BeneFIT PT’s Anatomy Series: The Ankle

We are continuing BeneFIT  Physical Therapy’s Anatomy  Blog Series this month with the Ankle Joint. Each month we will feature a different part of the body.  BeneFIT PT’s staff is highly trained in knowing all about human anatomy so that we can effectively help our patients with their specific areas of concern, rehabilitation and strengthening.

Our ankles take a beating and keep us chugging right along.  The mobility of our ankle joint is super important as we walk over uneven terrain, grass, and hiking trails to allow our feet to roll over the bumps and our legs to move forward over our feet.  It has to be stable enough to provide the support for when we quickly change directions, like when we cut in various sports, as well as to handle the load of us trying to immediately slow down from a run or when landing from a jump.  Finally, it has to be stable for our balance.

With so many functions you might be wondering how it handles all of that work?  To that end, let’s dive into the joint and figure things out!


When you look all the way down you leg to your ankle we typically see those 2 bumps on either side above our foot and think there it is…our ankle.  But did you know that really our ankle is comprised of 2 joints.?  The first is the ankle joint.  It is what we think of as our ankle – those two bumps on either side of the bottom of our leg.  It is comprised of 3 bones:

  • Tibia – the larger of the two lower leg bones, and what makes the bump on the inside of our leg.
    Ankle bones

    The Bones of the Ankle

  • Fibula – the smaller bone of the lower leg, and what makes the bump on the outside of our leg.
  • Talus – this is a small bone between the tibia and fibula.

When we look down at our ankle we don’t really see that talus bone so well.  It sits between the two bumps, which are called the lateral malleolus (which is the bottom of the fibula) and the medial malleolus (which is the bottom of the tibia).   Most people think the bottom of our ankle joint is our heel but that is actually  a part of the second joint called the subtalar joint.  It is comprised of 2 bones:

  • Talus – this is still the small bone between the malleoli of the tibia and the fibula.
  • Calcaneus – this is the heel bone on the bottom of our foot.

Even though we commonly refer to both joints as our ankle we can have issues in one joint that can effect the other joint and create pain, discomfort, and issues for our ankle in general.


Common ligaments of the ankle

Ankle ligaments for both the inside and outside of the ankle | ©Vectormind

Despite the fact that pretty much everyone at one time or another has sprained their ankle, the ankle possess some strong ligaments which hold the bones together.  Remember ligaments are what connect bone to bone to keep joints stable.  There are 3 primary ligaments in the ankle:

  • Anterior Tibiofibular Ligament – connects the tibia to the fibula and helps the two bones from separating when put weight through our leg.
  • Lateral Collateral Ligaments – Thera are actually 3 of these ligaments that connect the fibula to the calcaneus and provide stability to either side of the outside ankle.  They are (in order of front to back) the Anterior talofibular ligament, the calcaneofibular ligament, and the posterior talofibular ligament.
  • Deltoid Ligaments – so named as the ligament is in a shape similar to a deltoid.  It attaches the tibia to the talus and calcaneus as well as provide stability to the insides of the ankles.

When we typically ‘roll our ankle’ the pain and swelling just below and in front of our lateral malleoli is due to injuring the anterior talofibular ligament.


Some of the common tendons that run past the Ankle.

Tendons are similar to ligaments except that they connect muscles to bones.  In the ankle there are multiple tendons that run through to attach muscles of the lower leg to the bones of the foot and ankle.  The muscles responsible for moving our ankle, foot, and toes predominately are located in towards the top of our lower legs.  From the bottom of these muscles long tendons run through the ankle and attach to different bones in our foot and toes.  This is almost identical to how the muscles and tendons of our forearms go through our wrists into our hands.    The main tendons include:

  • Achilles Tendon – attaches the calf muscle to the heel bone (calcaneus).
  • Flexor Hallicus Longus – runs along the inside of the ankle and attaches to the big toe.
  • Flexor Digitorum – runs along the inside of the ankle and attaches to remaining toes.
  • Peroneal Tendons – a set of two tendons that run along the outside of the ankle and attach at the the shaft of the small toe (5th metatarsal) and the bottom of the foot.
  • Posterior Tibialis Tendon – runs down the inside of the ankle and attaches at the mid-foot as well as helps maintain the foot’s arch.
  • Anterior Tibialis Tendon – runs down the front of the leg and attaches to the bones of the midfoot. 


There are four primary motions that our ankles make.  Standing on our tippy-toes or pointing our foot down like pushing a gas pedal is called Plantarflexion (PF).  Anytime, in standing or sitting,  we keep our heels down and point towards the ceiling with our foot and toes is called Dorsiflexion (DF).  Keeping our legs straight and rigid but then moving our feet towards each other as if we were going to hold something between the big toes or our feet is called Inversion (Inv).  On the other hand, keeping our legs straight and rigid but moving our feet away from each other is called Eversion (Ever).

These are the primary four motions our ankle makes but we can combine these four motions simultaneously to create new motions making our ankle one of the most mobile joints in the body!  Swinging your foot around in a circle, or spelling the alphabet with our feet are examples of how these four motions can be used at the same time to create more mobility.  All of these motions are the responsibility of four main muscles groups:

  • Peroneals – 2 separate muscles, peroneus longus and brevis. These muscles allow the ankle to bend outward and down (eversion/plantarflexion). 
  • Gastrocnemius & Soleus – better known as the calf muscles, these 2 muscles connect to the heel bone (calcaneus) by way of the achilles tendon. These muscles allow the ankle to bend downwards (similar to pushing a gas pedal).
  • Posterior Tibialis – this muscle provides support to the arch of the foot and allows the ankle to invert (turn inwards).
  • Anterior Tibialis – located on the front/lateral portion of the anterior lower leg (shin) this muscles allows the ankle to bend upward (dorsiflexion). 

All of these muscles working together not only provide all that mobility but they are responsible for making our ankles stable to support our planting and pushing off, and improve our balance!  Typically they are working overtime because they have to provide support and stability in all the mobile positions the ankle can achieve!

Bringing it All Together

As you can see the ankle joint is more involved than just ankle sprains.  The ankle has a number of different common injuries you might have to deal with based on the combination of bone, muscle, ligament, or nerves involved in the injury.  Touching base with your Physical Therapist can speed up the process in figuring out what exactly is causing your pain…even without seeing an Orthopedist or getting an MRI!

If you’re having any issue with your ankle currently and want to get it checked out just contact either of our offices.  Our Doctors of Physical Therapy can see you without a prescription, covered by your insurance, often times within 24 hours from your call!