Click Image to Enlarge. Joints are the areas where 2 or more bones meet. Most joints are mobile, allowing the bones to move. Joints consist of the following:. This is a type of tissue that covers the surface of a bone at a joint. Cartilage helps reduce the friction of movement within a joint. Synovial membrane. Your feet have the same three types of hinge joints as your hands.
Metatarsophalangeal joints connect the tarsals foot bones with the bottom phalanges, proximal interphalangeal joints connect the first and second phalanges and distal interphalangeal joints connect the second and third phalanges. Just like your thumb, the big toe only has two phalanges, so it doesn't have a distal interphalangeal joint. There are two large hinge joints in the knee: the tibiofemoral joint, which attaches your thigh femur to your lower leg tibia , and the patellofemoral joint, which attaches the femur to the patella kneecap.
The knee joint is the largest joint in the human body. It is technically a modified hinge joint since you can rotate your knee slightly. Your ankle joint is another type of hinge joint that is responsible for the motion of your feet at the ankles. The hinge joint location of the ankle is made up of three separate joints:. Like the knee joint, this hinge joint is rather unique in that it allows for some side-to-side movement. However, it functions primarily in an open-and-close movement. The temporomandibular joint in your jaw is a special joint with many different functions.
It can function as a hinge joint when it allows you to open and close your mouth. However, like an arthrodial sliding joint, it can also move from side to side. Jaw joints are typically classified as ginglymoarthrodial joints to describe both their hinge and sliding functions.
Can you imagine our bodies without hinge joints? We certainly wouldn't be able to walk, eat, type, write, swim, or perform any other type of movement that requires flexing or extending our limbs. On this page. Types of joints Freely moving joints Types of movement Structure of a joint Joint conditions Where to get help. Types of joints Joints are described by how much movement they allow. The three broad classes of joints include: Immovable — the two or more bones are in close contact, but no movement can occur — for example, the bones of the skull.
The joints of the skull are called sutures. Slightly movable — two or more bones are held together so tightly that only limited movement is permitted — for example, the vertebrae of the spine. Freely movable — most joints within the human body are this type. Motion is the purpose of the joint. Freely moving joints The six types of freely movable joint include: Ball and socket joint — the rounded head of one bone sits within the cup of another, such as the hip joint or shoulder joint.
Movement in all directions is allowed. Saddle joint — this permits movement back and forth and from side to side, but does not allow rotation, such as the joint at the base of the thumb. Hinge joint — the two bones open and close in one direction only along one plane like a door, such as the knee and elbow joints. Condyloid joint — this permits movement without rotation, such as in the jaw or finger joints. Pivot joint — one bone swivels around the ring formed by another bone, such as the joint between the first and second vertebrae in the neck.
Gliding joint — or plane joint. Smooth surfaces slip over one another, allowing limited movement, such as the wrist joints. Types of movement To achieve movement, the joint may: Slide one broad and flat surface across another — examples include the bones in the wrist or ankle. Increase or decrease the angle between the two bones — this only occurs in the long bones of the body arms and legs : for example, when the arm is bent or extended. Allow a circular movement — this is how ball and socket joints work: for example, the shoulder.
Allow rotation without displacing the bones: for example, the head as it turns from side to side swivels the cervical vertebrae on top of one another. Structure of a joint Joints are held together and supported by tough bands of connective tissue called ligaments.
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