Biceps Muscle: 4 Aspects You Should Know

The biceps muscle acts on the elbow joint, allowing flexion to stimulate its work, this article will discuss the aspects to know.

Generalities of the biceps muscle

In the elbow joint, composed of the humerus, radius, and ulna, there is the radioulnar joint, which moves in a horizontal and transverse plane, providing supination and pronation movement, and on the side of the elbow, it works on the sagittal plane, providing flexion and extension movement of the same (1).

It is composed of several ligaments, with which the anterior musculature of the arm is composed of the biceps muscle (biceps brachii, brachioradialis, and brachialis and pronator teres), and these are mainly elbow flexors.

On the other hand, they are characterized by having 2 heads (hence the terminology biceps), it is also considered a multiarticular muscle (along with the triceps), as it works on more than one joint, in this case in the shoulder-elbow (2).

That said, this article will discuss four of its main characteristics of the biceps muscle, the bones involved, the main joint or joints, the injuries that may appear, and some aspects of how to program training oriented to the biceps muscle.

Characteristics of the bones and joints of the elbow

The upper limb is composed of bones, joints, and muscles, for this purpose the bones involved are the scapula, humerus, radius, ulna, and the bones of the hands.

That said, the humerus is a paired bone, located in the arm, its main characteristics are: it is a paired and long bone, presenting 2 epiphyses and a diaphysis.

In the same line, Lloret Riera, M. (2012), mentions that in the proximal epiphysis of the humerus, there is a prominence in the external and upper part called the greater tubercle, and an anterior one called the lesser tubercle. These two continue the respective crests, where the bicipital groove is formed (1).

Likewise, in the elbow joint, three characteristic joints can be found:

• The humeroulnar joint (trochlea)
• The humeroradial joint (condylar)
• The superior and inferior radioulnar joint (trochoid)

Elbow region and its joints

In this region, at the anatomical level, there are 3 joints, but they function as four (2):

1. The humeroulnar joint joins the proximal epiphysis of the ulna, known as the diarthrodial joint of the trochlear complex, like a pulley.
2. The humeroradial joint, joins the proximal epiphysis of the radius, is a condylar joint with ellipsoidal surfaces. They have in common that they share the intrinsic annular ligament of the radius, which joins the head of the radius with the lesser sigmoid cavity of the ulna.
3. On the side of the superior radioulnar joint, it joins the epiphysis of the radius and the proximal epiphysis of the ulna, it is a trochoid joint, likewise, the inferior radioulnar joint joins the distal epiphysis of the radius with the distal epiphysis of the ulna.

Elbow region and its characteristic movements

These movements are characteristic of the mentioned joints, which the elbow region presents 2 axes of movement (3):

1. In a first axis, of the transverse type, the movements it allows are flexion and extension of the joint.
2. And in a second axis of movement, the vertical axis will observe the movements of pronation (internal rotation) and supination (external rotation).

That said, the muscles of the arm that act on the elbow joint can be found, these muscles are characterized by being ventral, and within the biceps muscles are the anterior biceps brachii muscle and the biceps brachii muscle, which are detailed below.

Biceps muscles that act on the elbow joint

At this point, the biceps muscle is mainly characterized by being ventral, which this group includes the anterior biceps brachii muscle and the biceps brachii.

1. The anterior brachialis, is a broad muscle that originates in the middle anterior third of the humerus and interosseous membrane, forming a muscle belly that inserts on the anterior surface of the coronoid process of the ulna, where its main action is a powerful flexor of the elbow.
2. On the side of the biceps brachii, it has its two heads, the short portion, and the long portion, it inserts on the bicipital tuberosity of the radius, and its main action is supination. Additionally, it only flexes the arm when it is in supination.

Mechanics of the biceps muscle

When talking about hand actions in relation to daily life activities, expressive or movement activities, it turns out that according to Weineck, J (2013), states that the activity of the arm flexors will have greater prominence compared to the extensor musculature of the arm (3).

In order to know the anterior musculature of the arm, composed of the biceps brachii, brachioradialis, brachialis, and pronator teres, it is necessary to mention that the tendons provide the necessary stability crossing the elbow joint, mainly providing security to it.

In summary, the characteristics, origin, insertion, and function of the biceps brachii muscle, brachialis muscle, and brachioradialis will be mentioned.

Biceps brachii muscle

It has two heads, the short one that originates in the coracoid process and the long head in the supraglenoid tubercle, it inserts on the tuberosity of the radius and is innervated by the musculocutaneous nerve.

This muscle has the peculiarity of crossing two joints, the elbow and the shoulder. At the elbow, it flexes and supinates the forearm, and the maximum force action is at 90º of elbow flexion.

The peculiarity of this muscle is its short lever arm, which means a minimal shortening of its fibers will produce a rapid and powerful movement.

Brachialis muscle

This biceps muscle is located below the biceps brachii, where it originates on the anterior and distal surface of the humerus, its insertion is on the tuberosity of the ulna and it is innervated by the musculocutaneous nerve.

It is a pure flexor of the forearm with a force similar to that of the biceps brachii, also when the arm is fixed, it pulls the trunk towards it, and also collaborates in performing arm flexions.

Brachioradialis muscle

The origin of the brachioradialis is located on the lateral border of the humerus, the styloid process of the radius is its insertion and it is innervated by the radial nerve.

After which, this biceps muscle has as its main function to develop maximum flexor strength, as it is located in the forearm region.

Once this muscle group is described, the peculiarity of it is to select exercises that prevent injuries to it, which in the following section is discussed.

