The following are the major muscles that will be encountered and may be divided during thoracic operations for trauma.

• Anterior Chest Wall: Pectoralis major and pectoralis minor muscles

  • Pectoralis major muscle: It originates from the anterior surface of the medial half of the clavicle, the anterior surface of the sternum, and the cartilages of all the true ribs (1–7 ribs). The 5-cm wide tendon inserts into the upper humerus.

  • Pectoralis minor muscle: It arises from the third, fourth, and fifth ribs, near their cartilages, and from the aponeuroses over the intercostal muscles. It inserts into the coracoid process of the scapula.

• Lateral Chest Wall: Serratus anterior muscle

  • Serratus anterior muscle: It originates from the lateral part of the first eight to nine ribs and inserts into the medial aspect of the scapula.

• Posterior Chest Wall: Latissimus Dorsi

  • Latissimus Dorsi muscle: It originates from the spinal processes of the lower thoracic spine and the posterior iliac crest and inserts into the upper portion of the humerus.