Welcome to Hicksville Physical Therapy’s patient resource about Wrist problems.
The wrist has to be at the same time extremely mobile and extremely durable as to give our hands full range of motion and enough strength to allow heavy gripping. It is for this reason that the wrist joint is one of the most intricate joints in the body. Most people don’t realize that the wrist is made up of many different components that allow our hands to perform a variety of motions.
This guide will help you understand:
The wrist is made up of the following components:
A total of 15 bones connect the forearm to the hand in what we know as the wrist. In this area alone there are 8 small bones called:
joins with the proximal row further towards the fingers and is made up of the trapezium, trapezoid, capitate, hamate, and pisiform bones.
The proximal row connects the two bones of the forearm, the radius and the ulna, to the metacarpal bones of the hand. The metacarpal bones are the elongated bones that lie within the palm of the hand attaching the carpals to the phalanges, which are the bones in the fingers and thumb.
What we refer to as the wrist joint is actually made up of many small joints due to the fact that every carpal bone is joint with the bone it touches. It’s no surprise that the wrist is known to be one of the most complicated joints in the human body.
Articular cartilage is a white, shiny, and rubbery material that covers the ends of bones of any joint. In the larger weight-bearing joints, articular cartilage can be up to one-quarter of an inch thick while being thinner in joints such as the wrist which, although flexible and durable, doesn’t support a lot of weight. This slippery cartilage allows the surfaces of joints to rub against one another without creating a level of friction that could damage the bone.
Any place of the body where two bones move against one another, or articulate, is coated with articular cartilage. This cartilage absorbs shock and provides a smooth surface that allows for easy motion. In the wrist, for example, articular cartilage coats the sides and ends of all the carpal bones that form connections with the forearm to the fingers.
Ligaments are elastic bands of soft tissue that connect two or more bones. In most cases, the area where ligaments meet surrounding a joint form a:
In the wrist, the 8 carpal bones are supported by a joint capsule, which is a tightly sealed sac-like envelope that surrounds a joint space. A joint capsule contains a lubricating fluid called synovial fluid which protects the capsule from being ruptured.
The collateral ligaments are two important ligaments which support the front and back of the wrists, connecting to the forearm.
The first is the ulnar collateral ligament (UCL) on the wrist’s outer. Starting at the ulnar styloid, the cord-shaped UCL connects to two places. One joints with the pisiform (one of the small carpal bones) and transverse carpal ligament (a thick band of tissue that crosses in front of the wrist). The other joints with the triquetrum (a small carpal bone near the ulnar side of the wrist). The UCL helps strengthen a structure called the triangular fibrocartilage complex (TFCC), preventing the wrist from bending too far towards the thumb. In short, this structure is a small disc of cartilage where the ulna meets the wrist.
The other collateral ligament on the wrist’s inner edge is called the radial collateral ligament (RCL). Starting on the outside of the radius, on a ball-shaped bone called the radial styloid, it connects to the edge of the scaphoid (the carpal bone below the thumb) and protects the wrist from bending too far away from the thumb.
The other collateral ligament on the wrist’s inner edge is called the radial collateral ligament (RCL). Starting on the outside of the radius, on a ball-shaped bone called the radial styloid, it connects to the edge of the scaphoid (the carpal bone below the thumb) and protects the wrist from bending too far away from the thumb.
Injury or problems with these ligaments can cause stretching and tearing, possibly leading to arthritis around the wrist.
The two carpal bones (the lunate and the triquetrum) articulate with the end of the ulna bone at the wrist.
The triangular fibrocartilage complex (TFCC), the unique structure mentioned above, sits between the lunate, triquetrum, and ulna. It acts as a cushion and improves the wrist’s range of motion.
There are multiple tendons that cross over the wrist joint, performing crucial functions.
Tendons join muscles to bones, and the tendons traverse the wrist start out as muscles in the forearm. Flexor tendons run across the palm side of the wrist and are responsible for curling the fingers and thumb as well as bending the wrist. They run beneath the transverse carpal ligament (as mentioned above) which lies on the palm side of your wrist as well, and keeps the flexor tendons from bowing outward when you curl your fingers, thumb, or wrist. The extensor tendons run across the back of the wrist through a narrow tunnels (compartments) lined with a slippery material called tenosynovium which, as you could guess, allows the tendons to glide through their compartments with almost know rough friction.
Starting further up in the forearm are the wrist’s main muscles which were discussed above. The tendons of these muscles cross the wrist and are responsible for movement in the fingers, thumb, and wrist.
All nerves that connect to the hand traverse the wrist. The radial nerve, the median nerve, and the ulnar nerve are three important nerves that begin together at the shoulder, carrying signals originating in the brain to the muscles responsible for movement in the arm, hand, fingers, and thumb. In turn, these nerves relay signals back to the brain about feelings such as touch, temperature, and pain.
surrounds the radius bone’s end facing the backside of the hand after running along the thumb-side edge of the forearm. It provides feeling to the backside of the hand from the third finger to the thumb, and from the back of the thumb to just beyond the main knuckle of the back surface of the ring and middle fingers.
that supply the hand with blood. The radial artery is the largest artery that traverses the front of the wrist, closest to the thumb, and is where the pulse can be taken in the wrist. Next to the ulnar nerve through Guyon’s Canal is the ulnar artery. Both of these arteries arch together with the palm of the hand and supply blood to the front of the hand and fingers. There’s different arteries traverse the other side of the wrist supplying blood to the hand and fingers.
Once you fully understand all the different ways we use our hands every day, you will understand just how hard daily life can be when the wrist doesn’t work the way it’s supposed to.
The wrist is without a doubt one of the more complex areas of the body. So if you experience any abnormal sensations or pain within this area, it’s important to immediately consult your doctor.
