Important dermatomes and Anatomical landmarks

Following is a list of spinal nerves and points that are characteristically belonging to the dermatome of each nerve :

  • C1 : Exception
  • C2 – At least one cm lateral to the occipital protuberance at the base of the skull. Alternately, a point at least 3 cm behind the ear.

  • C3 – In the supraclavicular fossa, at the midclavicular line.

  • C4 – Over the acromioclavicular joint.

  • C5 – On the lateral (radial) side of the antecubital fossa, just proximally to the elbow.

  • C6 – On the dorsal surface of the proximal phalanx of the thumb.

  • C7 – On the dorsal surface of the proximal phalanx of the middle finger.

  • C8 – On the dorsal surface of the proximal phalanx of the little finger.

  • T1 – On the medial (ulnar) side of the antecubital fossa, just proximally to the medial epicondyle of the humerus.

  • T2 – At the apex of the axilla.

  • T3 – Intersection of the midclavicular line and the third intercostal space

  • T4 – Intersection of the midclavicular line and the fourth intercostal space, located at the level of the nipples.

  • T5 – Intersection of the midclavicular line and the fifth intercostal space, horizontally located midway between the level of the nipples and the level of the xiphoid process.

  • T6 – Intersection of the midclavicular line and the horizontal level of the xiphoid process.

  • T7 – Intersection of the midclavicular line and the horizontal level at one quarter the distance between the level of the xiphoid process and the level of the umbilicus.

  • T8 – Intersection of the midclavicular line and the horizontal level at one half the distance between the level of the xiphoid process and the level of the umbilicus.

  • T9 – Intersection of the midclavicular line and the horizontal level at three quarters of the distance between the level of the xiphoid process and the level of the umbilicus.

  • T10 – Intersection of the midclavicular line, at the horizontal level of the umbilicus.

  • T11 – Intersection of the midclavicular line, at the horizontal level midway between the level of the umbilicus and the inguinal ligament.

  • T12 – Intersection of the midclavicular line and the midpoint of the inguinal ligament.

  • L1 – Midway between the key sensory points for T12 and L2.

  • L2 – On the anterior medial thigh, at the midpoint of a line connecting the midpoint of the inguinal ligament and the medial epicondyle of the femur.

  • L3 – At the medial epicondyle of the femur.

  • L4 – Over the medial malleolus.

    S1 – On the lateral aspect of the calcaneus.

  • S2 – At the midpoint of the popliteal fossa.

  • S3 – Over the tuberosity of the ischium or infragluteal fold.

  • S4 and S5 – In the perianal area, less than one cm lateral to the mucocutaneous zone.

Leave a Reply

Your email address will not be published.