What is a Saddle Joint?

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In human body, a joint is where two bones get together. Joints, also called articulations, are where two bones come together. Apart from the hyoid bone, all the bones in the neck, form a joint. Joints are often classified by the amount of motion they permit. Some of the joints are fixed, like those in the skull, permit for no movement. Other joints, like those between the vertebrae of the spine, permit for some movement. Most of the joints are free moving synovial joints. Typically, the joints hold the bones together and permit for movement of the skeleton. A saddle joint is a joint (as the carpometacarpal joint of the thumb) with saddle-shaped articular surfaces that are convex in one direction and concave in another and that allow movements in all directions except axial rotation. Saddle joint is one of five types of synovial joints in the human skeletal system. Saddle joint is also known as a sellar joint as the adjacent surfaces at the ends of each bone are saddle-shaped, with the saddles meeting to form an X shape.

 

What are different types of joints in human hand?

The hand moves in various difficult ways and there is a multifaceted range of articulations that allow flexibility of movement. The joints of the hand and wrist include hinge, gliding, condyloid and saddle joints. A hinge joint permits the movement from side to side.

  • Fingers: The joints of the fingers (interphalangeal articulations), including the thumb, are hinge joints that permit for flexion and extension only.
  • Proximal Knuckles: The knuckles of the hand or metacarpal-phalangeal joints (MCP) are condyloid joints that permit flexion and extension and some degree of lateral movement away.
  • Wrist and palm: The internal joints of the wrist and palm (metacarpal-carpal and inter-carpal joints) are at times classified as gliding joints. The wrist and hand are considered as an uneven array of gliding, condyloid, and saddle joints letting for the intricate movements of the wrist, which comprise varying combinations of flexion, extension and lateral deviation.
  • Wrist and arm: The wrist has a condyloid joint between the radius, ulna and carpal bones allowing for smooth movement in flexion, extension, and lateral deviations.

 

What are the  various types of joints?

There are several types of joints in the body including fibrous, cartilaginous and synovial joints. The synovial joints are distinguished by the incidence of synovial fluid within a space that summarizes the articulating surfaces, the surfaces that touch each other of the joint. The synovial capsule reduces the friction between the bones allowing more smooth movement. The only synovial joint in the body with the dissimilarity of being considered a saddle joint is the carpometacarpal (CMC) joint in the thumb. It is situated approximately an inch (2.54 cm) above the wrist at the base of the thumb, sandwiched between the carpal bones and the metacarpal You do not have access to view this node. There are six different types of joints that provide movement within the You do not have access to view this node. They are as listed below:

  • Ball and Socket Joints: Ball and socket joints are created when the round head of one end of a bone fits into the hollow space of another bone. This bony ball fits into a cup-like socket. Ball-and-socket joints provide the greatest range of movement of all the freely movable joint types, as indicated by Inner Body. Also, a ball-and-socket joint permits for rotation of the long bones, providing the arms and legs with an extraordinary range of multifaceted movement. The shoulder joint, an instance of a ball and socket joint, is created by the humerus (the upper arm bone) fitting into the socket of the shoulder blade. This joint is the body's most mobile joint as it is very thin. Ball and Socket Joints allow the bone to move in a 360 degree angle. Conversely, the hip joint is a deep ball and socket joint that offers less movement but is very stable.
  • Saddle joint: In a saddle joint, the opposing surfaces are reciprocally concave-convex. A saddle joint is formed when the surfaces of both bones that are joined have a concave and a convex region. This permits the two bones to harmonize each other and offers a wide range of motion. According to Minnesota State University, the only saddle joint in the human body, is the thumb. The carpometacarpal joint at the base of the thumb is the only saddle joint in the human body. The lower bone of the joint is identical to a saddle. The upper bone fits into the "saddle". The saddle You do not have access to view this node lets the thumb to move toward the palm, enabling a person to clutch objects between his thumb and fingers.
  • Gliding You do not have access to view this node: A gliding joint happens when an even, or slightly even, surface of the two bones glide along each other. This type of joint allows for mobility in one direction without any circular motion. The carpal bones in the wrist and the tarsal bones in the ankle form gliding You do not have access to view this node.
  • Hinge joint: A hinge joint is the simplest type of joint. It supplies flexion and extension movement comparable to a hinge on a door. According to Inner Body, the knee joint, the largest joint in the body is a hinge joint and the elbow. The elbows, the knees, and the middle and end joints of the fingers are hinge joints. According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, hinge joints are susceptible to injury when lateral forces are applied to the You do not have access to view this node. A lot of knee injuries happen in this way.
  • Ellipsoidal or Condyloid joint: A condyloid or ellipsoidal joint is formed when the oval portion of a bone fits into an oval part of the other You do not have access to view this node. Condyloid joints permit for angular movement without rotation. One instance of a condyloid joint is where the metacarpals, the bones in the palm of the hand unite with the phalanges the bones of the fingers. The joint at the base of the index finger is an ellipsoidal You do not have access to view this node. Additional joints in the wrist, hands and feet are also ellipsoidal You do not have access to view this node.
  • Pivot joint: A pivot joint is formed when the round or conical part of a bone fits into a ring formed by a tendon at the other You do not have access to view this node. This permits for rotation at the You do not have access to view this node. The top of the spine that links to the neck is an instance of a pivot You do not have access to view this node. Pivot joint allows for turning motions without sideways dislocation or bending. The joint between the first and second cervical vertebrae (atlas-axis) is a pivot synovial joint and permits for most of the head's range of motion, in addition to maintaining the immovability of the head on the neck.
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