Arches and Orthotic Support
Our feet are the foundation of support for the pelvis and spine. In addition, they support the whole weight of the body; they provide balance; they propel us; they safely absorb heel-strike shock and adapt to walking stresses. The feet provide the necessary stability to perform daily activities. They are functionally and literally the foundation of it all.
Central to the success of the pedal foundation is the arched structure, which is actually a complex of three arches: the medial longitudinal arch, the lateral longitudinal arch, and the anterior transverse (metatarsal) arch.
Each arch consists of several bones bound together by tough, plastic-like ligaments and tendons. The strong connective tissue ensures that the structure is flexible and movable, yet is able to tolerate both sustained stress and sudden, high forces. Together, these three arches form an extremely strong, supportive 'plantar vault' that distributes the weight of the entire body.
The Structural Design of a three-arched plantar vault is very good at supporting weight and carrying high loads, while remaining flexible. During normal standing the load of the body is balanced over the center of the foot, anterior to the ankle. This places the greatest amount of load at the apex of the three arches. This force is then distributed along the 'buttresses' of the arches to the heel (which bears 50% to 60% of body weight) and the metatarsal heads (which bear 40% to 50% of body weight).
Arch Collapse If any one of these three arches is compromised the entire plantar vault loses its structural integrity. In addition to losing the support of the compromised arch, biomechanical stresses distress the other arches and symptoms develop. Lack of development or loss of this configuration results in abnormal force concentrations, which eventually cause degenerative and symptomatic clinical conditions (Fig. 3). Because the feet are under continuous gravitational pressure when bearing the body's weight, the collapse of one or more arches over time is a common experience for bipedal creatures.
Interestingly, the symptoms of a collapsed arch can be expressed anywhere in the musculoskeletal system - from the legs to the pelvis, and even into the back and neck. Custom-made, flexible orthotics align and support the structures of the feet in a near-normal physiologic position, to prevent dysfunction, and to improve the function of movable body parts.
Pes Planus (flat foot)
Numerous scientific studies over the years demonstrate that the arches are maintained almost completely by the passive connective tissues. Passive connective tissue does not have the viscoelastic properties that allow the arch to naturally reform after stress due to overload. It is only in the propulsive ('toe-off') phase of walking and during running that the intrinsic and extrinsic muscles come into play. This is the reason that strengthening exercises have never been found to be successful in re-developing a poorly formed or collapsed arch. The good news, however, is that most flat feet are flexible and respond rapidly to orthotic support. Studies also show that orthotics help with non-specific symptoms, such as fatigue associated with playing nine holes of golf. A rigid flat foot is rarely encountered, and is usually due to a bony anomaly. These unusual cases require specialized treatment, and will possibly require surgery.
Excessive pronation. At heel strike and during the initial part of stance phase, the foot normally pronates. This absorbs some of the shock of heel strike and accommodates uneven terrain. However, if the foot stays in pronation beyond heel strike, it is hyperpronating, or going into prolonged pronation. This movement occurs primarily at the subtalar and talonavicular joints, with excessive loading affecting all of the arches, but the medial arch most acutely.
Excessive pronation causes an obvious flattening of the medial longitudinal arch, with a medial and inferior movement of the navicular bone. This arch collapse destroys the structural support of the plantar vault, making the body at risk for subluxations as the musculoskeletal system attempts to adapt and compensate.
What Can Orthotics Do?
Dr. Shoals doesn't seem to know this but there are THREE arches in each foot. We all know of the medial longitudinal arch. But there is also the lateral longitudinal arch on the outside of the foot and the transverse arch which runs sideways behind the toes.
These arches create a Plantar Vault of support and function. Your knees, hips and spine sit atop this foundation. If the foundation becomes unbalanced then the structures above become unbalanced.
All It Takes is a Quick Glance at the Feet
Dr. Hall uses a state-of-the-art lazer scanner to map the contours of your feet. This is literally a map to the health of your foot's arches. That's right; each foot has multiple arches. After analyzing the map, flexible, CUSTOM orthotics can then be made.
1. Dr. Hall uses a state-of-the-art computer digitized scanner to scan your feet. You will view the digital picture and discuss your unique foot imbalances.
2. He will then determine which orthotics are right for you, based on the results of the scan, your activity levels and shoe styles you wear.
3. Skilled technicians build your custom-made orthotics using 16 precise measurements based on their analysis of your feet. Your lifestyle, age, weight and activity level are all considered when your custom-made orthotics are created.
4. The new orthotics are sent back to Hall Chiropractic in about a week. Dr. Hall will then check you for proper fit and talk to you about proper wear and care for them.