The ‘why’ of foot scanning

When is it appropriate, and what evidence helps determine the need?

I recently received an email from a colleague that I would like to share with you. I think it’s important to have this discussion because it involves components of our individual practice philosophy and technique preferences, and is an opportunity to expand our minds to new information that is available due to advances in science and research.

Discussions like this aren’t meant to make judgments about what is right or wrong in the way one practices, but I hope it encourages us to ask questions that lead to decisions based on evidence over preference, habit or false assumption. So much has changed in the 35 years I have practiced, and we are constantly exposed to new information that gives us the opportunity to fine-tune our practices to help us provide better care for patients.

Here is the question I received from our colleague:

“Dr. Jensen, I have a question that has plagued me for some time, and since you are a highly experienced seminar presenter, I thought you would have the background and knowledge to answer it for me.

Some of my colleagues have alleged that fitting a person with orthotics before their structure is totally corrected will only serve to perpetuate their imbalances. I have therefore been hesitant to scan patients early in their treatment for fear of compromising my own efforts to improve their structural problems. Is there any validity to this reasoning? If so, how can I be sure I am scanning patients at the very best possible time, for to scan them too soon would ‘lock in’ the structural pattern being exhibited by the body at that time and stall any further progress.”

Prescribing three-arch functional orthotics

This question relates to prescribing functional orthotics for patients who are evaluated using a 3D laser scanning device that reveals the integrity of the three arches of the feet and can demonstrate asymmetries between the feet.

We know the feet can contribute to biomechanical stresses that include increased pronation of the foot, and rotational stresses in the foot, knee and hip joint which can cause torquing stresses in the pelvis. This imbalance can then affect the lumbar spine and create functional and postural stresses in the thoracic and cervical spine.

Assessing foot structure

There are a variety of means to quantify structure, including visual observation, computerized postural assessment and X-ray evaluation.

While visual assessment is subjective, X-ray and computer-based postural assessment can be considered a reliable, evidence-based method of comparing changes in structure and function. X-rays allow us to observe biomechanical stresses by measuring gravity lines, angular and rotational distortions, and leg length inequality as well as degenerative changes and pathology.

Digital postural assessment allows us to quantify angular and rotational distortions as well as functional movement assessment. Both X-ray and posture assessment allow accurate pre- and post-care comparisons.

Regarding the feet, the Navicular Drop Test* is a very reliable, evidence-based assessment of the function of the foot. This test shows us, by measuring the amount of navicular drop from a seated, non-weight-bearing position to a standing, full-weight-bearing position, if the feet provide a balanced, symmetrical foundation, or if they are a source of biomechanical stress. Prior to the availability of the foot imaging technology we have available, the Navicular Drop Test was part of my new-patient assessment from the beginning of my practice. I observed that it was a consistent source of structural imbalance in the feet and lower extremities.

When to incorporate custom orthotics

I have heard the argument that prescribing orthotics before correcting structural imbalances only prolongs or perpetuates those imbalances. My personal experience with orthotics does not reflect that assertion.

As a young man playing high school sports, I was plagued with numerous injuries including sprained ankles, pulled muscles and persistent low-back pain. Sports injuries resulted in my introduction to chiropractic, which revealed that I had the classic right short leg, right PI ileum, 4^th and 5^th lumbar subluxation pattern, as well as the typical mid-thoracic and cervical subluxations we commonly find.

Chiropractic adjustments and some commonly used therapies almost always provided relief, but it was temporary. This always led to another adjustment, temporary relief and a gradual return of my right short leg and PI Ileum pattern that persisted from age 15-25, at which time I was introduced to functional, custom flexible orthotics. The common denominator for the repeating episodes of low-back pain seemed to be my feet.

• If we are to correct the structural imbalances in our patients, what does that entail?
• Do we adjust the problem spinal areas to correct them before supporting the feet with custom orthotics?
• If that is the path, what keeps the feet from affecting the biomechanics of the problem spinal area?
• Do we work to correct the feet with adjusting and strengthening exercises?

I adjust patients’ feet and I think that is very important, but foot adjustments don’t change the structure and function of the plantar fascia, which is the primary source of arch structure. There are some very effective spinal rehabilitation protocols that make extraordinary changes in structure, but there must be follow-up reevaluation to ensure that overpronating feet don’t contribute to a gradual loss of the correction. Muscles that are neurologically inhibited due to nociceptive input are limited in their ability to properly engage, which affects structural balance.

So, we are in a catch-22 of sorts. If we only adjust the spine to correct structure and the feet are creating imbalances that affect posture and movement, the patient will feel better, but eventually the biomechanical distortions will create stress and inflammation in the tissue and the pain will return. This creates an environment of muscular recruitment, weak posture, loss of fine motor control, balance and coordination, and an acceleration of the aging process.

For 35 years, I have evaluated the feet on the first visit. If the feet are asymmetrical and pronating excessively, I immediately recommend custom orthotics that support all three arches of the foot. The thing we must understand is that the three-arch orthotics allow the foot to pronate during full weight-bearing, but they block the foot from overpronating. The corrections in the orthotic create a stretch reflex in the belly of the abductor hallicus, abductor digiti minimi and the flexor digitorum brevis muscles, changing postural tone neurologically.

In my experience, custom flexible three-arch orthotics aren’t a structural correction as much as they are a modulator of neurological function and postural engagement. When the foot pronates excessively, the stretch of the golgi tendon organ in the muscular insertions creates an inhibitory response in postural tone.

I have many examples of significant postural improvements in patients who started using custom three-arch orthotics within a week of starting care. In my experience, using custom orthotics early in care will not “lock” someone into their structural pattern. To the contrary, custom orthotics begin to change balance, posture and functional movement that can be observed and quantified during the initial examination using proprioceptive test orthotics and on subsequent follow-up evaluations.

There are many ways to approach patient care, but it is incumbent upon us to use the best evidence available to make our care recommendations.

* (The Revised Navicular Drop Test: Inter- and Intra- Examiner Reliability of an Improved Test for Medial Arch Collapse, John K Hyland DC, Gary Brazzell, 2001 WFC – 6th Biennial Congress, Paris, France, May 24-26, 2001)

BRIAN JENSEN, DC, is a graduate of Palmer Chiropractic College and owner of Cave Spring Chiropractic in Roanoke, Va. He has been in practice for over 35 years. As a member of the Foot Levelers Speakers Bureau, he travels the country sharing his knowledge and insights. See continuing education seminars with him and other Foot Levelers Speakers at footlevelers.com/continuing-education-seminars.