The triceps is the so-called triceps brachii muscle, a muscle on the back of the upper arm. This muscle allows the forearm to be extended at the elbow joint. Both overuse and inactivity can cause discomfort with the triceps.
What is the triceps?
The German translation of the triceps brachii muscle, colloquially known as the triceps, is three-headed arm muscle. It belongs to the skeletal muscles and here to the group of upper arm muscles. The triceps is located along the entire length of the back of the upper arm. Parts of the triceps pass over two joints, the shoulder and the elbow. Because it is an arm extensor muscle, it is also called the three-headed arm extensor. The antagonists or opponents of the arm extensors are the arm flexors. The term “three-headed” is based on the fact that the triceps consists of three muscle heads. Skeletal muscles are always attached to the skeleton or fascia by tendons in at least two places, the origin and the attachment. When there are multiple origins, the muscle heads (Latin caput) are the different origin parts of a muscle. The triceps has three origin parts or three muscle heads that have a common attachment. The triceps is responsible for extension and rotation of the forearm in the elbow joint.
Anatomy and structure
The three muscle heads of the triceps are the long head (caput longum), the internal head (caput mediale), and the lateral head (caput laterale). The caput longum originates below the glenoid cavity on the scapula. It forms the lateral and medial axial gaps. The axial gaps are vascular and nerve pathways in the shoulder region. The medial and lateral caput originate on the posterior aspect of the humerus. The three muscle heads converge to form a common, tendinous attachment at the olecranon. The olecranon is the bony end of the ulna, one of the bones of the forearm. From here, fibers radiate to the joint capsule of the elbow and the forearm fascia. The tendon of the triceps, which forms the attachment, already begins in the middle of the muscle and is composed of two aponeuroses. Aponeuroses are connective tissue structures that serve as the tendinous attachment of muscles. Of the two aponeuroses of the triceps, one covers the lower part of the muscle on the outside, while the other extends deep into the muscle. Beneath the triceps tendon is a bursa that provides protection from excessive friction between the muscle and the bony olecranon.
Function and tasks
The triceps, along with the anconeus muscle, also known as the elbow or olecranon muscle, allows extension of the forearm at the elbow joint. The triceps also allow the arm to be pulled (adduction) toward the body through the shoulder joint, as well as leading the arm backward (retroversion). The caput mediale and the caput laterale are responsible for extension. Adduction and retroversion can occur through the caput longum. Another function of the triceps is the fixation of the elbow joint. This prevents the arms from buckling when supported and enables fine movements of the hand, such as when writing. The triceps is the antagonist of the biceps, which in medical terminology is called the musculus biceps brachii and also belongs to the upper arm muscles, but is an arm flexor. In addition, the triceps is an antagonist of the brachialis muscle, the upper arm muscle that lies behind the biceps on the outside of the upper arm. When the forearm is flexed, the biceps contracts and the triceps extends. When the forearm is extended, this works in the opposite way: the triceps contract and the biceps relax. In contrast to the heart muscles and the smooth muscles of the internal organs, the skeletal muscles, and thus also the triceps, can be moved voluntarily and consciously. In addition to movement, skeletal muscles also stabilize joints such as the shoulder. Muscles also generate some of the body’s heat.
Diseases and ailments
Various ailments of different causes can occur in the triceps area. Pulling or burning pain along the entire back of the arm or stabbing, pinpoint pain can occur, as can tension or restricted range of motion. Pain may radiate to the upper back and into the fingers. Mild swelling may also occur.This can be caused by external force, such as an accident, or by tendonitis. Inflammation of the triceps tendon is caused by the tendon rubbing against the bone when it is overloaded (for example, by heavy weights during weight training). Untreated tendonitis can develop into chronic inflammation. Underloading due to inactivity can cause discomfort, as can severe overloading. Activities in which the arms are held permanently in front of the body, such as working at a desk or during long car rides, can lead to constant stretching of the caput longum. On a permanent basis, this can lead to a passive overload of the triceps. During various sports, such as swimming, tennis or volleyball, active overloading of the triceps can occur. The so-called epicondylitis is the colloquial tennis elbow. Epicondylitis is not limited to tennis players, but the irritation of the tendon insertions of the triceps occurs particularly frequently here. During weight training or bodybuilding, various exercises such as bench presses or push-ups can put a lot of strain on the triceps. In rare cases where the triceps are subjected to extreme stress, muscle fiber tears can also occur, tearing the muscle tissue.
