A cough is a respiratory reaction that helps protect the lungs from irritating or damage substances. Coughing is a reflex action and involves rapid inhalation, closing off of the throat, increase in internal pressure in the chest, and forceful exhalation. The normal muscles of breathing as well as accessory respiratory muscles are involved in coughing.
Normal Respiratory Muscles
The normal respiratory muscles used in coughing include the abdominal muscles, intercostal muscles -- running between adjacent ribs, and diaphragm. The abdominal and intercostal muscles tighten and the diaphragm relaxes causing increase in chest pressure, as this decreases the volume of your chest cavity.
The diaphragm and external intercostal muscles act during inhalation. The abdominal muscles -- the rectus abdominis, internal and external obliques, and the transversus abdominis and the internal intercostal muscles are involved in compression and exhalation.
Prolonged coughing can cause soreness or even strain in the abdominal or rib muscles.
Accessory Repiratory Muscles
Because coughing is a very forceful action and often is prolonged, the accessory respiratory muscles are normally involved in coughing. These muscles are primarily responsible for other actions of the body but assist in the the process of breathing under stress, coughing or other large air movements.
Other accessory respiratory muscles include the scalenes, sternoclidomastoid, upper trapezius, levator costorum, paraspinals and subclavius for inhalation; and, the pectorals, serratus anterior, latissimus dorsi, serratus posterior muscles. The primary function of these muscles is to move your shoulders and your neck, however they assist with breathing by expanding your chest cavity when your diaphragm is weak.
With prolonged coughing or other respiratory difficulty, these muscles can become sore, hypertonic or even strained.
Muscles of the Throat
In addition to inhalation and exhalation, the throat closes initially in coughing and there can be pain or soreness in the muscles involved in this portion of a cough. The muscles of the throat that control the flow of air through the trachea --windpipe -- are the pharyngeal constrictors, tongue and other pharynx muscles. These muscles move your larynx to temporarily block your trachea to build up an explosive release of air when you cough.