The Foot Explained

Biomechanics, compensation, and treatment of the foot

Movement Debrief Episode 119 is in the books. Below is a copy of the video for your viewing pleasure, and audio if you can’t stand looking at me. Here is the setlist:

  • What is the relative foot position during inhalation and exhalation?
  • What strategies can be used to improve pronation and supination limitations?
  • How can I improve dynamics in a flat foot?
  • How does the foot move during a squat?
  • How do bunions form?

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and the audio version:    

Zac Cupples iTunes

Show notes

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Here is the video where Bill discusses how compensations form

Here is the Hruska clinic shoe list, a great list of shoes for various foot types

Here are some heel wedges. They are great for tipping the calcaneus one way or another.

If you need to beef up some arches, these are the best I’ve found.

If you need a good podiatrist, Dr. Paul Coffin makes good ones. He can measure and ship all across the US.

If you need to drive calcaneal inversion, peep this move. The front leg is where the supination is being driven:

If you need to drive calcaneal eversion, try this. The front leg is getting eversion:

If you’d like to combine both, this one is money:

If you want the best heel ramp in the biz, you need to get this one.

Bunions: Overview

Pathogenesis of hallux valgus

Below is a picture of a bunion:

Them foot veins tho (photo credit: Lamiot)

and here is what it looks like if you were to zoom in to the bones:

Note the varus through the first metatarsal and valgus through the phalanx (photo credit: BruceBlaus)

Here is an example of knee valgus, aka a knee bunion 😉

same poop (photo credit: Biomed Central)

Foot respiratory mechanics 

If your feet supinate are you using an inhalation strategy? If you pronate are you using and exhalation strategy? 

Address supination and pronation deficits 

Would banded squats be a good exercise for someone who is a crazy chronic supinator? This would drive hip/femur Abduction to encourage pronation at the foot…and with chronic pronators, squats w/ an adductor squeeze to drive hip/femur Adduction to allow for supination. How would this fit in with a narrow ISA w/ supination? ( Narrow ISA=Narrow IPA= needs adductor squeeze to widen IPA)

Flat feet 

Do you think you can address flat feet, and how you may be able to manage it?

Foot mechanics during the squat

Also, do you mind explaining on a debrief why calcaneal movement drives such profound changes or capacity for one to increase their squat depth. Much appreciated as always!


I often see a foot resting in plantar flexion but also with a bunion. I am having a hard time wrapping my head around this as I think of a plantarflexed foot as a foot in supination and associate a bunion with a pronated foot. Please help!

Sum Up

  • Inhalation = supination; exhalation = pronation
  • Drive external rotation to enhance supination, internal rotation to enhance pronation
  • Flat feet occur with pronation either through the calcaneus or a first ray compensation. Improving movement on a flat foot requires working the opposing movement strategy.
  • Squats should accompany foot supination due to their inhale bias
  • Bunions are an exhalation (dorsiflexion and eversion) compensation at the metatarsal and phalanx. Treatment would involve reversing this relationship to improve movement options.

Photo credit: Mikael HäggströmM.D.