The wrist muscles and forearm muscles do so much more than give you strength in your arm and wrist. These muscles also play a part in helping you move your hand and fingers. There are 18 different muscles!
Here’s a preview of these muscles:
- Flexor pollicis longus: Helps you bend the tip of your thumb.
- Flexor digitorum profundus: Helps you bend your index, middle, ring and small fingers.
- Flexor digitorum superficialis: Helps you bend the middle joint of each finger, except for the thumb, which allows you to do things such as eating with chopsticks.
- Flexor carpi ulnaris: Helps you move your wrist away from the thumb, which is helpful in playing darts.
- Brachioradialis: Helps you twist your forearm so your palm is either facing up or down.
- Flexor carpi radialis: Helps you bend the wrist and move it toward the thumb.
- Palmaris longus: Helps you bend the wrist.
- Extensor pollicis brevis: Helps you straighten the thumb.
The wrist joints lie between the many different bones in the wrist and forearm. Many wrist injuries (such as fractures, also known as a broken bone) involve the joint surface. There are three joints in the wrist:
- Radiocarpal joint: This joint is where the radius, one of the forearm bones, joins with the first row of wrist bones (scaphoid, lunate, and triquetrum).
- Ulnocarpal joint: This joint is where the ulna, one of the forearm bones, joins with the lunate and triquetrum wrist bones. This joint is commonly injured when you sprain your wrist. Some people are born with (or develop) an ulna that is longer than the radius, which can cause stress and pain on the joint, known as ulnocarpal abutment (impaction) syndrome.
- Distal radioulnar joint: This joint is where the two forearm bones connect. Pain with this joint can sometimes be a challenging problem to treat.
Learn more about the joints of the wrist and also the bones of the wrist in our Anatomy section. You can also visit www.HandCare.org for information on conditions and injuries of the hand, wrist, arm and shoulder.
A wrist fracture is a medical term for a broken wrist. Breaking your wrist can involve any of the eight small bones that make up the wrist, which are connected to the forearm bones called the radius and the ulna. The radius is the most common bone to break in a wrist fracture. This injury typically happens from falling on an outstretched hand, but it can also result from traumatic events such as a car accident. While wrist fractures can vary in severity, here are five signs that you may have broken your wrist rather than simply spraining it:
- Pain and swelling in the wrist
- Inability or difficulty using the hand or wrist
- Deformed-looking wrist
- Pain with finger movement
- Numb or tingling fingers
Guest post by Avery Arora, MD
Medical science has advanced considerably over the years when it comes to replacing damaged joints. Knee and hip replacements have become commonplace, but chances are you have not heard all that much about wrist replacement surgery. This is because it is somewhat less common, but as with other types of joint replacement, it can restore good quality of life to a patient who needs it.
Wrist replacement, also referred to as arthroplasty, works by removing the damaged cartilage and bone in the wrist joint. Then, the wrist bone is resurfaced using implants created from polyethylene and metal alloy to duplicate the function of a healthy joint. The operation has a very high success rate and can reduce or even eliminate the pain. Conditions like bone fractures and other traumas, rheumatoid arthritis and osteoarthritis that do not respond to other treatment methods can be dramatically improved.
Wrist replacement surgery, in addition to reducing or eliminating pain, can deliver improved mobility and allow you to return to the activities you once enjoyed. It is likely that you will even be able to participate in low-impact sports.
Dr. Khurram Pervaiz answers your questions about wrist sprains:
My doctor told me I have a “wrist sprain.” What is that?
A sprain is an injury that involves damage to the ligaments of the wrist. This damage may range from a simple stretch injury with inflammation and irritation of the ligament to a partial tear of the ligament.
What causes a wrist sprain?
Wrist sprains are most commonly caused by trauma. This trauma may range from a simple fall to a car accident or a sports injury. Athletes who participate in sports that involve impact to the wrist are particularly at risk. Gymnastics, cheerleading, martial arts, and CrossFit are some examples of sports that can cause wrist impact.
What are some of the symptoms of a wrist sprain?
The most common symptom of a wrist sprain is pain and swelling of the wrist. Limited function with weakness and lack of use of the hand and wrist may also occur.
The “pinkie” side of the wrist is also known as the ulnar side. Pain on this side can be very common. It can result from injury to bones, cartilage, ligaments or tendons. Due to this wide range of causes, it can be difficult to determine why the pain is happening. Here are some possible causes of ulnar-sided wrist pain:
- Wrist fracture
- Arthritis of the joint(s) between the bones
- Ulnar Impaction Syndrome (when the ulna is longer than the radius, which can cause it to “bump into” the smaller wrist bones)
- Inflammation or irritation of the tendons that bend and extend the wrist
- Triangular Fibrocartilage Complex Injury (TFCC) (when the connection between the ulna bone and other structures in the wrist is torn by an injury or frayed over time)
- Nerve injury or compression
- Tumors, most commonly ganglion cysts, that are benign
Hand surgeon Avery Arora, MD talks about common causes of wrist pain.
Even though the wrist is a relatively small part of the body, it has eight bones, as well as ligaments, tendons and tissue. The wrist also happens to be easy to damage, which could cause not only pain but also limited use of the wrist and hand. A wide range of things can affect the wrist.
1. Repetitive Motion
One of the most common reasons that people develop pain in their wrists is due to repetitive motion. Motions that cause your hands to do the same things, even simply staying in the same position for a long period can have terrible effects on the wrist. Driving for too long, typing and more can cause irritation in the joints, as well as stress fractures in some cases. This can lead to chronic pain for many patients.
2. Physical Impacts
Physical impacts, such as falling on your wrist or having something hit your wrist is a cause of injury and pain as well. An impact can cause a fracture, as well as a strain or a sprain. Even if the impact does not break a bone, it can harm the nerves, and cause tissue damage and swelling.