Brilio.net - Joints are important components in the human body that allow bone movement and provide flexibility. Based on the direction of movement, joints are divided into several types, each of which has a specific function in helping body movement. This article will explain the types of joints based on the direction of movement along with examples, so that it can help understand how each joint works and its role.
Joints are the junctions between two bones that allow movement. Their function is to provide flexibility and mobility to the body's skeleton, allowing humans to perform various physical activities such as walking, running, and lifting objects. Joints are divided into several categories based on the direction of their movement, each based on the type of movement they can produce.
Types of joints based on the direction of movement
There are several types of joints based on their direction of movement, which can be grouped based on how much and how they allow movement. Here is a further explanation of each type of joint.
1. Hinge joint
Hinge joints are joints that only allow movement in one direction, namely forward and backward. The movement that occurs in this joint is similar to the way a door hinge works. The most common examples of hinge joints are the joints in the elbow and knee. In the elbow, this joint allows the arm to bend and straighten. Joints based on the direction of movement in this category only allow flexion (bending) and extension (straightening).
Hinge joints play an important role in everyday activities such as bending the arm to pick up an object or straightening the leg when walking. Limited flexibility in one direction makes these joints stable and strong, but also limits the range of motion.
2. Saddle joint
Saddle joints are a type of joint that allows movement in two directions, namely forward and backward and sideways. This joint has a structure that resembles a saddle, with bones that can move in various directions, but are still limited to two main axes. An example of a joint based on the direction of movement that falls into this category is the joint found in the thumb.
The saddle joint in the thumb allows humans to perform oppositional movements, which are pinching movements that are very important in activities such as grasping objects or holding writing instruments. The uniqueness of this joint provides more flexibility than a hinge joint, but still limits full rotational movements.
3. Ball-and-socket joint
Ball and socket joints are joints that allow movement in almost all directions. In these joints, the end of a bone is round (a ball) and fits into a cup-shaped cavity of another bone. The most common examples of joints based on the direction of movement are the shoulder and hip joints. These joints allow flexion, extension, abduction (movement away from the body), adduction (movement toward the body), rotation, and circular motion (circumduction).
Ball and socket joints provide the greatest flexibility of any joint type, allowing humans to perform a wide range of movements such as rotating the arms and moving the legs in various directions. This flexibility is important in activities that involve dynamic movements, such as sports and physical work.
4. Pivot joint
A pivot joint is a joint that allows rotational movement, where one bone rotates on another bone. An example of a joint based on the direction of movement that falls into this category is the joint between the upper neck bone (atlas) and the skull bone. The movement produced by a pivot joint is turning the head to the right and left.
This type of joint is also found in the elbow joint, precisely between the radius (lower arm bone) and the ulna. The rotational movement that allows the palm of the hand to face up or down is the result of the movement of the pivot joint. Although the resulting movement is limited to rotation, this joint is very important in everyday activities.
5. Saddle joint (Condyloid joint)
Saddle joints, also known as condyloid joints, are joints that allow movement in two directions, namely forward-backward and sideways. An example of a joint based on the direction of movement is the joint in the wrist that connects the radius bone to the carpal bones. This joint allows flexion, extension, abduction, and adduction, although it is not as flexible as a ball and socket joint.
Condyloid joints are also found in the jaw joint, which allows opening, closing, and lateral movements of the jaw. The flexibility provided by this joint is quite large, especially in the wrist which is used in various activities such as typing or lifting objects.
6. Gliding joint
Gliding joints are joints that allow bones to slide past each other, with movement limited to one or more directions. The movements produced by these joints tend to be small, but are important in providing stability to the bone structure. Examples of joints based on the direction of movement are the joints in the spine and the joints between the carpal bones in the wrist.
Although the resulting movements are not very wide, gliding joints are very important in maintaining flexibility and mobility of the spine, especially when bending, twisting, or straightening the back.
Joints play a crucial role in enabling movement and mobility of the body. Based on the direction of movement, there are several types of joints that have specific characteristics and functions, ranging from hinge joints that only allow movement in one direction, to ball-and-socket joints that allow movement in all directions. The types of joints based on the direction of movement include hinge joints, ball-and-socket joints, saddle joints, pivot joints, condyloid joints, and gliding joints.
Understanding the types of joints and how they work helps you understand how your body moves and functions in everyday activities. Each type of joint has its own function and works together to allow your body to move with the flexibility needed for various activities.