The hand generally consists of the wrist, fingers, and palm. The wrist connects the hand to the bones of the forearm. It is not a large joint, but rather several small joints that allow flexibility of movement in many directions. In this article, we will shed light on the composition and movement of the wrist, and the most common injuries that it may suffer.

What is the wrist?

The wrist, also known as the carpus, is connected to the radius and ulna (the two forearm bones), and is made up of a group of small bones, joints, cartilage, and ligaments that allow it to move in different directions.

wrist components

It consists of the bones and joints of the wrist, some cartilage and ligaments, and here are the details:

carpal bones

The carpal bones are a group consisting of eight small bones of irregular shape, but they tend to be square, oval, or triangular, as the sources indicate. This group of bones gives the hand its flexibility and strength, as the wrist and hand will not function in the same way as it is customary if that joint is composed of one bone. large or two bones, and the following is an overview of these bones:

• scaphoid bone: It is a long, canoe-like bone located under the thumb.
• lunate bone: It is a crescent-shaped bone located lateral to the scaphoid bone.
• trapezium: It is a square-shaped bone with rounded ends located above the navicular bone and below the thumb.
• trapezoid bone: It is a wedge-shaped bone located next to the quadrate bone.
• capitate bone: It is an oval or vertical bone located in the middle of the wrist.
• canine bone hamate: It is also wedge-shaped and is located under the little finger.
• triquetrum: It is a pyramid-like bone located under the canine bone.
• Pisiform bone: It is a small pea-shaped bone located on top of the trigeminal bone.

wrist joints

The wrist consists of three main joints, which makes it more stable, and gives the hands a wide range of motion for more movements and postures, as the wrist joints allow moving the wrist up and down, and these joints allow the bending and rotation of the hands, and the following are these joints:

• Radiocarpal joint: This joint is found at the meeting point of the radial bone – the broader bone in the two forearm bones – with some of the carpal bones, namely the scaphoid, lunate and triangular bones, and is mainly located on the side towards the thumb.
• Ulnocarpal joint: This joint is located between the ulna – the smaller bone of the forearm – and between the crescent and triangular bones, and is located towards the pinky finger.
• Distal radioulnar joint: This joint is considered one of the joints of the wrist, but it does not include any of the carpal bones, and it connects the ulna and the radius.

Cartilage and ligaments

A disc of fibrous cartilage, located between the radius and ulna, separates the radioulnar joint from the rest of the wrist. There is the joint capsule, which contains the synovial membrane, which secretes synovial fluid to lubricate the joints.

The wrist contains the radiocarpal ligaments that hold the hand with the forearm in circular motions, while the intercarpal ligaments strengthen the bones.

wrist movement

The wrist joint moves in two axes, which allows it to perform several movements, namely flexion, extension, adduction, and abduction. The forearm muscle controls all of these movements.

wrist injuries

There are many injuries that the wrist may suffer, including the following:

• Carpal tunnel syndrome, which is pressure on the nerves in the wrist.
• Carpal bone fractures.
• Arthritis.
• Tendon infections.
• Sprains and strains that may affect ligaments, muscles and tendons.
• gout.