IB Sports, exercise and health science B.1.1.2 Planes of Movement and Axes of Rotation in Human Motion Notes

Movement and Rotation in Planes and Axes

1. Movements occur within a plane and are controlled by the muscles, joints, and nervous system.
2. Each plane allows specific types of movement, and understanding them is crucial for analysing human motion in sports and exercise.

The Three Anatomical Planes

1. The human body moves in three anatomical planes: sagittal, frontal, and transverse.
2. Each plane allows different types of movement.

1. Sagittal Plane

1. The sagittal plane divides the body into left and right halves.
2. Movements in this plane occur forward and backward and involve changes in joint angles.

Common Movements in the Sagittal Plane

1. Flexion: Decreasing the angle between two bones (e.g., bending the knee in a squat).
2. Extension: Increasing the angle between two bones (e.g., straightening the knee in a squat).
3. Dorsiflexion: Lifting the toes towards the shin (e.g., during the back phase of a running stride).
4. Plantarflexion: Pointing the toes downward (e.g., pushing off in a sprint start).

2. Frontal Plane

1. The frontal plane divides the body into front (anterior) and back (posterior) halves.
2. Movements in this plane occur side-to-side.

Common Movements in the Frontal Plane

1. Abduction: Moving a body part away from the midline (e.g., raising the arms in a lateral raise).
2. Adduction: Moving a body part toward the midline (e.g., bringing the arms back down in a lateral raise).
3. Inversion: Turning the sole of the foot inward (e.g., rolling an ankle).
4. Most ankle sprains are inversion sprains because inversion is what the ankle does when an athlete rolls it on an uneven landing.
5. Eversion: Turning the sole of the foot outward.
6. Lateral flexion is bending the spine sideways towards one shoulder, returning to neutral, then bending towards the other shoulder.
7. Elevation: Raising a body part (e.g., shrugging the shoulders).
8. Depression: Lowering a body part (e.g., dropping the shoulders).

3. Transverse Plane

1. The transverse plane divides the body into top (superior) and bottom (inferior) halves.
2. Movements in this plane involve rotation.

Common Movements in the Transverse Plane

1. Rotation: Twisting a body part around its axis (e.g., turning the head side to side).
2. Pronation: Rotating the forearm so the palm faces downward.
3. Supination: Rotating the forearm so the palm faces upward.
4. Horizontal Flexion: Moving the arm across the body at shoulder level (e.g., chest fly).
5. Horizontal Extension: Moving the arm away from the body at shoulder level.

Axes of Rotation

Each movement in a plane occurs around an axis that is perpendicular to that plane.

1. Sagittal Axis (Anteroposterior Axis)

1. Runs front to back through the body.
2. Perpendicular to the frontal plane.
3. Movements around this axis include abduction and adduction.