What is anatomical position?
The reference pose: standing tall, facing forward, arms by the sides, palms forward. Every movement and direction is described from anatomical position.
- Supine means lying face up.
- Prone means face down.
What is flexion?
Flexion (FLEK-shun) is bending a joint so its angle closes. Flex means bend. The joint folds shut.
- The lifting half of a curl is elbow flexion.
- Going down into a squat, the knee angle closes, so it is knee flexion. The hips flex too.
- Rectus abdominis flexes the spine in a crunch.
What is extension?
Extension (ik-STEN-shun) is straightening a joint so its angle opens, back towards anatomical position. Extend means stretch out, make longer.
- Lowering a curl, or locking out a press-up.
- Driving back up out of a squat is extension at both the knee and the hip.
- Gluteus maximus extends the hip: the top of a squat, deadlift or hip thrust.
- Erector spinae extends the spine: deadlifts, back extensions.
What is the difference between abduction and adduction?
Both are judged against the midline, the imaginary line down the centre of the body.
| Term | Say it | Word parts | What it does | Gym example |
|---|---|---|---|---|
| Abduction | ab-DUK-shun | ab = away, duction = leading | Moves a limb away from the midline | A lateral raise is shoulder abduction |
| Adduction | ad-DUK-shun | ad = towards, duction = leading | Moves a limb back towards the midline | Lowering a lateral raise is shoulder adduction |
To abduct someone is to take them away. ADD it back to the body. Instructors often say A-B-duction and A-D-duction so nobody mixes them up.
What do anterior, posterior, medial and lateral mean?
- Anterior (an-TEER-ee-er) means towards the front. Tibialis anterior sits at the front of the shin.
- Posterior (poss-TEER-ee-er) means towards the back. The hamstrings sit on the posterior thigh.
- Medial (MEE-dee-ul) means closer to the midline. Your big toe is on the medial side of your foot.
- Lateral (LAT-er-ul) means further from the midline. A lateral raise lifts the arms out to the sides.
These words turn up inside muscle names too, as in tibialis anterior.
Which joints can do which movements?
- A hinge joint moves in one direction only, bending and straightening, like a door. The elbow and the knee.
- A ball and socket joint can move in every direction, including rotation. The hip and the shoulder.
- A condyloid joint bends forwards, backwards and side to side, but can't truly rotate. The wrist.