03/16/2026
Muscle Monday: The Intercostal Muscles
The intercostal muscles are the small muscles that sit between each of your ribs. Even though they’re small, they play a big role in breathing, rib mobility, and upper body movement.
There are three layers of intercostal muscles that work together to support the ribcage and assist with breathing.
✨ Origin:
• Upper border of one rib
✨ Insertion:
• Lower border of the rib above
These muscles help:
• Expand and stabilize the ribcage during breathing
• Assist with inhalation and exhalation
• Support trunk rotation and side bending
• Maintain healthy rib mobility
When the intercostals become tight or irritated, you may notice:
• Tenderness between the ribs
• Pain with deep breathing
• Rib or side discomfort when twisting
• Tightness in the mid-back or chest
• A feeling of restricted breathing
Because they connect each rib, these muscles are constantly working — especially with posture changes, repetitive movements, or shallow breathing.
Keeping the ribcage mobile can help improve breathing, reduce tension, and allow the upper body to move more comfortably.
✨ If your ribs, mid-back, or breathing feel tight, these muscles might need some attention.