What are dermatomes and how do they relate to spinal nerves. How are dermatomes tested in clinical settings. Why are dermatome maps important for diagnosing neurological conditions. What controversies exist regarding dermatome mapping.

The Fundamentals of Dermatomes: Mapping Skin Sensation to Spinal Nerves

Dermatomes are distinct areas of skin innervated by specific spinal nerve roots. The term “dermatome” combines the Greek words “derma” (skin) and “tome” (cutting or thin segment). These sensory distributions play a crucial role in understanding the relationship between the nervous system and skin sensation.

There are 30 dermatomes in total, corresponding to:

• 8 cervical nerves (C1-C8, with C1 having no dermatome)
• 12 thoracic nerves (T1-T12)
• 5 lumbar nerves (L1-L5)
• 5 sacral nerves (S1-S5)

Each dermatome relays sensory information from a specific skin region to the brain. This arrangement allows healthcare professionals to pinpoint potential nerve root issues based on patterns of sensory disturbance.

The Clinical Significance of Dermatomes

Why are dermatomes important in clinical practice? Dermatomes serve as a valuable diagnostic tool for identifying spinal nerve root problems. When a patient experiences sensory changes in a particular skin area, clinicians can use dermatome maps to trace the issue back to a specific spinal segment.

Dysfunction or damage to a spinal nerve root can manifest as symptoms in the corresponding dermatome. These symptoms may result from:

• Infection
• Compression
• Traumatic injury

Dermatome Distribution: A Comprehensive Overview

Understanding the specific areas innervated by each spinal nerve is essential for accurate diagnosis and treatment. Here’s a breakdown of key dermatome distributions:

Cervical Dermatomes (C2-C8)

• C2: Temple, forehead, occiput
• C3: Neck, posterior cheek, temporal area
• C4: Shoulder and clavicular area
• C5: Deltoid area, anterior aspect of the arm to the base of the thumb
• C6: Anterior arm, radial side of the hand to thumb and index finger
• C7: Lateral arm and forearm to index, long, and ring fingers
• C8: Medial arm and forearm to long, ring, and little fingers

Thoracic Dermatomes (T1-T12)

• T1: Medial side of forearm to the base of the little finger
• T2: Medial side of upper arm to medial elbow, pectoral and midscapular areas
• T3-T6: Upper thorax
• T5-T7: Costal margin
• T8-T12: Abdomen and lumbar region

Lumbar Dermatomes (L1-L5)

• L1: Back, over trochanter and groin
• L2: Back, front of thigh to knee
• L3: Back, upper buttock, anterior thigh and knee, medial lower leg
• L4: Medial buttock, lateral thigh, medial leg, dorsum of foot, big toe
• L5: Buttock, posterior and lateral thigh, lateral aspect of leg, dorsum of foot, medial half of sole, first, second, and third toes

Sacral Dermatomes (S1-S4)

• S1: Buttock, thigh, and leg posterior
• S2: Similar to S1
• S3: Groin, medial thigh to knee
• S4: Perineum, genitals, lower sacrum

The Evolution of Dermatome Mapping: Historical Perspective and Current Debates

The concept of dermatomes has a rich history in medical science, evolving from early attempts to link anatomy with sensory physiology. How did our understanding of dermatomes develop over time?

Two primary dermatome maps have gained recognition in the medical community:

1. The Keegan and Garret Map (1948): This map aligns dermatomes with the developmental progression of limb segments.
2. The Foerster Map (1933): This widely used map depicts the medial area of the upper limb as innervated by T1-T3, reflecting pain distribution patterns in conditions like angina or myocardial infarction.

The Foerster Map has become the standard in healthcare settings and forms the basis for the dermatomes used in the American Spinal Cord Injury Association Impairment Scale (ASIA Scale).

Contemporary Challenges in Dermatome Mapping

Despite their widespread use, dermatome maps face scrutiny in modern medical research. What are the key issues surrounding current dermatome maps?

• Significant variations between different maps
• Individual differences in dermatome patterns
• Evidence suggesting inaccuracies in traditional maps
• Limited recent attempts to verify original dermatome maps

In response to these challenges, Lee et al. conducted a comprehensive review of dermatome map discrepancies. Their work resulted in a proposed “evidence-based” dermatome map that synthesizes elements from previous maps. While the term “evidence-based” may be debatable in this context, their effort represents a systematic approach to consolidating the most credible available evidence.

Clinical Applications: Dermatome Testing in Neurological Examinations

Dermatome testing forms an integral part of neurological examinations. How do healthcare professionals use dermatome knowledge in clinical practice?

The primary purposes of dermatome testing are:

1. To determine if sensory loss in a limb corresponds to a single spinal segment, suggesting a nerve root lesion (radiculopathy)
2. To assign a neurologic “level” to a spinal cord lesion

Conducting a Dermatome Examination

What is the proper technique for testing dermatomes? The ideal dermatome examination involves the following steps:

1. Use both a pin and cotton wool for testing
2. Ask the patient to close their eyes
3. Instruct the patient to provide feedback on sensations felt
4. Systematically test different dermatome areas, comparing sides for symmetry
5. Document any areas of altered sensation or numbness

By carefully mapping sensory changes, clinicians can gain valuable insights into potential nerve root or spinal cord issues.

