Joint questions

dmguido · Joined: 12 Jan 2010 Posts: 1

Hi, I am a student in Radiography and am having a hard time understanding the following question.

State two reasons why the routine for examinations, including joints often consists of three projections.

In class my Instructor, told us the folloing:

"Three projections are usually required when radiographing parts of the body where joints or articulations are in the primary interest."

1. AP or PA
2. Lateral
3. Oblique

I can not find it in my texbook either...please help because I have a test on Thursday-01/14/2010