upper extremity - shoulder complex Flashcards
how does the shoulder girdle attach onto the thorax?
sternoclavicular and scapulothoracic joints
attachment through sternoclavicular joint onto thorax
this is the only true attachment of the entire upper body onto the thorax
what does the shoulder girdle consist of?
2 clavicles and 2 scapulae on on either side of the body
role of the shoulder girdle?
provides stability & mobility for muscles of the glenohumeral joints
what does the clavicle articulate with?
the manubrium of the sternum & the acromion of the scapula
how does the clavicle articulate with the manubrium?
through the sternoclavicular joint
what kind of joint is the sternoclavicular joint?
a saddle joint
movements allowed by the sternoclavicular joint
elevation/depression;
protraction/retraction;
anterior/posterior rotation along frontal axis in sagittal plane
how does the clavicle articulate with the acromion?
through the acromioclavicular joint
what kind of joint is the acromioclavicular joint?
a planar joint
movements allowed by the acromioclavicular joint
gliding in all directions to assist sternoclavicular & scapulothoracic joints in providing mobility to glenohumeral joint
what is the clavicle’s purpose?
serves as attachments for multiple muscles & ligaments of the upper extremity
what does the scapula articulate with?
with the clavicle at the acromioclavicular joint
what does the scapula come into contact with?
the posterior aspect of the rib cage
what is the scapula’s purpose?
serves as a muscle attachment site for many of the shoulder joints muscles
what are the specific motions of the scapula?
upward/downward rotations; internal/external rotations; anterior/posterior tilts; elevation/depression; abduction/adduction
what stabilizes the sternoclavicular joint?
anterior & posterior sternoclavicular ligaments;
articular disc;
interclavicular ligaments;
anterior/posterior costoclavicular ligament
what are the movements allowed by the sternoclavicular joint?
elevation/depression;
protraction/retraction;
anterior/posterior rotation
what is the range of motion for elevation/depression in the sternoclavicular joint?
elevation: 35°-45°
depression: 10°
what is the range of motion for protraction/retraction in the sternoclavicular joint?
15°-30° for both protraction & retraction
what is the range of motion for anterior/posterior rotation in the sternoclavicular joint?
anterior rotation: N/A
posterior rotation: 20°-35°
what stabilizes the acromioclavicular joint?
presence of a disc;
acromioclavicular ligaments;
coracoacromial ligaments;
coracoclavicular ligaments
what are the coracoclavicular ligaments?
conoid (medial) and trapezoid (lateral) ligaments
what joints does the shoulder complex depend on?
- glenohumeral joint
- sternoclavicular joint
- acromioclavicular joint
- scapulothoracic joint
what does the latissimus dorsi attach onto?
iliac crest & thoracolumbar fascia
what are the ligaments found in the glenohumeral joint?
superior, middle, & inferior glenohumeral ligaments & the coracohumeral ligament
does the glenohumeral joint provide stability or mobility?
mobility
distal attachments for superior glenohumeral ligament
anatomic neck;
above lesser tubercle
primary motions of superior glenohumeral ligament
external rotation; inferior/anterior translations of humeral head
distal attachments for middle glenohumeral ligament
along anterior aspect of anatomic neck & blends with subscapularis tendon
primary motions of middle glenohumeral ligament
external rotation;
anterior translation of humeral head in 45°-90° of abduction
distal attachment for inferior glenohumeral ligament
broad sheet to the anterior-inferior/posterior-inferior margins of anatomic neck
what are the three parts of the inferior glenohumeral ligament?