Controversies in Dermatome Mapping: Addressing Inconsistencies and Variations

While dermatomes are a fundamental concept in neurology, the field is not without controversy. What are the main points of contention in dermatome mapping?

• Variability between individuals: Dermatome patterns can differ significantly from person to person, making standardized maps challenging to apply universally.
• Overlap between adjacent dermatomes: The borders between dermatomes are often not as clear-cut as maps suggest, with considerable overlap in sensory innervation.
• Inconsistencies between maps: Different dermatome maps may show variations in the exact areas innervated by specific spinal nerves.
• Limited recent validation: Many commonly used dermatome maps are based on older studies, with few contemporary attempts at verification.
• Potential inaccuracies in original studies: Some researchers argue that the foundational studies used to create dermatome maps may have been flawed.

These controversies highlight the need for ongoing research and potentially updated approaches to dermatome mapping in clinical practice.

Beyond Traditional Dermatomes: Emerging Perspectives in Sensory Innervation

As our understanding of the nervous system evolves, new perspectives on sensory innervation are emerging. How might these insights impact our view of dermatomes?

Complex Innervation Patterns

Recent research suggests that sensory innervation may be more complex than traditional dermatome maps indicate. Some key findings include:

• Multiple nerve root contributions: Some skin areas may receive sensory input from more than one spinal nerve root.
• Dynamic innervation: The pattern of sensory innervation may change slightly over time or in response to injury.
• Peripheral nerve plexuses: The intermingling of nerve fibers in structures like the brachial and lumbosacral plexuses adds complexity to sensory distribution.

Functional Dermatomes

The concept of “functional dermatomes” is gaining traction in some circles. This approach focuses on the practical sensory function of skin areas rather than strict anatomical boundaries. How might functional dermatomes differ from traditional maps?

• Emphasis on sensory perception rather than theoretical nerve root distribution
• Consideration of individual variations in sensory processing
• Integration of central nervous system influences on sensory interpretation

While still an evolving concept, functional dermatomes may offer a more nuanced approach to understanding sensory innervation patterns.

Dermatomes in Practice: Clinical Case Studies and Diagnostic Challenges

To better understand the practical application of dermatome knowledge, let’s explore some clinical scenarios. How do healthcare professionals use dermatome patterns to diagnose and treat patients?

Case Study 1: Cervical Radiculopathy

A 45-year-old office worker presents with numbness and tingling along the outer aspect of her right arm and thumb. Based on dermatome maps, which nerve root is likely involved?

Analysis: The symptoms align with the C6 dermatome, suggesting potential compression or irritation of the C6 nerve root. Further examination and imaging studies would be necessary to confirm the diagnosis and determine the underlying cause, such as a herniated cervical disc or cervical spondylosis.

Case Study 2: Lumbar Disc Herniation

A 32-year-old athlete complains of pain radiating down the back of his left thigh and calf, along with numbness in his big toe. Which dermatome pattern does this suggest?

Analysis: The symptom distribution corresponds to the L5 dermatome, indicating possible L5 nerve root involvement. A lumbar disc herniation at the L4-L5 level could explain these symptoms. MRI imaging and additional neurological testing would be appropriate next steps.

Diagnostic Challenges

While dermatomes provide valuable diagnostic clues, several factors can complicate their interpretation:

• Overlapping innervation: Adjacent dermatomes may have significant overlap, blurring the lines between nerve root territories.
• Individual variations: As mentioned earlier, dermatome patterns can vary between individuals.
• Multiple level involvement: Some conditions may affect multiple nerve roots, creating complex sensory patterns.
• Central nervous system factors: Conditions affecting the spinal cord or brain can produce sensory changes that don’t follow typical dermatome patterns.

These challenges underscore the importance of considering dermatome patterns as one piece of the diagnostic puzzle, always in conjunction with a thorough clinical examination and appropriate imaging studies.

The Future of Dermatome Mapping: Innovations and Research Directions

As medical technology and our understanding of neuroscience advance, what does the future hold for dermatome mapping and its clinical applications?

Advanced Imaging Techniques

Emerging imaging technologies may provide new insights into sensory innervation patterns. Some promising areas include:

• High-resolution MRI: Improved visualization of nerve roots and their relationships to surrounding structures
• Functional neuroimaging: Mapping sensory processing in real-time to better understand individual variations
• Diffusion tensor imaging: Tracing nerve fiber pathways from the spinal cord to peripheral tissues

Quantitative Sensory Testing

More sophisticated methods of quantifying sensory function may lead to more accurate and personalized dermatome maps. Potential approaches include:

• Computer-assisted sensory mapping: Using precise stimuli and patient feedback to create detailed sensory maps
• Thermal and vibration threshold testing: Assessing different types of sensory fibers for a more comprehensive picture
• Electrical stimulation techniques: Precisely activating specific nerve fibers to map sensory distributions

Artificial Intelligence and Big Data

The integration of AI and large-scale data analysis could revolutionize our understanding of dermatomes. Potential applications include:

• Pattern recognition: Identifying subtle sensory distribution patterns across large patient populations
• Predictive modeling: Anticipating individual variations in dermatome patterns based on genetic and anatomical factors
• Personalized dermatome mapping: Creating tailored sensory maps for individual patients to guide diagnosis and treatment

As research in these areas progresses, we may see a shift towards more dynamic and personalized approaches to understanding sensory innervation patterns. This evolution could lead to more accurate diagnoses and targeted treatments for a wide range of neurological conditions.

