This is also called the musculoskeletal system. It is responsible for body movements, provides a structural framework to protect internal organs and acts as a reservoir for the storage of minerals like calcium and phosphate. The system is composed of bones, joints and muscles.
These provide the rigid framework on which the muscles and other structures are attached. There are various types, sizes and shapes of bones in the body to suit their functions. Some bones contain marrow for red cell production. The tiny bones in the ear aid in conduction of sound waves for hearing.
Bones are linked by joints. There are 3 main subtypes: fibrous, fibrocartilaginous and synovial joints.
Fibrous and fibrocartilaginous joints are found linking bones in areas where there is little requirement for movement. An example is in the backbone.
Synovial joints are complex structures with several types of cells, and are found where a wide range of movement is required. Examples include the shoulder, hip, elbow and knee joints. Cartilages cover the end of bones in synovial joints and synovial fluid fills the joint space to reduce friction during movement.
Skeletal muscles are responsible for body movement and respiration. They are composed of bundles of cells embedded in fine connective tissue containing nerves and blood vessels. These connective tissues merge with a thicker layer of connective tissue on the surface of the muscle to form the tendon. Muscles are attached to bones by these tendons.
Symptoms of Musculoskeletal Diseases
It is quite easy to notice when there is a problem with this system as loss of function usually accompanies musculoskeletal diseases. The symptoms include:
- Pain in a single joint
- Multiple joint pain
- Bone pain without fracture
- Pain around the joint
- Low back pain
- Neck pain
- Muscle pain and weakness
Pain in a single joint
Short lasting pain is most commonly due to crystals (gout) or infection (sepsis). Other causes include arthritis in one joint, trauma (especially if there is bleeding into the joint), bleeding into the joint from clotting abnormality, and foreign body reaction (e.g. plant thorn).
Pain lasting for more than 6 weeks may be due to foreign body (e.g. plant thorn), infection (e.g. tuberculosis), arthritis in one joint, and cancer of the joint lining.
Multiple joint pain
This may be due to generalised arthritis, growth hormone excess (acromegaly) and gout. Many viral infections can cause multiple joint pain and inflammation lasting for a short while.
Fractures present with bone pain at a particular site usually occurring after trauma, which is worsened by movement of the affected part.
Fractures resulting from relatively minor trauma are typical of osteoporosis (reduced bone density). Fractures can also occur unexpectedly in bone that is structurally abnormal. Structural abnormality may be due to calcium and vitamin D deficiency and spread of cancer to bones.
High–energy fractures result from major trauma and can affect normal bones. Fractures can also in healthy individuals such as athletes and military recruits who are exposed to repetitive trauma.
Bone pain without fracture
In the absence of fracture, bone pain is characteristically localised to the affected bone, rather than the joint; present at rest and worse at night, and not reproduced by joint movement. It may be caused by cancer of the bone or one that has spread to the bone from other sites, chronic infection or bone death.
Pain around the joint
This may affect a single area or multiple areas. Single area affectation such as shoulder or hip pain usually results from an over-usage strain or injury to any structure around the joint such as muscles, ligaments and tendons. Predisposing factors include increasing age, obesity and occupational or recreational usage.
Pain affecting multiple regions may be due to widespread muscle pain, excessive joint movement, adrenal and thyroid under-activity, Parkinson’s disease and some drugs.
Low back pain and neck pain
Most times, the exact cause of a pain in the lower back is not clearly known. Specific causes may however include inflammation of the joints of the backbone, compression of the nerves arising from the spinal cord, displacement of the disc between the backbone, and fracture of the backbone.
Neck pain may be caused by bad posture, inflammation, abnormal bone structure, bone tumours, muscle pain or referred pain from other sites.
Muscle pain and weakness
Muscle pain may be due to inflammation, thyroid or adrenal disease, low potassium in the blood, drugs, alcohol and infections from viruses and bacteria.