Proper posture analysis starts with the feet

Since most feet are typically asymptomatic…it is easy for the chiropractor to ignore this component of posture analysis

In order to analyze and monitor functional weight-bearing posture of the human frame, in my opinion, one must include the functional analysis and measurement of the feet. In 1984, Drs. Gillett and Liekens wrote in the 11^th edition of the Belgian Chiropractic Research Notes regarding posture analysis that the sacrum is not the base of the spine, it is the ischia in the sitting posture, and the feet when standing.¹

Pronation and subtalar joint motion

As we know, the vast majority of adults present in chiropractic offices with pronation of the feet and ankles. We all have a very accurate picture in our minds of what pronated feet look like when the patient is barefoot and weight-bearing. They look like their feet have rolled inward/internally and all three arches of the feet decrease to some degree.

But a more technical definition of pronation with respect to pronation of the foot/ankle is a combination of three motions at the subtalar joint. These three motions are:

1) eversion (sole out),

2) dorsiflexion (toes up), and

3) abduction (toes out).

So, a pronated foot, compared to the same foot not pronated, will be longer, wider, and flatter when weight-bearing.

It appears this process takes many years to develop, usually through adolescence, when growth centers of the lower extremity are still active. And more times than not, this developed bilateral foot pronation is asymmetrical. If this asymmetry is projected superiorly to the femur head heights when the body is in a functional, weight-bearing state, it will be an involved component of pelvic tilting.

Since most feet are typically asymptomatic, with a structural interplay between foot pronation and pelvic tilting,⁵ it is easy for the chiropractor to ignore this component of posture analysis.

Posture analysis and measuring pronation

Probably the most accurate ways of measuring for foot pronation in a functional position are with a foam casting kit or a digital scanner which create a three-dimensional model of the feet.

But there are also many visual indicators for foot pronation. These include:

1) foot flare,

2) posterior/lateral heel wear on shoes,

3) patellar approximation which is a “knock-kneed” look,

4) Achilles tendon bowing, and

5) callouses under the 2^nd, 3^rd, and 4^th metatarsal heads which is created by these metatarsal heads approximating the plantar surface because of a flattened anterior transverse arch.

The structural integrity of the arches of the feet is primarily ligamentous in nature.^2,3 We humans average approximately 5,000-7,000 steps per day. When the heel strikes the ground, approximately 2½ times the body weight is exerted.

If one multiplies this number by the number of steps we have taken in our lives, it is no surprise why these ligaments that support the three arches of the feet plastically deform. This is the reason why I recommend flexible functional orthotics for nearly all of my patients.

In my experience, the use of flexible stabilizing orthotics, and strapping or taping of the feet, are not corrective but supportive. When a patient walks without orthotics in their shoes, or supportive taping is taken off the feet, the feet return to the unsupported structure when weight bearing.

As Dr. Monte Greenawalt, the inventor and founder of Foot Levelers, taught me as a student, “The feet are designed for flexible locomotion.” Therefore, an orthotic that supports all three arches. (medial longitudinal, lateral longitudinal, and anterior transverse), and allows for the normal or optimal range of motion, will stabilize the feet in a symmetrical manner through the weight bearing gait cycle.

Pronation and the kinetic chain

We must also keep in mind that a pronated foot is a fixated, hypo mobile complex to some degree. This may cause some amount of micro-hypermobility in knees, hips, and sacroiliac joints. We know as chiropractors applying posture analysis that many of our patients experience knee, hip, and low back symptomatology along with various degrees of degeneration due to developed bilateral, asymmetrical foot pronation.

My experience clinically is that patients can benefit greatly from a combination of chiropractic foot adjustments and stabilizing flexible orthotics. My style of adjusting the feet utilizes seven adjustments that address the navicular, cuboid, cuneiforms, metatarsal heads, talus, calcaneus, and the fibula.

The adjustments will provide a stimulus to facilitate the firing of type 1, 2, and 3 mechanoreceptors in and around the joints. This in turn will inhibit the firing of type 4/nociceptors at a level of the spinal column. The firing of nociceptors will potentially do two things:

1) They are initiators of pain. So, if nociception is strong enough to elicit the action potential in the sensory cortex, the patient will experience some degree of pain,⁶ and

2) In a cumulative way, excessive continuous nociception will reflexively activate the sympathetic nervous system. In this situation, autonomic indicators such as blood pressure, heart rate, and respiratory rate will increase putting the patient in a somewhat hyper-excitable central state (sympathetic nervous system activation)^4,6.

So, we can potentially affect any painful symptomatology and affect the body globally by facilitating the inhibition of the sympathetic nervous system.

In my opinion, both accurate analysis with measurement, and appropriate management with flexible functional orthotics, and lower extremity chiropractic adjustments, are necessary to properly address patients’ foot pronation and balance the weight-bearing loads of the human frame.

MARK N. CHARRETTE, DC, is a 1980 summa cum laude graduate of Palmer College of Chiropractic who writes for Foot Levelers. He is a frequent guest speaker at many chiropractic colleges and has taught over 1,900 seminars worldwide on extremity adjusting, biomechanics, neurology, philosophy and spinal adjusting techniques. His lively seminars emphasize a practical, hands-on approach. He is a former All-American swimmer who has authored a book on extremity adjusting and also produced an instructional video series. Having developed successful practices in California, Nevada, and Iowa, he currently resides in Irving, Texas.

References

1. Belgian Chiropractic Research Notes. 11^th H. Gillet, DC, M. Liekens, DC, Procedure manual by Charles M. Rollis, DC, 1984. MPI.  p.85-86
2. Basmajian JV et al. The Role of Muscles in Arch Support of the Foot: An Electromyographic Study. J of Bone and Joint Surgery, Vol 45, No 6 September 1963.
3. Huang et al: Biomechanical Evaluation of Longitudinal Arch Stability.  Foot & Ankle, Vol. 14, No. 6, July/August 1993
4. Patterson M, The Spinal Cord: participant in disorder. Journal of Mani: 1993: 9(3) 2-11.
5. Harrison D, et al (1988) CBP Vol IV., CBP Inc.
6. Kabell, J. Sympathetically maintained pain. In Wills W. ed Hyperalgesia and Allodynia. Raven Press. NY: 1992