Dermatomes – Physiopedia

Original Editor – Lucinda Hampton

Top Contributors –

Naomi O’Reilly,

Anas Mohamed,

Lucinda hampton,

Joao Costa,

Nikhil Benhur Abburi,

Rachael Lowe,

Kim Jackson and

Blessed Denzel Vhudzijena

Lead Editors  

Contents

• 1 Dermatomes
• 2 History
• 3 Purpose
• 4 Technique
• 5 Controversies
• 6 Clinical Significance
• 7 References

The term “dermatome” is a combination of two Greek words; “derma” meaning “skin”, and “tome”, meaning “cutting” or “thin segment”. Dermatomes are areas of the skin whose sensory distribution is innervated by the afferent nerve fibres from the dorsal root of a specific single spinal nerve root, which is that portion of a peripheral nerve that “connects” the nerve to the spinal cord.

Nerve roots arise from each level of the spinal cord (e. g., C3, C4), and many, but not all, intermingle in a plexus (brachial, lumbar, or lumbosacral) to form different peripheral nerves as discussed above. This arrangement can result in a single nerve root supplying more than one peripheral nerve. For example, the median nerve is derived from the C6, C7, C8, and T1 Nerve Roots, whereas the ulnar nerve is derived from C7, C8, and T1.

In total there are 30 dermatomes that relay sensation from a particular region of the skin to the brain – 8 cervical nerves (note C1 has no corresponding dermatomal area), 12 thoracic nerves, 5 lumbar nerves and 5 sacral nerves. Each of these spinal nerves roots.^[1] Dysfunction or damage to a spinal nerve root from infection, compression, or traumatic injury can trigger symptoms in the corresponding dermatome. ^[2]

^[3]

Table. 1 Dermatomes

Nerve Root			Dermatome
Cervical	C2	Supply Skin of Neck	Temple, Forehead, Occiput
	C3		Entire Neck, Posterior Cheek, Temporal Area, Prolongation forward under Mandible
	C4		Shoulder Area, Clavicular Area, Upper Scapular Area
	C5	Supply the Arms	Deltoid Area, Anterior aspect of entire arm to base of thumb
	C6		Anterior Arm, Radial side of hand to thumb and index finger
	C7		Lateral Arm and Forearm to index, long, and ring fingers
	C8		Medial Arm and forearm to long, ring, and little fingers
Thoracic	T1		Medial side of forearm to base of little finger
	T2	Supply the chest and abdomen	Medial side of upper arm to medial elbow, pectoral and midscapular areas
	T3 – 6		Upper Thorax
	T5 – 7		Costal Margin
	T8 – 12		Abdomen and Lumbar Region
Lumbar	L1		Back, over trochanter and groin
	L2		Back, front of thigh to knee
	L3	Supply Skin of Legs	Back, upper buttock, anterior thigh and knee, medial lower leg
	L4		Medial buttock, latera thigh, medial leg, dorsum of foot, big toe
	L5		Buttock, posterior and lateral thigh, lateral aspect of leg, dorsum of foot, medial half of sole, first, second, and third toes
Sacral	S1		Buttock, Thigh, and Leg Posterior
	S2	Supply Groin	Same as S1
	S3		Groin, medial thigh to knee
	S4		Perineum, genitals, lower sacrum
Coccygeal	The dermatome corresponding with the coccygeal nerves is located on the buttocks, in the area directly around the coccyx. [4][5]

The idea of dermatomes originated from initial efforts to associate anatomy with the physiology of sensation. Multiple definitions of dermatomes exist, and several maps are commonly employed. Although they are valuable, dermatomes vary significantly between maps and even among individuals,^[6] with some evidence suggesting that current dermatome maps are inaccurate and based on flawed studies.^[7][8]

The medical profession typically recognised two primary maps of dermatomes. Firstly, the Keegan and Garret Map (Fig.1) from 1948, which illustrates dermatomes in alignment with the developmental progression of the limb segments. Secondly, the Foerster Map from 1933, which portrays the medial area of the upper limb as being innervated by T1-T3, depicting the pain distribution from angina or myocardial infarction. This latter map is the most frequently used in healthcare and accounts for the dermatomes used in the American Spinal Cord Injury Association Impairment Scale (ASIA Scale). In recent years there have been few attempts at verifying these original dermatome maps. Lee et al conducted an in-depth review that examined the discrepancies among dermatome maps. They put forth an “evidence-based” dermatome map that combined elements of previous maps (Fig.3). Though the application of the term “evidence-based” may be somewhat questionable, their proposed map represents a systematic attempt to synthesise the most credible evidence available.^[6][7]

Testing of dermatomes is part of the neurological examination. They are primarily used to determine whether the sensory loss on a limb corresponds to a single spinal segment, implying the lesion is of that nerve root (i.e., radiculopathy), and to assign the neurologic “level” to a spinal cord lesion^[9].

