origin: transverse process of 1st 4 cervical vertebrae
insertion: vertebral border of scapula between superior medial angle and
scapular spine;
action: elevates scapula to inferiorly rotate glenoid cavity; working
with the upper
Trapezius , elevates and adducts scapula;
reversed origin insertion action: when scapula is fixed, laterally flexes
and slightly rotates cervical spine;
nerve supply: dorsal scapula, C3, C4,
C5;
synergists: rhomboid and
Trapezius
