For many years, I practiced planks with little awareness of how to stabilize and support my body for optimal efficiency. Although I felt like my planks were pretty good, it wasn’t until I journeyed through the YTU Level 1 Training that I realized I needed to be more engaged and stabilized when bearing weight on my shoulders. It was during day 3 of the training when a lightbulb in my head suddenly turned on. Ah, welcome to my new found awareness of the serratus anterior and its importance in stabilization of the shoulder. It was a revelation moment!
The serratus anterior is a broad, thin muscle that lies along the posterior (back) and lateral (side) rib cage. It originates from the external (outer) surfaces of ribs 1 through 9 and inserts into the anterior (front) surface of the medial (inner) border of the scapula (shoulder blade). Most of the muscle is deep to the scapula, however the portion of the serratus below the axilla (armpit) is superficial. To simplify, serratus anterior looks something like a large nine-fingered hand. The palm of this large hand is under the shoulder blade while the fingers extend out over the ribs and then weave into the obliques.
Serratus anterior is often referred to as the “boxers muscle” or “big swing muscle”. When contracted, it protracts the scapula and appears to lengthen the arm by wrapping the shoulder blade towards the front of the body and chest. A boxers punch and reach come from the effectiveness of the scapula and serratus to protract and retract. The latter is enabled by the serratus anterior’s antagonist, the rhomboids. This free movement of the scapula is also aided by the presence of some fatty layers (“gliding planes”) which cushion the serratus anterior from the ribcage and from the subscapularis muscle.
Before we move on, let’s physically explore scapular protraction and retraction as mentioned above. One of the many things I love about Yoga Tune Up® is the process of breaking down traditional yoga poses and movement into bite size and digestible pieces. Jill explains this movement in an exercise called “Protraction/Retraction Push-ups” on her Pranamaya Yoga Link Shoulder Shape-Up DVD. Set yourself up on your mat on all 4’s, hands directly under your shoulders and knees under your hips. Draw the shoulder blades together (retraction) and then spread them apart by pushing the ground away from you (protraction), continue through these movements back and forth without bending the elbows. This movement isolates the scapula. (Check out a video demo here.) Can you feel the scapula sliding across your back? You could take this one step further and explore doing one side at a time. Practice with mindfulness and awareness; does one scapula move more freely?
Come back later this week to read my next article and get a handle on cues for practicing plank with optimal biomechanics to feel the engagement of the very important serratus anterior muscle.