Anatomical terms and the skeletal, articular and muscular systems

Sport scientists describe the body from one agreed starting posture called the anatomical position: standing upright, facing forward, feet flat and parallel with the toes pointing forward, arms hanging by the sides with the palms facing forward. Every directional term and movement name is defined from this posture, even when the athlete is upside down on a trampoline or lying on a bench.

Using a shared reference stops confusion such as one coach calling the shin the 'front' while another calls it the 'top'.

Directional terms come in pairs. Anterior means towards the front and posterior towards the back. Superior means above or towards the head and inferior below or towards the feet. Medial means closer to the midline of the body and lateral further from it. Proximal and distal are used for limbs: proximal is closer to where the limb attaches to the trunk, distal is further away. Superficial means nearer the body surface, while deep means further inside.

Movement types describe what happens at a joint. Flexion decreases the angle between two bones; extension increases it. Abduction moves a limb away from the midline and adduction moves it back towards the midline. Rotation turns a bone around its long axis, and circumduction moves the distal end of a limb in a circle, combining flexion, extension, abduction and adduction. Supination turns the forearm so the palm faces up or forward; pronation turns the palm down or back.

In the foot, inversion turns the sole inward (towards the midline) and eversion turns it outward; these movements occur mainly at the joints between the tarsal bones just below the ankle joint. Most rolled ankles, in netball as in other sports, are inversion injuries.