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  • Journal of the American Podiatric Medical Association is published by MDPI from Volume 116 Issue 1 (2026). Previous articles were published by another publisher in Open Access under a CC-BY (or CC-BY-NC-ND) licence, and they are hosted by MDPI on mdpi.com as a courtesy and upon agreement with American Podiatric Medical Association.
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1 November 2017

A Response to “A Novel Treatment Approach to Over-Pronation Dysfunction: A Follow-Up”

Department of Podiatry, Orlando Veterans Affairs Medical Center, 13800 Veterans Way, Orlando, FL 32827
J. Am. Podiatr. Med. Assoc.2017, 107(6), 573-575;https://doi.org/10.7547/17-053
Version Notes
To the Editor:
It is always refreshing for the Journal to publish anecdotes from the readership, in describing successful treatment of injuries and pathologies that many practitioners may find challenging. Although Mr. Wiley’s article is purely an anecdote, he has followed the history for many years; from such anecdotes postulates can be developed as to mechanisms of injury, sequelae of injury, and improved treatment modalities. I will never criticize the success of Mr. Wiley’s report, and indeed I am quite interested in more details than he provides.
The author states that his original injury was a talar dislocation that ruptured the medial collateral ligaments of the ankle. This is indeed a serious injury. Any such dislocation would also rupture the capsular ligaments of the talonavicular joint, which would include the spring ligament. As Davis, et al [1] noted, there are significant attachments of the deltoid ligament to the superomedial calcaneal navicular ligament (SCNL), which is a major load-bearing structure of the medial arch. This ligament acts as part of the acetabulum tali, and therefore, loss of it will result in failure to support the medial side of the talar head, and the forefoot will abduct, dorsiflex, and appear to invert relative to the talus [2].
Mr. Wiley uses mechanical terminology in ways that are ambiguous and imprecise. Such terms as “locked,” “rigid,” and “stable” are often used by the lay population to mean that the foot is functioning correctly. Why? The purpose of gait requires a ground force pushing the individual forward. Rules of efficiency would dictate that one would try to cover any distance with the fewest number of steps. Stride length is increased when the heel rises from the ground and the foot rotates around the metatarsophalangeal joints [3]. During this propulsive period of gait, the foot can be modeled to functioning as a second-class lever. Any lever requires that the elements between the force, the pivot point, and the load be “rigid.” However, is the foot really rigid during propulsion? Hicks [4] demonstrated that as the first metatarsophalangeal joint dorsiflexes, the distance between the plantar calcaneal enthesis and the first metatarsal head has to decrease in order for the sesamoids to move around the metatarsal head. Hunt, et al [5] showed that the greatest amount of movement in the foot joints occurs during the propulsive period of gait, when the forefoot has to plantarflex, adduct, and evert relative to the rearfoot. The plantarflexion movement of the rearfoot against the forefoot is in the opposite direction of the torque created by ground resistive forces, pushing upward against the metatarsal heads. So we can say that the foot is not rigid; however, it is functioning as a rigid body lever. This is just one example of the common misuse of mechanical terminology by today’s average clinician. I use it to encourage more mechanical precision in our writing and teaching in the future.
This writer questions the nonreferenced statement that forefoot varus is the most common cause of pronation of the rearfoot. Certainly forefoot varus is a cause of pronation, but many other causes have been postulated and identified, including short Achilles tendon, rearfoot varus, internal torsional problems, and medially displaced subtalar joint axis [6-11]. In the numerous pedobarographic studies I have performed over the years, it is noted that almost always, all metatarsal heads will touch the ground during the midstance period of gait. It is logical to conclude from these studies, then, that for the calcaneus to evert from being perpendicular to the ground, that the forefoot must have a range of motion that allows the plane containing all five metatarsal heads to invert relative to the rearfoot.
Unfortunately, as one reviews the literature on the incidence of forefoot varus, one is struck by the wide variability in results. A careful reading of the various methodologies employed in measuring the forefoot to rearfoot relationship shows a great variability in the techniques of measuring. Root et al [12] originally measured the forefoot to rearfoot relationship with the subtalar joint in neutral and the midtarsal joint in its maximally pronated position. This maximally pronated forefoot position was based on the initial, but erroneous, concept of the “osseous locking position” proposed by Elftman [13]. However, by the time of publication of his second book, Root et al [14] had rejected the concept of “osseous midtarsal joint locking” and instead stated that the end range of motion of the forefoot to rearfoot was created by ligamentous tension. This meant that the end range of motion of the midtarsal joint in the pronation direction was a spongy end range of motion, and was dependent on how much pronation torque was being applied. Root always taught, though, that the end range of motion should be at that point where the ligamentous tension started, and he continued to cast feet with this definition. Even this end range of motion definition is nebulous [15]. Those who have maintained that a majority of flat feet are caused by forefoot varus have usually not attempted to move the midtarsal joint to its pronation end range of motion. An example is the report by Chen et al [16], noting that flat feet had more forefoot varus than did normal arch feet. However an examination of their technique shows that they used a crush-box cast of the feet to evaluate the measurement, with no knowledge about whether the midtarsal joint was maximally pronated. Phillips and Phillips [17] used a Root clinical technique and reported in an average clinic population consisting of both pronated and supinated feet, that the average forefoot to rearfoot relationship was approximately 2° valgus.
