A Different Perspective on Foot Posture and Alignment

A Different Perspective on Foot Posture and Alignment

As an athlete, I had pain under my foot, Achilles tightness, knee pain, and tight adductors and hip flexors.  In the summer going into my junior year in college, I saw a physical therapist who recommended I try wearing supportive insoles.  I can remember running 100’s at the football field with the insoles in, and my body feeling completely different: the pain was gone, and my quads, hamstrings, and glutes were firing like I had never felt before.  The only problem was that I flattened out those insoles after a couple weeks.

Over the next five years, I had three different pairs of custom orthotics prescribed to me; I was chasing the feeling of the first time running in the insoles.  The orthotics had varying degrees of success; interestingly, all three assessments were different, all three methods for capturing the foot were different, and the end product was significantly different as well. 

The Foot Alignment Assessment

After I had a right knee scope, I was still looking for answers.  My Physical Therapist worked on my hips, but I was still having knee pain, especially during single leg exercises such as hopping.  He had said before that the knee is going to go where the hip and foot tell it to, and since my hips were moving much better, he sent me to a colleague for a foot and ankle assessment.  This assessment was vastly different than my previous foot assessments.  The assessment included a full movement screen, including squatting, single leg movements, and tangible measurements on the foot while standing and lying down on a table.

This Physical Therapist told me that I was standing with my rearfoot everted (pronated position), which I knew.  He also told me that when my foot was non weight bearing, my rearfoot was relatively neutral, but my forefoot was inverted over ten degrees.  He explained that four degrees inverted and lower is considered neutral, and that ten degrees is considered significant. 

The non weight bearing measurement is taken while the individual is lying face down on a table with the lower shin and feet hanging off the end of the table.  The foot is then placed into a sub talar neutral position and measured with a goniometer.  If the forefoot is significantly inverted (medial side rotated upwards) in relation to a neutral talus (lower part of the ankle joint) and lower leg, the foot may rotate towards the medial side when the foot becomes weight bearing.  Imagine a restaurant table with a short leg: the table is going to rock towards that short leg (medial forefoot in this case) when you put weight on it.  In my opinion, this can be magnified when you perform actions on a single leg, such as hopping, because you do not have the other foot to provide additional contact points and balance out the body.

Everted Rearfoot Weight Bearing (L)

Neutral Rearfoot Weight Bearing (L)

Inverted Forefoot Alignment 6* (L)

Neutral Forefoot Alignment (L)

Receiving this assessment changed my perspective on foot posture and function.  After receiving this assessment, there were two important questions to answer: what does the research say about this foot alignment, and what is the best plan for improving the function of the foot? 

Introduction to Forefoot Varus and Forefoot Supinatus Research

There is previous research and discussion on this topic.  The term forefoot varus is used to describe an inverted forefoot alignment in non weight bearing with sub talar neutral.  Research shows that forefoot varus is very common, but the degree of varus alignment can vary. 1,2

Research shows that the degree of standing everted rearfoot posture is correlated with the degree of non weight bearing inverted forefoot alignment. 2,3  For example, someone standing 10 degrees of everted rearfoot may have 8 degrees of inverted forefoot.  In addition, the degree of inverted forefoot is also correlated with a measurement of navicular drop. 2

These graphs, from “Forefoot Varus Predicts Subtalar Hyperpronation in Young People” illustrate the relationship between the forefoot angle and the rearfoot eversion angle, as well as the forefoot angle and navicular drop.

In my opinion, Navicular drop is more challenging to measure than the non weight bearing forefoot alignment and standing rearfoot posture.  In addition, it is important to note that the correlation is with Navicular drop, not the height of the Navicular bone.  As discussed in the flat feet post, excessive pronation results in lower arches, but not all low arches have excessive pronation.

Greater degrees of forefoot varus have association with lower stability: in 2004, researchers grouped participants with 7 or more degrees of forefoot varus and under 7 degrees of forefoot varus.  The results of the study showed poorer postural stability in the subjects with higher forefoot varus. 4  Another studied showed correlation between forefoot varus and excessive hip internal rotation: “These results indicate that FV influences the transverse plane hip movement patterns during a functional weight-bearing activity. Considering that excessive hip internal rotation has been associated with knee injuries, these findings might contribute for a better understanding of the link between FV and injuries of the proximal joints of the lower limb.” 5

Research also indicated that forefoot varus may be an alterable soft tissue deformity rather than an unalterable bone deformity.  “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.” 6  This is an important note because it may potentially change rehab and performance plan of the foot type. 

