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Planes of Movement
We can’t quite turn our heads all the way around to the back, and we can’t twist our spine 360º. However, we still have remarkable mobility...and injuries to any of our joints will lessen our ability to move. When we move our hands in figure 8’s, we are moving within these three planes of movement. Here is an explanation of each plane:
Sagittal plane: Divides your body into symmetrical right and left halves. Movements in this plane include flexion or extension. (The imaginary line goes from the middle of the top of your head straight down to your toes.)
Frontal or Coronal plane: Divides the body into front (anterior) and back (posterior) parts. Movements in this plane include adduction, abduction or lateral flexion. (The imaginary line goes down your side from your head to your feet.)
Transverse or Horizontal plane: Divides the body into upper and lower parts. Movements in this plane include lateral and medial rotation, pronation, and supination. (The imaginary line is at your waist.)
Here are five common joint movements:
Flexion vs. Extension:
When you flex or bend your elbow, you are decreasing the angle between the upper arm bone and the lower arm bone.
When you extend or straighten your elbow, you are increasing that angle. Any joint can be flexed or extended.
Therefore, flexion refers to a movement that decreases the angle between two body parts. Flexion and extension of the elbow is as described above.
All joints can flex and extend. The knee, for instance, bends when it's flexed and is straight when it is extended.
Abduction vs. Adduction:
When you abduct your leg, it moves away from the body’s midline of the body.
When you adduct your leg, it moves toward the midline of the body.
So, abduction is the motion of a structure away from the midline while adduction refer to motion towards the center of the body.
The centre of the body is defined as the midsagittal plane (see comments above).
Inversion vs. Eversion:
Inversion occurs when you turn the soles of your feet so that they face each other. Inversion, then, is the movement of the sole towards the median plane.
Eversion occurs when you turn the soles of your feet so that they face away from each other or away from the body. Eversion is the movement of the sole of the foot away from the median plane.
Dorsiflexion vs. Plantarflexion:
Bending your foot at the ankle so the toes move up toward the shin is dorsiflexion.
Bending the foot at the ankle so the toes point down is plantarflexion.
Dorsiflexion is a term that refers to the backward motion of a body part. This is often used with respect to hands, feet, fingers, and toes. When you bend your fingers back, this is dorsiflexion. Plantarflexion refers to the bending of the foot or toes toward the sole of the foot.
Supination vs. Pronation:
Palms up or forward or ankles leaning out is supination.
Palms down or back or ankles leaning in is pronation.
You are supine when you lie on your back.
You are prone when you lie on your stomach.
The supine position means lying horizontally with the face and torso facing up, as opposed to the prone position, which is face down. When used in surgical procedures, it allows access to the peritoneal, thoracic and pericardial regions; as well as the head, neck and extremities.
Hyperextension is an extension beyond the normal anatomical position; it is an unnatural bend of any joint. For example, imagine your knee going the opposite of the “normal” way — that’s hyperextension. It kind of makes you cringe just to think about it, doesn’t it? You can probably imagine how either locking or hyperextending a joint could harm it permanently.
Using these terms when exercising
It's important to understand these concepts, even if you don't know the terms, especially if you have limited range of motion because of a disability or injury. Your goal may be full range of motion but sometimes that it is a slow process.
I am a BCRPA-certified fitness instructor in Vancouver, BC. I teach four classes at the West End Community Centre in Vancouver, BC, mostly designed for the older adult. The Inevitable Disclaimer: Everything published here expresses only my opinion, based on my training and research. What you do with the information is entirely your own responsibility. I am not liable for any injury you suffer that seems to be related to anything you read here. Always consult your doctor before beginning an exercise program. For other articles, return to the table of contents.
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