Dermatomal and Myotomal Maps and Level testing
Posted by dkwinter

Source: Academic Life in Emergency Medicine


Testing Motor Function by Level 

C1-C4 Spontaneous breathing
C5 Shoulder abduction (deltoid)
C6 Wrist extension (carpi radialis longus and brevis)
C7 Elbow extension (triceps)
C8 Finger flexion (flexor digitorum superficialis/profundis, lumbricals)
T1 Finger adduction&abduction (dorsal/palmar interossei, abductor digiti quinti)
T1-T12 Intercostal and abd muscle
T12-L3 Hip flexion (iliopsoas)
L2-L4 Hip flexion, knee extension (quadriceps), hip adduction
L4 Ankle dorsiflexion and inversion (anterior tibialis)
L5 Big toe extension (ext hallucis longus), heel walk (ext digitorum), hip 
abduction (gluteus medius)
S1 Ankle plantarflexion and eversion (peroneus longus), toe walk (peroneus 
brevis), hip extension (gluteus maximus) 
S2-S4 Rectal sphincter tone