There are three layers of Intercostal Muscles: External, Internal, and Inner Intercostals.
External Intercostals help with inhalation and lift the ribs as we can see from the direction of their fibers on the image.
Internal and Inner Intercostals depress the ribs and help with exhalation.
Have you ever had a bruised or broken rib? Or perhaps a fall when the "wind was knocked out you?" Or when you fell off a bike, or fell sideways in another way?
Most of us have had these non-life-threatening little physical traumas.
Typically, the Intercostals rapidly contract to protect us from the trauma. Occasionally, these muscles will remain contracted for longer periods of time and limit the movement of the ribs.
A bruised or broken rib will often heal with some internal scar tissue within the Intercostals, which again limits their elasticity and restricts movement.
After a few of these 'dings' on the ribcage, our freedom of movement may be compromised.
Massage can certainly help with that!
Few massage therapists work on the Intercostals during a typical massage session, although we sure do cover it in massage schools.
A skillful massage therapist can free up the scar tissue, mobilize 'stuck' ribs, and help create more space between the ribs. This work can potentially improve posture, get rid of on-going ribcage pain, tightness of breath, and even help reduce anxiety.
In addition to massage, here are two helpful suggestions to mobilize the ribcage.
1. Practice consciously expanding the ribcage on the inhalation, and contracting the ribcage on the exhalation.
2. Stretch the ribcage gently. Yoga has many postures and exercises that stretch the Intercostals: Cat and Cow Stretch, Cobra Pose, Bow Pose, and Seated and Supine Twists.