Joints are the areas where two or more bones meet. Most joints are mobile, allowing the bones to move. Joints consist of the following:
Cartilage. 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. A tissue called the synovial membrane lines the joint and seals it into a joint capsule. The synovial membrane secretes synovial fluid (a clear, sticky fluid) around the joint to lubricate it.
Ligaments. Strong ligaments (tough, elastic bands of connective tissue) surround the joint to give support and limit the joint’s movement. Ligaments connect bones together.
Tendons. Tendons (another type of tough connective tissue) on each side of a joint attach to muscles that control movement of the joint. Tendons connect muscles to bones.
Bursas. Fluid-filled sacs, called bursas, between bones, ligaments, or other adjacent structures help cushion the friction in a joint.
Synovial fluid. A clear, sticky fluid secreted by the synovial membrane.
Femur. This is the thighbone.
Tibia. This is the shin bone.
Patella. This is the kneecap.
Meniscus. This is a curved part of cartilage in the knees and other joints.
What are the different types of joints?
There are many types of joints, including joints that do not move in adults, such as the suture joints in the skull. Joints that do not move are called fixed. Other joints may move a little, such as the vertebrae. Examples of mobile joints include the following:
Ball-and-socket joints. Ball-and-socket joints, such as the shoulder and hip joints, allow backward, forward, sideways, and rotating movements.
Hinge joints. Hinge joints, such as in the fingers, knees, elbows, and toes, allow only bending and straightening movements.
Pivot joints. Pivot joints, such as the neck joints, allow limited rotating movements.
Ellipsoidal joints. Ellipsoidal joints, such as the wrist joint, allow all types of movement except pivotal movements.
The foot is one of the most complex parts of the body, consisting of 28 bones connected by numerous joints, muscles, tendons, and ligaments. The foot is susceptible too many types of injuries. Foot pain and problems can cause pain and inflammation, resulting in limited movement and mobility.
The elbow is a hinge joint between the lower end of the humerus bone in the upper arm and the upper end of the radius and ulnar bones in the lower arm. The arm is bent and rotated at the elbow by the biceps muscles in the upper arm. Ligaments located at the front, back, and sides of the elbow help stabilize the joint.
The hand is composed of many different bones, muscles, and ligaments that allow for a large amount of movement and dexterity here are the findings. There are 3 major types of bones in the hand itself, including:
Phalanges. The 14 bones that are found in the fingers of each hand and also in the toes of each foot. Each finger has 3 phalanges (the distal, middle, and proximal); the thumb only has 2.
Metacarpal bones. The 5 bones that compose the middle part of the hand.
Carpal bones. The 8 bones that create the wrist. The 2 rows of carpal bones are connected to 2 bones of the arm–the ulna bone and the radius bone.
Numerous muscles, ligaments, and sheaths can be found within the hand. The muscles are the structures that can contract, allowing movement of the bones in the hand. The ligaments are fibrous tissues that help bind together the joints in the hand. The sheaths are tubular structures that surround part of the fingers.
In addition, there are arteries, veins and nerves within the hand that provide blood flow and sensation to the hand and fingers.