Dermatome (anatomy) - Important Dermatomes and Anatomical Landmarks

Important Dermatomes and Anatomical Landmarks

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

• 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 horizonal 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.
• L5 - On the dorsum of the foot at the third metatarsophalangeal joint.
• 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