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DorsiFLEX: Physical Therapy Device for the Treatment and Prevention of Plantar Fasciitis, and More

Jim Cooper, a world-class runner during the 1980s and early 1990s, developed bilateral plantar fasciitis late in his running career. He sought help from a physical therapist, he says, and was given stretching exercises to do—wall leans, heel drops, and pulling on his toes with a towel—none of which seemed to help.

“I started looking at the position of my foot when it hurt the worst,” he says. “And I noticed that my toes were inclined upwards and on a different plane than the arch of my foot.” Armed with this observation, he started stretching his feet with his toes turned upward, and his plantar fasciitis started clearing up almost immediately, he says. After not finding a suitable product on the market that could help with this stretching exercise, Cooper applied his mechanical engineering degree to develop a device to incline the toes upward; he received a patent for that device, which he called the Footflex, in 1992.

The original Footflex was made of wood. It had 3 angles in the strict sagittal plane. While that original device is no longer commercially available, it led to a lasting friendship and, 20 years later, to a collaboration on subsequent versions of that first device with customer Steve Sims. Sims was also a distance runner as well as the former massage therapist for the University of North Carolina women’s soccer team and Duke University’s track and cross-country teams. The two bonded over their love of running and mutual loathing of plantar fasciitis, Cooper says.

In August of 2012, the two men got together to discuss design improvements to the Footflex and developed a new prototype. They were joined by Cameron Bell, a Duke engineering graduate and former distance runner for Duke. “I was told by a number of medical professionals that while the original product was good, it would be much better if it could function in the manner in which the foot functions…,” Cooper says. With this guidance, their “goal was to develop an innovative product to employ the Windlass Mechanism of Biomechanics that can variably and selectively position the foot in a neutral position, everted position, or inverted position while performing traditional foot, ankle, and lower-leg stretching and strengthening exercises.” They received a patent, for what is now known as the DorsiFLEX, on June 14, 2016, and the trademark “dorsiflex” on May 16, 2017.

The current model is made of a cast aluminum base with machined aluminum outside “fingers” which are anodized black in color. The “inner fingers” are 3D molded glass-filled nylon. There is a rubber non-slip surface for the foot on the base. The positioning of the vertical and/or lateral angle is adjustable via indexed holes. The patented design of the fingers allows placement of the forefoot both vertically and laterally, simultaneously.  As stated in the patent, “The fingers are adjustable relative to the base about a first axis to a variety of different angular orientations in the first plane. The fingers are also able to be adjusted at different angular positions relative to one another to provide for additional stretching of the foot in one or more additional planes.” The stretch is controlled using bodyweight. Multiple ranges of motion make the DorsiFLEX adaptable for most any foot condition and rehabilitation starting point and allows for personalized approaches to injury recovery. “The DorsiFLEX works very well for plantar fasciitis rehabilitation and prevention when the primary cause is lost ankle range of motion due to muscle tightness or muscle weakness,” Cooper says. “We have also learned the DorsiFLEX has an application for helping people with Achilles tendon problems, turf toe, and hallux rigidus problems.”

While no clinical studies have been conducted on the device, “in an effort to ensure we develop a viable product and not a gimmick, we have constantly sought healthcare and clinical input in the development, design, and manufacture of the DorsiFLEX,” Cooper says. And so far, no one has told them they are wasting their time. Additionally, feedback from consumers and healthcare professionals has been positive, he says, with most people experiencing pain reduction in 4 weeks or less and significant to total pain reduction in 8 weeks or less. “Reports back from users are that the DorsiFLEX does what is promised, provides a targeted and amplified stretch of all the muscles in the lower leg and foot causing the problem,” something that cannot be done with a slant board or heel drops on stairs, Cooper says. “It is multifunctional when compared to other products due to variability and adjustments…and can be used to perform eccentric exercises while also doing static work.”

Other differentiating features from products available on the market (to the best of the team’s knowledge) includes the ability to isolate the medial longitudinal arch leading to the big toe and isolate the bands of the plantar fascia and muscles of the foot leading to the smaller toes. Further, because the angles are indexed and measurable, the foot position is reproducible. Users can repeat the stretch and measure improvement at a known quantifiable angle—a feat, Cooper points out, that cannot be done with a rolled-up towel or while stretching against the wall. Moreover, he says that because the device is stable and easy to use, compliance is high. He recommends that users keep it in front of the bathroom vanity to incorporate stretching every day while brushing their teeth.

Out of 300 devices sold to date, of which about 10% have been sold to healthcare professionals, only 2 have been returned–DorsiFLEX has a 100% satisfaction guaranteed return policy. The only negative feedback received on the DorsiFLEX, according to Cooper, is the price ($165) and weight (5 pounds). Toward this end, the team is moving from the metal model to 3D injection molded manufacturing using a composite material, which will result in a lighter weight. The device will have a sleeker look, legs will be added so users can incline the base while also inclining the toes, and the gap between the base and fingers will be closed in response to user input, Cooper explains. The new model is in the prototyping and testing stage. If all goes as planned, a market launch date is anticipated during the first quarter of 2021.

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