Stronger, Lighter, Quicker: TCOP Creates More Effective Orthotic and Prosthetic Devices for Patients Worldwide

By Josh Garcia
Wednesday, May 1, 2019

Tillges Certified Orthotic Prosthetic Inc. (TCOP) takes advantage of prepreg carbon fiber materials and 7-axis robotic carver technology at its sister central fabrication facility, Tillges Technologies, to quickly create custom orthotic and prosthetic devices that offer patients more stability, control and comfort.

Since its founding in 1992, TCOP has served patients in need of orthotics and prosthetics while keeping an eye toward innovation. Twenty years later, TCOP’s desire to advance the orthotics and prosthetics industry led to the creation of Tillges Technologies. This central fabrication facility is vital to product development and has allowed TCOP to craft new devices for patients both locally and worldwide.

“Tillges Technologies was born out of our development of the PressureGuardian, a pressure-monitoring system used primarily for diabetic wound care,” says Michael Tillges, CPO, Co-Vice President of TCOP. “Now, we’re building products for other companies and sending them out on a national and international level — to places such as Australia, Europe and Canada.”

Today, TCOP provides services for a number of conditions, including foot drop, multiple sclerosis, spinal cord injury, stroke, Charcot-Marie-Tooth disease, partial-foot amputation, ankle instabilities, vascular conditions, postmastectomy needs and more. TCOP is considered a one-stop shop for all orthotic, prosthetic, vascular and mastectomy needs.

Prepreg and Propulsion

Since the creation of the PressureGuardian, Tillges Technologies has manufactured a steady stream of new products, including its Propulsion line of orthotic and prosthetic devices. Prepreg carbon fiber, rather than conventional plastic materials, is used to make the devices.

“Typically, lower-limb orthotic and prosthetic devices for partial-foot amputees are made of plastics,” Michael Tillges says. “However, composites such as prepreg carbon fiber are becoming more popular for bracing purposes because they allow for a more holistic approach to treating lower-limb deficiencies.”

Prepreg carbon fiber is a light, durable and dynamic material made from a combination of carbon fiber and epoxy resin. Outside of orthotic and prosthetic devices, it has seen applications in both the military and race car industries.

“We’ve been offering prepreg carbon fiber bracing for more than a decade, but we saw a big need for custom prepreg knee-ankle-foot orthoses among our patients,” Michael Tillges says. “That’s why we developed our own prepreg in house — we weren’t happy with what other manufacturers were offering.”

The name prepreg signifies that the manufacturer has preimpregnated the carbon fiber material with the correct amount of epoxy resin before it arrives at TCOP.

“We source the prepreg material in rolls and control how much resin per carbon strand is applied to each roll,” says Thomas Tillges, Operations Manager at TCOP. “With the right resin-to-carbon fiber ratio, we can maximize the brace’s structural properties while reducing excess weight and bulk.”

Once the resin bonds with the carbon fiber material, the fibers become fixed in a geometric shape. This semirigid structure causes the material to become stronger than many metals while retaining a dynamic quality. The material can absorb and release energy at a nearly 1-1 ratio when force is applied to it, which makes it perfect for the construction of ankle-foot orthoses (AFOs) and knee-ankle-foot orthoses (KAFOs).

“Compared to standard plastic AFOs and KAFOs, composite materials like prepreg carbon fiber allow for reactive motion, such as plantar flexion in the loading, stability and control of the tibial progression,” says Steve Tillges, CPO, Co-Vice President of TCOP. “They restore propulsion to a patient’s gait, which is why Propulsion is the name of our prepreg line.”

Patients also benefit from the lighter weight of prepreg carbon fiber, which makes the Propulsion line of devices more comfortable to wear and use compared with plastic AFOs and KAFOs.

“Many physicians dislike ordering KAFOs because of how bulky they are when they’re made of plastic,” Steve Tillges says. “The materials we use and the way we design our KAFOs means the devices are streamlined and can fit easily underneath pants and other clothing, which preserves both comfort and cosmetic appearance.”

Prepreg carbon fiber devices are fully custom braces. Every device is tailored to a patient’s height, weight and activity level and can be personalized with different sleeves and fabrics to match patients’ lifestyles and aesthetic preferences.

“The sheets of prepreg carbon fiber come with a wide array of fiber orientations,” Thomas Tillges says. “We apply these sheets layer by layer to add strength, torsion and flex where needed, which allows us to really hone in the design of the brace based on the mechanical properties of a patient’s gait.”

