Musculature of the thoracic wall include 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 are the:

• Pectoralis major muscle;
• Pectoralis minor muscle;
• Serratus anterior muscle;
• Levatores costarum muscles;
• External intercostal muscles;
• Internal intercostal muscles;
• Innermost intercostal muscles;
• Subcostal muscles;
• Transversus thoracis muscle.