Biceps Brachii Muscle

Fig. 3 Time series of relative changes of J i,/along the time of isometric contraction of the biceps brachii muscle.

The anterior group of muscles and tendons includes the biceps brachii and the brachialis that lie in the cubital region between the brachioradialis muscle laterally and the pronator teres muscle medially. The biceps brachii muscle is located superficial to the brachialis and has a long distal tendon that is not surrounded by muscle, making it more susceptible... 

Characteristic, categorizable elements can be seen upon cutting across any skeletal muscle, such as musculus biceps brachii (the biceps). A closer look reveals finer and finer structures. Each hatched or shaded element of Fig. 9.1 in the lower sketch of this figure, respectively, is presented in more detail in a hierarchical fashion. 

Flexion may be active or passive. Active flexion ends at approximately 145 degrees and is primarily limited by opposition of the contracting muscles of the arm and forearm. The range of passive flexion is slightly larger as the muscles relax and are flattened. There is some restriction as well that comes with the approximation of the raised coronoid process of the ulna into the shallow corollary depression in the humerus. Bony opposition and tension in the triceps and posterior capsular ligaments also limit flexion. The primary flexor muscle is the brachialis, which is assisted by the biceps brachii and the brachioradialis. 

Dartnall TJ, Nordstrom MA, Semmler JG (2008) Motor unit synchronization is increased in biceps brachii after exercise-induced damage to elbow flexor muscles. J Neurophysiol 99 1008-1019. 

The anterior compartment of the arm houses three muscles the coracobrachialis, the biceps brachii and the brachialis (Fig. 7.2). The coracobrachialis takes its origin from the tip of the coracoid process, medial to the insertion of the short head of the biceps, and continues down and laterally to insert onto the medial aspect of the middle third of the humeral shaft. The biceps brachii is formed by a combination of two muscle bellies the long head and the short head. As already described in Chapter 6, the long head originates from a long tendon which... 

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