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 skul l . Alternately, a point at least 3 cm behin d 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 phal anx 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 antecubi tal fossa , just pr oximal ly 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 - Intersectio n 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 betwee n the level o f the xi phoid p rocess and the le vel of t he umbilicus. • T8 - Intersection of the midclavicular line and the horizontal level at one half the distance betwee n the level o f the xi phoid p rocess and the le vel of t he umbil icus. • 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 poplit eal foss a. • S3 - Over the tuberosity of the ischium or infragluteal fold • S4 and S5 - In the periana l area, less than one cm lateral to the mucocutaneous zone