Scapula Anatomy

Scapulothoracic Joint

relationship between scapula and rib cage, since not directly attached to rib cage there is a lot of potential for movement

Movement of scapula

elevation, depression, protraction, retraction, upward rotation and downward rotation

muscles of the scapula

levator scapula, rhomboids, trapezius, serratus anterior, pectoralis minor

levator scapula

muscle that lifts or elevates the scapula; runs along the lateral posterior parts of the neck; levator scapula + rhomboids = deep layers of back

Origin of levator scapula

transverse processes of C1-C4 vertebrae (the part of the C1-C4 vertebrae that stick out to either side)

Insertion of levator scapula

superior angle of scapula (pointed part at top of scapula)

actions of the levator scapula

elevation and downward rotation of scapula, lateral flexion and extension of head and neck

deep layers of the back

rhomboids and levator scapula

origin of rhomboids

spinous processes (parts of vertebrae that sticks out to the back or posteriorly) of vertebrae T2-T5 (major portion) and C7&T1 (minor portion)

insertion of rhomboids

vertebral border from the Root of the Spine (the edge of scapula that is closest to the spine) to the Inferior Angle(angle corner at bottom of scapula) (major portion)

root of spine of scapula (medial most part of the scapula, minor portion)

actions of rhomboid

retraction (adduction), downward rotation, and assists in elevation of scapula

trapezius

4 sided muscle that makes up superficial layer of the back

Origin of Trapezius

• Trapezius Upper Section - Base of the Occiput(base of bone at bottom of skull), Ligamentum Nuchae(ligament or connective tissue at the nape of the neck or tendinous sheath at base of neck), and Spinous Processes of C1-C7

• Trapezius Middle Section - Spinous Processes of C7-T3

• Trapezius Lower Section - Spinous Processes of T4-T12

insertion of trapezius

• Trapezius Upper Section - Lateral Clavicle and Acromion Process (projection of bone at edge of shoulder)

• Trapezius Middle Section - Spine of the Scapula (horizontal ride of shoulder)

• Trapezius Lower Section - Root of the Spine of the Scapula

action of trapezius

• Upper Portion - Elevation of the Scapula + Upper Rotation of the Scapula

• Middle Portion - Retraction (Adduction) of the Scapula + Upper Rotation of the Scapula

• Lower Portion - Depression of the Scapula + Upper Rotation of the Scapula

serratus anterior

Boxer’s muscle; strongest protractor and very strong upward rotator muscle; named by shape and position

origin of serratus anterior

surface of upper 8 or 9 ribs

insertion of serratus anterior

medial border of scapula and all fibers converge at inferior angle of scapula

action of serratus anterior

protraction of scapula, assists in upper rotation (synergist with trapezius), stabilizes scapula to ribs

origin of pectoralis minor

ribs 3, 4, 5

insertion of pectoralis minor

coracoid process (beak-like projection) of scapula

actions of pectoralis minor

depression, downward rotation and protraction (adduction) of scapula