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Extension

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

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Anatomically, extension is the verb used to indicate movement of a body part in relation to another so as to straighten their relationship. The usual direction is posterior. For example, extension of the hip involves movement of the femur in a posterior direction with rotation at the hip.

Exceptions include:

  • knee extension, which entails movement in an anterior direction
  • thumb extension, involving movement of the thumb across the plane of the palm
  • extension of the foot, termed plantarflexion

An alternative definition for extension is an increase in the angle between bones or body areas.

Extension is the opposite of flexion.


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