Other Muscles: More Detail: The Shoulder Girdle: Function & Issues

Serratus Anterior

[The serratus anterior is] always well-developed on superheroes. – Andrew Biel, Trail Guide to the Body 2010 p 86

  • 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
  • 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
  • See more on these muscles in Anatomy of the Shoulders: Functions & Issues


  • Rhomboid major originates from T3 to T5 and inserts on lower border of scapula
  • Rhomboid minor originates from C7 to T1 and inserts on upper third of scapula
  • Adduct the scapula
  • The upper rhomboids “are particularly strained by their effort to pull the shoulder blades back into place” when the pec minor is tight and/or shoulders are chronically rounded (Doug Keller)
  • Tension in these muscles can cause chronic pain along edges of shoulder blades nearest spine


  • Large diamond-shaped muscle muscle covering the upper back, shoulders and neck
  • Used in shrugging shoulders

Levator Scapulae

  • Originates from C1 to C4
  • Elevates and rotates shoulder blades downward
  • Laterally flexes the neck
  • Works with trapezius to shrug shoulders upward
  • These muscles can be strained when there is rounding of the shoulders
  • Tension in these muscles can create pain in the sides of the neck and make it difficult to turn the head (Doug Keller)

Pectoralis Minor

  • Originate from ribs 3 to 5
  • Smaller of two chest muscles
  • Pulls shoulder blade down and forward and stabilizes shoulder blade
  • Chronic tightness promotes rounding of shoulders


  • Located on the cap of the shoulder
  • Triangular-shaped
  • Virtually all movements involving the shoulder use the deltoid

Sternocleidomastoid (SCM)

  • On the side and front of neck
  • Superficial
  • laterally flexes head and neck to same side
  • Rotates head and neck to opposite side