Dermatome Testing is done ideally with a pin and cotton wool. Ask the patient to close their eyes and give the therapist feedback regarding the various stimuli. Testing should be done on specific dermatomes and should be compared to bilaterally.

• Light Touch Test – Light Touch Sensation – Dab a piece of cotton wool on an area of skin ^[10]
• Pinprick Test – Pain Sensation – Gently touches the skin with the pin ask the patient whether it feels sharp or blunt

During the review of systems, asking the patient to carefully describe the pattern or distribution of sensory symptoms (e.g., tingling, numbness, diminished, or absent sensation) provides the therapist with preliminary information to help guide the examination and to assist in identifying the dermatome(s) and nerve(s) involved.^[11]

Light touch dermatomes are larger than pain dermatomes. When only one or two segments are affected, testing for pain sensibility is a more sensitive method of examination than testing for light touch.^[9]

Dermatomes have a segmented distribution throughout your body. The exact dermatome pattern can actually vary from person to person. Some overlap between neighboring dermatomes may also occur. There exist some discrepancies among published dermatome maps based on the methodologies used to identify skin segment innervation.

In a clinical commentary, Downs and Laporte discuss the history of dermatome mapping, including the variations in methodologies employed, and the inconsistencies in the dermatome maps used in education and practice.^[11] [[Laporte C. Conflicting dermatome maps: educational and clinical implications. journal of orthopaedic & sports physical therapy. 2011 Jun;41(6):42^[12]7-34.]]

Dermatomes are important because they can help to assess and diagnose a variety of conditions. Neurological screening of dermatomes helps to assess patterns of sensory loss that can suggest specific spinal nerve involvement. For instance, symptoms that occur along a specific dermatome may indicate disruption or damage to a specific nerve root in the spine.

• Nerve Entrapment
• Radiculopathy
• Spinal Cord Injury
• Herpes Zoster ^[2]

1. ↑ Wikipedia Dermatome. Available from: https://en.wikipedia.org/wiki/Dermatome_(anatomy) (last accessed 23.4.2019)
2. ↑ ^2.02.1 Medical news today What and where are dermatomes? Available:https://www.medicalnewstoday.com/articles/what-are-dermatomes (accessed 25.5.2022)
3. ↑ M Roehrs. Dermatomes. Available from: https://www.youtube.com/watch?v=CYZBH6NX8wg&feature=youtu.be (last accessed 23.4.2019)
4. ↑ Medical news today What and where are dermatomes? Available:https://www.medicalnewstoday.com/articles/what-are-dermatomes (accessed 25.5.2022)
5. ↑ David J. Magee. Orthopedic Physical Assessment. 6th edition. Elsevier. 2014.
6. ↑ ^6.06.1 Apok V, Gurusinghe NT, Mitchell JD, Emsley HC. Dermatomes and dogma. Practical neurology. 2011 Apr 1;11(2):100-5.
7. ↑ ^{7.07. 1} Lee MW, McPhee RW, Stringer MD. An evidence-based approach to human dermatomes. Australasian Musculoskeletal Medicine. 2013 Jun;18(1):14-22.
8. ↑ Downs MB, Laporte C. Conflicting dermatome maps: educational and clinical implications. journal of orthopaedic & sports physical therapy. 2011 Jun;41(6):427-34.
9. ↑ ^9.09.1 Liebenson C, editor. Rehabilitation of the spine: a practitioner’s manual. Lippincott Williams & Wilkins; 2007.Available: https://www.sciencedirect.com/topics/medicine-and-dentistry/dermatome (accessed 25.5.2022)
10. ↑ Slide share. Dermatomes and myotomes. Available from: https://www.slideshare.net/TafzzSailo/special-test-for-dermatomes-and-myotomes (last accessed 23.4.2019)
11. ↑ ^11.011.1 Susan B.O’Sullivan, Thomas J. Schmitz, George D. Fulk. Physical Rehabilitation. 6th edition. F. A. Davis Company. 2014.
12. ↑ Downs MB, Laporte C. Conflicting dermatome maps: educational and clinical implications. journal of orthopaedic & sports physical therapy. 2011 Jun;41(6):427-34.

Dermatomes – Physiopedia

Original Editor – Lucinda Hampton

Top Contributors –

Naomi O’Reilly,

Anas Mohamed,

Lucinda hampton,

Joao Costa,

Nikhil Benhur Abburi,

Rachael Lowe,

Kim Jackson and

Blessed Denzel Vhudzijena

Lead Editors  

Contents

• 1 Dermatomes
• 2 History
• 3 Purpose
• 4 Technique
• 5 Controversies
• 6 Clinical Significance
• 7 References

The term “dermatome” is a combination of two Greek words; “derma” meaning “skin”, and “tome”, meaning “cutting” or “thin segment”. Dermatomes are areas of the skin whose sensory distribution is innervated by the afferent nerve fibres from the dorsal root of a specific single spinal nerve root, which is that portion of a peripheral nerve that “connects” the nerve to the spinal cord.

Nerve roots arise from each level of the spinal cord (e.g., C3, C4), and many, but not all, intermingle in a plexus (brachial, lumbar, or lumbosacral) to form different peripheral nerves as discussed above. This arrangement can result in a single nerve root supplying more than one peripheral nerve. For example, the median nerve is derived from the C6, C7, C8, and T1 Nerve Roots, whereas the ulnar nerve is derived from C7, C8, and T1.

