Learning why and how people move
What this domain tests
This domain covers why and how people move, using biophysical principles from anatomy, biomechanics and exercise physiology. You must apply principles to a movement, explain the effect on performance or safety, and use correct terminology.
Core rules and concepts
- Anatomy: bones, joints (hinge, ball-and-socket, pivot) and muscles work as levers. Most musculoskeletal levers are third-class: effort is between the axis and the load, which favours speed and range rather than force.
- Biomechanics: force summation (sequencing body segments), Newton's three laws, stability (base of support, centre of gravity), and projectile motion (angle, speed, height).
- Physiology: the aerobic and anaerobic energy systems supply ATP; the cardiorespiratory system delivers oxygen and removes carbon dioxide. Intensity and duration determine the dominant system.
- Efficiency and safety: correct technique can increase force or speed and reduce injury risk.
Worked example
Analyse a netball chest pass. The player steps forward, rotates the hips and trunk, then extends the elbows and wrists-this is force summation, with larger, slower segments contributing first and smaller, faster segments last. The pass is a projectile: a flatter, faster release reduces flight time, while a higher release can clear a defender. At the elbow, the triceps produces effort; the forearm is the load and the elbow is the axis, so it is a third-class lever. The reasoning links each principle to performance.
Traps
- Labelling the elbow as a second-class lever; most body levers are third-class.
- Confusing the agonist (prime mover) with the antagonist.
- Thinking a 45° projectile angle is always best; it depends on release height and speed.
- Naming a principle without explaining its effect on the movement.