Kinesiology Chapter 2- Shoulder & Arm

Supraspinatus

*rotator cuff muscle ACTION: -abduct shoulder(glenohumeral joint) -stabilize head of humerus in glenoid cavity ORIGIN: supraspinous fossa of scapula INSERTION: greater tubercle of the humerus NERVATION: suprascapular C4,5,6

Infraspinatus

*rotator cuff muscle ACTION: -laterally rotate shoulder(glenohumeral) -adduct shoulder (G/H) -stabilize head of humerus in glenoid cavity ORIGIN: infraspinous fossa of scapula INSERTION: greater tubercle of humerus NERVATION: suprascapular C4,5,6

Glenoid

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Lateral Condyle

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Supraglenoid Tubercle

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Lateral Epicondyle

A small, tuberculated eminence, curved a little forward, and giving attachment to the radial collateral ligament of the elbow-joint, and to a tendon common to the origin of the Supinator and some of the Extensor muscles.

Teres Major

ACTION: -extend the shoulder(glenohumeral joint) -adduct the shoulder(G/H joint) -medially rotate shoulder(G/H joint) ORIGIN: inferior angle and lower 1/3 of lateral border of scapula INSERTION: crest of lesser tubercle of humerus NERVATION: lower subscapular C5,6,7

Latissimus Dorsi

ACTION: -extend the shoulder(glenohumeral joint) -adduct the shoulder(G/H joint) -medially rotate shoulder(G/H joint) ORIGIN: inferior angle of the scapula, spinous processes of last six thoracic vertebrae, last three or four ribs, thoracolumbar aponeurosis and posterior iliac crest INSERTION: intertubercular groove of the humerus NERVATION: thoracodorsal C6, 7, 8

Deltoid

ACTION: All fibers- abduct the shoulder Anterior fibers - flex shoulder (G/H Joint) -medially rotate shoulder (G/H Joint) -horizontally adduct shoulder (G/H) Posterior fibers -extend shoulder (G/H Joint) -laterally rotate shoulder (G/H Joint -horizontally abduct shoulder (G/H) ORIGIN: lateral 1/3 of clavicle, acromion, and s spine of scapula INSERTION: deltoid tuberosity NERVATION: axillary C5 & 6

Trapezius

ACTION: upper fibers; bilaterally-extend head & neck unilaterally-laterally flex the head and neck to the same side -rotate the neck and head to the opposite side -elevate the scapula(scapulothoracic joint) -upwardly rotate the scapula(S/T joint) middle fibers; -adduct the scapula(S/T joint) -stabilize the scapula(S/T joint) lower fibers; -depress the scapula(S/T joint) -upwardly rotate the scapula(S/T joint) ORIGIN: external occipital protuberance, medial portion of superior nuchal line of the occiput, ligamentum nuchae and spinous processes of C-7 (C=cervical) through T-12 (T=thoracic) NERVATION: spinal portion of cranial nerve XI (accessory) and ventral ramus C2, 3, 4

Deltoid Tuberosity

About the middle of this surface is a rough, triangular elevation for the insertion of the Deltoideus.

Olecranon Fossa

Above the back part of the trochlea is a deep triangular depression, in which the summit of the olecranon is received in extension of the forearm.

Coronoid Fossa

Above the front part of the trochlea is a small depression, which receives the coronoid process of the ulna during flexion of the forearm.

Coracoid Process

Beak-like projection found inferior to the shaft of the clavicle. It is often found in the deltopectoral groove. Can be tender when palpated, so proceed carefully.

Humerus

Bone of the arm. Proximal end articulates with the glenoid fossa of the scapula to form the glenohumeral joint. glenohumeral joint is a synovial, ball-and-socket joint with a wide range of motion. The deltoid muscle and other tendons surround the proximal end and glenohumeral joint.

Acromioclavicular Joint

Connects the acromion process of the scapula to the lateral end of the clavicle. Stabilizers include aponeurosis of the trapezius and deltoid. Also includes the conoid trapezoid.

Sternoclavicular Joint

Connects the medial end of the clavicle to the sternum and cartilage of the first rib. Ligaments include anterior and posterior sternoclavicular ligament, the interclavicular ligament, and the costoclavicular ligament.

Lateral Border

Extends superiorly and laterally from the inferior angle toward the axilla or "armpit". Attachment site for the teres major and teres minor muscles and due to the thickness of these tissues, might not be as clearly defined as the medial border.

Clavicle

Forms the anterior portion of the shoulder girdle. It is a long bone, curved somewhat like the italic letter f, and placed nearly horizontally at the upper and anterior part of the thorax, immediately above the first rib. It articulates medially with the manubrium sterni, and laterally with the acromion of the scapula.

