UNIT 2 - UE SECOND ORDER

Posterior Axio-Appendicular Muscles

1. Latissimus dorsi

Latissimus dorsi - O

1. Iliac crest

2. Thoracolumbar fascia

3. Inferior angle of scapula

4. Ribs 9-12

5. SP T7-L5

Latissimus dorsi - I

1. Intertubercular sulcus of humerus (floor)

Latissimus dorsi - A

1. Extend humerus

2. Adduct humerus

3. Medially rotate humerus

Latissimus dorsi - N

1. Thoracodorsal N (C6-C8)

Latissimus dorsi - B

1. Thoracodorsal A

2. Artery branch of subscapular A (from axillary A)

Latissimus dorsi clinical significance

1. Assist in movements like climbing, swimming, crutch walking

2. Postural correction

3. Shoulder extension

4. Transfer procedures to restore shoulder (ABD) after rotator cuff tear

Anterior Axio-Appendicular Muscles

1. Pectoralis major

2. Pectoralis minor

3. Subclavius

4. Serratus anterior

Pectoralis major - O

• Clavicular head

  1. Anterior medial ½ of clavicle

• Sternocostal head

  2. Anterior surface of sternum

  3. Superior six costal cartilages

  4. Aponeurosis of external obliques

Pectoralis major - I

1. Lateral lip of the intertubercular sulcus of humerus

Pectoralis major - A

• Clavicular head

  1. Flexes humerus

• Sternocostal head

  2. Extends humerus from flexion

  3. ADD humerus

  4. Medially rotates humerus

Pectoralis major - N

1. Medial pectoral N

2. Lateral pectoral N

   • (C5-T1)

Pectoralis major - B

1. Pectoral branches of thoracoacromial A

Pectoralis major clinical significance

1. Push, pull, and overhead reaching

2. Strain injuries in sports/weightlifting

Pectoralis minor - O

1. 3rd-5th ribs near costal cartilages

Pectoralis minor - I

1. Coracoid process (scapula)

Pectoralis minor - A

1. Stabilizes scapula by drawing inferiorly and anteriorly against thoracic wall

Pectoralis minor - N

1. Medial pectoral N

Pectoralis minor - B

1. Pectoral branches of thoracocromial A

2. Lateral thoracic A

Pectoralis minor clinical significance

1. Pectoralis minor syndrome

   • Type of thoracic outlet syndrome

Subclavius - O

1. Junction of 1st rib and costal cartilages

Subclavius - I

1. Inferior surface of the middle third of clavicle

Subclavius - A

1. Anchors and depresses clavicle

Subclavius - N

1. Subclavius N

Subclavius - B

1. Clavicular branch of thoracacromial A

Subclavius clinical significance

1. Protect subclavian vessels in clavicular fractures

2. Postural imbalances

3. Tension across thoracic outlet

Serratus anterior - O

1. External lateral ribs 1-8/9

Serratus anterior - I

1. Anterior medial border of scapula

Serratus anterior - A

1. Protract scapula

2. Holds scapula in thoracic wall

3. Superiorly rotates scapula

Serratus anterior - N

Long thoracic N (C5-C7)

