Biceps Brachii

Biceps Brachii is a large muscle located in the upper arm. The muscle has two heads, a long head, and a short head, that start at different points near the shoulder and then merge together into a single muscle belly. The biceps brachii is a well-known muscle, often associated with physical strength and fitness due to its prominence when well-developed.

Contrary to popular belief, the biceps brachii is not the most powerful flexor of the forearm. Although the biceps is the most prominent muscle of the upper arm, it primarily serves to support and stabilize the deeper brachialis muscle whenever lifting or lowering the forearm.

biceps brachii
Muscle Model at Physio Hub

Biceps Brachii

Anatomy

[Origin]

  • Short head: Tip of coracoid process of scapula
  • Long head: Supraglenoid tubercle of scapula

[Insertion]

  • Tuberosity of radius and fascia of forearm via bicipital aponeurosis

[Action]

  • Supinates forearm and, when it is supine, flexes forearm; short head resists dislocation of the shoulder

Clinical Relevance

Rupture of Tendon of Long Head of Biceps Brachii

Rupture of the tendon usually results from wear and tear of an inflamed tendon as it moves back and forth in the intertubercular sulcus of the humerus. This injury usually occurs in individuals over 35 years old.

Typically, the tendon is torn from its attachment to the supraglenoid tubercle of the scapula. The rupture is commonly dramatic and is associated with a snap or pop. The detached muscle belly forms a ball near the center of the distal part of the anterior aspect of the arm.

Rupture of the biceps tendon may result from forceful flexion of the arm against excessive resistance. However, the tendon ruptures more often as the result of prolonged tendinitis that weakens it. The rupture results from repetitive overhead motions, such as in swimmers and baseball pitchers.

The long head of the biceps tendon contributes relatively little to the overall function of the shoulder. The short head of the biceps tendon, as well as other muscles in the area, can compensate for the function of the long head when it is torn. Therefore, many people with a long head of the biceps tendon tear can still maintain good arm function.

~ Evidence-Based Exercises ~

According to an EMG study, the exercises that demonstrated significant muscle contractions of Biceps Brachii are;

  • Concentration Curl
  • Cable Curl
  • Chin-Ups

Anatomically, the long head of the biceps is thought to be more active during exercises where the arm is behind the body due to its origin on the scapula. Exercises like incline dumbbell curls and cable curls with the cable set behind you might target this head more.

On the other hand, the short head could be more active during exercises where the arms are in front of the body, due to its origin on the coracoid process of the scapula. Preacher curls, where your arms are resting on a slanted bench in front of you, might emphasize the short head more.

Remember, while these exercises may emphasize one head of the biceps more than the other, both heads will be involved to some extent in all these exercises.

Concentraion Curl

man arm curl

Cable Curl

man arm curl

Chin-Ups

man chin up

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