The partial-foot prostheses within the Propulsion line have also filled a lingering gap for both patients and referring providers regarding partial-foot amputations.

“One area where a lot of physicians and physical therapists struggle is knowing what type of prosthesis or brace to order for a patient with a foot amputation,” Steve Tillges says. “Partial-foot amputees are a very underprescribed population who can really benefit from Propulsion foot prostheses. We’ve seen patients who have used walkers for years walk out of here without needing a cane after they received their prosthesis.”

The Propulsion line’s elongated toe lever reduces pressure at the distal end of residual limbs and provides extra balance and stability for people who have undergone all levels of partial-foot amputations, from toe amputations to the Chopart level.

“When the foot is partially amputated, patients don’t have a lever arm to propel them into their next step,” Steve Tillges says. “Our longer toe lever allows patients to take more even and natural strides, which expends less energy and allows them to live a more efficient and active lifestyle.”

Precision and Productivity

Unlike other orthotic and prosthetic device providers that might have to wait weeks for delivery of a custom device, TCOP can examine a patient and have a device ready for them in a fraction of the time.

“Typically, we can evaluate patients and fit them with a carbon fiber Propulsion brace or prosthesis the next day,” Michael Tillges says. “We’re really focused on serving our local patient population by fabricating devices quickly and getting them to patients faster than most companies can. For instance, we have been offering same day prosthetic casting and fitting appointments while utilizing our Symphonie casting system.”

Part of this quick turnaround is thanks to the 7-axis robotic carver installed at TCOP/Tillges Technologies.

“We work with an engineering group from Italy that provides us with fabrication solutions,” Thomas Tillges says. “We collaborated with the group for nine months on the 7-axis robotic carver unit before we brought it in-house.”

The 7-axis robotic carver was originally designed for the automotive, aerospace, marble and stone industries. While robotic carvers in general have found applications in the orthotics and prosthetics space, it’s rare to find a robotic carver with this many axes at a central fabrication facility like Tillges Technologies.

“If a facility isn’t creating orthotic and prosthetic devices by hand, then it’s using some type of carver,” Michael Tillges says. “Our 7-axis robotic carver is one of only three in the country that are being used in the orthotic and prosthetic field.”

A robotic carver is essentially a robotic arm with a carving tool, and every axis it has allows it to move in a different direction. Additional axes mean additional degrees of freedom and a wider range of motion, allowing for more efficiency and complexity during manufacture of prosthetic and orthotic devices.

For example, a robotic carver with one axis would only be able to move along one directional plane, such as left and right along the x-axis. A 2-axis robotic carver can move up and down along the y-axis in addition to left and right along the x-axis, while a 3-axis robotic carver can move backward and forward along the z-axis in addition to utilizing the x- and y-axes.

The 7-axis robotic carver is able to speed production times due to its large number of axes and integration with computer-aided design/computer-aided manufacturing (CAD/CAM) software.

“CAD/CAM allows us to scan a patient’s limb or torso instead of using a plaster cast,” Thomas Tillges says. “We can modify the scan on the computer, which improves our manufacturing efficiency by upward of 60 percent.”

In addition, the CAD/CAM integration allows TCOP and Tillges Technologies to automate and standardize a large part of the production process, which improves quality control and further decreases the time it takes to make a device.

“CAD/CAM offers us a level of standardization that helps separate us from other orthotic and prosthetic manufacturers,” Thomas Tillges says. “We are always looking for ways to streamline production, improve quality and reduce turnaround time.”

More Than Technology

Along with having access to literal cutting-edge technology at Tillges Technologies, TCOP does more than simply fit patients for orthotic and prosthetic devices. TCOP’s team of certified clinicians, assistants, fitters and other staff members collaborates closely with physicians and therapists to meet the needs of patients comprehensively.

“We try to identify other needs that the patient might have in addition to the deficiency that the device will address,” Michael Tillges says. “We also refer patients back to physicians if we see something that could be treated without a device.”

In some cases, TCOP helps educate patients and physicians to address misconceptions or concerns about orthotic and prosthetic devices.

“Some patients don’t necessarily need to wear a brace all day long,” Steve Tillges says. “They might start the day without wearing the brace, but around lunchtime, they may need an AFO to get them through the afternoon and evening.”

TCOP also remains part of patients’ care teams after they have received their orthosis or prosthesis. By following up with patients regularly, TCOP is able to refer them back to physicians or physical and occupational therapists for treatment or rehabilitation when necessary.

To learn more about how TCOP uses modern technology to fabricate advanced orthotic and prosthetic devices, visit