<http://schema.org/articleBody>
"&amp;lt;h3&amp;gt;Myotomes&amp;lt;/h3&amp;gt;&amp;lt;p&amp;gt;Like a dermatome, a myotome is a zone in the body that is served by one spinal nerve root. \u00A0The difference is that a dermatome is a zone in which sensory nerves travel on their way back to the central nervous system with information about things you feel - heat, pain, itches, your body&amp;amp;#39;s position, how stretched out your muscles are, and more. \u00A0Myotomes, on the other hand, are zones where &amp;lt;em&amp;gt;motor&amp;lt;/em&amp;gt; nerves travel as they fulfill their responsibilities of signalling your muscles to contract.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Both myotomes and dermatomes are &amp;amp;#34;mapped,&amp;amp;#34; which provides doctors and physical therapists with a reference for determining - based on observation and testing - \u00A0the specific nerve root(s) or spinal core level(s) that may have been compromised and/or are causing symptoms.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Myotomes and dermatomes are a part of the somatic (voluntary) nervous system, which is part of the peripheral nervous system. The peripheral and central nervous systems communicate with one another regularly.&amp;lt;/p&amp;gt;&amp;lt;h3&amp;gt;Muscles and Nerves, Oh My!&amp;lt;/h3&amp;gt;&amp;lt;p&amp;gt;Every muscle cell in your body needs input from a nerve in order to stay healthy. \u00A0Without at least some communication between nerve and muscle (a phenomenon called tone that is very useful for keeping your joints stable), the muscle begins to decay. \u00A0&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;This communication happens at a very important place in the muscle fiber cell called the motor endplate. \u00A0The nerve cell, along with the endplate is known as the neuromuscular junction.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;One nerve cell\u00A0innervates\u00A0several muscle fibers. \u00A0This is called a motor unit. Every\u00A0fiber\u00A0that is part of a motor unit contracts (works) when its respective nerve is fired. \u00A0It&amp;amp;#39;s an all or nothing proposition. \u00A0To avoid muscle and nerve &amp;amp;#34;burn out,&amp;amp;#34; motor units take turns firing.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;All this is happening at the\u00A0microscopic\u00A0level, mind you, but depending on the size of the muscle and the jobs it\u00A0does, a nerve cell can innervate as few as 6-10 muscle cells (think fingers that play piano, chop vegetables, sew, write, or muscles around the eye&amp;amp;#39;s that help focus, blink away tears, keep you safe on the road and more.) to hundreds (think mid-back and arm muscles, where fine coordination is not as important.)\u00A0&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Another way to understand motor units is from the perspective of the muscle. \u00A0A many-fibered muscle contains an innumerable collection of motor units.&amp;lt;/p&amp;gt;&amp;lt;h3&amp;gt;Myotomes - A Global Nerve-Muscle Perspective&amp;lt;/h3&amp;gt;&amp;lt;p&amp;gt;Now that you know what a motor unit is --- \u00A0understanding a myotome is a matter of viewing things from a more global perspective.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;A myotome is the group of muscles on one side of the body that are enervated by one spinal nerve root.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Doctors use their knowledge of the location of myotomes (and\u00A0&amp;lt;a href=&amp;quot;https://www.verywell.com/dermatomes-and-dermatome-distribution-296693&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;1&amp;quot;&amp;gt;dermatomes&amp;lt;/a&amp;gt;) during the\u00A0&amp;lt;a href=&amp;quot;https://www.verywell.com/how-is-acute-low-back-pain-diagnosed-296712&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;2&amp;quot;&amp;gt;physical exam&amp;lt;/a&amp;gt;. To identify the specific spinal nerve(s) that may underlie muscle weakness,\u00A0they perform isometric strength tests according to the myotome map.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Below this section is a chart that gives the names of the nerves and the action they produce by innervating the responsible muscles, i.e., the map.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Before I show you that, let me just say that the myotome deciphering process can at times be sloppy. In other words, even though myotomes (as well as dermatomes) have been &amp;amp;#34;mapped,&amp;amp;#34; in practicality, the zones are not always clear cut and distinct. \u00A0There is often overlap, where nerves will innervate muscles in zones other than the ones in which they&amp;amp;#39;re officially &amp;amp;#34;mapped.