Learn more. The hand is composed of many different bones, muscles, and ligaments that allow for a large amount of movement and dexterity. There are 3 major types of bones in the hand itself, including:. The 14 bones that are found in the fingers of each hand and also in the toes of each foot. The AC joint is a smaller joint associated with the shoulder. The acromium is part of the scapula shoulder blade and the clavicle also called the collarbone.
The AC joint is where the scapula and clavicle come together. There are three major ligaments, the acro-mioclavicular, coracoacromial, coracoclavicular.
This joint is involved with raising and lowering the arm and moving the arm forward and backward. An AC separation is a common injury of this joint which occurs from a fall or a direct blow to the shoulder. Many shoulder separations are treated without surgery, but some may require surgery to reconstruct the coracoacromial or coracoclavicular ligaments.
Osteoarthritis is also common and can be treated sometimes with surgery. The sternoclavicular joint is the junction of the sternum breastbone and clavicle collarbone. There is an articular disc of fibrocartilage within the joint.
The motion of this joint permits the clavicle to move up and down and front to back. There are no tendons that attach to this joint area. A posterior back SC joint dislocation can be a serious injury and puts vital structures at risk such as the heart, aorta, superior vena cava, esophagus, and trachea. Anterior front dislocations can also occur and are often somewhat less serious, but can cause pain and clicking.
It becomes stiff easily after injury and has very limited side to side motion. MP joints are important for both power grip and pinch activities and are where the fingers move with respect to the hand. Common problems at the MCP joint includes arthritis and collateral ligament injuries. Wrist Joints Radiocarpal Joint The radiocarpal joint consists of the radius, one of the forearm bones, and the first row of wrist bones consisting of the scaphoid, lunate, and triquetrum. Ulnocarpal Joint The ulnocarpal joint includes the ulna, one of the forearm bones, as well as the lunate and triquetrum.
Distal radioulnar The distal radioulnar joint is at the wrist where the two forearm bones meet. Scaphotrapeziotrapezoid Joint STT The scaphotrapeziotrapezoid joint is at the base of the thumb in the wrist.
Elbow Joints Ulnohumeral joint The ulnohumeral joint is formed by the coming together of the humerus and ulna bones. Radiocapitellar The radiocapitellar joint is formed by the coming together of the radius and the capitellum, which is a part of the humerus.
Proximal radioulnar Pronation and supination occur at this joint, which is the act of rotating your palms to face upward and downward. Ligaments bind your foot bones together along with the tendons of your foot muscles. This helps to hold your foot bones firmly in the arched position, but still allows some give and springiness. Home Explore the BBC. This page has been archived and is no longer updated. Find out more about page archiving. Prehistoric Life. The mind The body. Nervous system.
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. Ellipsoidal joints. Ellipsoidal joints, such as the wrist joint, allow all types of movement except pivotal movements.
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