What are accessory muscles?

Accessory Muscles of Inspiration. The accessory muscles used when breathing in -- called accessory muscles of inspiration -- include the scalene, sternocleidomastoid, trapezius and pectoralis major muscles. These muscles are found around the shoulders, neck and upper chest. read more

accessory muscles of respiration - in labored breathing, the use of muscles other than the diaphragm and intercostals. the sternocleidomastoid, spinal, neck, and abdominal muscles and even the platysma, may be used. their use is a sign of an abnormal or labored breathing pattern. read more

The most common sign associated with an accessory muscle is the appearance of a soft tissue mass. Differential diagnosis without an exploratory operation is difficult because of the similar appearance of some tumors or soft tissue masses, such as ganglia. read more