&amp;amp;#34;&amp;lt;/p&amp;gt;&amp;lt;table align=&amp;quot;center&amp;quot; border=&amp;quot;1&amp;quot; cellpadding=&amp;quot;1&amp;quot; cellspacing=&amp;quot;1&amp;quot;&amp;gt;&amp;lt;thead&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;th&amp;gt;Spinal Level (Nerve)&amp;lt;/th&amp;gt;&amp;lt;th align=&amp;quot;center&amp;quot;&amp;gt;Action&amp;lt;/th&amp;gt;&amp;lt;th&amp;gt;Muscles&amp;lt;/th&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;/thead&amp;gt;&amp;lt;tbody&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;C1 &amp;amp;amp; C1&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Neck Flexion&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Rectus lateralis, Rectus capitis anterior, longus capitis, &amp;lt;a href=&amp;quot;https://www.verywell.com/longus-colli-and-other-deep-neck-flexion-muscles-296952&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;3&amp;quot;&amp;gt;longus colli&amp;lt;/a&amp;gt;, longus cervicus, &amp;lt;a href=&amp;quot;https://www.verywell.com/scm-or-sternocleidomastoid-neck-muscle-297064&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;4&amp;quot;&amp;gt;sternocleidomastoid&amp;lt;/a&amp;gt;&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;C3&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Neck Side Flexion&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Longus capitis, longus cervicus, trapezius, scalenus \u00A0medius&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;C4&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Shoulder Elevation&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Diaphragm, trapezius,&amp;lt;a href=&amp;quot;https://www.verywell.com/levator-scapula-muscle-296483&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;5&amp;quot;&amp;gt; levator scapula&amp;lt;/a&amp;gt;, scalenus anterior &amp;amp;amp; medius&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;C5&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Shoulder Abduction&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Rhomboid major &amp;amp;amp; minor, deltoid, supraspinatus, infraspinatus, teres minor, biceps, scalene anterior &amp;amp;amp; medius&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;C6&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Elbow Flexion; Wrist Extension&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Serratus anterior, &amp;lt;a href=&amp;quot;https://www.verywell.com/latissimus-dorsi-muscle-297067&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;6&amp;quot;&amp;gt;latissiumus dorsi&amp;lt;/a&amp;gt;, subscapularis, teres major, pectoralis major (clavicular head) biceps brachii, coracobrachialis, brachioradialis, supinator, extensor carpi radialis longus, scalenus anterior, medius &amp;amp;amp; posterior&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;C7&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Elbow Extension; Wrist Flexion&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Serratus anterior, latissiumus dorsi, pectoralis major (sternal head), pectoralis minor, pronator teres, flexor carpi radialis, flexor digitorum superficialis, extensor carpi radialis longus,\u00A0extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, scalenus medius &amp;amp;amp; posterior&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;C8&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Thumb extension; Ulnar Deviation&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Pectoralis major (sternal head), pectoralis minor, triceps, flexor digitorum superficialis, flexor digitorum profundus, flexor pollicus longus, pronator quadratus, flexor carpi ulnaris, extensor pollicus longus, extensor pollicus brevis, extensor indicis, abductor pollicus brevis, flexor pollicus brevis, opponens pollicus, scalenus medius &amp;amp;amp; posterior.\u00A0&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;T1&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;\u00A0&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;\u00A0&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;T2-12&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Not tested&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Thoracic nerves control muscles in the trunk and abdomen, and are generally not tested.&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;L1-2&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Hip Flexion&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Psoas, iliacus, sartorius, gracilis, pectineus, adductor longus, adductor brevis&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;L3&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Knee Extension&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Quadriceps, adductor longus, magnus &amp;amp;amp; brevis.