To avoid confusion in medicine and physical therapy, there exists standard medical and anatomical terms.  To describe physical movement, we use these same terms.

So as not to overwhelm you, I’d like to introduce some of the Anatomical Directional Terms that will help you to better understand the upcoming information in this Anatomy 101 section.

Medial: Toward the mid-line, middle, away from the side.

• Example: If I were to draw an imaginary line dividing equally the two sides of your body, this line would be called the mid-line.
• Example: Your navel is located on your mid-line.
• Example: When you lift your arms away from the sides of your body up to shoulder height (like an airplane), you have moved your arms away from the mid-line.
• Example: When you return your arms towards the sides of your body (from the airplane position), you are moving your arms back toward the mid-line.

Lateral: Toward the side, away from the mid-line 

• Example: A movement which moves a bone or structure lateral (away) from the mid-line, in the direction of the outside (right or left sides) of the body.
• Example: In relation to your mid-line, your hip bones are laterally located.
• Example: When your straight arms are touching the sides of your body they are close to the mid-line.  When your straight arms are out to the side (like an airplane) they are lateral. Hence, the exercise Lateral Deltoid Raise refers to this action.

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However, the actual term of motion for lifting your straight arms out to the side (like an airplane) is called Abduction, literally, to take away from.  The term of motion for returning the arms towards the mid-line is called Adduction, literally, to move towards or bring together.