L5.5.6.1.1: Anterior Upper Arm

• ANTERIOR UPPER ARM

  [a] Deltoid

  [b] Coracobrachialis

  [c] Biceps Brachii

  [d] Brachialis

  [e] Long Head of Triceps Brachii

  [f] Medial Head of Triceps Brachii

  [g] Subscapularis

  [h] Teres Major

  
• Deltoid

  ○ Prime movers of arm abduction

  ○ Freshy, triangle-shaped muscles that form the rounded shape of your shoulders

  ○ Favorite injection site when relatively small amounts of medication must be given intramuscularly

  ○ Origin winds across the shoulder girdle from the spine of the scapula to the clavicle

  ○ Inserts into the proximal humerus
• Coracobrachialis

  ○ Long and slender muscle of the anterior compartment of the arm

  ○ Extends from the coracoid process of scapula to the shaft of the humerus

  ○ Responsible for flexion and adduction of the arm at the shoulder joint
• Biceps Brachii

  ○ Most familiar muscle of the arm

  ○ Bulges when elbow is flexed

  ○ Originates by two heads from the shoulder girdle

  ○ Inserts into the radial tuberosity

  ○ Movements:

  ■ Acts to supinate the forearm

  ■ Lifts the radius

  ■ Powerful prime mover for flexion of the forearm
• Brachialis

  ○ Lies deep to the biceps brachii

  ○ Movements:

  ■ Prime mover in elbow flexion

  ■ Lifts the ulna
• Subscapularis

  ○ Largest, strongest muscle of the rotator cuff

  ○ Rotator cuff muscles are essential in shoulder movement and help maintain glenohumeral joint stability

  ○ Lies at the anterior surface of the scapula