The planes of human motion

What are the planes of human motion and why should we care?

If you’re a student of physical therapy, chiropractic or other medical profession, you’ll get this in school if you haven’t already. If you’re planning to certify in personal training or as a strength and conditioning coach will need to know it. Whilst for the most part, many o us don’t really need to know too much about the planes of human motion, it is something that any athlete or gym goer will come across from time to time throughout their health and performance journey.

Here is the simple version of the planes of human motion.

In its simplest form:

• Sagittal. Forward and backward movement;
• Frontal. Side to side movement;
• Transverse. Rotational movement.

When picturing how this looks, just imagine slicing through the human body like this:

• First through the centre, dividing the body from the left to the right to make up the sagittal plane;
• Next through the body from the left side to the right, separating the front and back halves to create the frontal plane;
• Finally cutting straight through the hips to divide the top of the body from the bottom, the transverse plane.

Not too hard right? It starts to get a little more complicated when you start to look at which motions move along each of the planes.

How to visualise the planes of human motion

Sagittal plane motion would include forward and backward motions, like sit-ups, back extensions or biceps curls. The sagittal plane cuts through the center of the body, so the motion is front to back or back to front, including straight forward running.

Squats involve flexion (forward motion) and extension (backward on the way up), so would fit into the sagittal plane.

Frontal plane motion would include leaning from left to right as in sidebends and lateral raises, or perhaps you might picture jumping jacks for a good image of movement along the frontal plane.

Transverse plane motion is the hardest to picture because the plane is horizontal as it divides the top from the bottom, so it can be hard to get your head around it being a rotating action. The main thing to remember is the rotation.

A good example of a transverse plane exercise would be medicine ball or cable wood chops, where the ball or cable moves across the body while a transverse activity would be swinging a golf club.

So, why is it important to know about or understand this?

It’s important to know that the planes  exist and to make sure our training programs include exercises along each of them. The most common gym exercises are on the sagittal plane, moving forward or back such as in horizontal or vertical pressing, pushups, crunches or even squats and lunges.

When creating exercise programs for clients, team mates or even just for yourself be sure to add some frontal plane and transverse plane exercises to bring up your built-in injury prevention.

Training in all three planes of motion is what’s going to help ensure good balance in your muscular body. Consistently training only within a single plane will basically do the opposite.

Human Movement Terminology

Now let’s take a look at a few other common movement terms used in anatomy and physical training. I’ll try to keep it brief and simple to give a base understanding and provide yourself with a bit of a cheatsheet in the event you decide to read an advance training article to further your knowledge or are recovering from an injury and need to understand what your surgeon or physiotherapist is telling you.

Prone vs supine
Prone is lying face down. Supine is lying face up.

Superior vs inferior
Superior means closer to the head. Inferior means closer to the feet.

Medial vs lateral
Medial refers to nearer to the center. Lateral refers to farther from the center.

Posterior vs anterior
Posterior is toward the rear. Anterior is toward the front.

Distal vs proximal
Distal means farther from the torso. Proximal means closer to the torso.

Extension vs flexion
Extension straightens a joint. Flexion bends the joint.

Supination vs pronation
Supination and pronation are used to describe action at the feet or forearm. In the feet, supination refers to an outward rolling action, while pronation refers to an inward rolling action.

With the forearm, supination refers to turning the palm up and pronation refers to turning the palm down.

Medial vs lateral rotation
Medial rotation turns toward the center of the body as in internal rotation. Lateral rotation turns away from the body externally.

Elevation vs depression
Elevation means upward; depression means downward. These terms are most often used to describe faulty scapula position, being either too high or too low.

Adduction vs abduction
Adduction brings the limb in toward the body. Abduction moves it away.

Dorsiflexion vs plantar flexion
Dorsiflexion at the ankle is to bring the toes toward the shin. Plantar flexion points the toes away.

Joint mobility vs flexibility
Joint mobility encompasses the ability of the joint to move through its full range of motion. Flexibility is about muscles, not joints, and is about lengthening the muscle to its optimal length.

Stability vs mobility
Stability is the muscle, tendon and ligament action needed to hold a joint in position.

Mobility requires the correct muscle action on one side of a joint and the necessary muscular flexibility on the other to produce full movement through a joint’s range of motion.

Activation vs dormant
Activation means an action to trigger a muscle that’s not firing well. Dormant refers to an inactive muscle group, at varying levels from fully inactive to fully engaged.

Tendons vs ligaments vs fascia vs myofascia
Tendons connect muscles to bones. Ligaments connect bone to bone. Fascia is connective tissue that covers soft tissue from head to toe, superficial to deep. Myofascia is fascia covering muscle.

Bilateral vs unilateral
Bilateral refers to both sides of the body working together. Unilateral is one side alone.

Concentric vs eccentric
Concentric shortens the muscle; eccentric lengthens.

For example, during the conduct of biceps curls the concentric action brings the wrist toward the shoulder whilst the eccentric action returns the weight to the start point with the arm extended.

Isometric vs isotonic
Isometric changes the muscle tension without changing the length. Isotonic changes the muscle tension while changing the length.

Origin vs insertion
Origin of a muscle is the stationary attachment site of muscle to bone. Insertion is the mobile attachment end site.

Primer mover vs synergist vs antagonist
Prime mover is the main muscle that carries out an action. Synergist assists the prime mover while the antagonist performs the opposite action.

Hopefully, that was simple enough to understand and a fairly comprehensive cheatsheet.