Let's Get to Know About Dermatomes


What is a Dermatome?

Dermatome is an area of skin innervated by a spinal nerve. Each dermatome has a different innervation area, so it can be used to determine the location of spinal nerve damage.

Dermatomes form during fetal development, when spinal nerves elongate and grow outward from the spinal cord. The spinal nerves then branch and form smaller branches, called sensory nerve fibers. These sensory nerve fibers then innervate the surrounding skin.

There are 30 dermatomal pathways in the body consisting of 8 cervical nerves (C1 does not have a specific dermatomal area), 12 thoracic nerves, 5 lumbar nerves and 5 sacral nerves. Dysfunction or damage to the spinal nerve roots due to infection, compression, or traumatic injury can trigger symptoms in the associated dermatomal areas.

Dermatomes have an important function in the human body. Dermatomes are responsible for transmitting sensory signals from the skin to the brain. These sensory signals can include pain, temperature, touch, and pressure. Dermatomes also play a role in controlling skin functions, such as sweat and oil glands.

Dermatomes are generally used as a way to assess lesions on sensory examination. By examining the dermatome area, we can determine approximately which nerve root is problematic.

Dermatome Distribution Table

Nerve RootsDermatom
CervicalC2Innervation of the neckTemples, Forehead, Back of Head
C3Entire Neck, Posterior Cheek, Temporal Area, Forward extension below Mandible
C4Shoulder Area, Clavicle Area, Upper Scapula Area
C5Innervation of the upper armDeltoid Area, Anterior aspect of the entire arm to the base of the thumb
C6Anterior Arm, Radial side of the hand to the thumb and index finger
C7Lateral Arm and Forearm to the index finger, long finger, and ring finger
C8Medial Arm and forearm to long, ring, and little fingers
ThoracalT1Medial side of the forearm to the base of the little finger
T2Innervation of the chest and abdomenMedial side of upper arm to medial elbow, chest and midscapular area
T3 – T6Upper Thorax
T5 – T7Costae Margin
T8 – T12Abdomen and Lumbar Area
LumbalL1Return, past the trochanter and groin
L2Back, front of thighs to knees
L3Innervation of the feetBack, upper back, anterior thighs and knees, medial lower leg
L4Medial buttocks, lateral thighs, medial legs, instep, big toe
L5Buttocks, posterior and lateral thighs, lateral aspect of the lower leg, instep, medial half of the foot, first, second, and third toes
SacralS1Buttocks, Thighs, and Posterior Legs
S2Innervation of the groyne areaButtocks, Thighs, and Posterior Legs
S3Groin, medial thigh to knee
S4Perineum, genitals, lower sacrum

Table of Major Dermatome Grades

Nerve RootsTingkat Dermatom
C5 – C6Lateral side of the upper leg
C8 – T1Medial side of the upper leg
C6 – C8Hand
C84th and 5th fingers
T4Nipple level
T10Navel level
L1Area inguinal
L1 – L4Front and inner side of the lower leg
L4 – S1Foot
L4Medial side of the big toe
L5 – S2lateral and posterior sides of the lower leg
S1Lateral border of the foot and toes 5
S2 – S4Perineum

Also read: Parkinson's: What is it and what is the role of physiotherapy

Reference :

  1. Whitman PA, Adigun OO. Anatomy, Skin, Dermatomes. [Updated 2022 Sep 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK535401/
  2. Physiopedia. Dermatome. diakses pada tanggal 26 Oktober 2023 melalui https://www.physio-pedia.com/Dermatomes
  3. Netter, F. H. 1. (2014). Atlas of human anatomy. Sixth edition. Philadelphia, PA, Saunders/Elsevier.


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