Further research categorizes a bone structure deformity as forefoot varus, and a soft tissue reducible deformity as forefoot supinatus. “The supination of the forefoot that develops with adult acquired flatfoot is defined as forefoot supinatus. This deformity is an acquired soft tissue adaptation in which the forefoot is inverted on the rearfoot. Forefoot supinatus is a reducible deformity. Forefoot supinatus can mimic, and often be mistaken for, a forefoot varus. A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous deformity that induces subtalar joint pronation, whereas forefoot supinatus is acquired and develops because of subtalar joint pronation.” 7

It is important to note that not every researcher or clinician makes this distinction in terminology: many researchers and clinicians refer to the measurement of an inverted forefoot as “forefoot varus,” and may not be using the term to only specifically describe bone structure deformities.

Summary

One problem when discussing foot posture is that can be very vague and unclear.  How much pronation is “over pronation” or excessive pronation?  One of the elements I like about measuring the standing rearfoot angle and non weight bearing rearfoot and forefoot angles is that is can put a tangible number into the “pronation” conversation.  While some say “everyone pronates” or “you need to pronate” this research clearly shows a bell curve (the next blog post will show the graphs from my research). 

This assessment can reveal compensations to excessive pronation, and also give insight to the potential contributing factors (whether there is a rearfoot alignment issue and if the ankle and foot have a high level of stiffness or hyper mobility).  In addition, it may provide insight in situations where athletes are able to control their movement fairly well during a standard assessment, but have pain or movement issues at high speeds and during competition.

The research indicates that inverted alignment of the forefoot can be bone structure or soft tissue driven.  In the opinion of physical therapists I have discussed this topic with, it is more often a soft tissue compensation.  The cause of the soft tissue deformity (sometimes referred to as forefoot supinatus) is caused by excessive pronation.  What causes the excessive pronation, in my opinion, is a combination of the structure of the body, mobility, stability, activity, and environment (including footwear structure).  The inverted alignment of the forefoot then further reinforces the excessive pronation pattern.

This can be a tough cycle to break out of because it is a foot problem, caused by a movement problem, that is further contributing to poor movement.  Therefore, movement as a whole, as well as the foot, may need to be addressed.  In the next two posts, we will review the research I conducted with over 140 athletes, as well as the potential plans to improve foot alignment and function.

There is a lot beyond the alignment of the foot that can contribute to stability of the foot and body as a whole.  However, I believe this can be an interesting new perspective on foot alignment.  If done properly, the measurements can be consistent and reliable.  The non weight bearing assessment should include the rearfoot alignment (to be discussed at a later point) and forefoot alignment. 

Although the standing rearfoot posture and non weight bearing forefoot alignment are correlated, I believe the non weight bearing forefoot alignment is important because individuals can shift how they are standing, especially if they have become aware of their foot posture and are trying to avoid standing pronated.  The non weight bearing assessment is much more difficult for an individual to cheat the test.  The non weight bearing alignment assessment not only gives a tangible measurement to the foot as a starting point, but can also provide insight to what may be occurring during movement.

References

1.       Garbalosa JC, McClure MH, Catlin PA, Wooden M. The Frontal Plane Relationship of the Forefoot to the Rearfoot in an Asymptomatic Population. Journal of Orthopaedic & Sports Physical Therapy. 1994;20(4):200-206. doi:https://doi.org/10.2519/jospt.1994.20.4.200

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2.       Silva RS, Ferreira ALG, Veronese LM, Serrão FV. Forefoot Varus Predicts Subtalar Hyperpronation in Young People. Journal of the American Podiatric Medical Association. 2014;104(6):594-600. doi:https://doi.org/10.7547/8750-7315-104.6.594

3.       Johanson MA, Greenfeld L, Hung C, Walters R, Watson C. The Relationship Between Forefoot and Rearfoot Static Alignment in Pain-Free Individuals With Above-Average Forefoot Varus Angles. Foot & Ankle Specialist. 2010;3(3):112-116. doi:https://doi.org/10.1177/1938640010365184

4.       Cobb SC, Tis LL, Johnson BD, Higbie EJ. The Effect of Forefoot Varus on Postural Stability. Journal of Orthopaedic & Sports Physical Therapy. 2004;34(2):79-85. doi:https://doi.org/10.2519/jospt.2004.34.2.79

5.       Scattone Silva R, Maciel CD, Serrão FV. The effects of forefoot varus on hip and knee kinematics during single-leg squat. Manual Therapy. 2015;20(1):79-83. doi:https://doi.org/10.1016/j.math.2014.07.001

6.       Lufler RS, Hoagland TM, Niu J, Gross KD. Anatomical Origin of Forefoot Varus Malalignment.  Journal of the American Podiatric Medical Association. 2012;102(5):390-395. doi:https://doi.org/10.7547/1020390

7.       Evans EL, Catanzariti AR. Forefoot Supinatus. Clinics in Podiatric Medicine and Surgery. 2014;31(3):405-413. doi:https://doi.org/10.1016/j.cpm.2014.03.009