It is noted that Mr. Wiley does not produce photographs to show the device and his foot in the device, in order that others could replicate it for further study, and it is hoped that he will publish more details in the future. The concept, though of a varus force on the heel in conjunction with a valgus force on the forefoot for correction of pronation is not very new. Steindler [18] had the same concept in which he placed a varus corrective wedge under the heel of the shoe and another valgus corrective wedge under the metatarsal heads of the shoe for the correction of a flat foot. Cotton [19] advocated the correction of flatfoot with a surgical procedure that would decrease the varus of the medial side of the foot. MacConaill [20] introduced the term “twisted plate” to describe the curved lamina pedis and noted that pronation of the foot untwisted the foot, and that the foot was in its position of minimal potential energy with the subtalar joint supinated and the forefoot in a twisted position. Perkins [21] proposed the correction of pes planus by reducing forefoot varus with a forced valgus torque on the forefoot under general anesthesia. Root [22] proposed a nonweightbearing casting technique for making in-shoe orthotics by maximally everting the forefoot against the rearfoot while the rearfoot was in a neutral position. This required the fabrication of a device that was quite rigid, so that it would continue to provide this eversion force against the forefoot when the patient stood on it. Sarraffian [23] further developed MacConaill’s model of the twisted plate, with pictures of the twisted lamina pedis, in which inversion of the forefoot against the rearfoot resulted from rearfoot eversion in stance, which placed greater tension on the plantar fascia. This model further illuminated the Hicks description of the plantar fascia acting like a windlass in providing for first metatarsophalangeal joint dorsiflexion during the propulsive period of gait, and requiring, therefore eversion of the forefoot against the rearfoot in order for hallux to dorsiflex during gait. Dananberg [24] used this concept in adding additional dorsiflexing force against the hallux during gait, to increase the plantarflexion of the medial column of the foot, which had a kinematic effect up the postural chain to increase the lumbar lordosis, and decrease fatigue in the spinal extension muscles. Bird et al [25] in a more quantitative study showed that onset of erector spinae and gluteus medius muscles was later in the gait cycle when a forefoot eversion wedge was used.
The effect of Root orthotics has been greatly investigated over the years, as to their ability to kinematically decrease the pronation of the foot. Although the results have been quite varied, the average study has pointed to the standard Root orthotic producing a mild decrease in the degree of pronation and a greater decrease in the velocity of pronation [26]. As noted earlier, the Root orthotic captured the foot in subtalar joint neutral position with the forefoot “maximally pronated” position, with the orthotic molded to this foot shape out of a “rigid” plastic. Many people have assumed that the plastic is inflexible; however, I have done some work already in this regard and found out that the so-called “rigid orthotic materials” are really quite torsionally flexible. In an ongoing research project, I have been able to produce orthotic failure in acrylic orthotics with 70 in-lbs. of torque. How much torque is exerted between the forefoot and rearfoot when the foot is pronating is unknown, but any clinician who uses acrylic for making orthotics knows that torsional breakage is not uncommon. Therefore, I do not agree with Mr. Wiley that resisting forefoot inversion torque between the forefoot and rearfoot is essential to resisting pronation, and many times the orthotics that are touted as being Root orthotics may not adequately resist the forefoot inversion torque to produce much effect, and that greater inversion torques on the heel and eversion torques on the forefoot are needed in a great number of orthotics. Certainly the Blake inverted orthotic and the medial skive orthotics have improved the inversion torque on the heel, but little has been done to simultaneously improve the eversion torque on the forefoot [27,28,29,30].
In summary, while it may appear that I am heavily criticizing Mr. Wiley, I want to say that overall, he has followed basic doctrine that Root and also many before and after him have advocated: that the key to flatfoot treatment is a combined inversion torque on the heel and an eversion torque on the forefoot, whether it be done by conservative or surgical means. We will definitely be looking forward to more research and details from Mr. Wiley as to how to increase the supination torsion on the rearfoot and the pronation torsion on the forefoot.

Funding

None reported.

Conflicts of Interest

None reported.

References

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A Novel Treatment Approach to Over-Pronation Dysfunction. A Follow-Up
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