the shoulder Flashcards
the shoulder girdle
position itself to allow movements of the shoulder joint
clavicle
collarbone, s-shaped. easily fractures. lateral end: acromial end. medial end: sternal end.
scapula
shoulder blade. inferior angle: base of scapula where lateral and medial borders meet. spine of scapula: runs across the posterior aspect of scapula
sternoclavicular (SC) joint
articulation between sternum and clavicle; slightly movable
Stability from: sterno, costo, inter clavicular ligaments plus an articular disc
Acromioclavicular (AC) joint
articulation between acromion process of scapula and clavicle; slightly movable
Connected by AC ligament
Coracoclavicular (CC) joint
articulation between coracoid process of scapula and clavicle; slightly movable
Connected by CC ligament (trapezoid and conoid)
This is where the “shoulder separation” injury occurs
shoulder joint movements
The girdle has to move to allow upper arms to move
Elevation: superior (upward) movement of scapula
Depression: return to anatomical position
Protraction (abduction): upward rotation and lateral tilt; hugging your friend
Retraction (adduction): downward rotation and medial tilt; bringing your shoulders back
pectoralis minor
anterior. origin: 3rd, 4th, 5th rib. insertion: coracoid process of scapula. action: abduction
serratus anterior
origin: anterior, lateral aspects of upper 9 ribs. insertion: medial border of scapula. action: abduction
subclavius
anterior. origin: 1st rib. subclavian groove of clavicle. action: assist ligament of SC joint for stability
levator scapulae
posterior. origin: transverse processes of the 1st 4 cervical vertebrae
Insertion: superior aspect of medial border of scapula
Action: elevation
rhomboids (major and minor)
posterior. Origin: 7th cervical vertebrae through 5th thoracic vertebrae
Insertion: medial border of scapula
Attachment: elevation and adduction of scapula
trapezius
posterior. Origin: base of skull and spinous processes of ALL cervical and thoracic vertebrae
Insertion: spine of scapula and posterior surface of clavicle
Attachment: upper=elevation; middle=adduction; lower=abduction
the shoulder joint
also called the glenohumeral joint. ball-and-scoekt joint. Shallow glenoid fossa allows for greater ROM but its less stable
scapula
specifically the glenoid fossa
humerus
upper arm bone
Anatomical neck: between greater and lesser tuberosities (also creates the bicipital groove)
Surgical neck: upper shaft
Deltoid tuberosity: lateral surface, halfway down shaft
ligaments
includes many but the following is emphasized
Glenoid labrum: forms on edge around the entire glenoid cavity; helps deepen the fossa
glenohumeral joints movement
Flexion: anterior measurement Extension: return to anatomical position Hypertension: beyond anatomical position Abduction: away from midline Adduction: toward the midline Internal rotation: medial rotation External rotation: lateral rotation Circumduction: combination of fundamental movements
pectoralis major
anterior. Origin: 2nd to 6th ribs; sternum; and medial half of clavicle
Insertion: anterior area of surgical neck of humerus
Action: flexion, adduction, internal rotation
coracobrachialis
anterior. Origin: coracoid process of scapula
Insertion: middle of medial side of humerus opposite deltoid tuberosity
biceps brachii (GH joint now…not elbow)
anterior. Origin of long-head: supraglenoid tubercle
Origin of short-head: coracoid process
Insertion: tuberosity of radius
Action of long-head: flexion and abduction
Action of short-head: internal rotation
subscapularis
anterior. located between the scapula and thorax. Origin: subscapular fossa
Insertion: lesser tuberosity of humerus
Action: IR and flexion
deltoid
3 parts; anterior, middle, posterior
Origin: anterior=lateral front of clavicle; middle=lateral edge of acromion process; posterior=inferior angle of spine of scapula
Insertion: deltoid tubercle on humerus
Action: primarily abduction
supraspinatus
located beneath deltoid
Origin: supraspinous fossa of scapula
Insertion: proximal facet of greater tuberosity of humerus
Action: primary abductor until 30 degrees then deltoid takes over