Scapular Muscles Review Flashcards
Name the bony landmarks on the skull
EOP (external occupital protuberance)
SNL (superior nuchal line)
Define the superior nuchal line
Ridge of bone that extends to the right & left on either side of EOP
Describe the location of the nuchal ligament
- part of origin for trapezius, specifically for upper trap
- starts at EOP, runs vertically down the midline of the spine touching each of the spinous processes in the cervical spine, finishing down @C7
Describe the unique structure and features of the nuchal ligament
- more weblic and broad than most ligaments we see
- more elastin: when in stretched position it can recoil back to resting position more easily
What motions pull the nuchal ligament apart?
- flexion of cervical spine
- elastin will help bring back into upright position
*Becomes continuous with another ligament that touches along the spinous processes (supraspinous ligament)
Describe the trapezius
- large muscle on posterior side of the body
- trapezoid shape (made by muscle fibers finding way over the shoulder girdle)
- origin quite lengthy, begins on skull along posterior aspect of occipital bone
- starts up at the skull along superior nuchal line>EDP>nuchal ligament
- from there we’ll touch down at each of the spinous processes from t1 to T12
- large muscle, some fibers travelling in opposite directions & broken into 3 groups
Describe the upper trapezius
- Upper fibres of the trapezius descending
- descending into lateral 3rs of clavicle (superior aspect), stops ~ at point where we hit the AC joint
- lifts lateral end of clavicle= ELEVATION OF SHOULDER
Describe the middle trapezius
- middle fibers run horizontally or straight across
- blending into acromion process (superior/medial side)
- more fibres on superior spine of scapula (remember! Acromion process > scapular spine
- bring scapula towards midline>retraction of shoulder girdle
Describe the lower trapezius
- lower fibres ascend to reach attachment
- SUPERIOR ROTATION of scapula (counterclockwise), glenoid fossa goes up
- does this by pulling medial side down
- if arm is way up over head, DEPRESS shoulder girdle from elevated position (draw scapula down along superior wall of the rib cage - posterior tilt)
Describe the levator scapula
- originates in cervical spine (transverse processes C1-C4)
- lands on superior angle of scapula, catches a little bit of medial border of scapula above the level of the spine
***Doesn’t elevate entire scapula! Lifts up the superior angle = INFERIOR ROTATION of scapula
Describe the rhomboid minor
- originates from spinous processes of c7 and t1
- travels anteriorly and laterally to land on medial border of scapula
- ends at root (spine level)
RETRACTS shoulder girdle
Helps levator in INFERIOR ROTATION of scapula
Describe the rhomboid major
- T2-T5
- travel anteriorly and laterally to land on medial border of scapula (distal to spine of scapula)
RETRACTS shoulder girdle
INFERIOR ROTATION of scapula
Describe the serratus anterior
- serrated appearance
- finger-like projections/origins
- origins along lateral aspects of each of the upper 8 ribs
- fibers run back all together as 1 muscle belly that fills the length of the medial border of the scapula
- diff actions from different parts because of it’s size
SANDWICH MUSCLE: sandwiched between scapula & ribcage, deep to scapula and superficial to ribs
Describe the function of the serratus anterior
“boxer’s muscle: punching motions
- upper fibers have horizontal line of pull
- if fibers grab medial border of scapula, scapula draws forward into PROTRACTION
- lower fibers are more oblique, come from ribs 8,7,6 & come up to hit medial border of scapula
= SCAPULAR ROTATION
Describe the structure and location of the pectoralis minor
- small triangle
- base @ rib attachments
- apex @ coracoid process
- base has serrated appearance (common feature of rib origination)
- comes from anterior aspect of ribs (3,4,5)
- comes up as 1 muscle belly into coracoid process (medial side)
