Muscles play an important role in sport. However, the passive musculoskeletal system, which includes bones and joints, is at least as important. People rely on their joints for every movement. They are often exposed to high loads, especially during sport. The nutrients glucosamine and chondroitin are often mentioned in connection with them. Glucosamine and chondroitin are components of connective tissue and synovial fluid. Minerals such as calcium, magnesium and zinc are also frequently mentioned in connection with joint nutrition. Joints are the movable connections between the individual bones. Each consists of a joint head and a joint socket. The fact that our bones can move against each other is due to them. The type of movement and the amplitude of movement depend on the shape of the joint and the surrounding muscles, ligaments and capsules. Different types can be categorised according to the shape of the joint surfaces. The best-known forms are the ball, hinge and saddle joints as well as the swivel, ovoid and condylar joints. The shoulder joint, for example, is a ball-and-socket joint, while the knee joint is a condylar joint. Each is enclosed by a joint capsule. The ends of the bones that meet are covered by so-called articular cartilage. Cartilage consists of elastic cell mass whose task is to absorb and evenly distribute loads.