JointA joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole. They are constructed to allow for different degrees and types of movement. Some joints, such as the knee, elbow, and shoulder, are self-lubricating, almost frictionless, and are able to withstand compression and maintain heavy loads while still executing smooth and precise movements.
ArthralgiaArthralgia (from Greek arthro-, joint + -algos, pain) literally means joint pain. Specifically, arthralgia is a symptom of injury, infection, illness (in particular arthritis), or an allergic reaction to medication. According to MeSH, the term "arthralgia" should only be used when the condition is non-inflammatory, and the term "arthritis" should be used when the condition is inflammatory. The causes of arthralgia are varied and range, from a joints perspective, from degenerative and destructive processes such as osteoarthritis and sports injuries to inflammation of tissues surrounding the joints, such as bursitis.