Post-Tib Tendonitis is a strain placed on the posterior tibial tendon. The posterior tibial tendon runs along the inside of the ankle and the foot. When there is post-tibial tendon disfunction, the tendon does not function to hold up the arch, resulting in flat feet. This can lead to heel pain, arch pain, plantar fasciitis and/or heel spurs. With post-tib tendonitis, pain will be more severe upon weight bearing, especially while walking or running.
Cause
Post-Tib Tendonitis occurs when the muscle is overused and the tendon (soft tissue) that connects the muscle to your bone is strained. Years of over-pronation (flat feet) can also lead to posterior tibial tendon dysfunction. If you keep overusing the muscle, damage to the tendon builds up and tendonitis develops. At first the pain or swelling may come and go quickly, but eventually the problem may become more permanent.