In total there are 30 dermatomes that relay sensation from a particular region of the skin to the brain – 8 cervical nerves (note C1 has no corresponding dermatomal area), 12 thoracic nerves, 5 lumbar nerves and 5 sacral nerves. Each of these spinal nerves roots.^[1] Dysfunction or damage to a spinal nerve root from infection, compression, or traumatic injury can trigger symptoms in the corresponding dermatome. ^[2]

^[3]

Table. 1 Dermatomes

Nerve Root			Dermatome
Cervical	C2	Supply Skin of Neck	Temple, Forehead, Occiput
	C3		Entire Neck, Posterior Cheek, Temporal Area, Prolongation forward under Mandible
	C4		Shoulder Area, Clavicular Area, Upper Scapular Area
	C5	Supply the Arms	Deltoid Area, Anterior aspect of entire arm to base of thumb
	C6		Anterior Arm, Radial side of hand to thumb and index finger
	C7		Lateral Arm and Forearm to index, long, and ring fingers
	C8		Medial Arm and forearm to long, ring, and little fingers
Thoracic	T1		Medial side of forearm to base of little finger
	T2	Supply the chest and abdomen	Medial side of upper arm to medial elbow, pectoral and midscapular areas
	T3 – 6		Upper Thorax
	T5 – 7		Costal Margin
	T8 – 12		Abdomen and Lumbar Region
Lumbar	L1		Back, over trochanter and groin
	L2		Back, front of thigh to knee
	L3	Supply Skin of Legs	Back, upper buttock, anterior thigh and knee, medial lower leg
	L4		Medial buttock, latera thigh, medial leg, dorsum of foot, big toe
	L5		Buttock, posterior and lateral thigh, lateral aspect of leg, dorsum of foot, medial half of sole, first, second, and third toes
Sacral	S1		Buttock, Thigh, and Leg Posterior
	S2	Supply Groin	Same as S1
	S3		Groin, medial thigh to knee
	S4		Perineum, genitals, lower sacrum
Coccygeal	The dermatome corresponding with the coccygeal nerves is located on the buttocks, in the area directly around the coccyx. [4][5]

The idea of dermatomes originated from initial efforts to associate anatomy with the physiology of sensation. Multiple definitions of dermatomes exist, and several maps are commonly employed. Although they are valuable, dermatomes vary significantly between maps and even among individuals,^[6] with some evidence suggesting that current dermatome maps are inaccurate and based on flawed studies.^[7][8]

The medical profession typically recognised two primary maps of dermatomes. Firstly, the Keegan and Garret Map (Fig.1) from 1948, which illustrates dermatomes in alignment with the developmental progression of the limb segments. Secondly, the Foerster Map from 1933, which portrays the medial area of the upper limb as being innervated by T1-T3, depicting the pain distribution from angina or myocardial infarction. This latter map is the most frequently used in healthcare and accounts for the dermatomes used in the American Spinal Cord Injury Association Impairment Scale (ASIA Scale). In recent years there have been few attempts at verifying these original dermatome maps. Lee et al conducted an in-depth review that examined the discrepancies among dermatome maps. They put forth an “evidence-based” dermatome map that combined elements of previous maps (Fig.3). Though the application of the term “evidence-based” may be somewhat questionable, their proposed map represents a systematic attempt to synthesise the most credible evidence available.^[6][7]

Testing of dermatomes is part of the neurological examination. They are primarily used to determine whether the sensory loss on a limb corresponds to a single spinal segment, implying the lesion is of that nerve root (i.e., radiculopathy), and to assign the neurologic “level” to a spinal cord lesion^[9].

Dermatome Testing is done ideally with a pin and cotton wool. Ask the patient to close their eyes and give the therapist feedback regarding the various stimuli. Testing should be done on specific dermatomes and should be compared to bilaterally.

• Light Touch Test – Light Touch Sensation – Dab a piece of cotton wool on an area of skin ^[10]
• Pinprick Test – Pain Sensation – Gently touches the skin with the pin ask the patient whether it feels sharp or blunt

During the review of systems, asking the patient to carefully describe the pattern or distribution of sensory symptoms (e.g., tingling, numbness, diminished, or absent sensation) provides the therapist with preliminary information to help guide the examination and to assist in identifying the dermatome(s) and nerve(s) involved.^[11]

Light touch dermatomes are larger than pain dermatomes. When only one or two segments are affected, testing for pain sensibility is a more sensitive method of examination than testing for light touch.^[9]

Dermatomes have a segmented distribution throughout your body. The exact dermatome pattern can actually vary from person to person. Some overlap between neighboring dermatomes may also occur. There exist some discrepancies among published dermatome maps based on the methodologies used to identify skin segment innervation.

In a clinical commentary, Downs and Laporte discuss the history of dermatome mapping, including the variations in methodologies employed, and the inconsistencies in the dermatome maps used in education and practice.^[11] [[Laporte C. Conflicting dermatome maps: educational and clinical implications. journal of orthopaedic & sports physical therapy. 2011 Jun;41(6):42^[12]7-34.]]

