Bones in the Wrist
By Demetria Velazquez
Bones in the Wrist
The wrist is made up of 8 bones connected to the two long bones in the lower arm. The two bones in the lower are called the Radius and the Ulna. The Radius is a long and thicker bone that is located on the thumb side of the wrist. The Ulna is a long but thinner bone that is located on the pinky side of the wrist. These 2 bones connect to the bones in the hand, known as the carpal bones, to make up the wrist.
Bones in the wrist:
The wrist is made up of 8 bones, the carpal bones. These bones connect to the 2 long bones in the lower arm, Radius, and Ulna. Together, the bones and joints allow the hand to move in several directions.
Carpal bones in the wrist:
The 8 carpal bones are usually referenced starting on the thumb, radius-side, to the pinky, ulna-side. A popular mnemonic to remember the carpal bones in order from thumb-side to pinky-side is “Sally Left The Party To Take Cathy Home.”
- Scaphoid – bone located under the thumb
- Lunate – next to the scaphoid bone
- Triquetrum – pyramid-shaped bone under the hamate bone
- Pisiform – small, round bone that sits on the triquetrum
- Trapezium – located above the scaphoid bone under the thumb
- Trapezoid – shaped like a wedge next to the trapezium bone
- Capitate – bone in the middle of the wrist
- Hamate – located on the pinky finger side of the wrist
How the carpal bones make up the wrist:
The long bone on the thumb side, the radius, connects with the first three carpal bones. These bones are the scaphoid, lunate, and triquetrum bones. The radius to these 3 carpal bones makes up the radiocarpal joint on the thumb side of the wrist.
The long bone on the pinky side, the ulna, connects with the lunate and the triquetrum carpal bones. The ulna’s connection to these 2 carpal bones makes up the ulnocarpal joint on the pinky side of the wrist.
The name of the bones in your fingers are metacarpals. These bones connect to the four carpal bones to make up the carpometacarpal joints. These four carpal bones are trapezium, trapezoid, capitate, and hamate.
The Function of the Bones in the Wrist:
The bones in the wrist make the wrist more stable while also allowing a wide range of movement. The bones connecting to the radius and ulna, creating the above-indicated joints, allow you to move your hand up and down to wave, twist to open a door, and move your hand side-to-side to move a mouse on your computer.
Common Wrist Injuries
The bones in the wrist are further connected by ligaments, muscles, and tendons, which can be injured in various ways since the wrist can move in many directions.
- Sprain – stretching the ligaments that connect the bones in the wrist by carrying something heavy or catching yourself from a fall.
- Fracture – breaking one of the carpal bones in the wrist or the part of the radius or ulna that connects to the carpal bones.
- A distal radius fracture is the most common kind of fracture in the wrist.
- A scaphoid fracture in the most commonly fractured carpal bone. It is usually fractured in a fall with the arm and hand outstretched to catch oneself.
- Stress injuries – These types of injuries occur over time due to the repetitive nature of certain movements with your hands and wrists. Typing, writing, or playing tennis can cause these types of injuries to the bones in the wrist, which may lead to carpal tunnel, ganglion cysts, or tendinitis.
JOI Physicians are currently offering ASAP fracture and injury care. Further, this is a new option for patients who would like to avoid the emergency room if they have suffered a fracture or soft tissue injury. To learn more about this service, read this article about fracture and injury care. Make an appointment by calling (904)JOI-2000.
Written by: Demetria Velazquez