Anatomy of the joints: basics
To better understand, prevent or treat a musculoskeletal disorder, a few basics are useful. |
As the name suggests, musculoskeletal disorders concern the muscles and os, but also the various fabrics which connect them and ensure the flexibility and the solidity of the joints. We describe here the elements that make up the movable joints, that is to say the large joints that allow extended movements (knee, ankle, elbow, shoulder, hip, etc.), and not those that are fixed (for example). example, the sacrum) or semi-movable (for example, the vertebrae).
- Articular cartilage : a type of pearly, smooth, non-vascularized connective tissue that covers the bone ends of all mobile joints.
- The joint capsule : fibrous and elastic envelope which surrounds and delimits the mobile joints. Joint capsules help, along with ligaments, to maintain joint structures in contact and ensure stability.
- La membrane synoviale : membrane that lines the internal face of the capsule of mobile joints. The synovium forms folds and has the function of nourishing and lubricating the joint surfaces by producing a fluid similar to egg white, the synovial fluid.
- Joint ligaments : whitish fibrous connective tissue, very resistant and elastic. Ligaments unite bones together.
- The meniscus : small fibrocartilaginous structure having the shape of a crescent (from the Greek meniscus = crescent), located between two movable articular surfaces (the most important are found in the knee and the jaw). The meniscus forms a cushion in the joint, which allows for intimate contact between surfaces and the sliding of the joint, as well as cushioning of impacts.
- Serous bursae : small closed pockets made of connective tissue filled with synovial fluid. Bursas are attached to bones near joints and prevent direct contact between a bone and a tendon, for example. Thus, they facilitate the sliding of structures and allow movement to be damped.
- Tendons : strips of fibrous tissue that are poorly innervated (absence or near-absence of nerves) and little or no vascularity (absence of blood vessels), which connect the muscles to the bones that they must move.
Impact of repetitive movements
Although a one-time accident (exceptional effort to lift a heavy object, extreme twisting, etc.), degenerative disease (rheumatoid arthritis, osteoarthritis, etc.) or infection can cause damage to either of the these tissues, the most common cause of musculoskeletal disorders remains the practice of repetitive movements. These movements cause light trauma which, over time, damages the tissues that connect the muscles to the skeleton.
Tendonitis or inflammation of a tendon is a common manifestation of this type of problem. By repeating the same movements, part of the bone rubs on a tendon and causes more or less significant lesions.
Delaying proper treatment for tendonitis can lead to damage to the various tissues and organs that are nearby. Thus, tendonitis can be complicated:
- in bursite : inflammation of a bursa;
- en synovite : inflammation of a synovial membrane;
- in ténosynovite : inflammation of the tendon and synovial membrane;
- in capsulitis : damage to the entire joint capsule, which causes blockage of the joint.
It can also happen that the affected tissue (s) compress and irritate certain nerves, as is the case with carpal tunnel syndrome.
Ultimately, untreated tendonitis can lead to stretching, tearing or tearing of a tendon, muscle or ligament (sprain) and various potentially irreversible damage to the tissues around the joints. When tendonitis settles chronically, a phenomenon of bodily adaptation causing various structural imbalances can cause problems in other parts of the body.
Bibliography
Rouen University Hospital Center. [Accessed March 15, 2004]. http://www.chu-rouen.fr
Garnier, Delamare. Dictionary of medical terms, Éditions Maloine, France, 1998.
Mayo Foundation for Medical Education and Research (Ed). Diseases & Conditions – Overuse injuries associated with hobbies, MayoClinic.com. [Consulté le 29 janvier 2004]. http://www.mayoclinic.com
Office québécois de la langue française. The large terminological dictionary. [Accessed March 15, 2004]. http://w3.granddictionary.com
Research and writing: Pierre Lefrançois and Marie-Michèle Mantha, M.Sc. Medical review: Dre Susan Labrecque, MD, M.Sc. Kinanthropologie, sports medicine graduate Text created on: April 5th |