There are two responses to RFS. One causes hyperpronation, and interestingly, the other causes supination.
We have defined people who freely release their feet to hyperpronate as releasers: The foot is released to follow the motion of the first metatarsal and big toe as they travel downward. The result is a partial or full collapse of the arch.
Releasers are among your patients who often suffer from foot, knee, back and neck pain and in general feel the effects of hyperpronation even at younger ages. Releasers often display a more collapsed posture. They often fall in the category of patients who respond less favorably to manual therapy because their poor posture tends to quickly undo the positive effects of treatment.
Releasers can typically be recognized by three or more of the characteristics of hyperpronation: Outward turning feet, forward leaning posture, unbalanced hips, increased lordosis, rounded shoulders, head forward, knees traveling inward, collapsing ankles, and an unstable gait.
Bracers respond to hyperpronation the exact opposite way of releasers. We have defined the term bracers for people who walk on the outside of their feet, as long as they can, to prevent or delay hyperpronation. Depending on the severity of their bracing pattern, their shoes wear on the outside of the heels and on the outside of the forefoot. Bracers overuse their muscles, anterior tibialis to control foot motion, vastus lateralis to control knee action, gluteus medius to control hip action, trapezius to control shoulder action and scalenes to control head action.
Bracers are not restricted in range of motion, but they are muscularly braced. The muscles on the front of their bodies (flexors) and muscles on the back of their bodies (extensors) are usually tight. Because bracers muscularly control their posture, they are typically asymptomatic for the first 3-4 decades of their life. Typically bracers complain of few, if any, joint problems until well into their forties, and if they have experienced joint problems they have been non-debilitating and not of much concern.
Bracers tend to carry a more erect body posture, and their feet may sometimes be slightly adducted (pointing inward), but may also be straight or slightly abducted (pointing outward).
They tend to roll to the outside of their feet, are more prone to ankle injuries, and generally may complain about muscle pain in their legs (shin splints) and fatigue as the day wears on. They will usually display a rigid, jarring walk, and on examination you will find their body to be rigid as well. You will recognize them by excessive body tension.
If there is no other recognized pathology in the foot, knee and hip that causes excessive supination, bracers are typically hyperpronators in disguise.
Bracers respond to medial column support, but must start with modest ground forces. A small amount, (3.5mm) will cause bracers to start relaxing the bracing pattern. They will typically feel a decrease in body tension.
Bracers will initially reject high ground forces, but when their bracing pattern is relaxed, they will accept the same ground forces as releasers.
In-toeing and Out-toeing
In-toeing and out-toeing are commonly seen compensations for hyperpronation. However, they can be indications of trauma or primary pathology in the hip or knee joints.
In-toed walking is often observed as a compensation in children hyperpronating significantly. Typically their First Metatarsal Deficit (FMD) (elevation of the big toe) is over 20mm. When they turn their feet inward, it prevents their feet from hyperpronating by carrying the body’s weight on the outside of their feet. Many of these children may develop high arches and bowed legs as they grow into adulthood. Because it is traditionally and cosmetically unacceptable to parents to see their children walking “Pigeon-toed”, they often remind them to turn their feet outward. These children, as they turn their feet outward, typically become bracers. That is, they are substituting in-toeing compensation for hyperpronation for bracing compensation.
An out-toed gait pattern is a common compensation to lurching (lateral drift). Turning the feet outward serves two functions: (1) It increases their base of support and thereby diminishes the balance instability seen with hyperpronation, and (2) Turning the foot outward on one side more than the other diminishes the drift in that direction.
When we decrease the degree of hyperpronation, the in-/out-toeing compensations automatically decrease (doesn’t require intentional or volitional interaction by the patient for it to occur). This occurs because (1) It takes less energy to walk with the feet pointing straight forward than turned outward or inward (Law of Conservation of Energy) and (2) The compensations are no longer needed by the body to insure stability (keep the body upright at all costs to prevent possible trauma from a fall). If there is no primary pathology in the knee or hip, the amount of in-/out-toeing will diminish commensurate with the degree of increased mechanical efficiency. As the hyperpronation is decreased, the toes point more and more forward.
If hyperpronation and primary hip pathology occur concomitantly, the degree of in-/out-toeing will diminish with use of Posture Control Insoles™, but not to the same extent as noted above.