Triceps Brachii - Muscle Physiology & Functional Anatomy

 

Triceps Brachii Muscle

Anatomy

 

Origin:

  • Long head

    • Infraglenoid tubercle of scapula

  • Lateral head

    • Posterior humerus (upper half)

  • Medial head

    • Posterior humerus (deep on lower half posterior humerus inferomedial to spiral groove & both intermuscular septa)

Insertion

  • Posterior part of upper surface of olecranon process of ulna & posterior capsule



Major Arteries:

  • Deep brachial artery (profunda brachii)

 

Neural Innervation:

  • Radial nerve

  • Axillary nerve (long head)

 

Trigger Points:

Trigger points of the Triceps BrachiiTriceps trigger points

 

Physiology

 

Concentric Functions:

  • Long head

    • Elbow extension

    • Assists in shoulder extension & abduction

  • Lateral head

    • Elbow extension

  • Medial head

    • Elbow extension

 

Eccentric Functions:

  • Long head

    • Assists in deceleration of shoulder flexion

    • Assists in shoulder extension & abduction

  • Lateral head

    • Decelerates elbow flexion

  • Medial head

    • Decelerates elbow flexion

 

Isometric Function:

  • Long head

    • Helps dynamically stabilize the glenohumeral joint

  • Lateral head


  • Medial head


Related Muscles

  • Anconeus


Antagonist:

Exercises:

 

 


More Images of the Triceps Brachii Muscle

Triceps Brachii Muscle

 


More Information about the Triceps Brachii Muscle

The triceps brachii muscle is biarticulate which means it has actions across 2 joints. 

The long head of the triceps assists in extension & adduction of the shoulder when it is externally rotated.  When the shoulder is internally rotated the ability of the long head of the triceps brachii to extend & adduct the shoulder is lessened.

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