Construction of the joints
A joint consists of two or more bones that move against each other. In most joints, the ends of those bones are covered with cartilage. The cartilage provides protection for your bones and helps with the sliding movement. This is necessary because there is usually a lot of force on the bones in the joints. Around the joint you have a haircut, also called joint haircut. The joint cavity is located within this style. The joint cavity is formed by the joint capsule that surrounds the joint. This contains the so-called synovium. This is a syrupy liquid that ensures that the movements of your joints go smoothly.
In some joints there are other structures to ensure that the bones are protected and that the movements go smoothly. Examples are the meniscus in your knee, the discuses in your vertebrae and bursa, which you have for example in the shoulder and elbow.
It is important that the bones stay together in a joint. For this you have the ligaments, which are also called ligaments. These bands are made of very strong connective tissue, which means they can absorb a lot of forces. The ligaments are part of the joint capsule. In some cases, the bones are connected to connective tissue or even completely grown. That is the case in the joints of the skull.
Types of joints
There are a number of different types of joints:
- Hinge joint. You can compare such a joint with a normal hinge. A hinge joint can only move in one direction, such as in the elbow.
- Roll joint. In such a joint two bones roll over each other. An example of a roller joint is in the forearm. The spoke bone and the elbow can move around each other, allowing you to turn your hands.
- Ball joint. A ball joint consists of a ball and a bowl. Such a joint can move in many directions. Examples of ball joints are the shoulder and the hip.
Function of the joints
Joints ensure the mobility of the skeleton. Together with the muscles, joints ensure that we can move. Some joints only cause movement in one direction, but there are also joints that can move in several directions.
Operation of the joints
Most joints are mobile, also called synovial joints. To make movement possible, joints must work together with the muscles. Muscles are connected to the bones via tendons. If you tighten a muscle, the muscle becomes shorter. A muscle that adheres above and below the joint can cause the joint to be bent or stretched by tensioning or relaxing.
Problems with the joints
Problems that may arise in your joints include:
- Joint complaints.
- Osteoarthritis (joint wear).