Plantar Fasciitis is inflammation of the connective tissue that connects the heel bone to the toes. Symptoms include intense heel pain.
There are many layers of muscle underneath the superficial plantar fascia that replicate the same symptom.
Postures where your weight lands mostly on your toes will cause the muscles in the bottom of your feet to tense for grip. This might include high heels, or a professor who leans forward on a podium, or even a runner.
Three muscles make up your achilles tendon, all of which attach to the other side of the heel and may cause heel pain. Soleus, also known as the heart of the lower leg, pumps blood to and from the foot. When people have swollen feet and ankles that is a tell tale sign that their soleus is tight and needs to be released.