What are joints?
Anatomically speaking, a joint is a movable connection between at least two bones. A distinction is made between true joints (in technical terms, diarthroses) and false joints (synarthroses). A true joint is one in which there is a gap between the ends of the bones - the so-called joint space -, when the joint surfaces are covered by articular cartilage and there is a joint capsule around the joint. False joints are cartilaginous bone connections or connective tissue bone connections. The cartilaginous bone connections that are best known to laypeople are found in the costal cartilage, for example, but also in the intervertebral discs (fibrocartilage).
What joints are there?
There are different types of joints. The most common are ball joints, ellipsoid or egg joints, saddle joints and cylinder joints. As the name suggests, ball joints can be recognized by the fact that a ball-shaped joint head fits into the bowl-shaped counterpart of the second bone. They are also referred to as triaxial joints, like shoulder joints or hip joints.
The ellipsoid joint is a biaxial joint. Here the ball is elliptically shaped, like the wrist between the radius and the carpal bones. Another biaxial joint is the saddle joint, which is actually a bit like a saddle and can move around two spatial axes (e.g. between the carpal bones and the metacarpal bones).
Finally, the cylinder joint is very reminiscent of a hinge, which is why it is also called a hinge joint (e.g. elbow joint). Another cylinder joint is the tenon joint, which works a bit like a tenon hinge on a door - we find this in humans between the radius and ulna.
Why do joints crack?
Many people know it and find it a bit scary: cracking joints. The reason for this is only half explained. It could be that the surfaces of the ankles are not even, and if these bumps rub against each other, it could crack. But it could also be small gas bubbles in the synovial fluid that are responsible for the noise.
How do joints stay healthy?
Bones and joints have a hard life and have to put up with everything that people want them to do. Walking, running, running, sitting, lying down. The knee and hip joints are the ones most stressed, but so are the false joints, the intervertebral discs. Depending on the stress, joints or the articular cartilage can wear out, which limits mobility or range of motion and causes pain, as in the case of arthrosis or osteochondrosis . Of course, arthrosis or a slipped disc can never be completely ruled out, but there is a lot that can be done to ensure that the joints function as long as possible and as pain-free as possible.
It is known that a change in diet can make a difference, especially in the case of arthritis. It is also not advisable to subject yourself to extreme physical exertion, such as running a marathon, once the joints have become noticeably worn. But in general, exercise is better than immobility, because exercise produces synovial fluid, which is of course good for the hinges - the joints! Exercise can be gymnastics, moderate walking, cycling or swimming. And you can even exercise while sitting, provided you have a chair or office chair that allows you to exercise while sitting, such as an ergonomic chair from Aeris.
Joints can remain healthy and naturally pain-free for a very long time if they are treated carefully and regular, healthy, natural exercise is provided.
