3.3 Dividing The Body
Sometimes, terms are used to help us describe and analyze how the body moves in space. Similar to how anatomical position gives a universal system for describing location, they provide a universal system for interpreting, describing and understanding movement.
Planes
Planes are flat, imaginary surfaces that slice the body into sections. All movements, whether they be at a specific joint or the whole body, happen along one of these planes.
| Plane | Description | Example Movement |
|---|---|---|
| A. Sagittal (red) | Divides the body into left and right halves | Walking forward; elbow bending; squats; somersault |
| B. Frontal (green) | Divides the body into front and back halves | Side shuffle, Jumping jacks, lateral shoulder raises |
| C. Transverse (purple) | Divides the body into top and bottom halves | Rotational movements, twisting, spinning |
Axes
Axes are imaginary lines that run through the body, around which movement occurs. Think of an axis like the pin in a door hinge; the door moves around that axis.
| Axis | Description | Movement Example |
|---|---|---|
| Horizontal | Runs side-to-side through the body | Flexion and extension |
| Anteroposterior | Runs front-to-back through the body | Abduction and adduction |
| Longitudinal | Runs top-to-bottom through the body | Internal or external rotation |
Relationship Between Planes and Axes
Every movement occurs in a plane and around an axis, and they are always perpendicular (at a 90-degree angle) to each other:
- Photo A (squats): Movements in the sagittal plane happen around the horizontal axis. When you do a squat, your knee joint moves in the sagittal plane, rotating around the horizontal axis.
- Photo B (jumping jacks): Movements in the frontal plane happen around the anteroposterior axis. When you perform a jumping jack, the arms and legs move in the frontal plane, rotating around the anteroposterior axis.
- Photo C: (pirouette spin): Movements in the transverse plane happen around the longitudinal axis. Rotational movements like pirouette spin move in the transverse plane, rotating around the longitudinal axis.
