The posterior tibial muscle originates on the back of the lower leg, deep to the calf muscle.  As it courses down the leg, it comes around the inside back of the ankle, under the inside ankle bone (medial malleolus) and attaches to the navicular bone and most of the bones in the middle part of the foot.  When it contracts, it inverts the foot, so it functions to help support the arch and resist arch collapse. In other words, it resists the foot and arch from undergoing too much pronation, sometimes termed overpronation.

When the posterior tibial tendon develops inflammation, it needs the same prescription of PRICE (protection, rest, ice, compression, elevation) as well as a trip to the foot care provider for treatment which may consist of taping to temporarily splint the foot, ankle and lower leg in a position of inversion to  rest the tendon. Non prescription and prescription orthotics play valuable roles in the prevention of the posterior tibial tendonitis becoming a more serious problem which we call POSTERIOR TIBIAL DYSFUNCTION(PTD),  or acquired flatfoot.

This occurs when the posterior tibial muscle and tendon have become weakened or stretched out to the point that they no longer are able to resist the arch collapsing (overpronating) and the foot becomes flat.

When this happens, it is extremely difficult for the person to raise up on the toes of the affected foot without feeling excruciating pain in the arch and many people with PTD are unable to accomplish this maneuver.  The foot takes on the “Too many toes sign” we foot care providers like to talk about, which is what we see when we stand behind people who have this tendon problem. We see their toes pointing to the outside of the foot rather than straight ahead as would be seen in the normal foot. This makes sense, as this foot has been allowed to maximally pronate, and if you consider the manifestation of pronation within the forefoot, it is forefoot abduction (away from the midline or great toe).

Reviewing pronation, there is eversion of the rearfoot, which means the top of the heel bone rolls towards the inside, dorsiflexion and abduction of the forefoot.  PTD is a maximally pronated, flattened, collapsed foot with the back of the foot going to the inside and the front of the foot going to the outside. A miserable, difficult foot to fit in shoegear, that becomes progressively more difficult to treat, the flatter and more misshapen it becomes. For this reason, those with flat, or flexible feet, a family history of PTD, or posterior tibial tendonitis, should seek out the care of a foot care provider with experience treating  PTD.  This likely will also be someone with experience in the understanding and fabrication of foot orthotics.  If the foot is not collapsed, it may respond favorably to non prescription orthotics and the aforementioned PRICE. Sometimes anti-inflammatory medications are offered orally or topically. Steroid preparations (cortisone like medicines) such as dexamethasone can be applied locally as well with a treatment called iontophoresis, which uses electrical current to help your body absorb these medicines. Injectable steroids (corticosteroids) are not generally recommended due to the possibility that they may cause complete rupture of the inflamed and weakened tendon.

If a footbed, arch support or orthotic are part of your treatment plan, make sure to maximize the ability of those supportive devices to resist arch flattening by wearing supportive boots that come above the ankle joint.  That will go a long ways towards inhibiting the affects of arch flattening on your ankle, lower leg and knee.  If you suffer from PTD, do yourself a favor by throwing fashion out the window and dedicate yourself to choosing your footgear based on how it feels with the supportive device and not how it looks.  As you can imagine from the previous statement, this condition is encountered more frequently in women, as is the case with most foot conditions.

If your foot (PTD occurs more frequently on one side only) or feet collapse, you need immediate attention, because failure to get treatment leaves one with less options. Advanced cases generally require wearing restrictive braces that come up the lower leg above the ankle or surgical procedures aimed at getting the foot to be straight and the arch to be elevated.  These procedures often involve the use of arthrodesis (fusion techniques), which remove the painful joint or joints and join two or more bones artificially with hardware (screws, plates, pins, wire, etc).  The joints most commonly fused are the rearfoot joints, where the majority of the eversion, dorsiflexion and abduction (the components of pronation) originate from.  These are the SUBTALAR JOINT(STJ) and MIDTARSAL JOINT (MTJ).  The subtalar joint is the joint below the ankle joint. Its cartilage separates the calcaneus (heel bone) from the talus( bone above the calcaneus and below the tibia).

The MTJ is actually 2 separate joints that work in concert with one another and the STJ while the foot pronates and supinates.  They are the calcaneocuboid joint and the talonavicular joints.  These joint complexes allow the foot to be the incredible adapter that it must be to perform all of the functions that it performs, on all of the varied surfaces that it carries us over. So permanently restricting the foot from ever performing these motions again is never the best option, due to the fact that the joints above and below the fusions are now called upon to do more than they were intended to and to move  unnaturally.  OSTEOARTHRITIS (DEGENERATIVE JOINT DISEASE) is expected earlier than usual in those overworked joints.

Fortunately with regular foot checkups and proper awareness of one’s family foot history, this debilitating foot deformity can often be prevented.