EXTENSION (KINESIOLOGY)

'Extension' is a movement of a joint. For example, extension is produced by extending the flexed elbow. The arm is now straight; it has been extended. If the head is tilted all the way back, it is said to be extended.
The movement in the opposite directions is called flexion. Flexion decreases the angle between the bones of the limb at a joint, while extension increases it.
With the foot, extension (elevation) is usually called dorsiflexion.
If a part of the body is overstretched, then one speaks of a 'hyperextension (as with the knee).
In some anatomical muscle names, particularly with muscles of the forearm and the Cnemis, the term occurs explicitly as the second word in the Latin spelling of the name (for example, Musculus extensor carpi ulnaris).

Contents

Muscles of extension

Upper limb

Lower limb

References

External links

Muscles of extension

Upper limb

★ of forearm at elbow^[1]

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★ Posterior compartment of the arm

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★ Triceps

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★ Anconeus

★ of hand at wrist^[2]

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★ Posterior compartment of the forearm

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★ Extensor carpi radialis longus

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★ Extensor carpi radialis brevis

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★ Extensor digitorum

★ of phalanges, at all joints

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★ Posterior compartment of the forearm

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★ Extensor digitorum

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★ Extensor carpi ulnaris

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★ Extensor digiti minimi (little finger only)

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★ Extensor indicis (index finger only)

★ of phalanges, at interphalangeal joints^[3]

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★ Lumbricals of the hand

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★ Dorsal interossei of the hand

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★ Palmar interossei

★ of thumb^[4][5]

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★ Extensor pollicis brevis (proximal phalange)

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★ Extensor pollicis longus (distal phalange)

Lower limb

★ of thigh/femur at hip^[6]

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★ Gluteus maximus

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★ Posterior compartment of thigh

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★ Biceps femoris

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★ Semitendinosus

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★ Semimembranosus

★ of leg at knee (L3-L4)^[7]

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★ Quadriceps

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★ Rectus femoris muscle

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★ Vastus medialis

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★ Vastus lateralis

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★ Vastus intermedius

★ of toes^[8][9]

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★ Extensor hallucis longus

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★ Extensor digitorum longus

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★ Extensor digitorum brevis

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★ Extensor hallucis brevis

References

1. http://www.exrx.net/Articulations/Elbow.html#anchor764495
2. http://www.exrx.net/Articulations/Wrist.html#anchor261877
3. http://www.exrx.net/Articulations/Fingers.html#anchor783765
4. http://www.exrx.net/Articulations/Thumb.html#anchor206622
5. http://www.exrx.net/Articulations/Thumb.html#anchor210115
6. http://www.exrx.net/Articulations/Hip.html#anchor845621
7. http://www.exrx.net/Articulations/Knee.html#anchor22459
8. http://www.exrx.net/Articulations/Toes.html#anchor231444
9. http://www.exrx.net/Articulations/Toes.html#anchor235208

External links

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