Serratus anterior - B

1. Lateral thoracic A

2. Superior thoracic A

Serratus anterior clinical significance

1. Winged scapula

2. Reaching/pushing motions

3. Stabilizes scapula protocols

Scapulohumeral Muscles

1. Deltoid

2. Supraspinatus

3. Infraspinatus

4. Subscapularis

5. Teres major

6. Teres minor

Deltoid - O

1. Lateral 1/3 clavicle

2. Acromion

3. Spine of scapula

Deltoid - I

1. Deltoid tuberosity of humerus

Deltoid - A

1. Anterior: flex and medially rotate

2. Middle: ABD (beyond 15 degrees)

3. Posterior extends and laterally rotates

Deltoid - N

1. Axillary N

Deltoid - B

1. Posterior circumflex humeral A

Deltoid clinical significance

1. Weak or atrophy = axillary N injury (shoulder dislocation)

Supraspinatus - O

1. Supraspinous fossa of scapula

Supraspinatus - I

1. Greater tubercle of humerus

Supraspinatus - A

1. Initiate ABD

2. Stabilizes humeral head in glenoid cavity

Supraspinatus - N

1. Suprascapular N

Supraspinatus - B

Suprascapular A

Supraspinatus clinical significance

1. Rotator cuff muscle

2. Common in rotator cuff tears (overhead athletes)

3. Weakness in ABD = pathology

Infraspinatus - O

1. Infraspinous fossa of scapula

Infraspinatus - I

1. Greater tubercle of humerus

Infraspinatus - A

1. Lateral rotation (ER)

2. May ADD

3. Stabilizes humeral head

Infraspinatus - N

1. Suprascapular N

Infraspinatus - B

1. Suprascapular A

2. Scapular circumflex A

Infraspinatus clinical significance

1. Rotator cuff muscle

Subscapularis - O

1. Subscapular fossa of scapula

Subscapularis - I

1. Lesser tubercle of humerus

Subscapularis - A

1. Medially rotates arm (IR)

2. Helps hold of humerus in glenoid cavity

Subscapularis - N

1. Upper subscapular N

2. Lower subscapular N

Subscapularis - B

1. Subscapular A

Subscapularis clinical significance

1. Rotator cuff muscle

Teres minor- O

1. Middle of lateral scapula

Teres minor - I

1. Greater tubercle of humerus

Teres minor - A

1. Lateral rotation arm (ER)

2. Weak ADD of arm

3. Stabilizes humeral head

Teres minor - N

1. Axillary N

Teres minor - B

1. Scapular circumflex A

Teres minor clinical significance

1. Rotator cuff muscle

Teres major - O

1. Posterior inferior angle of scapula

Teres major - I

1. Medial lip of intertubercular sulcus of humerus

Teres major - A

1. ADD arm

2. Extends arm

3. Medially rotates arm

   • Latissimus dorsi little helper

Teres major - N

1. Lower subscapular N

Teres major - B

1. Subscapular A

2. Thoracodorsal A

Teres major clinical significance

1. Internal rotation and stabilization post-rotator cuff surgery

2. Rarely injured

Anterior Arm Muscles

1. Biceps brachii (long head, short head)

2. Coracobrachialis

3. Brachialis

Biceps brachii - O

1. Long head: Supraglenoid tubercle (scapula)

2. Short head: Coracoid process (scapula)

Biceps brachii - I

1. Tuberosity of radius

Biceps brachii - A

1. Long head: Weak arm flexor

2. Both heads: Most powerful supinator of forearm

   • Supine = flexes forearm

3. Short head: Resists dislocation of humerus

Biceps brachii - N

1. Musculocutaneous N

Biceps brachii - B

1. Brachial A

Biceps brachii clinical significance

1. Ruptures reduce supination strength

2. Limit functional tasks like screwdriving or lifting

Coracobrachialis - O

1. Coracoid process (scapula)

Coracobrachialis - I

1. Middle 1/3 medial humerus

Coracobrachialis - A

1. Flex arm

2. ADD arm

3. Resist dislocation of shoulder

Coracobrachialis - N

1. Musculocutaneous N

Coracobrachialis - B

1. Brachial A

Coracobrachialis clinical significance

1. Pierced by the musculocutaneous N = landmark in:

   • Nerve entrapment syndromes

   • Surgical dissections

Brachialis - O

1. Anterior distal ½ of humerus

Brachialis - I

1. Coronoid process (ulna)

2. Ulnar tuberosity (ulna)

Brachialis - A

1. Flex forearm (elbow) in ALL positions

Brachialis - N

1. Musculocutaneous N

2. Radial N

Brachialis clinical significance

1. Primary flexor of elbow

2. Remains active (all positions)

   • Elbow rehab post-fracture or immobilization

Posterior Arm Muscles

1. Triceps brachii

2. Anconeus

Triceps brachii - O

1. Long head: Infraglenoid tubercle (scapula)

2. Lateral head: Posterior humerus (above radial groove)

3. Medial head: Entire posterior humerus (below sulcus)

Triceps brachii - I

1. Proximal end of olecranon (ulna) via tendon

Triceps brachii - A

• Long head

  1. Weak arm extensor

• All heads

  2. Prime extensor of forearm (elbow)

  3. Resists dislocation of humerus (in ADD)

Triceps brachii - N

1. Radial N

Triceps brachii - B

1. Deep brachial A

Triceps brachii clinical significance

1. Vital to weight bearing and pushing motions

2. Long head: shoulder stabilization during crutch walking or transfers

Anconeus - O

1. Lateral epicondyle of humerus

Anconeus - I

1. Olecranon

2. Proximal ulna

Anconeus - A

1. Assist triceps in extend forearm

2. Stabilizes elbow joint

Anconeus - N

1. Radial N

Anterior Forearm Muscles

1. Pronator teres

2. Flexor carpi radialis (FCR)

3. Palmaris longus

4. Flexor carpi ulnaris (FCU)

5. Flexor digitorum superficialis (FDS)

6. Flexor digitorum profundus (FDP)

7. Flexor pollicis longus (FPL)

8. Pronator quadratus

Pronator teres - O

1. Coronoid process

2. Medial epicondyle of humerus