- axillary pouch
- anterior band
- posterior band
primary motion of axillary pouch of the inferior glenohumeral ligament in the glenohumeral joint
90° of abduction &
anterior/posterior & inferior translations
primary motion of anterior band of the inferior glenohumeral ligament in the glenohumeral joint
90° of abduction;
full external rotation;
anterior translation of humeral head
primary motion of posterior band of the inferior glenohumeral ligament in the glenohumeral joint
90° of abduction & full internal rotation
distal attachment for coracohumeral ligament in glenohumeral joint
anterior side of tubercle;
blends with superior capsule & supraspinatus tendon
primary motion of coracohumeral ligament in glenohumeral joint
external rotation & inferior translation of humeral head
what is the range of motion for flexion/extension in the glenohumeral joint?
flexion: 180°
extension: 65°
what is the range of motion for abduction/adduction in the glenohumeral joint?
abduction: 180°
adduction: 50°-75°
what is the range of motion for internal/external rotation in the glenohumeral joint?
internal rotation: 75°-85°
external rotation: 60°-90°
what muscles have significant action on the scapulothoracic joint?
elevators, depressors, protractors, retractors, & upward/downward rotators
what are the elevator muscles of the shoulder girdle?
upper trapezius;
levator scapulae;
major/minor rhomboids
what are the depressor muscles of the shoulder girdle?
lower trapezius;
latissimus dorsi;
pectoralis minor;
subclavius
what is the protractor muscle of the shoulder girdle?
serratus anterior
what are the retractor muscles of the shoulder girdle?
middle trapezius;
major/minor rhomboids;
lower trapezius
what are the upward rotator muscles of the shoulder girdle?
serratus anterior & the upper/lower trapezius
what are the downward rotator muscles of the shoulder girdle?
major rhomboid & pectoralis minor
origin of upper trapezius
external occipital protuberance;
ligamentum nuchae;
spinous processes of C2-C7
insertion of upper trapezius
acromion and clavicle
actions of upper trapezius
elevation & upper rotation of scapula; elevation, posterior rotation, & retraction of clavicle
origin of levator scapulae
transverse processes of C1-C4
insertion of levator scapulae
superior angle of scapula
action of levator scapulae
elevation of scapula
origin of rhomboid minor
spinous processes of C7-T1
insertion of rhomboid minor
medial border of scapular spine
actions of rhomboid minor
retraction and elevation of scapula
origin of rhomboid major
spinous processes of T2-T5
origin of rhomboid major
spinous processes of T2-T5
insertion of rhomboid major
medial border of scapular spine
actions of rhomboid major
retraction & elevation of scapula
origin of lower trapezius
spinous processes of T4-T12
insertion of lower trapezius
spine of scapula
actions of lower trapezius
retraction, depression, & upward rotation of scapula
origins of latissimus dorsi
spinous processes of T6-L5;
ribs 10-12;
iliac crest (via thoracolumbar aponeurosis)
insertions of latissimus dorsi
inferior angle of scapula;
medial border of intertubercular groove (humerus)
actions of latissimus dorsi
depression of scapula;
extension, adduction, & internal rotation of humerus
origin of serratus anterior
ribs 8-9
insertion of serratus anterior
anterior surface of medial border of scapula
actions of serratus anterior
protraction & upward rotation
what is the purpose of the actions for the serratus anterior muscle?
maintains the scapula is in contact with thoracic wall
origin of pectoralis minor
anterior surface of ribs 3-5
insertion of pectoralis minor
coracoid process of scapula
actions of pectoralis minor
protraction & downward rotation
origin of middle trapezius
spinous processes of C7-T4
insertion of middle trapezius
acromion & spine of scapula
actions of middle trapezius
retraction & upward rotation of scapula
which muscles act on the clavicle?
upper trapezius, sternocleidomastoid, anterior deltoid, pectoralis major, & subclavius
origin of subclavius
1st rib
insertion of subclavius
inferior surface of clavicle (subclavian groove)
action of subclavius
depression & protraction of the clavicle
what are the types of muscles found in the shoulder?
