What is the aponeurosis?

The connections of muscles to bone are generally considered to be long tendons and collagens. However, muscles can also be attached by flat, sheet-like tendons called aponeurosis. In essence, the aponeurosis is the membranous expansion of a muscle or muscle group. Under a microscope, it looks similar to a tendon, but it has fewer nerves and blood vessels.

There are various aponeuroses in the body, but the best known aponeuroses are found on the abdomen, palms, and soles. In the abdomen, the external oblique, which is the largest and most superficial flat abdominal muscle, has its own aponeurosis. As the fibers of the external oblique run toward the midline, they become aponeurotic. The thinnest part of the external fascia called the linea alba can be found in the midline by drawing a vertical line across the navel. With pregnancy or abdominal surgery, the external oblique aponeurosis can be weakened, which is why abdominal exercises are recommended after these events.

The palmar aponeurosis can be found on the hand. It overlies the soft tissues and tendons of the flexor muscles. When there is a progressive increase in the fibrous tissue of this structure, a condition called Dupuytren's contracture or palmar fibromatosis occurs. The fibrous bands that connect it to the bases of the fingers become shorter and thicker. This leads to marked bending or bending of the digits, so that the digits cannot be straightened.

People who get Dupuytren's contracture are often in their 40s or older. The most commonly affected fingers are the ring finger and little finger, while the thumb and index finger are usually spared. Progression is usually slow and painless. If it causes significant handicap or disability, Dupuytren's contracture could be addressed through surgery. However, the procedure is not curative and is fraught with complications, such as nerve and artery injury and infection.

The plantar aponeurosis is located on the sole of the foot. The central part is very thick, but it tapers laterally and anteriorly. It is also called the plantar fascia, because the fasciae are connective tissues that are dense and regularly distributed. The main function of this structure is to support the arches of the foot and hold the structures of the foot together. As it progresses toward the digits, it divides into five bands that cover the digital tendons.

Inflammation of the plantar aponeurosis characterized by pain is called plantar fasciitis. It frequently occurs in athletes due to repetitive trauma to the soles. Foot deformities, obesity, and age-related atrophy of the foot fat pad may also be predisposing factors.

Non-surgical treatments for plantar fasciitis include rest, cold therapy, physical therapy, stretching, and motion-controlled running shoes. Pharmacotherapy includes administering anti-inflammatory drugs such as corticosteroids, aspirin, ibuprofen, and other nonsteroidal anti-inflammatory drugs (NSAIDs). Orthotics or foot supports may also be tried. Surgery is the last resort due to the risk of injury and infection of nerves or arteries.

Go up