Maulik describes the technical language employed by physicians in talking or writing to each other. However, it is unlikely that your patients will be familiar with that terminology, so using it will not produce the action you desire—and it may intimidate your patient, or annoy her.
I have consulted my wife, who not only has been such a patient but also taught medical students examination skills for many years, and she advises against the use of technical language. Do not say "assume a lateral position"; say "roll onto your left/right side". Do not speak of "auscultating"; say "listen to".
She further advises that you treat your patient as a colleague in the process, not as the mere occasion for you to practise your skills. Be courteous and precise about what you want and why. Don't just say "turn this way, turn that way"—say something like
Now: if you could turn to face me [or "to your left" or "your right", or "roll onto your left/right side"], that will help me [do whatever you are going to do next]. That will give us ["us", not just "me"] a better idea about [whatever it is you are trying to find out].
"Long-form" language like this will help build rapport with your patient, demystify the process, and dissipate her anxiety. It will also make her an active and knowledgeable participant in the examination, which will greatly facilitate your future collaboration.