Thirty years ago, Dr. Brian Rothbart DPM owned a thriving surgical podiatry practice in California. About the only thing that bothered him about his practice was the fact that he thought too many of his and his colleagues’ patients re-developed the problems that were corrected during surgery. Dr. Rothbart suspected the reason for these reoccurrences was based on underlying factors unfamiliar to his profession and therefore not being considered. Driven by curiosity and a belief that there were undiscovered solutions, Dr. Rothbart returned to the college campus.
Dr. Rothbart DPM, PhD, is a skilled biomechanist who has dedicated 25 years of his professional life to studying the biomechanical relationship of hyperpronation as it relates to the body in motion. By combining biomechanics, and 21st Century 3D computer modeling, Dr. Rothbart described the complex motion of the bones in the foot and lower extremity during normal gait and was able to clearly demonstrate the mechanics of hyperpronation
Noting that as many infants hyperpronate, as do children and adults, Dr. Rothbart suspected that it was a congenital problem and not a condition developed during childhood. In studying the clinical literature on the development and growth of the fetus, Dr. Rothbart was able to fully explain the origin of hyperpronation and support all his biomechanical findings.
As is often the case, once you are able to describe the problem in detail, the key elements of the solution become self-evident. The approach to reduce and even eliminate hyperpronation became clear and could be implemented with simple tools.
Dr. Rothbart described hyperpronation as a particular motion of the bones in the foot and ankle. As weight transfers to the forefoot during the gait, the ankle rolls inward and downward. The collapse of the body foundation,(the foot and ankle) in turn affects the posture and motion of the entire
When a typical hyperpronator stands with the feet in a subtalar neutral position, the first metatarsal and big toe are not in weight bearing contact with the ground. When the foot is released to its natural weight bearing stance, the first metatarsal and big toe travel a distance downward to become weight bearing. The ankle follows the motion of the big toe and collapses toward the ground. This motion exaggerates as the weight is shifted onto the forefoot.
Dr. Rothbart is the first to describe this relationship, so we call this foot mechanics “Rothbart’s Foot Structure” (RFS).
The fact that over 80% of the population hyperpronates is commonly accepted, but nobody had ever addressed the question of why. As it turns out, that answer was given years ago in descriptions of the development of the fetus.
At eight weeks old, the feet of the fetus are positioned such that the soles of the feet are facing each other. As the fetus develops, the creation and growth of the bones in the lower extremities go through an untwisting process. This untwisting motion also applies to the bones in the foot including the talus, the first metatarsal and phalanges. It is documented in the medical literature that this untwisting process stops earlier in some fetuses, later in others, and it leads to a corresponding difference in the deficit between the big toe and the ground.
Cadaver studies have documented a significant variance in the angular position of the head of the talus.
In a recent study (2002), Dr. McPoil documented how the first metatarsal remains unexpectedly dorsiflexed through a substantial portion of the gait cycle. His observations seem to verify Dr. Rothbart’s finding and the result is that the 2nd metatarsal carries most of the weight.
As a result of his findings, Dr. Rothbart created a dynamic foot support system. The term “support system” is not meant in the traditional “orthotic passive support sense”. The dimensioned wedge shape placed under the first metatarsal and big toe provides a tactical input to the medial column triggering a proprioceptive response. The muscles in the lower extremity are performing the actual correction. Dynamic hyperpronation is significantly reduced, torsional forces in the lower extremities are reduced, the knees move over the feet as they should, and the result can be a profound change in body posture.