Intertubercular Groove/ Biciptial Groove

Groove that runs between the greater and lesser tubercles. Lodges the long tendon of the Biceps brachii and transmits a branch of the anterior humeral circumflex artery to the shoulder-joint. It runs obliquely downward, and ends near the junction of the upper with the middle third of the bone. In the fresh state its upper part is covered with a thin layer of cartilage, lined by a prolongation of the synovial membrane of the shoulder-joint; its lower portion gives insertion to the tendon of the Latissimus dorsi. It is deep and narrow above, and becomes shallow and a little broader as it descends

Conoid Tubercle

In the natural position of the bone, surmounts the coracoid process of the scapula, and gives attachment to the conoid ligament.

Greater Tubercle

Larger of the tubercles, lateral side of humerus. Its upper surface is rounded and marked by three flat impressions: the highest of these gives insertion to the Supraspinatus; the middle to the Infraspinatus; the lowest one, and the body of the bone for about 2.5 cm. below it, to the Teres minor. The lateral surface of the greater tubercle is convex, rough, and continuous with the lateral surface of the body.

Acromial End

Lateral End of the clavicle. A small, flattened, oval surface directed obliquely downward, for articulation with the acromion of the scapula.

Acromion

Lateral side of the spine of the scapula and is located at the top of the shoulder. It has a flat surface that articulates with the clavicle's lateral end. Serves as an attachment site for the deltoid and trapezius muscles.

Infraglenoid Tubercle

Located at the most superior aspect of the lateral border of the scapula. Not a distinguishable point, but a small which serves as an attachment site for the long head of the triceps brachii. Lies deep to the teres minor and deltoid muscles.

Superior Angle

Located at the superior end of the medial border. Attachment site for the levator scapula muscle.

Supraspinous Fossa

Located superior to the spine of the scapula. It is small in size, but quite deep. Supraspinatus muscle attaches to and lies in the basin so the fossa is hard to access directly.

Sternal End

Medial end of the clavicle. Is triangular in form, directed medialward, and a little downward and forward; it presents an articular facet, concave from before backward, convex from above downward, which articulates with the manubrium sterni through the intervention of an articular disk.

Lateral Supracondylar Ridge

Presents an anterior lip for the origin of the Brachioradialis above, and Extensor carpi radialis longus below, a posterior lip for the Triceps brachii, and an intermediate ridge for the attachment of the lateral intermuscular septum.

Lesser Tubercle

Smaller of tubercles on proximal end of humerus; medial to the greater tubercle. Is more prominent than the greater: it is situated in front, and is directed medialward and forward. Above and in front it presents an impression for the insertion of the tendon of the Subscapularis.

Head

Smooth rounded, proximal end of humerus. Nearly hemispherical in form, (*54 is directed upward, medialward, and a little backward, and articulates with the glenoid cavity of the scapula.

Inferior Angle

Superficial and is located at the medial border's lower end. Inferior to superior angle.

Spine of Scapula

Superficial ridge located just off the top of the shoulder. It runs at an oblique angle to the body, spanning from the acromion to the medial border. Attachment site for the posterior deltoid and middle and lower fibers of the trapezius.

Medial Supracondylar Ridge

The inferior third of this border is raised into a slight ridge, which becomes very prominent below; it presents an anterior lip for the origins of the Brachialis and Pronator teres, a posterior lip for the medial head of the Triceps brachii, and an intermediate ridge for the attachment of the medial intermuscular septum.

Medial Epicondyle

The larger and more prominent than the lateral, is directed a little backward; it gives attachment to the ulnar collateral ligament of the elbow-joint, to the Pronator teres, and to a common tendon of origin of some of the Flexor muscles of the forearm; the ulnar nerve runs in a groove on the back of this epicondyle.

Capitulum

The lateral portion of this surface consists of a smooth, rounded eminence. It articulates with the cup-shaped depression on the head of the radius, and is limited to the front and lower part of the bone. On the medial side of this eminence is a shallow groove, in which is received the medial margin of the head of the radius.

Medial Border

The long edge of the scapula that runs parallel to the vertebral column. Can measure 5 to 7 inches in length depending on body type. Attachment site for the rhomboids and serratus anterior and is deep to the trapezius.

Trochlea

The medial portion of the articular surface. Presents a deep depression between two well-marked borders; it is convex from before backward, concave from side to side, and occupies the anterior, lower, and posterior parts of the extremity.

Infraspinous Fossa

Triangular area inferior to the spine of the scapula; filled with infraspinatus muscle.

Scapula

Triangular-shaped bone of the upper back. Has several fossae, corners and ridges that serve as attachment sites for sixteen muscles.

Glenohumeral Joint

True shoulder joint. Ball and socket joint, with lots of mobility. Connects humeral head into the glenoid fossa.