At times treatment can include a walking boot or even casting. Ultimately, we just want to reduce the pull on the growth plate until the patient finished growing in that area.
On the 5th metatarsal this is called Iselin's Disease. You can see two photos from radiopaedia.org that shows this condition. (http://radiopaedia.org)
As you can see the area on the little toe side of the foot at the base there is a little piece of bone where the peroneous brevis attaches. The goal of treatment is to reduce pain.
If you would like to learn more about this condition here is a helpful article you can download and read (it is quite technical but has some good pictures). If I can help you understand more about it please ask me a question below.
To your health,
Dr. Donald Pelto