The structure of the joint, including the way in which the surfaces interact, the flexibility of surrounding tissues, and position of ligaments, muscles and tendons all play an essential role in determining the type of movement that occurs across the joint. Structural classification of Joints This classification is based on the differences in the type of material and mechanism by which the bone surfaces interact.
Sutures consist of two bones situated close together that unite by either interlocking or overlapping one another. Syndesmosis: A syndesmosis is a fibrous joint which consists of two bones which are united by a sheet of fibrous tissue.
An example of this type of joint is the interosseous membrane in the forearm, which links the ulna and the radius. Emphasis: Emphasis consists of a bone with processes (tooth) that slot into a socket, producing a joint which can't move.
Mobility of a joint of this type indicates an abnormality, for example a loose tooth in an adult. In cartilaginous joints the union between the bones occurs via cartilage.
These joints are good for shock absorption and provide structural strength. The cavity of the joint is lined by a membrane which is responsible for the production of the fluid.
Image courtesy of Dr Ivan Seen (Virtual Medical Vision) There are six major types of synovial joints according to this classification system.
Plane joints : These joints permit gliding and sliding movements owing to the fact that the articular surfaces of the bones are flat meaning they only allow movement to occur in a single plane (uni axial joints). Image courtesy of Dr Ivan Seen (Virtual Medical Vision) Ball and socket joints : Ball and socket joints consist of spherical head articulating with a dome shaped cup.
Due to their structure these types of joints allow movements in multiple planes and are called multiaxial joints. WB Saunders 2002 Moore KL & Valley AF.
The other bone’s end is convex (turned outward), and looks like a rider in a saddle. These highly flexible joints are found in various places in the body, including the thumb, shoulder, and inner ear.
Unlike hinge joints, such as those between the bones in your fingers, saddle joints have a much greater range of motion than a simple backward-and-forward movement. When you bend your elbow, you decrease the angle between your upper arm and your forearm.
For example, spreading your fingers wide moves them away from the midline down the center of your hand. This is also a fairly common site for osteoarthritis, which can cause pain, weakness, and stiffness in your thumb and inner wrist.
This joint is where your clavicle (collarbone) meets your aquarium, which is the upper part of your sternum (breastbone). It allows you to raise your arm over your head, among other movements, and also supports your shoulder.
However, high-impact collisions, falls, or car accidents can all damage your sternoclavicular joint. This joint is located in your inner ear, where it connects two small bones called the mallets and Indus.
The incudomalleolar joint’s main function is to help transfer vibrations in your ear, which are perceived as sounds by your brain. However, the ones you do have been crucial to many daily activities, from listening to music to grasping things in your hand.
It is one of the five types of synovial joints in the human skeletal system. The bone resting on the saddle moves in an oval shape quite similar to a condyloid joint.
The types of movement a saddle joint allows are flexion, extension, adduction and abduction. All types of gripping motion are provided by saddle joint such as using a pen, grasping your mobile phone and steering the wheel of your car.
As each possesses both concave and convex surfaces that curve around each other, it is said that the joint achieves articulation by reciprocal reception. The movements allowed by the CMC joint include flexion and extension; adduction and abduction; circumduction, a circling motion, and opposition, or the touching of the thumb to the tips of the other four fingers.