Term
Shoulder Musculature
Latissimus Dorsi |
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Definition
Origin - Spinous processes of T7-T12. Iliac crest of the pelvis. Thoracolumbar fascia. Ribs 9-12.
Insertion - Inferior angle of the scapula. Intertubercular groove of the humerus.
Isolated Function - Concentrically accelerates shoulder extension, adduction, and internal rotation.
Integrated Function - Eccentrically decelerates shoulder flexion, abduction, and external rotation. Eccentrically decelerates spinal flexion. Isometrically stabilizes the lumbo-pelvic-hip complex and shoulder.
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Term
Shoulder Musculature
Serratus Anterior |
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Definition
Origin - Ribs 4-12.
Insertion - Medial border of the scapula.
Isolated Function - Concentrically accelerates scapular protraction.
Integrated Function - Eccentrically decelerates dynamic scapular retraction. Isometrically stabilizes the scapula.
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Term
Shoulder Musculature
Rhomboids |
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Definition
Origin - Spinous processes C7-T5.
Insertion - Medial border of the scapula.
Isolated Function - Concentrically produces scapular retraction and downward rotation.
Integrated Function - Eccentrically decelerates scapular protraction and upward rotation. Isometrically stabilizes the scapula.
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Term
Shoulder Musculature
Rhomboids |
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Definition
Origin - Spinous processes C7-T5.
Insertion - Medial border of the scapula.
Isolated Function - Concentrically produces scapular retraction and downward rotation.
Integrated Function - Eccentrically decelerates scapular protraction and upward rotation. Isometrically stabilizes the scapula.
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Term
Shoulder Musculature
Lower Trapezius |
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Definition
Origin - Spinous processes of T6-T12.
Insertion - Spine of the scapula.
Isolated Function - Concentrically accelerates scapular depression.
Integrated Function - Eccentrically decelerates scapular elevation. Isometrically stabilizes the scapula.
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Term
Shoulder Musculature
Middle Trapezius |
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Definition
Origin - Spinious processes of T1-T5.
Insertion - Acromion process of the scapula. Superior aspect of the spine of the scapula.
Isolated Function - Concentrically accelerates scapular retraction.
Integrated Function - Eccentrically decelerates scapular elevation. Isometrically stabilizes the scapula.
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Term
Shoulder Musculature
Upper Trapezius |
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Definition
Origin - External occipital protuberance of the skull. Spinous process of C7.
Insertion - Lateral third of the clavicle. Acromion process of the scapula.
Isolated Function - Concentrically accelerates cervical extension, lateral flexion, and rotation.
Integrated Function - Eccentrically decelerates cervical flexion, lateral flexion, and rotation. Eccentrically decelerates scapular depression. Isometrically stabilizes the cervical spine and scapula.
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Term
Shoulder Musculature
Levator Scapulae |
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Definition
Origin - Transverse processes of C1-C4.
Insertion - Superior vertebral border of the scapulae.
Isolated Function - Concentrically accelerates cervical extension, lateral flexion, and ipsilateral rotation when the scapulae is anchored. Assists in elevation and downward rotation of the scapulae.
Integrated Function - Eccentrically decelerates cervical flexion and contralateral cervical rotation and lateral flexion. Eccentrically decelerates scapular depression and upward rotation when the neck is stabilized. Stabilizes the cervical spine and scapulae.
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Term
Shoulder Musculature
Pectoralis Major |
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Definition
Origin - Clavicular: Anterior surface of the clavicle. Sternocostal: Anterior surface of the sternum, cartilage or ribs 1-7.
Insertion - Greater tubercle of the humerus.
Isolated Function - Concentrically accelerates shoulder flexion (clavicular fibers), horizontal adduction, and internal rotation.
Integrated Function - Eccentrically decelerates shoulder extension, horizontal abduction, and external rotation. Isometrically stabilizes the shoulder girdle.
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Term
Shoulder Musculature
Pectoralis Minor |
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Definition
Origin - Ribs 3-5
Insertion - Coracoid process of the scapula.
Isolated Function - Concentrically protracts the scapula.
Integrated Function - Eccentrically decelerates scapular retraction. Isometrically stabilizes the shoulder girdle.
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Term
Shoulder Musculature
Deltoid -
Anterior, Middle, and Posterior |
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Definition
Origin - Anterior: Lateral third of the clavical. Middle: Acromion process of the scapula. Posterior: Spine of the scapula.
Insertion - Deltoid tuberosity of the humerus.
Isolated Function - Anterior: Concentrically accelerates shoulder flexion and internal rotation. Middle: Concentrically accelerates shoulder abduction. Posterior: Concentrically accelerates shoulder extension and external rotation.
Integrated Function - Anterior: Eccentrically decelerates shoulder extension and external rotation, isometrically stabilizes the shoulder girdle. Middle: Eccentrically decelerates shoulder adduction, isometrically stabilizes the shoulder girdle. Posterior: Eccentrically decelerates shoulder flexion and internal rotation, isometrically stabilizes the shoulder girdle.
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Term
Shoulder Extension
Biceps Brachii |
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Definition
Origin - Short head: Coracoid process of the scapula. Long head: Tubercle above glenoid cavity on the humerus.
Insertion - Radial tuberosity of the radius.
Isolated Function - Concentrically accelerates elbow flexion, supination of the radioulnar joint, and shoulder flexion.
Integrated Function - Eccentrically decelerates elbow extension, pronation of the radioulnar joint, and shoulder extension. Isometrically stabilizes the elbow and shoulder girdle.
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Term
Shoulder Musculature
Triceps |
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Definition
Origin - Long head: Infraglenoid tubercle of the scapula. Short head: Posterior humerus. Medial head: Posterior humerus.
Insertion - Olecranon process of the ulna.
Isolated Function - Concentrically accelerates elbow extension and shoulder extension.
Integrated Function - Eccentrically decelerates elbow flexion and shoulder flexion. Isometrically stabilizes the elbow and shoulder girdle.
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