Two Types of Flat Feet

The terms flat feet and over pronation are often connected and associated as a bad thing that needs to be corrected.  We hear individuals and athletes say, “I have flat feet, so I can’t do this” or “I have flat feet, so I need that.”  Where does this come from?

In some cases, over pronation, flat feet, and poor movement are connected, and may have injury risk.  One example would be: the individual cannot control the loading phase of gait, the foot goes into excessive pronation during this phase, the medial arch lowers and lengthens as part of this movement, and there is a poor position at the foot that can have consequences within the foot itself, or at the ankle, Achilles, knee, hip, or lower back.

Pronation includes the forefoot inverting, the rearfoot everting, and the medial arch lengthening and lowering.  Repeated excessive pronation over time can lead to the foot compensating to stay in this position.  Essentially, the foot excessively rotating towards the inside flattens out the arch on the inside half of the foot arch over time.

However, it is important to understand that this is not always the case.  The appearance, position, and the function of the foot are three separate elements. 

There are many types of feet with different arch heights, positions at different phases of gait, and function levels.  As it relates to “flat feet” there are two very different examples to consider:

1.      Flat foot, over pronation, poor function.  Individual may struggle during the loading phase and the transition to propulsion.  Potential injury history or risk of injury associated with this foot type and movement.  An intervention may be needed to improve the function of the foot. 

2.      Flat foot, but in a good position with good function.  Able to load and transition to propulsion very well.  Low injury history, low injury risk according to movement assessment.  An intervention may not be needed.

The height of the arch alone is an incomplete assessment and a poor indicator of function.  It is important to assess the position and function of the foot and body as a whole.  An example of a full coaching assessment would be:

1.      Overall body posture

2.      Rotation range and symmetry (feet together or shoulder width: turn left and right)

3.      Full body movement: squat

4.      Single leg movement: (walk up stairs, step up, lateral lunge, reverse lunge, and/or forward lunge)

a.      Exercise selection for assessment depends on the individual and level of assessment.  For an assessment of an older individual, observing walking up and down stairs may be sufficient; but for an active athlete, movements where a single foot is loading and leaving the ground may need to be observed.

5.      Foot posture: static standing position

6.      Foot alignment (non weight bearing): rearfoot and forefoot alignment in sub talar neutral, dorsi flexion, and plantar flexion

7.      Foot function: calf raise

8.      Gait assessment: observing the body as a whole, including the foot and ankle during, walking, jogging, or sprinting (depending on the individual and their activities)

I do not like the term “flat foot” because it is usually has a negative meaning, especially for athletes who have been told that have a flat foot and because of that, there is either a restriction or some intervention that is said to be needed.  When discussing the appearance of the foot in relation to the arch, I would prefer to use the terms low arch, moderate arch, or high arch.

We described two very different types of low arches: a low arch that is the result of excessive pronation, and a low arch with very good movement.  But, in between these two very different examples, there are many possibilities.  An additional example to consider would be an individual with a low arch who has a moderately pronated foot posture, but has pretty good overall movement and low injury history.  What should the athlete, coach, or clinician do in this scenario?  This is a very important question because a high percentage of athletes may fall into this category.

In my opinion, the single leg movement part of the assessment becomes very important in these situations.  As a high school or college athlete, their injury history may be low due to their age, but that does not mean that they are not at risk of injury.  The athlete may be able to move pretty well while on both feet, but when isolated onto one foot, there may be some weaknesses that appear.

The key takeaway is that flat feet are not always what they seem to be.  Some individuals with low arches may have poor foot posture and function, and be at risk of injury; some individuals with low arches may have good foot posture and function.  The goal is to improve understanding of the foot and ankle to be able to create better assessments, performance plans, and to realize when a clinical assessment may be necessary.

Thanks for reading!

Coach Brooks