Acute and chronic pain originating from deep somatic structures represent a major part of complaints in patients seeking health services. In a large survey, it was found that approximately 50% of the respondents had experienced pain or unpleasantness originating from musculoskeletal structures within two weeks before the interview. Moreover, musculoskeletal pain complaints were the main reason for 10% of all visits to a clinical practice in the United States. Thus, it is generally accepted that pain from deep tissues constitutes a special diagnostic and therapeutic challenge, and insights into the peripheral and central neurobiological mechanisms are necessary to improve diagnosis and management strategies.