flexors/extensors, abductors/adductors, external/internal rotators, & rotator cuff muscles
origins of pectoralis major
medial 1/3 of clavicle;
sternum;
cartilage of ribs 1-7
insertion of pectoralis major
lateral border of intertubercular groove
actions of pectoralis major
flexion, adduction, internal rotation, & horizontal adduction of the shoulder; depression & protraction of clavicle
origin of anterior deltoid
lateral 1/3 of clavicle
insertion of anterior deltoid
deltoid tuberosity
actions of anterior deltoid
flexion, internal rotation, & horizontal adduction of the shoulder; depression of clavicle
origin of biceps brachii
supraglenoid tubercle (on labrum)
insertion of biceps brachii
radial tuberosity & biceps aponeurosis
actions of biceps brachii
flexion & abduction of the shoulder; flexion & supination in forearm
origin of coracobrachialis
coracoid process of scapula
insertion of coracobrachialis
anteromedial surface of humeral distal to crest of lesser tubercle
actions of coracobrachialis
flexion & adduction of the shoulder
origin of latissimus dorsi
spinous processes of T6-L5;
ribs 10-12;
iliac crest via thoracolumbar aponeurosis
insertion of latissimus dorsi
inferior angle of scapula;
medial border of intertubercular groove
actions of latissimus dorsi
depression of scapula;
extension, adduction, & internal rotation of humerus
origin of teres major
posterior surface of inferior angle of scapula
insertion of teres major
medial border of intertubercular groove
actions of teres major
extension, adduction & internal rotation of humerus
origin of triceps brachii
infraglenoid tubercle
insertion of triceps brachii
olecranon (ulna)
actions of triceps brachii
elbow extension;
extension & adduction of shoulder
origin of posterior deltoid
inferior border of scapular spine
insertion of posterior deltoid
deltoid tuberosity
actions of posterior deltoid
extension & external rotation of the shoulder
origin of middle deltoid
lateral border of acromion
insertion of middle deltoid
deltoid tuberosity
action of middle deltoid
abduction of the shoulder
origin of supraspinatus
supraspinous fossa of the scapula
insertion of supraspinatus
superior portion of the greater tubercle
actions of supraspinatus
first 15° degrees of abduction;
external rotation in shoulder
origin of teres minor
lateral border of posterior surface of scapula
insertion of teres minor
greater tubercle
actions of teres minor
lateral rotation of shoulder
origin of infraspinatus
infraspinous fossa of scapula
insertion of infraspinatus
greater tubercle
actions of infraspinatus
lateral rotation of shoulder
origin of subscapularis
subscapular fossa (anterior face of scapula)
insertion of subscapularis
lesser tubercle
actions of subscapularis
medial rotation & adduction of the shoulder
which muscles are part of the rotator cuff
supraspinatus, infraspinatus, teres minor, subscapularis
stabilizing action of supraspinatus at glenohumeral joint
compresses humeral head against glenoid fossa;
restricts superior translation of humerus
stabilizing action of infraspinatus at glenohumeral joint
exerts a depressive force on the humeral head
stabilizing action of teres minor at glenohumeral joint
exerts a depressive force on the humeral head
stabilizing action of subscapularis at glenohumeral joint
exerts a depressive force on the humeral head
associated adverse kinematic effect of reduced activation of serratus anterior, middle, & lower trapezius
reduced upward rotation, posterior tilt, & external rotation of scapula
associated adverse kinematic effect of excessive activation of upper trapezius
reduced posterior rotation of the clavicle
associated adverse kinematic effect of reduced activation/degeneration of rotator cuff muscles
excessive superior migration of humeral head during abduction/flexion;
reduced external rotation of glenohumeral joint during abduction/flexion
associated adverse kinematic effect of tightness of posterior capsule of glenoidhumeral joint & posterior rotator cuff muscles
abnormal position of humeral head relative to glenoid fossa;
excessive internal rotation of scapula
associated adverse kinematic effect of tightness of pectoralis minor or short head of biceps
excessive internal rotation or anterior tilt of scapula
associated adverse kinematic effect of excessive thoracic kyphosis
excessive internal/anterior tilt &
reduced upward rotation of scapula