The posterior tibial tendon derives from the posterior tibialis muscle. The tendon runs alongside the medial aspect (inside aspect) of your ankle and inserts primarily on the navicular bone (the boney prominence above the inside arch of your foot). The posterior tibial tendon is responsible for maintaining the integrity of your foot arch.
Tendinosis is caused by overuse when the body cannot adapt to meet demands placed on it. Overuse can be precipitated by muscle imbalance, improper footware, improper technique in sport, poor biomechanics, etc. Certain systemic conditions such as rheumatoid arthritis can predispose someone to tendinopathy or tenosynovitis (inflammation of the tendon sheath).
As with any tendinopathy, pain and decreased performance are the major symptoms. At early stages, the pain may initially improve with activity, worsen towards the end, and cause soreness that night or the next day. There may be subjective and objective strength loss. Pain will typically occur in a distribtion that follows the tendon.
Procedural options for chronic tendon dysfunction include regenerative-type injections (such as platelet-rich plasma [PRP]) that can theoretically provide long lasting pain relief and improved function by stimulating the body’s own natural healing response. There is some evidence that needling the tendon alone can stimulate bloodflow and healing. A procedure called TENEX can be done under ultrasound as well which uses a small oscillating needle to debride (suck out) the damaged parts of the tendon.