posterior arm

• Triceps brachii origin

  -lateral head: superior/lateral humerus

  -medial head: posterior humerus

  -long head: infraglenoid tubercle of scapula
• Triceps brachii insertion

  decranon
• triceps brachii action

  extend at elbow

  -long head: extend and adduct humerus
• triceps brachii innervation

  radial nerve