Plantar Fasciitis is inflammation of the plantar fascia (a thick fibrous tissue that runs along the bottom of the foot that connects your heel bone to your toes). What that means is that you are essentially overusing your plantar fascia. We see this condition in people who stand or walk a lot for their jobs or people who are active (ex: runners, dancers, ballet, soccer players, etc.).
Achilles tendinitis is the inflammation of the Achilles tendon. This is caused by an overuse of the Achilles tendon. We commonly see this in active individuals like runners and sports such as basketball, tennis, and soccer.
Marrow edema/stress reaction is the inflammation of the calcaneus (heel bone). This is also known as a bone bruise. This usually occurs either with sudden trauma to the heel (ex: a ballet dancer or gymnast landed hard on his/her heel) or repetitive microtrauma to the heel.
Tarsal tunnel syndrome is a condition where the tibial nerve is irritated. This usually happens in individuals who have flatfeet or overpronate. Biomechanically, when that happens, the structures on the medial (closest to midline of the body) ankle, including the tibial nerve, gets compressed and, over time, the compression irritates the nerve and causes it to swell. One of the branches of the tibial nerve is the medial calcaneal nerve, also known as Baxter nerve, and an entrapment of that can cause heel pain.