Describe the planes and axes of movement and use them to analyse sporting actions such as somersaults and twists

What this dot point is asking

SEAB wants you to describe the planes and axes of the body and use them to analyse sporting movements, including rotations like somersaults and twists. The central idea is that any movement can be described by the imaginary flat surface (plane) it happens in and the imaginary line (axis) it rotates around, giving a precise language for movement analysis.

The answer

The three planes of movement

A plane is an imaginary flat surface that slices through the body, and a movement is said to occur "in" the plane it lies along.

• The sagittal plane divides the body into left and right halves. Forward and backward movements happen in it, such as a running stride, a biceps curl or a somersault.
• The frontal plane divides the body into front and back halves. Side-to-side movements happen in it, such as a star jump or a cartwheel.
• The transverse plane divides the body into top and bottom halves. Rotational movements happen in it, such as a spin or a turn.

The three axes of movement

An axis is an imaginary line the body rotates around. Each plane has a matching axis at right angles to it.

• The transverse (frontal) axis runs side to side. Rotation around it happens in the sagittal plane, such as a forward somersault.
• The sagittal (anteroposterior) axis runs front to back. Rotation around it happens in the frontal plane, such as a cartwheel.
• The longitudinal (vertical) axis runs head to toe. Rotation around it happens in the transverse plane, such as a spin or twist.

Combining planes and axes

Pairs go together: sagittal plane with transverse axis, frontal plane with sagittal axis, transverse plane with longitudinal axis. Complex moves combine pairs. A twisting somersault rotates in the sagittal plane (the somersault) and in the transverse plane (the twist) at the same time.

Examples in context

Example 1. A diver performing a forward somersault with a twist. The somersault rotates in the sagittal plane about the transverse axis, while the twist rotates in the transverse plane about the longitudinal axis. Judges and coaches use this language to describe and score the dive precisely, which is why analysis matters in sport.

Example 2. A gymnast doing a cartwheel. The whole body rotates sideways in the frontal plane about the sagittal axis. Describing it this way distinguishes it clearly from a forward roll (sagittal plane, transverse axis), showing how planes and axes separate visually similar moves.

Try this

• Cue. State the plane and axis for a forward roll. (Sagittal plane, transverse axis, because it is a forward-backward rotation.)

• Cue. Name the plane and axis for an ice skater's spin. (Transverse plane, longitudinal axis, because the body rotates around its own vertical line.)

• Cue. Explain why a star jump is a frontal-plane movement. (The arms and legs move out to the sides, a side-to-side movement, which happens in the frontal plane about the sagittal axis.)