The triceps muscle of the arm, also known as the triceps (from the Latin name: musculus triceps brachii), is the main extensor of the elbow joint. Due to the fact that it is clearly visible through the skin, it is one of the most frequently trained muscles in this area of ​​the body.

The triceps muscle of the upper arm belongs to the posterior group of the arm muscles because it largely forms the posterior surface of the upper arm. Together with the biceps muscle and the deltoid muscle, it also forms the characteristic outline of the human arm.

Triceps muscle of the arm (triceps) - structure

The triceps brachium starts distally from three different attachments and ends with one end attachment of the common tendon of all three heads that attaches to the posterior surface of the ulna of the ulna. The starter trailers are located in the following places:

  • Long headbegins at the subtile tubercle of the scapula;
  • The lateral headbegins on the posterior surface of the humerus above the radial groove, and also on the lateral intermuscular septum;
  • Medial headbegins on the posterior surface of the humerus from the radial groove down to the capsule of the elbow joint.

The long head runs partially under the deltoid muscle. The medial head forms a deep layer on the posterior surface of the shoulder and lies directly on the humerus. The other two heads (side and long) lie superficially - on the deep head.

Tricep's synovial wallets

In the area of ​​the tendon of the end triceps muscle of the shoulder there are several bursae that do not connect with the articular cavity.

In adults, there is a constant subcutaneous bursa of the ulnar which is located between the ulnar process and the skin. Within the tendon above the elbow, and sometimes also between the tendon and the joint capsule, there is often also a second bursa associated with the end attachment of the triceps muscle.

Triceps muscle of the arm (triceps) - features

The primary function of the triceps brachial muscle isstraightening the elbow . Together with the elbow muscle, it is the main and almost exclusive extensorthis pond.

All three heads can work together, but a long head can also contract separately. Both short heads are single-aisled, while the long head extends over two joints. Therefore, its effect on the shoulder joint may be up to two times stronger than on the elbow joint.

The long head isthe strongest extensor of the shoulder in the shoulder jointand verystrong adductor . In this respect, it is stronger than the large pectoral muscle and second only to the greater pectoral muscle.

In the elbow joint, two-thirds of the straightening work is done by short heads. Together with the flexors, the triceps muscle of the shoulder stronglyfixes the elbow joint .

When the arm is lowered, the work of the muscle is replaced by the force of gravity. As a result, the strength of the more frequently anti-gravity flexors is more than a third greater than that of the triceps brachii. This is why the resting elbow is slightly bent.

The triceps muscle of the arm acts on the elbow joint only as an extensor and has no collateral function, unlike the biceps muscle of the arm which, in addition to flexing, also performs the inversion movement. Due to the fact that it attaches to the articular capsule of the elbow joint, the triceps also plays an important role in the mechanics of the joint. Because it pulls the bag and smoothes out the folds that could tuck into the joint if it was relaxed.

Triceps injuries

The triceps muscle of the arm is one of the most frequently trained muscles in armwrestling. Therefore, the most common injuries and injuries related to the triceps are related to its overload and they are:

  • triceps strain ;
  • tearing the triceps ;
  • breaking the triceps ;

The above injuries usually result from the lack of a proper warm-up and overestimating the capabilities of the three-headed arm.

Triceps exercises

The triceps arm training is most effective when you perform forearm and arm extensions in a way that involves all three heads of the triceps muscle. The best effect can be achieved by using exercises with additional resistance, for example in the form of a load - of course, adapted to your abilities. You can learn more about this in the article on triceps exercises:

Triceps muscle of the arm - innervation and vascularization

The innervation of the triceps muscle is the radial nerve that departs from thebrachial plexus .

They provide blood for triceps:

  • posterior artery surrounding the arm (departs from the axillary artery);
  • deep arm artery (departs from the brachial artery);
  • ulnar collateral arteries (departing from the brachial artery).

Triceps muscle of the arm (triceps) - abnormalities and variations

Contrary to its name, the triceps muscle of the arm can have four heads. The extra head can start in different places:

  • on the side edge of the shoulder blade;
  • on the cob;
  • on the shoulder joint bag;
  • on the humerus.

The initial tendon of the long head of the triceps often connects with the tendon of the latissimus. This band is a remnant of the muscle present in great apes.

Bibliography

Bochenek A., Reicher M., "Human Anatomy", volume I, PZWL Medical Publishing, Warsaw 2012.

Category:

Anatomy