What the Hell does that Word Mean – Basic Anatomy Terms

by Capt James Rodgers | May 25, 2021

Sometimes it is useful to be able to accurately describe the human skeleton and the way that it moves without sounding like a jackass. When I read Starting Strength or read through articles on the site, I will usually run into a lot of words that I do not understand. I do not like it when I do not understand things, and I bet that there are a lot of people out there who feel the same way. I have no education or training whatsoever in anatomy, kinesiology, or medicine so this article is my attempt to make the intimidating and complicated-sounding language used to describe human anatomy more accessible to the layman. Not every term will be covered, since it is not required to know terms for things such as sticking your jaw forward (protrusion) or bending your ankle sideways (inversion/eversion) when describing a deadlift (or at least I hope not).

To understand the basics of the descriptive terms used in anatomy, you need to know:

1. How the locations of things are described.
2. How the movements of things are described.

Once you have a grasp of directions and how things move, you will be well-positioned to string together sentences that are accurate and coherent. If you want to learn about this topic from some people with actual training and experience in the field, I highly recommend that you check out the free educational site Kenhub for videos and other interactive media.

Some of the terms on that site, in the medical literature and in the anatomy literature vary according to authorship and tradition. The terms used on this website and in the Aasgaard Company materials will be described in this article.

Planes and Directions: How the Locations of Things are Described

The human body is a three-dimensional object, and to accurately locate things, you need to describe from what direction you are looking at something. These directions are planes. The anatomical plane system is a series of views that slice through the body. Think of the planes like you would think of planes of glass that cut straight through the body. There are three planes to be concerned about: sagittal, horizontal and frontal.

In the Sagittal plane, the plane of glass slices through the body from front to back, parallel to a side wall, along the middle of the body from the nose to the back of the head. If you look at someone oriented in the sagittal plane, you will see the left or right side of a person’s face in profile. I remember the term by thinking “sagittal” equals “side.”

In the Horizontal plane, the plane of glass slices through the body at the midsection parallel to the plane of the floor. If you look at someone oriented in the horizontal plane, you will see either the top of their head or the bottoms of their feet. I remember this term by thinking that the horizon is flat and if you want to see it, you’ll need to look straight down or up.

In the Frontal plane, the plane of glass slices through the body through the shoulders and ears from left to right, parallel to the wall in front of you. If you look at someone oriented in the frontal plane, you will see them straight on from the front or from the back. I don't need much help remembering this term.

The Median is a reference line that runs along the exact center of the body. It bisects the body on the sagittal axis when viewed from the frontal plane. I remember this term by medial = middle.  

Once you can explain from what direction you are looking at the body, you can start talking about directions. These directions are usually given in reference to the median or in reference to other body parts, while standing in “Normal Anatomical Position” – the body standing upright, facing the observer, arms hanging at the sides with palms facing forward. The directions are described in pairs, indicating opposite directions. The most important ones to understand are superior/inferior, anterior/posterior, medial/lateral, and proximal/distal.

Superior/Inferior: These two terms indicate the location of anatomy with reference to which one is above the other while standing in normal anatomical position. Superior means higher and inferior means lower. Your skull is superior to your spine. Your foot is inferior to your knee.

Anterior/Posterior: These two terms indicate the location of anatomy with reference to the front and back; anterior means the front and posterior means the back. Your face is anterior to the back of your head. Your lower back is posterior to your belly.

Medial/Lateral: These two terms indicate the location of anatomy with reference to the median. Medial means that something is closer to the median and lateral means that something is farther from the median. Your nipple is medial to your armpit and your ear is lateral to your eye.

Proximal/Distal: These terms indicate the location of anatomy in the limbs with reference to how close something is to the Center of Mass (COM) of the body. Proximal means that something is closer and distal means that something is further. Your knee is proximal to your ankle and your elbow is distal to your shoulder.

Anatomical Movements: How the Movements of Things are Described

Anatomical movements are used to describe the nature of movement about a joint. A very important thing to remember is that the movements are always described with reference to a plane or axis. Every time there is a movement, think about the reference plane on which the movement is viewed so that terms like the changes in joint angles make sense. Basic terms to understand that relate to gross movement of limbs are flexion/extension, abduction/adduction, external and internal rotation, and pronation/supination.

Flexion/Extension: With flexion and extension, you view the body and define the angles created in terms of the sagittal plane. Flexion and extension refers to the bending and straightening of a joint. Generally, when a joint flexes (bends), the angle between the two reference bones separated by the joint when viewed from the sagittal plane decreases. When a joint extends (straightens), the angle between the two reference bones separated by the joint when viewed from the sagittal plane increases. Example: there is more flexion of the knee joint at the bottom of the squat than there is in the deadlift.

Abduction/Adduction: Abduction and adduction are movements that occur relative to the median. Abduction and adduction are viewed from the frontal plane and for our purposes, they are used to describe movement of the arms and legs away from and towards the median. Abduction is when a limb moves away from the median. Adduction is when a limb moves towards the median. Example: performing the cue “knees out” in the squat results in abduction of the femur.

External and Internal Rotation: This describes movements that occur in the horizontal plane relative to the median. External rotation is the rotation of a limb away from the median. Internal rotation is the rotation of a limb towards the median. Example: performing the knees-out cue in the squat descent is also external rotation of the femurs. With flexed elbows, the motion occurs in the sagittal plane.

Pronation/Supination: These are special types of rotation that describe the motion of the forearm resulting in a hand position with palms facing up or down. Supination is palms up and pronation is palms down. With extended elbows, supine is palms forward and prone is palms backward. There is a useful mnemonic to remember this: Supination to the Sky and Pronation to the Plants. Example: the mixed grip in the deadlift features one hand in supination and one hand in pronation.

You now know enough anatomy vocabulary to be confusing. Good luck.