Myotome Muscles Upper Limb Neurological Examination
The anatomical term myotome refers to the muscles served by a spinal nerve root. A myotome is, therefore, a set of muscles innervated by a specific, single spinal nerve. The term is also used in embryology to describe that part of the somite which develops into the muscles. An area of the skin that is innervated by the sensory fibers that stem from a specific nerve root is called a dermatome.
A dermatome is an area of skin that’s supplied by a single spinal nerve. Your spinal nerves help to relay sensory, motor, and autonomic information between the rest of your body and your central nervous system (CNS).
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.
The sensory exam involves evaluation of pain (or temperature), light touch, position sense, vibration, and discriminative sensations. This portion of the exam is very subjective, and may become unreliable if repeated in quick succession. Therefore, your exam should not be rushed, but must proceed efficiently.