Anatomy & Organs

Musculoskeletal system – structure, function & diseases

Musculoskeletal system

The musculoskeletal system includes a complex organ system of the body that not only enables the physical shape to be secured, but also serves to maintain posture and, last but not least, physical movement and locomotion. Together with the supporting apparatus, the passive musculoskeletal system, the body’s active musculoskeletal system forms a functional unit.

What is the musculoskeletal system?

When it comes to the musculoskeletal system, a distinction is primarily made between the passive and active musculoskeletal system, although the differentiation is not always made clearly, since muscles are also flexible due to their contraction.

The active musculoskeletal system, which primarily serves the movement (mobility) of the body, includes the skeletal muscles , whereby auxiliary and appendage organs also belong to the active musculoskeletal system: tendons , fascia , tendon sheaths and bursa belong to these so-called auxiliary organs of the active musculoskeletal system. The passive musculoskeletal system includes the skeleton as a supporting apparatus and the associated parts such as bones , joints , cartilage , ligaments and intervertebral discs .

Anatomy & Structure

The passive musculoskeletal system primarily enables the body to be shaped and supported. The musculoskeletal system consists of a fixed part and movable organs. The bony skeleton enables the necessary shaping and support of the body. The movement, in turn, is made possible by the skeletal muscles, which are part of the active musculoskeletal system.The tendons, which are firmly attached to the bone on the one hand and anchored in the respective muscle on the other hand, act as force transmitters. If necessary, the direction of pull of some tendons is redirected by ligaments. These also have the task of securing and strengthening joints that are under stress.

Function & Tasks

The skeleton as the most important part of the musculoskeletal system is made up of differently shaped bones. These include flat bones or tubular bones as well as other types of bone that are partially fused together. They not only maintain the shape and mobility of the body, but also protect the internal organs and thus enable them to function properly (example: the skeleton of the chest , without which breathing could not take place). Joints connect the bones to each other and thus determine the range and direction of movement of the bones.

The skeletal muscles, which are part of the active musculoskeletal system, serve as a link between two different bones and are connected to the bone via at least one joint using tendons. When a muscle shortens, the two bones in the joint are pulled towards each other. Muscles themselves can only contract (pull together), stretching them back to the starting position requires one or more muscles, which in turn attach to the other side of the joint and exercise the opposite direction of movement; this type of muscle is called the antagonist in medicine. But there are also muscles that are divided into two or more parts and attach at different points, even at different ends of the bones. Prominent examples of this are biceps , tricepsor quadriceps .

In order to translate the force that muscles develop into bone movement, the two functional assemblies must be connected. This is ensured by the tendons, which consist of firm yet collagenous and flexible connective tissue . The fibers of the tendons are arranged parallel to the direction of tension. The tendons in the muscle are directly attached to the muscle fibers and originate at the protrusions or roughened areas of the bone. In addition to tendons and tendon plates as well as tendon sheaths, the ligaments that are part of the musculoskeletal system are also important. They usually consist of collagen fibers, sometimes also of elastic connective tissue.

Their task is to support the joints or to prevent the mobility of the bones against each other and thus prevent overstretching of tendons or muscles. The ligaments are found either directly in the joints or around them. The bursae are also part of the musculoskeletal system: like a protective cushion, they can be found in those places that can pose a potential danger to tendons, in order to protect them from chafing and damage. Bursae are smaller pads of skin placed under the tendon on the vulnerable areas and filled with fluid. This allows the tendon pressure to be evenly distributed.


If there is pain in the lower back, the knees can no longer be fully loaded or the joints are affected, then one generally speaks of diseases of the musculoskeletal system. These belong to one of the most common complaints and describe all diseases that affect bones, joints and muscles. The human musculoskeletal system forms the framework of the body. Its pillars enable support, balance, movement and, in the truest sense, “progress”. And so diseases of the musculoskeletal system are perceived as a major limitation, as they very often have a sensitive effect on mobility, freedom of movement and the ability to cope with stress in everyday life.The body is not only held together by the musculoskeletal system, but also supported and carried throughout our lives. The passive parts of the musculoskeletal system include bones, cartilage and joints; it only acquires real activity through the skeletal muscles. Osteoporosis , which often affects women after menopause , is one of the most common diseases of the musculoskeletal system. Commonly referred to as bone loss, this is a breakdown (necrosis) of the bone substance, which can also only affect individual parts of the musculoskeletal system (e.g. pelvis or thighs). As the disease progresses, the risk of spontaneous bone fractures is inevitably increased and healing after such fractures is also more difficult.

A calcium-rich diet and adequate intake and formation of vitamin D are of outstanding importance here in order to support bone remineralization. As with osteoporosis, another disease of the musculoskeletal system, soft tissue rheumatism (fibromyalgia), mainly affects women. Hardening and pain in the muscles are just a few of the symptoms of this mostly chronic disease. Another common disease of the musculoskeletal system is osteoarthritisthat affects the joints. In the form of pain and stiffness in the affected joints, arthrosis is often caused by incorrect loading and overuse of the affected joints. While arthrosis is a degenerative process and joint wear and tear, inflammation in the joints – also known as arthritis – is accompanied by swelling, redness, overheating and joint effusion.

In addition to purulent arthritis, which causes severe damage to the affected joint, there are also some sub-forms, the most common of which is rheumatoid arthritis , also known as chronic polyarthritis. This condition can appear at a young age. The diseases of the musculoskeletal system include a variety of other conditions. Since there are possible points of contact with all areas of the body, not only orthopedists are involved in diagnostics and therapy, but also oncologists , neurologists , general practitioners, sports and pain medicine specialists, as well as osteopaths , physiotherapists or masseurs.

Typical & common bone diseases

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.