Arm Muscles
Triceps brachii: Action
1. Extension of forearm 2. Extension of arm
Aconeus: Action
1. Extension of forearm 2. Stabilize elbow joint against flexion or pronation-supination
Coracobrachialis: Action
1. Flexion of arm 2. Adduction of arm
Biceps brachii: Action
1. Flexion of arm 2. Flexion of forearm 3. Supination of forearm
Brachialis: Action
Flexion of forearm
Biceps brachii: Innervation
Musculocutaneous nerve
Brachialis: Innervation
Musculocutaneous nerve
Coracobrachialis: Innervation
Musculocutaneous nerve
Brachialis: Origin & Insertion
Origin: 1. Lower half of anterior surface of humerus 2. Intermuscular septa Insertion: 1. Ulnar tuberosity
Coracobrachialis: Origin & Insertion
Origin: 1. Coracoid process of scapula Insertion: 1. Anteromedial surface of midshaft of humerus
Anconeus: Origin & Insertion
Origin: 1. Lateral epicondyle of humerus Insertion: 1. Lateral side of olecranon of ulna
Triceps brachii: Origin & Insertion
Origin: 1. Long head- infraglenoid tubercle of scapula 2. Lateral head- posterior surface of humerus above/lateral to radial nerve & lateral intermuscular septum 3. Medial head- posterior surface of humerus below/medial to radial nerve & both intermuscular septa Insertion: 1. Proximal end of olecranon of ulna
Biceps brachii: Origin & Insertion
Origin: 1. Short head- tip of coracoid process of scapula 2. Long head- supraglenoid tubercle of scapula Insertion: 1. Radial tuberosity 2. Bicipital aponeurosis into fascia of forearm
Aconeus: Innervation
Radial nerve
Triceps brachii: Innervation
Radial nerve