Base of Support, and Balance

to Teach Them Easily in Elementary PE

Hi, this is Young-in! �

Today, we’ll look at the basic biomechanical concepts of center of gravity, base of support, and vertical line, and explore how to use them to teach the principles of balance in a way that’s clear and easy for elementary students to understand.

1️⃣ What is the Center of Gravity?

The center of gravity is an imaginary point where we can think of all of our body weight as being concentrated. When a person is standing upright in the attention position, the center of gravity is roughly located a little below the belly button, inside the body. But this point is not fixed—it constantly changes depending on posture.

When jumping: raising the arms makes the center of gravity move upward.

When crouching: lowering the body makes the center of gravity move downward.

When leaning: tilting the body to one side makes the center of gravity move toward that side.

In short, students need to understand:

“When your posture changes, the position of your center of gravity changes too.”

2️⃣ Base of Support: “The Area of Ground You’re Standing On”

The base of support is the area of the ground covered by the body parts (feet, hands, etc.) that are in contact with the floor, plus the space between them.

Standing with feet wide apart → the base of support is wide (more stable).

Standing on one leg → the base of support is very narrow (less stable).

Crawling on all fours (bear walk) → using both hands and feet makes the base of support as large as possible (very stable).

The wider the base of support, the larger the range within which we can maintain balance, and the more stable we become.

3️⃣ The Key Principle of Balance: “Keep the Line Inside the Base!”

Here is the most important rule:

“For the body to be stable, the vertical line dropped from the center of gravity must fall within the base of support (the feet).”

Wrestling: When an opponent pushes you and the vertical line from your center of gravity moves outside your base of support (outside your feet), you lose balance and fall.

Balance beam: Students stretch their arms out to the side to help keep the vertical line from their shifting center of gravity within the narrow beam, which is their base of support.

You can explain it to students like this for faster understanding

“Imagine a laser beam shooting straight down from your belly button to the floor.
If that laser stays between your feet, you won’t fall!”

4️⃣ Balance Activities You Can Use Right Away in Class

�‍♀️ Static Balance

Standing on one leg

Yoga tree pose

Holding still on a balance beam

�‍♂️ Dynamic Balance

Walking on a line

Walking while dodging obstacles

Push-and-pull games

Instead of just saying, “Keep your balance!”, give specific biomechanical feedback such as:

“Spread your feet wider (increase your base of support) and lower your belly button (lower your center of gravity)!”

This helps students learn to adjust their posture on their own.

� Classroom Application – Young-in’s Teaching Tips

✅ Tip ① “Draw Your Center Line” Activity (Visualization)

Take photos of students while they’re moving (side view, front view), print them out or show them on a tablet. Have them draw a line from their center (belly button) down to the floor.

Let them discover this rule by themselves: “If this line falls inside the feet (base of support) → stable. If it goes outside → you lose balance.”

✅ Tip ② “Adjust the Base of Support” Pushing Game (Hands-on Experience)

Have students play a palm-to-palm pushing game with a partner twice:

Round 1: Stand with feet together (narrow base of support) and push → they lose balance easily.

Round 2: Stand with feet wide apart and bend the knees
(wide base of support + lower center of gravity) → they can resist much better.

This is one of the best ways to let students feel the difference in stability with their own bodies.

� In Closing

Balance is the foundation of all sports skills and a safety mechanism that helps prevent injuries. Once students understand the principles of center of gravity and base of support, they move beyond just copying movements and begin to think for themselves about “what I should do so I don’t fall over.” How about spending today’s PE lesson helping your students “find the center of their body”? �