| Serratus ventralis | Origin - First ten ribs. Insertion - Medial surface of scapula. Action - Draws scapula to thorax. |
| Levator scapulae | Origin - Last five cervical vertebrae. Insertion - medial surface of scapula. Action - Draws scapula cranioventrally. |
| Transversus costarum | Origin - Lateral border of sternum. Insertion - First rib. Action - Draws sternum crainially. |
| Scalenus | Origin - Ribs. Insertion - Cervical transverse process. Action - Flexes the neck. |
| External intercostal | Origin - Border of rib. Insertion - Border of adjacent rib. Action - Protracts the ribs. |