The musculature of the thoracic wall is composed of muscles that fill and support the intercostal spaces, muscles extending between the sternum and the ribs, and those that cross several ribs between costal attachments.

The thoracic wall muscles include the following:

• Pectoralis major
• Pectoralis minor
• Subclavius
• Serratus anterior muscle
• Intercostal muscles
  • External intercostal muscles
  • Internal intercostal muscles
  • Innermost intercostal muscles
• Subcostal muscles
• Transversus thoracis
• Levatores costarum (sing. Levator costae)

In the next slides, learn more in detail about each thoracic wall muscle!