/LP
Bionic Prosthetics & Orthotics

Munster Office 
759 45th Ave Suite 102 Munster, IN 46321
P: 219.803.0464
F: 219.228.8347

Lafayette Office
5 Executive Drive, Suite D-2
Lafayette, IN 47905
P: 765.838.8222
F: 317.252.0867 

Tollfree: 1-8555-BIONIC