External Rotation

External rotation (or lateral rotation) is rotation away from the center of the body.

The muscles of external rotation include:

  • of arm/humerus at shoulder
    • Deltoid muscle
    • Infraspinatus
    • Teres minor
  • of thigh/femur at hip
    • Gluteus maximus
    • Lateral rotator group
      • piriformis
      • gemellus superior
      • obturator internus
      • gemellus inferior
      • obturator externus
      • quadratus femoris
    • Sartorius
  • of leg at knee
    • Biceps femoris
  • of eyeball (motion is also called "extorsion" or excyclotorsion)
    • Inferior rectus muscle
    • Inferior oblique muscle

Famous quotes containing the words external and/or rotation:

    A State, in idea, is the opposite of a Church. A State regards classes, and not individuals; and it estimates classes, not by internal merit, but external accidents, as property, birth, etc. But a church does the reverse of this, and disregards all external accidents, and looks at men as individual persons, allowing no gradations of ranks, but such as greater or less wisdom, learning, and holiness ought to confer. A Church is, therefore, in idea, the only pure democracy.
    Samuel Taylor Coleridge (1772–1834)

    The lazy manage to keep up with the earth’s rotation just as well as the industrious.
    Mason Cooley (b. 1927)