Anatomy of Shoulder, Arm, and Elbow (Lab 5)

For each of the six principle movements allowed at the glenohumeral joint, specify the muscles involved and their innervation. 1. Flexion

deltoid (axillary n) biceps brachii and coracobrachialis (musculocutanous n) pectoralis major (medial and lateral pectoral n)

For each of the six principle movements allowed at the glenohumeral joint, specify the muscles involved and their innervation. 3. Abduction

deltoid (axillary n) supraspinatus (suprascapular n)

Explain the anatomical basis of the following pathologies of the arm and elbow: student's bursitis.

elbow bursitis involving the subcutaneous bursa results from repeated excessive pressure on the elbow (as in leaning your elbow on the table)

For each of the six principle movements allowed at the glenohumeral joint, specify the muscles involved and their innervation. 4. Adduction

teres major (lower subscapular n) pectoralis major (medial and lateral pectoral n) latissimus dorsi (thoracodorsal n)

For each of the six principle movements allowed at the glenohumeral joint, specify the muscles involved and their innervation. 6. Lateral rotation

teres minor (axillary n) deltoid (axillary n) infraspinatus (suprascapular n)

Be able to demonstrate the following movements of the digits of the hand: abduction, adduction, flexion, extension; be able to use these terms properly when discussing movements of the digits of the hand.

-Abduction: fingers spread out -Adduction: fingers come back together -Flexion: fingers bend to come toward palm -Extension: fingers straighten

Be able to demonstrate the following movements of the thumb: flexion, extension, abduction, adduction, opposition; be able to use these terms properly when discussing movements of the digits of the hand.

-Abduction: moves the thumb away from the fingers at right angles to the palm -Adduction: returns the thumb to be next to the forefinger -Flexion: bends the thumb across the palm -Extension: extends the thumb to be away from but still in the same plane with the rest of the fingers. -Opposition: rotates the thumb around so the pad of the thumb is directly facing the pads of the other fingers

Be able to demonstrate the following movements of the wrist: abduction, adduction, flexion, extension; be able to use these terms properly when discussing movements at the wrist and the position of the hand.

-Abduction: wrist moves away from body while in anatomical position -Adduction: wrist returns to midline -Flexion: wrist bends forward to raise the palm of the hand -Extension: wrist bends backward so the palm of the hand now faces the ground

Specify the primary actions of the muscles contained within the each of the compartments in the arm and forearm; specify the primary actions of the intrinsic muscles of the hand.

-Anterior Arm: Flexion of the elbow joint -Posterior Arm: Extension of the elbow joint -Anterior Forearm: Flexion of the wrist -Posterior Forearm: Extension of the wrist -Intrinsic muscles of the hand: generate delicate movements of the digits of the hand and modify the forces produced by tendons coming into the fingers and thumb from the forearm.

List the muscles in the anterior and posterior compartments of the arm and distinguish their actions at the ulnohumeral and radiohumeral joints of the elbow; specify the innervation of each of these muscles. -Anterior Compartment

-Biceps brachii (long and short heads): flexor of the elbow at the radiohumeral joint, supination of the forearm when the elbow is flexed. -Coracobrachialis muscle: flexor of the arm at the glenohumeral joint. -Brachialis muscle: flexor of the elbow at the ulnohumeral joint. -Innervation: musculocutaneous nerve

Specify the spinal cord segments assessed by the following deep tendon reflexes: biceps, triceps, brachioradialis.

-Biceps: C6 -Triceps :C7 -Brachioradialis: C5-C6

Be able to demonstrate the following movements of the shoulder (glenohumeral joint): flexion, extension, abduction, adduction, medial (internal) rotation, lateral (external) rotation; be able to use these terms properly when discussing movements at the shoulder.

-Flexion: arm raises forward -Extension: arm extends backward -Abduction: arm away from body -Adduction: arm toward body -Medial rotation: arm (humerus) is rotated toward the midline -Lateral rotation: arm (humerus) is turned away from midline NOTE: during medial and lateral rotation, protonation/supination is NOT occurring. The palm remains anterior and the elbow remains flexed during these movements.

Be able to demonstrate the following movements of the elbow: flexion, extension; be able to use these terms properly when discussing movements at the elbow.

-Flexion: elbow flexes (bends) and lifts the forearm forward -Extension: elbow extends (straightens) and returns the forearm down

Be able to demonstrate the following movements of the forearm: pronation, supination; be able to use these terms properly when discussing movements of the forearm and the position of the hand.

-Protonation: rotating the forearm/hand at the elbow joint to turn the palm posterior. During this, the radius and ulna cross over each other. -Supination: return the palm to anterior position and uncross the ulna and radius.

Explain the anatomical basis of subacromial bursitis and supraspinatus tendinitis.

-Subacromial bursitis: this can be due to repetitive motion and irritation of the bursa -Supraspinatus tendinitis: supraspinatus tendon is particularly vulnerable to this due to its relatively avascular tendon and potential impingement on the coracoacromial arch.

Explain the role of scapular movement in glenohumeral joint function; list the joints involved and the muscle activity required to abduct the arm 180 degrees.

-The role of scapular movement in glenohumeral joint function is to increase the total range of motion possible at the shoulder. -In order to abduct the arm 180 degrees, the deltoid, supraspinatus, trapezius, and serratus anterior muscles must all work together on the glenohumeral joint, as well as the acromioclavicular joint -The supraspinatus "initiates" abduction -From 60-90 degrees, the deltoid and supraspinatus work together to abduct the arm -Once above 90 degrees, the trapezius and serratus anterior work together to continue abduction

Specify the muscles of the arm that act upon both the shoulder and the elbow and describe their actions at each joint.

