[headline style=”1″ align=”center” headline_tag=”h2″]Introduction to Understanding the Foot


The foot and ankle, which contains 26 bones and over 100 muscles, tendons, and ligaments is often times overlooked, misunderstood, or often times scary for clinicians to treat.

It is often the source problem in lower extremity musculoskeletal pathology. Normal foot and ankle mobility and stability is needed to walk, run, and even twist during rotational movement patterns. When this part of the body isn’t working optimally, other areas of the body, even far from the feet can become painful and irritated.

Although it appears complex, the foot really is simple when you understand what the foot does functionally….

In this post I’ll disclose the foot terminology, simple anatomy of the foot and ankle, the function of the foot & ankle, and finally, the most important joints you need to assess and treat in the foot.

[headline style=”1″ align=”center” headline_tag=”h2″]Understanding Foot Terminology & Axis Orientation


We have all heard of the words pronation, supination, inversion, eversion, adduction, abduction, and dorsiflexion and plantar flexion in regards to the foot. However, often times these terms confuse practitioners and students.

The terms pronation and supination refer to three motions.

1) Dorsiflexion

2) Eversion,

3) Abduction.

When the foot goes through pronation it is going through all three of the motions at the same time since the majority of the joints of the foot are situated with an axis not in any one plane but, rather, mixed.  This is why motions occur in all three planes.

In contrast, supination is:

1) Plantar Flexion

2) Inversion

3) Adduction.

Again, when the foot goes through supination it is going through all three of these motions due to the axis orientation. This is especially true in the STJ and MTJ.

Now, where the terms get lost is translation is when clinicians start to say the terms inversion and eversion. Many uses these terms synonymously with pronation and supination. This is because the joints that do pronate or supinate may only have a little bit of dorsiflexion, plantar flexion, or adduction and abduction…..

Instead they have a lot more frontal plane motion so many just call the motions eversion or inversion since the transverse and sagittal plane motion are negligible.

For instance, the subtalar joint axis lies primarily in the sagittal plane and rotates quite nicely into inversion and eversion. However, because the axis is more in the sagittal plane rather than the frontal plane, their is minimal DF and PF.

Likewise, instead of calling foot motion internal and external rotation, the terms adduction and abduction were adopted to further make this a challenge.

To see all this applied check out this video:


[headline style=”1″ align=”center” headline_tag=”h2″]Anatomy of the Foot and Ankle


The foot can be broken down into three key areas:

  1. Rearfoot
  2. Midfoot
  3. Forefoot


The rearfoot is the talus and calcaneus and the midfoot consists of the  navicular, cuboid, and the 1-3 cuneiform. Meanwhile, the forefoot is everything else distally.







The ankle consists of the three bones:

  1. Talus
  2. Tibia
  3. Fibula


I know you all knew this but I had to put in :- )

[headline style=”1″ align=”center” headline_tag=”h2″]Function of the Foot & Ankle


The foot really has four functions:

  1. Maintains Balance Through Equilibrium Reactions 
  2. Shock Absorber
  3. Rigid Lever
  4. Torque Converter


The foot helps us maintain an upright posture when we are stepping on uneven terrain or experience a shift in our center of gravity. For instance, if I am pushed to towards the right, the right foot will supinate, meanwhile the left foot will evert.

This helps keep our COG within our BOS and prevents us from falling. Like wise, if pushed anteriorly the ankle will compensate to prevent falling.

The second function is being a shock absorber during walking and running. This occurs primarily when rear foot pronates which allows the foot to adapt to the ground and reduce shock.

In contrast to becoming a shock absorber, the foot also needs to act as a rigid lever when propelling off our leg in gait. This happens when the STJ inverts and locks up the the MTJ.  This allows the body to roll over the first MTP and place weight through the first ray.

This is very, very, very, important mechanism for the entire body by the way.

Finally, the foot is needed to enhance rotation in the lower limb and trunk. For instance, when the foot pronates the lower leg will internally rotate. This literally will turn on the muscles of the hips and core secondary to this mechanism. This is just one of the many reasons why subtalar joint pronation and supination is crucial.


[headline style=”1″ align=”center” headline_tag=”h2″]Important Joints To Assess In the Foot



There are several different joints  in the foot and ankle. You should only assess these five joints.  This is why the foot is complex yet so simple to treat 🙂

Here are the 5 joints you will want to assess and treat:

  1.  SubtalarJoint
  2.  Ankle joint
  3. Midtarsal Joint
  4. The 1st TMT
  5. The 1st MTP


Although all these joints are important, everything starts with the subtalar joint. This joint basically “sets the stage” for the remaining joints to do their part. It often times becomes pathological when it doesn’t pronate or supinate at the times needed or none at all.


Over the new few weeks I will be building on this post and will actually show you how you can assess and treat these different joints.

[headline style=”1″ align=”center” headline_tag=”h2″]Conclusion On Assessing The Foot & Ankle


As you can see….

The foot and ankle really are quite simple once you understand what it needs to do in function.

In the coming weeks I will be posting more videos on how to assess all these joints. I think you will find your skill-set in assessing and treating the foot will improve dramatically by following my upcoming posts.

By the way, if your treating patients with plantar fasciitis usually the subtalar joint doesn’t resupinate which makes the windlass mechanism ineffective. Very simple to treat most of the time.

More on this later….