Individual muscles Flashcards
Biceps brachii
Muscle Action: ● Flex the elbow. ● Supination of the forearm. ● Flex the shoulder
Origin point - Anterior of the scapula.
Insertion Point - Upper radius.
Triceps brachii
Muscle Action ● Extension of the elbow. ● Extension of the shoulder. ● Abduction of the shoulder.
Origin point - Posterior upper humerus and scapula.
Insertion Point - Upper ulna.
Deltoid
Muscle Action
All fibers
● Abduct the shoulder.
Anterior fibers
● Flex, medially rotate and
horizontally adduct the
shoulder.
Posterior fibers
● Extend, laterally rotate
and horizontally abduct
the shoulder.
Origin point - Clavicle and scapula.
Insertion point - Upper humerus.
Trapezius - Upper fibres
Muscle action ● Extend the head and neck. ● Laterally flex the head and neck to the same side. ● Rotate the head and neck. ● Elevate the scapula. ● Upwardly rotate the scapula.
Trapezius - middle fibers
Muscle Action
● Adduct the scapula.
● Stabilize the scapula
Trapezius - Lower fibers
Muscle Action
Depress the scapula.
Upwardly rotate the
scapula.
Trapezius
Origin point - Base of skull, spinous processes of C7-T12.
Insertion point - Lateral clavicle and upper surface of the scapula
Latissimus dorsi
Muscle Action ● Adduction of the shoulder. ● Extension of the shoulder. ● Internal rotation of the shoulder.
Origin point - Lower 7 thoracic vertebrae, inferior angle of the scapula, thoracolumbar fascia and the iliac crest.
Insertion point - Anterior upper Humerus.
Teres Major
Muscle Action ● Adduction of the shoulder. ● Extension of the shoulder. ● Internal rotation of the shoulder.
Origin point - Inferior angle of the scapula.
Insertion point - Crest of the lesser tubercle of the humerus.
Rhomboid major and minor
Muscle Action ● Adduct of the scapula. ● Elevation of the scapula. ● Downwardly rotate the scapula.
Origin point - Spinous process C7-T5.
Insertion point - Medial border and inferior angle of scapula.
Pectoralis major
Muscle Action All fibres ● Adduction of the shoulder. ● Medial rotation of the shoulder. Upper fibres ● Flex the shoulder. ● Horizontally adduct shoulder. Lower fibres ● Extend shoulder.
Origin point - Clavicle, sternum and cartilage of first to sixth ribs.
Insertion point - Head of humerus
Pectoralis minor
Muscle Action
● Depressions of the
scapula.
● Retraction of the scapula.
Origin point - Anterior surface of 3rd-5th Ribs.
Insertion point - Coracoid process of the Scapula.
Levator Scapula
Muscle Action ● Elevation of the shoulder girdle. ● Lateral flexion of the neck. ● Extension of the neck.
Origin point - Transverse processes of C1-C4.
Insertion point - Superior angle of the scapula.
Rotator Cuff
Muscle Action
Teres minor
● Adduction, external rotation and stabilisation of the shoulder joint.
Infraspinatus
● Adduction, horizontal extension, external rotation and stabilisation of the shoulder joint.
Supraspinatus
● Abduction and stabilisation of the shoulder joint.
Subscapularis
● Internal rotation, adduction and stabilisation of the shoulder joint.
Quadriceps
Muscle Action All fibres ● Extension of the knee. Rectus femoris ● Flexion of the hip.