Thorax Movements

Question 1

Muscles in Elevation of the Thorax (inspiration)

Answer 1

• Diaphragm
• External intercostals
• scalenes (accessory)
• Sternocleidomastoid (accessory)
• Pec Major and Minor (accessory)
• Serratus anterior (accessory)
• Serratus posterior superior (accessory)
• Lats (accessory)

Question 2

Muscles in Depression of the Thorax (expiration)

Answer 2

• Internal Intercostals (forced expiration)
• Abdominal Muscles: Rectus and transversus abdominis and external and internal obliques
• Serratus Posterior Inferior
• Transversus Thoracis

Question 3

Muscles in Lateral Flexion of Thorax

Answer 3

• External Oblique
• Internal Oblique
• Quadratus Lumborum
• Erector Spinae

Question 4

Muscles in Rotation of Thorax

Answer 4

• External Oblique (opposite side)
• Internal Oblique (same side)
• Multifidus
• Rotatores