KIN 245 Chapter 4: The Shoulder Girdle

Serratus anterior action

-abduction (protraction): draws the medial border of the scapula away from the vertebrae -upward rotation: longer, lower fibers tend to draw the inferior angle of the scapula farther away from the vertebrae, rotating scapula upward slightly

Pectoralis minor action

-abduction (protraction): draws the scapula forward and tends to tilt the lower border away from the ribs -downward rotation: as it abducts it draws the scapula downward -depression:when the scapula is rotated upward it assists in depression

Pectoralis minor

-anterior -abduction -downward rotation -depression

Subclavius

-anterior -depression -abduction

Acromioclavicular (AC)

-arthrodial joint -20 to 30 degree total gliding and rotational motion accompanying other shoulder girdle and shoulder joint motions -often injured joint

Pectoralis minor palpation

-difficult to palpate but can be palpated under the pectorals major muscles and just inferior to the coracoid process during resisted depression

Rhomboid muscles major and minor palpation

-difficult to palpate due to being deep to the trapezius -may be palpated though the relaxed trapezius during adduction

Depression: scapula

-downward or inferior movement of the scapula -normal position after a shoulder shrug

Serratus anterior palpation

-frontal and lateral side of the chest below the 5th and 6th ribs just proximal to their origin during abduction

Key bony landmarks

-manubrium -clavicle -coracoid process -inferior angle -spine of scapula -acromion process -glenoid fossa -lateral border -medial border -superior angle

Rhomboid muscles major and minor action

-minor and major muscles work together -adduction: draw the scapula toward the spinal column -downward rotation: from upward rotated position, draw the scapula into downward rotation, -elevation: slight upward movement accompanying adduction

Scapula and clavicle

-move as a unit -primarily involved in the movement of the shoulder girdle -only bony link to the axial skeleton is the clavicle's articulation with the sternum

Lateral tilt (outward tilt): scapula

-movement during abduction in which the scapula rotates about its vertical axis -posterior movement of the medial border and anterior movement of the lateral border

Posterior tilt (downward tilt): scapula

-movement of the scapula about the frontal axis occurring during hyper flexion of the glenohumeral joint -superior border moving posteroinferiorly -inferior angle moving anterosuperiroly

Abduction (protraction): scapula

-movement of the scapula laterally away from the spinal column -reaching for an object in front of the body

Adduction (retraction): scapula

-movement of the scapula medially toward the spinal column -pinching the shoulder blades together

Sternoclavicular (SC)

-multiaxial anthrodial joint -clavicle moves anteriorly 15 degrees with protraction -clavicle moves posteriorly 15 degrees with retraction

Scapulothoraic

-not a true synovial joint, does not have regular synovial features -movement is dependent on the sternoclavicular (SC) and acromioclavicular (AC) joints -25 degress abd/adduction movement -60 degree up/downward rotation -55 degree elevation/depression -supported by its muscles and lacks ligamentous support

Pectoralis minor muscle

-origin: anterior surfaces of the 3rd to the 5th ribs -insertion: coracoid process of the scapula

Rhomboid muscles: major and minor

-origin: spinous processes of the 7th cervical and 1st five thoracic vertebrae -insertion: medial border of the scapula, below the spine of the scapula

Subclavius muscle

-origin: superior aspect of the 1st ribs at its junction with its costal cartilage -insertion: inferior groove in the midpoint of the clavicle

Serratus anterior muscle

-origin: surface of the upper nine ribs at the side of the chest -insertion: anterior aspect of the whole length of the medial border of the scapula

Levator scapulae muscle

-origin: transverse processes of the upper four cervical vertebrae -insertion: medial border of the scapula from the superior angle to the scapular spine -action: elevates the medial margin of the scapula, weak downward rotation, weak adduction -palpation: difficult to palate because it is deep to the trapezius, best palpated at insertion just medial to the superior angle of the scapula

5 muscles involved in shoulder girdle movements

-pectoralis minor -serratus anterior -trapezius -rhomboid -levator scapulae -origin: on the axial skeleton -insertion: located on scapula and/or on clavicle -essential in providing dynamic stability of the scapula so that it can serve as a relative base of support for the shoulder joint

Rhomboid

-posterior -adduction -downward rotation -elevation

Levator scapulae

-posterior -elevation

Trapezius

-posterior -upper fibers: elevation, extension and rotation of the head at the neck -middle fibers: elevation, adduction and upward rotation -lower fibers: adduction, depression and upward rotation

Serratus anterior

-posterior and lateral -abduction and upward rotation

Medial tilt (inward tilt): scapula

-return from lateral tilt, movement during extreme adduction, scapula rotates about its vertical axis -anterior movement of the medial border -posterior movement of the lateral border

