Inventor and Designer of Postural Control Insoles

Published in the Podiatry Forum:  Anatomical Origin of Forefoot Varus Malalignment - 23rd September 2012

Below I have delineated several key axioms that are presented in almost every embryological textbook:

  • Axiom 1: In the developing limb, all torsional changes occur sequentially, centrally to distally (proximally to distally in the lower limb)
  • Axiom 2:  Supinatus is the term used to describe the inverted structural twist of the part relative to the midline of the body (or part of the body, e.g., the midline of the foot)

The following two axioms are eluded to only.  I have developed these concepts more fully in my clinical research (Rothbart BA 2002. Medial Column Foot Systems: An Innovative Tool for Improving Posture.  Journal Bodywork and Movement Therapies)

  • Axiom 3:  When the calcaneus (heel bone) goes through its' ontogenetic torsional development, it takes the lateral embryological column with it (the cuboid, the intermediate and lateral cuneiforms, the lateral growth center of the navicular and 4 lateral metatarsals and adjoining phalanges)
  • Axiom 4:  When the talus (bone sitting on top of the calcaneus) goes through its' ontogenetic torsional development, it takes the medial embryological column with it (medial growth center of the navicular, internal cuneiform, first metatarsal, and adjoining phalanx and hallux)

KEY EVENTS in Late Embryogenesis (approximately Week 6 - Week 8 Post Ovulation) - which can result in inherited abnormal foot structure - summarized:

I.  The Clubfoot Deformity

  • Around Carnegie Stage 21 (CS21), the plantar surfaces of the right foot is facing the plantar surface o the left foot.  That is, both feet (heel to toe) are in supinatus.
  • If the ontogenetic torsional development of the foot stops prematurely at this stage of development, the child is born with a Clubfoot Deformity (Bohm M 1929.  The embryologic origin of clubfoot.  Journal Bone and Joint Surgery (AM), 11:229.)

II. The PreClinical Clubfoot Deformity

Around CS22, the heel bone has partially unwound (and with it, the lateral embryological column of the foot). If the ontogenetic torsional development of the foot stops at this stage, the heel bone would still retain a slight valgus torsion, but the entire embryological medial column of the foot would be in supinatus.

What would this foot look like?

I suggest that when the PreClinical Clubfoot is placed into its anatomical standing (obviously post gestation) neutral position (e.g., Subtalar Joint Congruity - not Roots 1/3 - 2/3rds definition)

  • The heel bone would still be in slight supinatus (but less so as it was in CS21)
  • But the talar bone would have just started its' OTD.  That is, the talar bone (and medial column of the foot) would, more or less, still be in full supinatusLooking at this foot structure, you would see the structurally inverted position of the heel bone and the elevated first metatarsal and hallux (assuming the foot is in its' anatomical neutral position).

III.  The Primus Metatarsus Supinatus Foot Structure (AKA Rothbarts Foot)

If the foot's ontogenetic torsional development stops prematurely in Late CS22/EarlyCS23, the calcaneus would have completed its' OTD.  But the talus would still retain some of its supinatus (and with it the medial column of the foot).

What would this foot look like?

  • The posterior bisection of the heel bone would be perpendicular to the transverse plane of the body (e.g., and with it the lateral 4 metatarsals and adjoining phalanges)
  • The talar bone (and medial column of the foot) would still be in supinatus (structurally elevated and inverted) Looking at this foot structure, you would see the entire plantar surface of the heel bone lying on the ground, but the first metatarsal and hallux would be structurally elevated and inverted.

Measuring Rothbarts Foot

In the mid-1990s, I approached Dr. Cummings and Higbie at Georgia State University.  I suggested a study to see if Rothbarts Foot could be reliably measured clinically.  The results of there study can be accessed in the following publication: Cummings GS, Higbie EJ 1997. A weight-bearing method for determining forefoot posting for orthotic fabrication. Physiotherapy Research International, Vol 2(1):42-50. [This study was funded by a grant from the College o Health Sciences at Georgia State University]

Anyone of these three-foot structures will eventually result in chronic muscle and joint pain throughout the body.


Anatomical Origin of Forefoot Varus Malalignment
Rebecca S. Lufler, T. M. Hoagland, Jingbo Niu, and K. Douglas Gross
J Am Podiatr Med Assoc 2012;102 390-395

Background: Forefoot varus malalignment is clinically defined as a non-weight bearing inversion of the metatarsal heads relative to a vertical bisection of the calcaneus in subtalar joint neutral. Although often targeted for treatment with foot orthoses, the etiology of forefoot varus malalignment has been debated and may involve an unalterable bony torsion of the talus.

Methods: Forty-nine feet from 25 cadavers underwent bilateral measurement of forefoot alignment using adapted clinical methods, followed by dissection and measurement of bony talar torsion. The relationship between forefoot alignment and talar torsion was determined using the Pearson correlation coefficient.

Results: Mean ± SD forefoot alignment was −0.9° ± 9.8° (valgus) and bony talar torsion was 32.8° ± 5.3° valgus. There was no association between forefoot alignment and talar torsion (r = 0.18; 95% confidence interval, −0.11 to 0.44; P = .22).

Conclusions: These findings may have implications for the treatment of forefoot varus since they suggest that the source of forefoot varus malalignment may be found in an alterable soft-tissue deformity rather than in an unalterable bony torsion of the talus.

I find Lufler's study very interesting but flawed.  I believe her conclusions are flawed for several reasons:

  • Connective tissue in the living foot is very different in constituency than connective tissue in the postmortem foot.  However, Lufler measured the PM Foot and then applied her findings to the in vivo foot
  • The difference in the connective tissue constituency between the living and dead foot would obfuscate the apparent correlation between the relative rearfoot to forefoot position and talar torsion

A study that would definitively prove (or disprove) the correlation between talar torsion and the position of the embryological medial column of the foot would be:

Measure for the Primus Metatarsus Supinatus Foot structure (as described by myself and Cummings and Higbie).  

Then take that same foot, after death, strip it down to the bony structure and measure the talar torsion directly off the foot.

Compare your measurements.  Do they correlate or not.  That is, does one see an incomplete torsional development of the talar head and neck, or not.

For obvious reasons, this would be a very difficult study to conduct.

What exactly are forefoot varus and forefoot supinatus?

Podiatrists use these terms to describe connective tissue changes in the foot resulting from positional shifts.

  • When the forefoot is positionally inverted relative to the rearfoot, they term it forefoot varus
  • When the forefoot is positionally everted relative the rearfoot, they term it forefoot valgus

However, one must keep in mind that these terms are used to describe symptoms (albeit positional symptoms), not primary pathology (etiology).

So, the question remains:  what is the cause of forefoot varus or forefoot supinatus.  All the explanations I have read to date (including some of the very complex biomechanical explanations) do not isolate primary causes, but instead, describe in great detail a series of interlinking positional shifts leading to the varus or valgus forefoot.

My first tenant in any therapy is to first isolate (determine) the cause of the symptoms. And then treat that cause directly.

If one treats symptoms (e.g., forefoot varus), the patient will end up in a life long process of pain management. Something that is very frustrating and expensive for the patient and should be avoided, if at all possible.

Embryology - The Key to Understanding the Inherited
Foot Structures that Result in Chronic Muscle and Joint Pain