Glenohumeral muscles Flashcards
Pectoralis Major
Clavicular fibres
ANTERIOR
action: flexion, medial rotation and adduction of the glenohumeral joint
origin: anterior surface of the medial half of the clavicle
insertion: bicipital/intertubercular groove (humerus)
Pectoralis Major
ANTERIOR
action: adduction, horizontal adduction and medial rotation, extension (from flexed position)
origin: anterior surface of the sternum, upper 6 costal cartilages
insertion: bicipital/intertubercular groove (humerus)
Coracobrachialis
ANTERIOR
action: adduction and horizontal adduction of the glenohumeral joint
origin: tip of the coracoid process
insertion: medial aspect of the mid shaft of the humerus
Subscapularis
ROTATOR CUFF MUSCLE
ANTERIOR
action: contributes to the stability of the humeral head in the glenoid cavity during humeral movement.
Internal/medial rotation
origin: medial 2/3rds of the costal surface of the scapula (subscapular fossa)
insertion: lesser tuberosity of the humerus, anterior part of the capsule of the shoulder joint
Biceps Brachii
ANTERIOR
actions: supination, flexion of the elbow, flexion of the shoulder, helps to stabilise the humeral head superiorly
origin: long head- supraglenoid tubercle of scapula
short head- coracoid process of scapula
insertion: via biceps brachii tendon on radial tuberosity
Infraspinatus
ROTATOR CUFF MUSCLE
POSTERIOR
action: works in combo with Teres Minor, contributes to the stability of the humeral head, external rotation of the shoulder
origin: infraspinatus fossa of the scapula
insertion: middle facet of the greater tuberosity of the humerus, capsule of the shoulder joint
Teres Minor
ROTATOR CUFF MUSCLE
POSTERIOR
action: works in combo with the infraspinatus, contributes to the stability of the humeral head, external rotation of the shoulder, adduction of the shoulder
origin: upper 2 thirds of the lateral border of the scapula
insertion: greater tuberosity of the humerus, capsule of the shoulder joint
Deltoid
SUPERIOR
action: main- abduction of the shoulder
anterior fibre- flexion and medial rotation
middle fibre - abducts
posterior - extension and lateral rotation
origin: anterior border of the lateral third of the clavicle, lateral border acromion, and lower lip of scapular spine
insertion: V shape deltoid tuberosity (lateral aspect shaft of humerus)
Supraspinatus
ROTATOR CUFF MUSCLE
SUPERIOR
action: contributes to the stability of the humeral head, initiates abduction (assists deltoid)
origin: superaspinous fossa of scapula
insertion: upper facet of greater tuberosity of humerus, shoulder joint capsule
Latissimus Dorsi
INFERIOR
action: extension, adduction, medially rotation, secures inferior angle of scapula against chest wall
origin: spinous processes of T7-S5, posterior part iliac crest, lower 4 ribs, inferior angle of scapula
insertion: bicipital/intertubercular groove of the humerus
Teres Major
INFERIOR
action: extension, adduction, medial rotation
origin: dorsal aspect of the inferior angle of scapula and the lateral border of the scapula
insertion: medial lip of the intertubercular groove
Triceps Brachii
INFERIOR
actions: elbow extension, assists adduction, extension of the shoulder joint, stabilises the humeral head inferiorly
origins:
long head- infraglenoid tubercle of the scapula
lateral head- upper half of posterior shaft humerus
medial head - lower half of posterior shaft humerus
insertion: olecranon process of ulna
