Serratus Anterior: The Shoulder Girdle: Function & Issues
Due to its common and vital role in teachings related to muscle balance of the shoulder girdle, we include more detail on the serratus anterior muscles here.
Location
- Broad, thin muscle covering the lateral ribcage
- It originates at the first eight or nine ribs and runs to the medial (inner) side of the scapula
- Referring to its location, it may be called the “bear hug” muscle
- Most of the serratus anterior is deep but the portion below the armpit is superficial
Function
- Helps hold shoulder blades against rib cage
- Helps to move shoulder blades away from each other (protraction)
- Used in push-up
- Supports upper back, shoulder and chest in Plank, Chaturanga Dandasana and many arm balances and inversions
- Helps in bringing arms overhead as in Virabhadrasana I
- Antagonist to the rhomboids
Issues
- A repetitive forward-head position leads to a rounded upper back and constantly protracted shoulder blades; this in turn causes the serratus muscles to be always “on” and therefore to become both tight and weak
- Winged scapula indicate a weak serratus anterior
- Tension or pain in the neck, upper trapezius or rhomboids may be referred pain from a weak serratus anterior
- Weak serratus muscles “can even contribute to shallow breathing” (Nishita Morris)
Why Serratus Muscles Are Often Both Tight & Weak
Over time, [a forward-head position] can lead the always “on” and contracted serratus anterior muscles fibers to become chronically shortened. It is easy for them to lose elasticity and potentially atrophy (hence the muscle tightness yet weakness). As a result, other muscles will attempt to create stability by taking on more the load. This may further contribute to weak serratus anterior muscles and even neck pain and shoulder impingement (most often caused by overused or irritated rotator cuff muscles). – Nishita Morris