&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;L4&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Ankle Dorsiflexion&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Tibalis anterior, quadriceps,tensor fasciae late, adductor magnus, obturator externus, tibialis posterior&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;L5&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Toe Extension&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Extensor hallucis longus, extensor digitorum longus, gluteus medius &amp;amp;amp; minimus, abturator internus, semimembranosus, semitendinosus, peroneus tertius, popliteus&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;S1&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Ankle Plantarflexion; Ankle Eversion; Hip Extension,; Knee Flexion&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Gastrocnemius, soleus, gluteus maximus, obturator internus, piriformis, biceps femoris, semitendinosus, popliteus, peroneus longus &amp;amp;amp; brevis, extensor digitorum brevis&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;S2&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Knee Flexion&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Biceps femoris, piriformis, soleus, gastrocnemius, flexor digitorum longus, flexor hallucis longus,\u00A0Intrinsic foot muscles (except abductor hallcuis), flexor hallucis brevis, flexor digitorum brevis, extensor digitorum brevis&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;S3&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;No Myotome&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;\u00A0&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;tr&amp;gt;&amp;lt;td&amp;gt;S4&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Anal Wink&amp;lt;/td&amp;gt;&amp;lt;td&amp;gt;Muscles of the pelvic floor and bladder&amp;lt;/td&amp;gt;&amp;lt;/tr&amp;gt;&amp;lt;/tbody&amp;gt;&amp;lt;/table&amp;gt;&amp;lt;h3&amp;gt;The Myotome Dance&amp;lt;/h3&amp;gt;&amp;lt;p&amp;gt;If you&amp;amp;#39;re the kind of person who learns by doing, I suggest you check out one or more of the YouTube videos linked below. \u00A0These were produced by physical therapy assistant school cohort groups (and one physiology class) from around the country. \u00A0Because each video has both strong and weak points educationally, it&amp;amp;#39;s probably a good idea to look at all of them. Note: \u00A0Most of the dances are done to a very fast beat. \u00A0I suggest you move at the pace your body (particularly your neck) can handle safely. \u00A0Most likely, this means going slower then the physical therapy students.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Overall, though, these dances may give you a good idea about what myotomes actually do, and why they are important. \u00A0And the music is pretty good, too.&amp;lt;/p&amp;gt;&amp;lt;ul&amp;gt;&amp;lt;li&amp;gt;&amp;lt;a href=&amp;quot;https://www.youtube.com/watch?v&amp;amp;#61;ZXLhwF2ptl0&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;externalLink&amp;quot; data-ordinal=&amp;quot;7&amp;quot;&amp;gt;Ladies in Blue do the Myotome Dance&amp;lt;/a&amp;gt;&amp;lt;/li&amp;gt;&amp;lt;li&amp;gt;&amp;lt;a href=&amp;quot;https://www.youtube.com/watch?v&amp;amp;#61;LZi4kAyzj9I&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;externalLink&amp;quot; data-ordinal=&amp;quot;8&amp;quot;&amp;gt;Dr. Burke-Doe&amp;amp;#39;s Physiology Class Dances to Bon Jovi&amp;lt;/a&amp;gt;&amp;lt;/li&amp;gt;&amp;lt;li&amp;gt; &amp;lt;a href=&amp;quot;https://www.youtube.com/watch?v&amp;amp;#61;C1ScUp3Mf1w&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;externalLink&amp;quot; data-ordinal=&amp;quot;9&amp;quot;&amp;gt;Austin Community College PTA Class of 2013 (with costume!)&amp;lt;/a&amp;gt;\u00A0 (Note: \u00A0This one is both dermatome and myotome.)&amp;lt;/li&amp;gt;&amp;lt;/ul&amp;gt;&amp;lt;p&amp;gt;&amp;lt;sub&amp;gt;&amp;lt;strong&amp;gt;Sources:&amp;lt;/strong&amp;gt;&amp;lt;/sub&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;sub&amp;gt;Barkhaus, P., M.D., et. al. EMG Evaluation of the Motor Unit - Electrophysiologic Biopsy. Medscape website. Last Updated: Aug 2013. Accessed: June 2015. &amp;lt;a href=&amp;quot;http://emedicine.medscape.com/article/1846028-overview&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;externalLink&amp;quot; data-ordinal=&amp;quot;10&amp;quot;&amp;gt;http://emedicine.medscape.com/article/1846028-overview&amp;lt;/a&amp;gt;&amp;lt;/sub&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;sub&amp;gt;Magee, David, J. Orthopedic Physical Assessment. 4th Edition. Saunders Elsevier. St. Louis, MO. 2006.&amp;lt;/sub&amp;gt;&amp;lt;/p&amp;gt;"^^<http://www.w3.org/2001/XMLSchema#string>
<https://www.verywell.com/what-is-a-myotome-296992>