Deep Somatic Pain
Deep somatic pain sits in contrast to the less common cutaneous and neuropathic pain. It is otherwise known as musculoskeletal pain as it appears to arise in the deeper tissues of the muscles, bones, and joints. The neurophysiology of deep somatic pain is likely to be different to cutaneous and neuropathic pain.
A related concept is somatic referred pain, which stands in distinction to visceral referred pain, and indicates that the somatic tissues are the source of pain referral. The pain can be referred to remote sites. The pattern is different to that found in dermatome maps, and has been termed the sclerotome.
The sensitivity of deep structures in decreasing order is periosteum, ligament, joint capsule, tendon, fascia, muscle. Pain from muscles tend to refer to the joint on which it acts. Spinal structures refer in a somewhat segmental fashion in the thoracic levels, and into the respective limbs in the cervical and lumbar levels. There are large degrees of overlap.