Injuries that can occur in the biceps muscle

For a long time, injuries to the biceps muscle have been studied, seeking treatment methods to recover the injury as best as possible, and it is where Kokkalis ZT, Sotereanos DG (2009), mention that the rupture of the distal biceps tendon occurs mainly in middle-aged men, athletes, especially those who practice strength and contact sports (6).

Consequently, injuries to the biceps muscle brachii, especially in the long head, have long been the subject of study by many professionals Kokkalis, Z.T. and collaborators (2009) and later Krumm, D and collaborators (2019), which has been defined that most injuries are at the level of the biceps muscle tendon, mentioned in Chren, R.E. and collaborators (2018), which due to wear of the soft parts can lead to tendinitis, this would affect shoulder mobility causing instability in the shoulder joint, and due to tendinitis or tendon wear, it could lead to biceps rupture (4, 5, and 6).

That said, and according to the research of Chen RE, Voloshin I. (2019), they state that there are three types of treatment depending on the degree of the injury, these can be non-surgical treatment, surgical procedures to repair the injury, and surgery (4).

In other words, another type of biceps muscle injury is those caused by disease or trauma, which in the latter Krumm D and collaborators (2019), state that it may be due to intense training with little recovery time, lack of stretching, or use of inadequate equipment (5).

Likewise, the most common injuries occur when the elbow goes from a state of complete flexion to an abrupt extension of the movements, which could lead to the biceps tendon generating an imbalance in collagen synthesis and this leads to rupture or tendinitis (6).

In summary, any surgical procedure will have as its main objective to recover the damaged area, seeking complete anatomical restoration, reestablishing the functionality of the elbow and the muscle as best as possible.

How to program training for the biceps muscle?

When training programs aimed at muscle hypertrophy or muscle mass gains are proposed, mechanical tension plays a very important role, as the musculature must be induced to generate optimal stimuli to achieve the desired gains (7).

Baz-Valle and collaborators (2022), in a systematic review propose different training volumes with the aim of muscle mass gains in the biceps muscle (7).

In their search, they detected that different volumes are worked, such as less than 12 weekly series, between 12 to 20 weekly series, and high volumes of 20 weekly series or more, after which the training volume is highly studied, but to achieve acceptable ranges of hypertrophy gains, not only mechanical tension must be taken into account, but other factors such as:

• Proximity to failure
• Intensity
• Frequency
• And time under tension.

In the same line, Pedrosa GF and collaborators (2023), state that the work intensity for the biceps curl could range between 50 to 70%, which in their research work involved a group of women who worked the preacher curl with dumbbells with a frequency of 3 times a week with a program duration of 8 weeks (8).

Even so, in addition to the mentioned variables, from the point of view of biomechanics of movement, to this day the Range of Motion in relation to the induction of muscle hypertrophy has been the subject of research.

Therefore, if the goal is to stimulate the biceps muscle, programming the variables with awareness, depending on the person, and seeking different ranges of motion, would seem to be an interesting proposal for muscle mass gains.

That said, it would be interesting to propose different types of biceps exercises that aim at strength and muscle mass gains in the biceps muscle.

Conclusions about the biceps muscle

Once this research is conducted, the importance of the biceps muscle has been observed, in the first instance for daily life activities, and for strength, throwing, or fighting athletes, as through the strengthening of this muscle group it can bring great sports results (6).

In contrast, the biceps muscle is revered in the society we live in, which accounts for the fact that a trained and voluptuous arm musculature would dignify the person as “strong.”

And to optimize the work of the biceps musculature, the variables to consider are volume, intensity, frequency, proximity to failure, time under tension, and range of motion.

For which, it is interesting to propose a correct progressive overload and use of the variables to avoid injuries, especially in the shoulder tendon and the distal biceps tendon.

Bibliographic references

1. Lloret Riera, M. (2012). Applied anatomy to physical and sports activity 3rd edition. Editorial Paidotribo. Bandalona, Spain.
2. Jo Ann Staugaard- Jones. (2014). Anatomy of exercise and movement. Editorial Paidotribo. Bandalona, Spain.
3. Weineck, J. (2013). Sports Anatomy 5th edition. Editorial Paidotribo. Bandalona, Spain.
4. Chen, R. E., & Voloshin, I. (2018). Long Head of Biceps Injury: Treatment Options and Decision Making. Sports medicine and arthroscopy review, 26(3), 139–144.https://doi.org/10.1097/JSA.0000000000000206
5. Krumm, D., Lasater, P., Dumont, G., & Menge, T. J. (2019). Brachial distal biceps injuries. The Physician and sportsmedicine, 47(4), 406–410. https://doi.org/10.1080/00913847.2019.1620653
6. Kokkalis, Z. T., & Sotereanos, D. G. (2009). Biceps tendon injuries in athletes. Hand clinics, 25(3), 347–357. https://doi.org/10.1016/j.hcl.2009.05.007
7. Baz-Valle, E., Balsalobre-Fernández, C., Alix-Fages, C., & Santos-Concejero, J. (2022). A Systematic Review of The Effects of Different Resistance Training Volumes on Muscle Hypertrophy. Journal of human kinetics, 81, 199–210. https://doi.org/10.2478/hukin-2022-0017
8. Pedrosa, G. F., Simões, M. G., Figueiredo, M. O. C., Lacerda, L. T., Schoenfeld, B. J., Lima, F. V., Chagas, M. H., & Diniz, R. C. R. (2023). Training in the Initial Range of Motion Promotes Greater Muscle Adaptations Than at Final in the Arm Curl. Sports (Basel, Switzerland), 11(2), 39. https://doi.org/10.3390/sports11020039