The lower (lumbar) spine allows your body to turn, twist, and bend. It also gives strength for standing, walking, and lifting. The lower back is involved in almost all movement. Pain in the lower back is very common.
Plantar means something on your foot. Fascia is one of the kinds of tissue that connect different body parts (called connective tissue). So the plantar fascia is a band of tissue that connects the heel and ball of your foot.
Arteries are blood vessels that carry blood from your heart to the rest of your body. "-Itis" means inflammation. So arteritis is inflammation of your arteries. Blood vessel inflammation in general is called vasculitis.