Dermatomes are important because they can help to assess and diagnose a variety of conditions. Neurological screening of dermatomes helps to assess patterns of sensory loss that can suggest specific spinal nerve involvement. For instance, symptoms that occur along a specific dermatome may indicate disruption or damage to a specific nerve root in the spine.

• Nerve Entrapment
• Radiculopathy
• Spinal Cord Injury
• Herpes Zoster ^[2]

1. ↑ Wikipedia Dermatome. Available from: https://en.wikipedia.org/wiki/Dermatome_(anatomy) (last accessed 23.4.2019)
2. ↑ ^2.02.1 Medical news today What and where are dermatomes? Available:https://www.medicalnewstoday.com/articles/what-are-dermatomes (accessed 25.5.2022)
3. ↑ M Roehrs. Dermatomes. Available from: https://www.youtube.com/watch?v=CYZBH6NX8wg&feature=youtu.be (last accessed 23.4.2019)
4. ↑ Medical news today What and where are dermatomes? Available:https://www.medicalnewstoday.com/articles/what-are-dermatomes (accessed 25.5.2022)
5. ↑ David J. Magee. Orthopedic Physical Assessment. 6th edition. Elsevier. 2014.
6. ↑ ^6.06.1 Apok V, Gurusinghe NT, Mitchell JD, Emsley HC. Dermatomes and dogma. Practical neurology. 2011 Apr 1;11(2):100-5.
7. ↑ ^{7.07. 1} Lee MW, McPhee RW, Stringer MD. An evidence-based approach to human dermatomes. Australasian Musculoskeletal Medicine. 2013 Jun;18(1):14-22.
8. ↑ Downs MB, Laporte C. Conflicting dermatome maps: educational and clinical implications. journal of orthopaedic & sports physical therapy. 2011 Jun;41(6):427-34.
9. ↑ ^9.09.1 Liebenson C, editor. Rehabilitation of the spine: a practitioner’s manual. Lippincott Williams & Wilkins; 2007.Available: https://www.sciencedirect.com/topics/medicine-and-dentistry/dermatome (accessed 25.5.2022)
10. ↑ Slide share. Dermatomes and myotomes. Available from: https://www.slideshare.net/TafzzSailo/special-test-for-dermatomes-and-myotomes (last accessed 23.4.2019)
11. ↑ ^11.011.1 Susan B.O’Sullivan, Thomas J. Schmitz, George D. Fulk. Physical Rehabilitation. 6th edition. F. A. Davis Company. 2014.
12. ↑ Downs MB, Laporte C. Conflicting dermatome maps: educational and clinical implications. journal of orthopaedic & sports physical therapy. 2011 Jun;41(6):427-34.

Hip Anatomy Shoulder dermatome, Abdomen, swimwear, anatomy, anatomy png

About this PNG

Image size

600x600px

File size

260.65KB

MIME type

Image/png

Download PNG ( 260.65KB )

resize PNG

width(px)

height(px)

License

Non-Commercial Use, DMCA Contact Us

org/ImageGallery” align=”middle”>

• human physiology, Human anatomy Muscle Human body Muscular system, muscles, miscellaneous, human, muscle png
  1000x1000px
  267.79KB

• human anatomy diagram, Spinal cord dermatome Peripheral nervous system Spinal nerve Myotome anatomy, miscellaneous, angle, anatomy png
  700x690px
  435.06KB

• Active Underwear Waist Shoulder Cosmetic treatment, arm, abdomen, active Underwear png
  667x1000px
  1.47MB

• Arm cryolipolysis Human arm Thigh skin, arm, physical Fitness, people, weight Loss png
  600x2415px
  1.1MB

• Human body Shoulder Hip Family medicine Clinic Organ, blood pressure, miscellaneous, purple, arm png
  1000x2304px
  1. 61MB

• skeleton illustration, Human skeleton Human body Anatomy, bones, miscellaneous, bones, human png
  615x1600px
  688.33KB

• Vladimir Active Undergarment Physical fitness Health Energy, fit girl, hand, fitness Professional, arm png
  419x740px
  223.54KB

• Yoga Body Health Flexibility Aromatherapy, yoga world, physical Fitness, sport, arm png
  1098x1000px
  1.18MB

• Back pain Shoulder pain Neck joint Muscle, back pain, miscellaneous, tshirt, arm png
  600x568px
  188.69KB

• human leg muscles illustration, Ankle Muscle Anatomy, miscellaneous, hand, foot png
  1434x1484px
  2. 22MB

• Human body Human leg Organ Homo sapiens Limb, sculpting, hand, people, monochrome png
  914x802px
  19.13KB

• HUMAN ANATOMY Human anatomy Muscular system Homo sapiens, others, physical Fitness, human, anatomy png
  512x512px
  109.71KB

• human body anatomy, Skeletal muscle Human skeleton Muscular system, Human muscle anatomy movement, people, human, anatomy png
  1100x1003px
  690.02KB

• Finger Arm Human body Homo sapiens, hand, hand, people, wrist png
  400x1549px
  384.03KB

• person touching both legs, Laser hair removal Waxing Epilation, hair, physical Fitness, hand, cosmetics png
  513x690px
  210. 86KB

• woman’s back pain illustration, Low back pain Neck pain, physical Fitness, pain, pain png
  1140x1706px
  395.36KB

