Tendon pain

Tendon pain is the most common complaint that people usually seek medical attention for. Patients report this symptom almost as often as pressure changes.

A tendon is a formation that is a connective tissue, the end structure of striated muscles, with the help of which they are attached to the bones of the skeleton.

The tendon includes compact parallel bundles of collagen fibers. Between them are arranged in rows of fibrocytes (tendocytes). Often, collagen type I takes part in the formation of tendons, in addition, collagen fibers of types III and V can be found. Collagen bundles are held together by proteoglycans. Blood vessels are parallel to the collagen fibers, which have transverse anastomoses. Due to their structure, tendons have high strength and low extensibility.

The shape of tendons varies – both cylindrical (often in long muscles) and flat, lamellar (aponeuroses of broad muscles).

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Diseases that cause pain in the tendons

Pain in the tendons can be a consequence of damage to the tendon apparatus, which occurs in the form of diseases such as tendinitis, tendinosis and tenosynovitis.

There are 3 degrees of tendinitis development:

1. acute inflammation;
2. when inflammation is advanced, coarse connective tissue begins to grow at an accelerated rate;
3. the transition of the inflammatory process into a chronic form and destructive changes in the tendon can provoke its rupture.

Most often, this disease affects the tendons located in the shoulder girdle and upper limb (especially the tendon in the biceps brachii). Among the factors that can lead to this type of injury are monotonous movements, prolonged physical training with insufficient rest breaks, defects in sports equipment, the age of the athlete and incorrectly chosen technique.

Tendinosis is a non-inflammatory degeneration and atrophy of the fibers inside the tendon, which is most often associated with chronic tendinitis. It can cause a partial or complete rupture of the tendon, which will be accompanied by pain in the tendons.

Tenosynovitis is an inflammatory process that occurs in the paratendon (the outer sheath of certain tendons, lined with synovial membrane). For example, the extensor tendon of the thumb may be affected if a person suffers from de Curvain's tenosynovitis.

Tendinitis is an irritation or inflammation of a tendon, the thick tissue that connects muscle to bone. It is often caused by repeated physical activity on the affected area, as well as a serious injury. There are activities, such as sports and others, that can increase your risk of developing this condition. So, if you do gardening, raking, carpentry, shoveling, painting, scraping (using a scraper or a stiff brush), tennis, golfing, skiing, throwing, you are at risk of developing tendinitis.

If you have poor posture at work and at home, or if you do not stretch well enough before doing sports exercises, this also increases the risk of tendonitis. Other risk factors include:

• deviations in the structure and arrangement of bones (for example, different leg lengths or arthritis of the joint), which increase the load on soft tissues;
• other ailments, for example, arthritis (rheumatoid, psoriatic, thyroid), gout, as well as a specific reaction of the body to medications;
• infection.

Tendinitis can affect anyone, but it is most often seen in older people. Over time, tendons become weaker, more susceptible to stress, lose elasticity, and become more vulnerable.

Tendinitis can affect almost any part of the body where a tendon connects muscle and bone. Common sites include the Achilles tendon, knee, hip, shoulder, elbow, and base of the big toe.

The symptom of tendinitis is, first of all, pain in the tendons and adjacent areas. The pain syndrome can increase gradually, or it can appear spontaneously and be acute, especially if there are calcium deposits. In addition, symptoms include decreased shoulder mobility, the so-called "adhesive capsulitis" or Duplay syndrome.

One of the causes of tendon pain is a rupture of a healthy tendon. A rupture occurs when the load on it exceeds all possible limits and the mechanical endurance level of the tissues. If the tendon has been subjected to significant overloads for a long time, the process of degeneration and dystrophy begins to develop in it. The degeneration of tendon tissues may depend on impaired blood supply, metabolic disorders, chronic inflammatory processes and hypothermia.

There are two types of tendon rupture: incomplete and complete. It occurs along the length of the tendon or at the point where it attaches to the bone. However, a bone fragment does not rupture. If there have been no degenerative changes in the tendon, then its rupture from the point of attachment occurs very rarely. This type of injury can affect the tendons of the supraspinatus muscle at the point where they attach to the greater tubercle of the humerus, the tendon of the biceps muscle at the point where it attaches to the acromial process of the scapula, the tendon of the biceps muscle that attaches to the tuberosity on the radius and the coracoid process of the scapula (observed extremely rarely). In addition, the tendon of the triceps brachii can tear off from the olecranon process. A slightly more common case is a rupture of the tendon stretch (aponeurosis) of the extensor of the finger, provided that there is a dislocation in the interphalangeal joint.

In the lower extremities, the most common injuries are ruptures of the quadriceps tendon, which attaches to the top of the patella, and also cases where the Achilles tendon is torn from the calcaneal tuberosity.

Ruptures of other tendons are almost never encountered. If a tendon ruptures, the victim experiences pain in the tendons at the site of their rupture, which occurs spontaneously, with strong physical exertion, throws, jumps. Movement in the affected muscle is impaired. Edema and swelling appear. If a tendon is completely torn, its end, which is connected to the muscle, goes along the length of the muscle, and the muscle itself becomes shorter and takes the form of a tubercle. Rupture of tendons along their entire length at a place that is remote from the attachment point on the upper limbs is rare, and is often incomplete.

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