Extension means 'straightening'.

When the knee is straight it is said to be extended. A normal range of motion at the knee includes flexion, extension and a small amount of hyperextension.

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Range-of-motion is a key concept in knee rehabilitation. This paper discusses how it is measured.

The patella - important anatomical relationships

The kneecap or patella is part of a chain of structures that help to straighten the knee.

Assisted passive extensions

Exercise to increase range of movement.

Short arc extensions

This is a quads exercise, for early

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