• Hand, Hands, two-handed gesture, hand, wrist, forelimb png
  1588x1788px
  1.57MB

• Laser hair removal Skin Depilason, depilation, physical Fitness, hand, cosmetology png
  518x665px
  195.15KB

• Human body Organ Human anatomy Human back, structure of human organs, hand, human, anatomy png
  1147x1378px
  1.92MB

• Zaira Nara Model Argentina Clothing, model, celebrities, blue, fashion png
  625x1176px
  803.56KB

• org/ImageObject”>

  Warne’s Fitness Fitness Center Fitness Center Personal trainer, others, miscellaneous, fitness, arm png
  371x750px
  276.78KB

• Organ Human body Homo sapiens Human digestive system Muscle, organ, superhero, hand, people png
  2000x5499px
  2.18MB

• man with muscle illustration, Muscular system Skeletal muscle Human body Human skeleton, human body, miscellaneous, physical Health, human Body png
  3000x2953px
  3.8MB

• Weight loss Exercise Diet Weight management Weight gain, Fitness Banner, physical Fitness, hand, weight Loss png
  500x571px
  236.97KB

• woman holding pair of dumbbells, Dietary supplement Bodybuilding Bodybuilding Physical exercise Fitness, weight loss, fitness Professional, sport png
  500x800px
  552. 62KB

• Human body Organ Homo sapiens Anatomy Human skin, body, miscellaneous, hand, human png
  3000x6675px
  601.21KB

• Hip Hime cut Human leg Black hair, hair, cg Artwork, black Hair, hand png
  420x1600px
  311.79KB

• Shoulder Arm Human leg Thigh, plank, physical Fitness, people, abdomen png
  913x608px
  40.28KB

• Homo sapiens Human body Human anatomy Biology, human body, miscellaneous, human, biology png
  1062x2344px
  3.19MB

• human muscular system illustration, Human body Muscular anatomy Muscular system Organ, Human body, physical Fitness, people, human png
  1100x810px
  522. 57KB

• Health Weight loss Dieta do Metabolismo Rápido Abdominal obesity, health, physical Fitness, swimsuit Top, nutrition png
  900x910px
  598.37KB

• Bodyweight training Physical fitness Fitness Center Weight loss, others, physical Fitness, weight Loss, fitness png
  488x1342px
  520.34KB

• Hip Fat Abdominal obesity Adipose tissue, arm, people, human, swimwear png
  864x576px
  309.72KB

• Deep vein thrombosis Human leg Hip Thrombus, legs, people, ankle, symptom png
  839x800px
  300.33KB

• woman holding pair of dumbbells, Forever Living Products Weight loss Detoxification Aloe vera Weight management, 60s, miscellaneous, physical Fitness, food png
  2627x4735px
  5. 45MB

• woman stretching, Yoga Pilates Physical exercise Asento Physical fitness, yoga mat, hand, sports, wrist png
  900x522px
  244.82KB

• woman using headphones, Fitness training boot camp Physical fitness, Summer playlist, miscellaneous, sport, boxing Glove png
  536x789px
  110.25KB

• woman wearing tank top and drawstring shorts, Chrome Weight Loss Diet Slimming Slim 10, slim body, miscellaneous, white, physical Fitness png
  640x1040px
  377.43KB

• Thumb Homo sapiens Human body Anatomy Drawing, humano, white, face, text png
  1000x1414px
  43.34KB

• Push-up strength training Exercise Plank Triceps shoulder muscle, others, physical Fitness, arm, arm png
  890x585px
  368. 2KB

• Human leg Arm Limb Human body Joint, results, hand, people, wrist png
  2019x1488px
  1.06MB

• woman exercising while holding two dumbbells, Physical fitness Fitness center Personal trainer, Weight Loss, fitness Professional, arm png
  1257x843px
  647.61KB

• human anatomy, Myofascial trigger point Massage Physical therapy Muscle, anatomy, miscellaneous, hand, arm png
  832x1950px
  527.27KB

• Active undergarment Thigh Thigh Physical fitness Knee, healthy body, arm, fitness Professional, shoe png
  280x906px
  259.41KB

• women measuring their waist, Human body Weight loss Waist surgery Detoxification Ms. thin waist sports and fitness, fitness, swimsuit Top, sports png
  763x1127px
  889.9KB

• Bodybuilding Physical fitness Training Muscle mass, jasmine, sport, fitness Professional, arm png
  726x700px
  107.62KB

• man standing in white underwear, Legs Legs, leg, people, leg, ankle png
  800x1198px
  457.65KB

• Skeletal muscle Muscular system Human skeleton Human body, skeleton, hand, human, bodybuilder png
  586x468px
  256.28KB

• Muscle Homo sapiens Human anatomy Human back, arm, people, human, fictional Character png
  1200x1200px
  1.07MB

• Vertebral CNS Neuron Vertebral column, Brain, face, hand, people png
  707x1080px
  687. 19KB

Explanation and location of 30 dermatomes – Drink-Drink

Contents

• Dermatomes in context
  • Your spinal nerves
  • Your dermatomes is each dermatome located?
    • Cervical spinal nerves
    • Thoracic spinal nerves
    • Lumbar spinal nerves
    • Sacral spinal nerves
    • Coccygeal spinal nerves
  • Diagram of dermatomes
  • Why are dermatomes important?
  • Conclusion

  A dermatome is a skin area innervated by one spinal nerve. The spinal nerves help transmit sensory, motor, and autonomic information between the rest of the body and the central nervous system (CNS).

