Health care professionals who provide rehabilitation services are expected to perform a variety of tests and measures to effectively examine and evaluate a patient’s condition. Somatosensation is critical for the reception and perception of sensation from the periphery (i.e., touch, pain, and temperature), and is an essential component of a complete clinical examination of the nervous system. Many conditions or lesions involving the Peripheral Nervous System (PNS) and/or the Central Nervous System (CNS) can affect somatosensory function. The examination and evaluation of somatosensation will allow the clinician to identify underlying peripheral and/or central nervous system dysfunction and to interpret the impact of identified changes on an individual’s motor function and activities of daily living. It is important for the health care practitioner to understand the anatomy of the somatosensory system in order to interpret the results of a sensorimotor examination.

Primary Anatomical Considerations
The perception of somatosensation requires that all components of the anatomical sensory pathway are intact. The primary anatomical considerations are listed below. Click HERE to download this outline as a PDF.

• Sensory Receptors – each responds to a specific type of stimulation.
  • Mechanoreceptors (i.e., cutaneous and deep [muscle, tendon, and joint proprioceptors]), respond to touch, pressure, stretch and vibration.
  • Chemoreceptors - respond to chemicals released by cells secondary to inflammation, injury, or infection.
  • Thermoreceptors - respond to changes in temperature.
• Afferent nerve fibers from sensory receptors.
• Sensory cell body - located in the dorsal root ganglia.
• Spinal cord or brainstem synapses.