Posterior Forearm Flashcards
Triceps brachii origin (long head)
Infraglenoid tubercle
Triceps brachii origin (medial head)
Posterior humerus medial to radial groove
Triceps brachii origin (lateral head)
Posterior humerus lateral to radial groove
Triceps brachii insertion
Proximal olecranon
Triceps brachii action (all heads)
Elbow extension
Triceps brachii action (long head)
Least active head
Weak adductor and extensor of the shoulder
Helps to resist glenohumeral dislocation
Triceps brachii action (lateral head)
Strongest head
Primarily active against resistance (elbow extension)
Triceps brachii action (medial head)
Always active
Elbow extension
Anconeus origin
Lateral epicondyle
Anconeus insertion
Lateral olecranon and posterior ulna
Anconeus actions
Assist in extension, elbow stabilization
Triceps brachii innervation
Radial nerve
Anconeus innervation
Radial nerve
Lateral border of the quadrangular space
Surgical neck of humerus
Medial border of the quadrangular space
Long head of triceps brachii
Superior border of the quadrangular space
Teres minor
Inferior border of the quadrangular space
Teres major
Contents of the quadrangular space
Axillary nerve and posterior circumflex humeral artery
Lateral border of the triangular space
Long head of triceps brachii
Superior border of the triangular space
Teres minor
Inferior border of the triangular space
Teres major
Lateral border of the triangular interval
Humeral shaft
Medial border of the triangular interval
Long head of triceps brachii
Superior border of the triangular interval
Teres major
Contents of the triangular space
Circumflex scapular artery
Contents of the triangular interval
Radial nerve and the profundus brachii artery
Origin of brachioradialis
Lateral supracondylar ridge