  Why are dermatomes important? How many are there? And where can they be found? Keep reading as we answer these questions and more.

  Dermatomes in context

  Each of your dermatomes is supplied by one spinal nerve. Let’s take a closer look at both of these components of the body.

  Your spinal nerves

  The spinal nerves are part of your peripheral nervous system (PNS). Your PNS works to connect the rest of your body to your CNS, which is made up of your brain and spinal cord.

  You have 31 pairs of spinal nerves. They form from nerve roots that branch off from the spinal cord. The spinal nerves are named and grouped according to the region of the spine they are associated with.

  Five groups of spinal nerves:

  • Cervical nerves. There are eight pairs of these cervical nerves, numbered C1 to C8. They come from your neck.
  • Thoracic nerves. You have 12 pairs of thoracic nerves, which are numbered T1 through T12. They occur in the part of the spine that forms the torso.
  • Lumbar nerves. There are five pairs of lumbar spinal nerves, labeled L1 to L5. They come from the part of the spine that forms the lower back.
  • Sacral nerves. Like the lumbar spinal nerves, you also have five pairs of sacral spinal nerves. They are connected to your sacrum, which is one of the bones in your pelvis.
  • Coccygeal nerves . You have only one pair of coccygeal spinal nerves. This pair of nerves originates in the coccyx or coccyx region.

  Your dermatomes

  Each of your dermatomes is connected to one spinal nerve. These nerves transmit sensations, such as pain, from a specific area of ​​the skin to the CNS.

  There are 30 dermatomes in your body. You may have noticed that this is one less than the number of spinal nerves. This is because the C1 spinal nerve usually does not have a sensory root. As a result, dermatomes begin with the C2 spinal nerve.

  Dermatomes have a segmented distribution throughout the body. The exact pattern of the dermatome can vary from person to person. There may also be some overlap between adjacent dermatomes.

  Since your spinal nerves exit the spine laterally, the dermatomes associated with your torso and nucleus are distributed horizontally. When viewed on a body map, they look a lot like stacked discs.

  The dermatome pattern on the limbs is slightly different. This is due to the shape of the limbs compared to the rest of the body. Typically, dermatomes associated with your limbs run vertically along the long axis of the limb, such as down the leg.

  Where is each dermatome located?

  Your dermatomes are numbered according to which spinal nerve they correspond to. Below, we describe each dermatome and the region of the body it is associated with.

  Be aware that the exact area that the dermatome can cover may vary from person to person. Some overlap is also possible. Thus, consider the diagram below as a general guide.

  Cervical spinal nerves

  • C2: mandible, occiput
  • C3: upper neck, occiput
  • C4: lower neck, upper shoulders
  • C5: collarbone, upper shoulders
  • C 6: shoulders, outer arm, thumb
  • C7: upper back, back of hand, index and middle fingers
  • C8: upper back, inside of hand, ring finger and little finger

  Thoracic spinal nerves

  • T1: upper chest and back, armpits, front of the arm
  • T2: upper chest and back
  • T3: upper chest and back

  90 005 T4: upper chest ( nipple area) and back

  • T5: middle chest and back
  • T6: middle chest and back
  • T7: middle chest and back
  • 90 246 T8: upper abdomen and mid back
  • T9: upper abdomen and middle back
  • T10: abdomen (navel area) and middle back
  • T11: abdomen and middle back
  • T12: lower abdomen and mid back

  Lumbar spinal nerves

  • L1: lower back, thighs, groin
  • L2: lower back, anterior and inner thighs
  • L3: 9 0247 lower back, anterior and inner thighs
  • L4: lower back, front thigh and calf, knee area, inner ankle
  • L5: lower back, front and outer calf, upper and lower foot, first four toes

  Sacral spinal nerves

  • S1: lower back, hamstring, back and inner calf, last toe
  • S2: buttocks, genitals, hamstrings and calves
  • S3: buttocks, genitals
  • S4: buttocks
  • S5: buttocks

  Coccyx-spinal nerves 90 237

  buttocks, coccyx area

  Diagram of dermatomes

  Why are dermatomes important?

  Dermatomes are important because they can help evaluate and diagnose various conditions. For example, symptoms occurring along a particular dermatome may indicate a problem with a particular nerve root in the spine.

  Examples of this include:

  • Radiculopathy. This refers to conditions in which the nerve root in the spine is compressed or pinched. Symptoms may include pain, weakness, and tingling. Pain in radiculopathies may follow one or more dermatomes. One form of radiculopathy is sciatica.
  • Shingles. Shingles is a reactivation of the varicella zoster virus (chickenpox) that is dormant in the nerve roots of your body. Shingles symptoms such as pain and rash occur along the dermatomes associated with the affected nerve root.

  Summary

  Dermatomes are areas of skin associated with a single spinal nerve. You have 31 spinal nerves and 30 dermatomes. The exact area each dermatome covers can differ from person to person.

  The spinal nerves help convey information from other parts of the body to the central nervous system.