Downward rotation: scapula

-returning the inferior angle medially and inferiorly toward the spinal column and the gleanoid fossa to its normal position -bringing the arm down to the side

Anterior tilt (upward tilt): scapula

-rotational movement of the scapula about the frontal axis occurring during hyperextension of the glenohumeral joint -superior border moving anteroinferiorly -inferior angle moving posterosuperiorly

Subclavius muscle action

-stabilization and protection of the strenoclavicular joint -depression -abduction

what provides stability to the acromioclavicular joint

-superior and inferior acromioclavicular ligaments

Coracoclavicualr joint

-syndesmotic type joint -functions through its ligaments to greatly increase the stability of the acromioclavicular joint

Upward rotation: scapula

-turning gleanoid fossa upward and moving the inferior angle superiorly and laterally away from the spinal column -raising the arm out to the side

Trapezius muscle origin

-upper fibers: base of skull, occipital protuberance, posterior ligaments of neck -middle fibers: spinous processes of seventh cervical and upper three thoracic vertebrae -lower fibers: spinous processes of the 4th through 12th thoracic vertebrae

Trapezius muscle action

-upper fibers: elevation of the scapula, upward rotation, extension and rotation of the head at the neck -middle fibers: elevation, upward rotation and adduction (retraction) of the scapula -lower fibers: depression, adduction (retraction), upward rotation of the scapula

Trapezius muscle insertion

-upper fibers: posterior aspect of the lateral 3rd of the clavicle -middle fibers: medial border of the accordion process and upper border of the scapular spine -lower fibers: triangular space at the base of the scapular spine

Trapezius muscle application

-upper fibers: thin and weak, provide some elevation of the clavicle, assist in the extension of the head -middle fibers: stronger and thicker, provide elevation, upward rotation, adduction of scapula -lower fibers: assist in adduction, rotate the scapula upward, weak

Elevation: scapula

-upward or superior movement of the scapula -shrugging the shoulders

T/F: The elevator scapulae muscle is responsible for upward rotation of the inferior angle of the scapula

False

T/F: The coracoclavicular ligament is particularly important in providing stability to the acromioclavicular joint

True

T/F: the actions of the serrates anterior muscle includes abduction and upward rotation

True

T/F: the insertion of the serrates anterior muscles is the anterior aspect of the whole length of the medial border of the scapula

True

T/F: the medial border of the scapula above the scapular spine is the insertion point of the elevator scapulae

True

T/F: the serrates anterior performs abduction in the transverse plane

True

movement of the scapula laterally away from the spinal column is termed

abduction

the rhomboids primary movements include: __________, downward rotation and elevation

adduction

the trapezius middle fiber primary movements include: elevation, ________, and upward rotation

adduction

the trapezius middle fibers primary movements include elevation, ______ and upward rotation

adduction

the trapezius upper fibers have the following insertion: posterior aspect of the lateral third of the ____

clavicle

the trapezius lower fibers primary movements include adduction, _____, upward rotation

depression

Which action is not performed by the trapezius?

downward rotation

Which of the following actions is performed by the levator scapulae

elevation

the trapezius upper fibers primary movements include _____, upward rotation, extension of the head at the neck and rotation of the head at the neck

elevation

upward or superior movement of the scapula is termed

elevation

T/F: the insertion of the pectorals minor is the coracoid process of the ulna

false

the trapezius upper fibers have the following origin: base of skull, _____ and posterior ligaments of the neck

occipital protuberance

________, has the following origin: anterior surfaces of the third to fifth ribs

pectoralis minor

the _______, have the following insertion: medial border of the scapula, inferior to the scapular spine

rhomboids

the serrates anterior has the following insertion: anterior aspect of the whole length of the medial border of the _____

scapula

Which muscle would be best strengthened by the bench press

serratus anterior

Which of the following muscles has a portion of its origin located on the ribs?

serratus anterior

the ____ muscle has the following origin: surface of the upper nine ribs at the side of the chest

serratus anterior

which muscle is located most anteriorly on the human body

serratus anterior

the trapezius lower fibers have the following insertion : triangular space at the base of the scapular _______

spine

which muscle performs stabilization and protection of the sternoclavicular joint

subclavius

the trapezius lower fibers have the following origin: spinous process of the 4th to 12th ____ vertebrae

thoracic

the levator scapulae has the following origin: _____ processes of the upper four cervical vertebrae

transverse

which muscle performs both elevation and depression

trapezius

which of the following muscles performs both elevation and depression?

trapezius

Raising the humerus high out to the side to ask a question involves which of the following motions

upward rotation

the primary movements of the serrates anterior include abduction and _____

upward rotation