-Triceps brachii long head: Extension of the arm at the shoulder joint and extension of the forearm at the elbow joint. -Biceps brachii: flexor of the arm at the shoulder joint and flexor of the forearm at the elbow joint.

List the muscles in the anterior and posterior compartments of the arm and distinguish their actions at the ulnohumeral and radiohumeral joints of the elbow; specify the innervation of each of these muscles. -Posterior Compartment

-Triceps brachii long head: extension of the glenohumeral joint and extension of the elbow joint. -Triceps brachii medial and lateral heads: extensors of the elbow joint -Brachioradialis: flexion of the elbow joint -Innervation: radial nerve

Be able to demonstrate the following movements of the scapula: upward rotation, downward rotation, protraction, retraction; be able to use these terms properly when discussing movements of the scapula on the thoracic wall.

-Upward rotation: the scapula rotates upward when the arm is abducted at the glenohumeral joint. -Downward rotation: the scapula rotates downward when the arm is adducted at the glenohumeral joint. -Protraction: Round the shoulders forward to separate the scapulae from each other. -Retraction: Pull the shoulders back to pinch the scapulae toward each other

List the six movements of the scapula on the posterior thoracic wall; specify the muscles involved in each.

1. Elevation: trapezius and levator scapulae 2. Depression: trapezius, pectoralis minor, and serratus anterior 3. Protraction: serratus anterior and pectoralis minor 4. Retraction: rhomboid major/minor and trapezius 5. Upward rotation: trapezius and serratus anterior 6. Downward rotation: levator scapulae and rhomboid major/minor

For each of the four rotator cuff muscles, specify their action, attachments and innervation. 1. Supraspinatus

Action: initiation of abduction at the glenohumeral joint. Also stabilizes the joint and prevents excessive motion. Innervation: suprascapular nerve. Attachment: superior facet of greater tubercle of humerus

For each of the four rotator cuff muscles, specify their action, attachments and innervation. 3. Teres minor

Action: stabilization and prevention of excessive motion at the glenohumeral joint. Also does lateral rotation Innervation: axillary nerve Attachment: inferior facet of greater tubercle of humerus

For each of the four rotator cuff muscles, specify their action, attachments and innervation. 2. Infraspinatus

Action: stabilization and prevention of excessive motion at the glenohumeral joint. Also does lateral rotation Innervation: suprascapular nerve. Attachment: middle facet of greater tubercle of humerus

For each of the four rotator cuff muscles, specify their action, attachments and innervation. 4. Subscapularis

Action: stabilization and prevention of excessive motion at the glenohumeral joint. Also does medial rotation Innervation: Upper and lower subscapular nerves. Attachment: lesser tubercle of humerus

Specify the principle joint action controlled by and the location of sensory testing for each of the ventral primary rami that contribute to the brachial plexus; be able to apply this information in assessing sensory and motor deficits in the upper limb.

Brachial plexus C5-C8. -C5-C7 Musculocutaneous nerve -C5-C6 Axillary nerve -C6-C8,T1 Median nerve -C5-C8,T1 Radial nerve -C8,T1 Ulnar nerve -Abduction of the arm at the glenohumeral joint is controlled predominantly by C5 -Flexion of the forearm at the elbow joint is controlled primarily by C6 -Extension of the forearm at the elbow joint is controlled mainly by C7 -Flexion of the fingers is controlled mainly by C8 -Abduction and adduction of the index, middle, and ring fingers is controlled predominantly by T1 -C5: upper lateral region of the arm -C6 palmar pad of the thumb -C7 pad of the middle finger -C8 pad of the little finger -T1 skin on the medial aspect of the elbow

For each of the six principle movements allowed at the glenohumeral joint, specify the muscles involved and their innervation. 2. Extension

Latissimus dorsi (thoracodorsal n) teres major (lower subscapular n) deltoid (axillary n) triceps brachii long head (radial n)

Explain the mechanism of injury and anatomical basis of Nursemaid's elbow; specify the ligament involved.

Sudden, forceful tug on a child's hand can dislodge the not yet fully formed radial head from the annular ligament.

Specify the joint involved and the ligaments injured in various grades of shoulder separation.

The joint involved in various grades of shoulder separation is the acromioclavicular joint. The ligaments typically injured include stretching of the acromioclavicular ligament to complete rupture of both the acromioclavicular and coracoclavicular ligaments.

Explain the primary function of the upper limbs.

The primary function of the upper limb is to be mobile for positioning the hand is space.

Explain the anatomical basis of the following pathologies of the arm and elbow: biceps tendonitis

back and forth movement of the tendon within the intertubercular groove can cause wear and tear of this tendon and lead to inflammation

For each of the six principle movements allowed at the glenohumeral joint, specify the muscles involved and their innervation. 5. Medial rotation

latissimus dorsi (thoracodorsal n) subscapularis (upper and lower subscapular n) teres major (lower subscapular n) deltoid (axillary n) pectoralis major (medial and lateral pectoral n)

Explain the anatomical basis of the following pathologies of the arm and elbow: Popeye deformity

rupture of the biceps tendon causes the muscle belly to retract and form a large bulge in the anterior arm