Obviously, from a functional point of view - an aspect that instead interests sportsmen most - the matter is much more complicated than that.
These muscles perform multiple biomechanical functions and participate, with the others we will discuss, in various movements of the upper limbs with greater interest in the forearm than in the arm.
We specify this because, as it should be clearly stated in the articles Pectoral training And Back training, the movement of the humerus on the glenohumeral joint is carried out by the muscles of the shoulders, back (especially upper and lateral) and chest - even if all the muscles related to the scapular movement should also be mentioned.
For further information: Back Training .
These joints are in fact three: humero-ulnar, humero-radial, radio-ulnar, and allow: flexion and extension of the forearm on the arm - then of the ulna and radius on the humerus - pronation (internal rotation) and supination (external rotation ).
- The anterior muscles are fundamentally involved in flexion, pronation and supination; let's talk about: brachial, brachial, brachioradialis and coracobrachialis biceps.
- The posterior muscles are mainly involved in flexion; we are talking about brachial triceps and anconeus.
Let's see them more accurately.
For further information: Pectoral training and elbow, and composed of two muscular bellies originating proximally (near the trunk) which unify distally (towards the extremity).
The biceps brachialis is one of the three muscles of the anterior and superior compartment of the arm, together with the brachialis and coracobrachialis muscles, with which it shares the innervation.
Both proximal heads arise from the scapula (coracoid process and supraglenoid tubercle) and join and then enter the upper forearm (radial tuberosity).
While affecting the shoulder and elbow joints, its main functions are flexion and supination (external rotation) of the forearm.
C "is however to say that external rotation requires at least a partial flexion of the humero-ulnar, is that the flexion is massively supported by the biceps (in percentage of involvement compared to others) alone when the forearm is externally rotated.
It is also important to point out that, in practice, the biceps can only exert a certain amount of force, regardless of the position of the forearm; when the position of the forearm changes, the compensation is paid by the other muscles.
This means that by varying the position of the forearm and of the humerus with respect to the shoulder, the biceps is still trained and substantially changes the commitment of the other synergists.
of the elbow.
It is located deeper than the brachial biceps and is part of the floor of the region called the cubital fossa.
The brachialis arises proximally on the anterior surface of the distal half of the humerus, near the insertion of the deltoid muscle (which it embraces with two angular processes). The distal tendon, on the other hand, is inserted on the tuberosity of the ulna and on the coronoid process of the same.
The brachialis is an extremely strong, albeit hardly visible, muscle.
Contrary to what many think in fact, it is the brachialis that performs the role of the main "motor" in the flexion of the elbow, it is not the biceps.
Compared to the biceps, the brachialis actually generates about 50% more flexing power.
Unlike the biceps though, the brachialis Not it fits on the radius and does not participate in the rotation of the forearm.
The misunderstanding arises from the greater "evidence" of the biceps, and from the consequent interest in the culture of aesthetic musculation.
during the slow flexion of the forearm - two actions that almost seem to oppose each other.
The brachioradialis is used to stabilize the elbow during rapid flexion and extension actions, when it is in a central position as in the "hammering" gesture.
While not being isolated or targeted by training, in functional terms it is of crucial importance - especially in the high expression of strength.
and the short head of the brachial biceps.It is located in the upper and medial part of the arm. It arises proximally to the apex of the coracoid process and inserts distally into the center of the medial surface of the humerus, between the origins of the brachial and brachial triceps.
The action of the coracobrachialis is to flex and adduce the arm at the level of the glenohumeral joint (shoulder). Furthermore, it resists the deviation of the arm from the frontal plane during abduction.
Therefore, with respect to the shoulder joint, the contraction of the coracobrachialis leads to two distinct movements: pulls the humerus forward by flexing the arm, and towards the torso while adducing it.
To a lesser extent, the humerus rotates internally.
Another important function of the coracobrachialis is the stabilization of the head of the humerus inside the shoulder joint, especially when the arm hangs freely at the side of the torso, opposing the force of gravity.
The coracobrachialis, while sharing the anatomical position with the biceps and brachialis, it is therefore not involved in the flexion of the forearm on the arm; does not train during common arm muscle-building routines.
and posterior to the great rotunda.The three heads converge in a single tendon inserted in the olecranon process of the ulna (although some research indicates that there may be more than one tendon) and at the posterior wall of the elbow joint capsule. Parts of the common tendon radiate into the fascia of the forearm and can almost cover the anconeus muscle.
Each of the three leaders can be considered an independent muscle with specific functional roles.
The triceps is a muscle extender of the elbow joint and an antagonist of the biceps and brachialis muscles. It can also stabilize the elbow joint when the forearm and hand are used for precision movements, such as when writing.
It has been suggested that:
- the long head is used above all when a conspicuous generation of force is required and when a synergistic control of the shoulder and elbow is required;
- the lateral head is delegated to movements that occasionally require a high intensity;
- the medial head allows more precise and not too strong movements.
With its scapular origin, the long head also acts on the shoulder joint and is involved in the retroversion and adduction of the arm. Helps stabilize the shoulder joint at the top of the humerus.
, resistant, fast etc.), it is the motor action as a whole that must be developed.Then, obviously, both on a functional and athletic level it may become necessary to refine the development of one or the other district, but this must be done only after an accurate evaluation.
If we talk about hypertrophy instead, so coveted by bodybuilders, the situation changes. We know there are many schools of thought on the subject, but below we will not make any comparison or comparison; we will limit ourselves instead to making useful considerations and providing practical advice for training the arms.
