Posterior Tibial Tendinitis
The posterior tibialis tendon starts in the back of the leg and courses along the inside of the ankle, attaching to the navicular, a prominent bone at the inside of the arch. The main function of the posterior tibial tendon is to maintain and support the arch, but the tendon is also a powerful plantarflexor, helping to propel the body forward when walking. When the posterior tibialis tendon is torn, it becomes weak and cannot functioning properly. The arch is no longer maintained and arch collapse will eventually occur if the tendon tear is not treated properly (See Flat Feet).Once the tendon has lengthened and lost strength, it can no longer support the arch and eventually the arch collapses. This results in a chronic condition called adult acquired flatfoot.