Introduction to Wrist and Hand Weakness
Take a few minutes to think about how often you depend on your hand and wrist strength. Did you open a jar today? Did you chop some vegetables? Did you prune some bushes? Did you pick up a heavy purse or briefcase? If you have strong hands and wrists, you probably didn’t even think about those structures as you performed these tasks. If you have wrist and hand weakness, though, these tasks might have been difficult, painful, or even impossible.
In this article, we’ll discuss some of the most common causes of wrist and hand weakness. Your hands’ grip strength, measured by the HandexerTM, is one way that a physical therapist (PT) or occupational therapist (OT) can evaluate their health. The HandexerTM can also be used to monitor your progress, with the guidance of a PT or OT, if you embark on a program to strengthen your wrists and hands.
Before you start reading the rest of this blog, you might want to revisit the article on the anatomy of the wrists and hands.
Overuse Injuries
Overuse injuries occur when repetitive movement damages the structures of your body. Structures of the hands, particularly the tendons, are especially likely to suffer from overuse injuries because we often use them to do the same tasks over and over again. (Think about the hours you might spend at a keyboard or doing manual labor.)
The most common overuse injury seen in the hands is tendinitis. Tendinitis causes inflammation (swelling) of the tendons that attach muscles to bones. Tendinitis can lead to significant pain, thus reducing the function of the wrists and hands. The image below shows just a fraction of the tendons of the wrists and hands. You can imagine how damage to any of these tendons will lead to less use of the wrists and hands, gradually causing them to become weaker and weaker.
Tendons of the hand
Sobotta’s Atlas and Textbook of Human Anatomy 1909 Public Domain
You can read a great article, published in the Journal of the American Academy of Orthopedic Surgeons, for more information about tendinitis.
People who spend a lot of time on the computer are at risk for another common overuse injury—carpal tunnel syndrome. While other factors can cause this disorder, excessive time on the computer or working with vibrating tools, such as a jackhammer, can irritate the median nerve. This can cause pain and tingling in both the hand and arm, but especially on the thumb side of the hand, eventually leading to significant hand weakness. You can read more about carpal tunnel syndrome in this blog.
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Fractures
Fractures of the forearm, wrist, and hand will lead to hand weakness due to pain and immobility. Think about the action you take when you trip on something and fall forward. You’ll probably put out your hands to catch yourself. If the surface is hard, and your bones have lost some mass due to osteoporosis (thinning of bone tissue), you might fracture your radius.
The graphic below shows you two different types of fractures of the radius (the forearm bone on the thumb side of your hand). In the top graphic, the fracture runs down the length of the bone and doesn’t interrupt its shape, so it’s called a non-displaced fracture.
The bottom graphic shows a more serious fracture. You can see that the two ends of the broken bone don’t meet, so it’s called a displaced fracture. This type of fracture will likely require surgery and casting, leading to greater hand weakness than the non-displaced fracture.
SMART-Servier Medical Art (unmodified)
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The image below shows you a fracture of the scaphoid bone—one of the bones in the first row of carpal bones that forms a joint with the radius. According to the Cleveland Clinic, this type of fracture makes up 15% of wrist injuries. It’s almost always caused by catching yourself with your hands when you fall forward.
This next graphic shows you an X-ray of a fracture of the fifth metacarpal bone. The metacarpal bones make up the flat part of your hand. Doctors often call this fracture a Boxer’s fracture because it usually happens when a person forcefully hits a hard object with their fist. If you look carefully at the top of the longest bone on your left, you can also see that this fracture has caused the bone to bend, requiring surgery. The finger, and possibly the entire hand, will then need to be immobilized while the bone heals, leading to hand weakness.
Fracture of the 5th Metacarpal
Robert J. Galindo (unmodified)
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This last graphic illustrating fractures affecting hand strength shows you a fracture of one of the bones of the fourth finger. In this case, the break has occurred in the middle phalanx of that finger. Because so many muscles attach to the phalanges (bones of the fingers), these types of fractures can be quite serious—again requiring splinting or possibly surgery if the bone is displaced. The strength of the entire hand and wrist will suffer because of a break in one of these small bones.
Phalanges Fracture
Laboratoires Servier (unmodified)
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Wrist and Hand Sprains and Strains
Wrist sprains occur when a sudden force causes an injury to the tendons and ligaments of the forearm. Wrist strains occur when a sudden force causes tearing of the muscles that control the wrist. The image below shows you evidence that this person has probably both sprained and strained his hand and wrist. You can see considerable swelling in his hand, especially just below his thumb, and you can see bruising in his forearm that travels across the elbow joint. This serious injury will require a long recovery time, resulting in a significant loss of wrist and hand strength.
Wrist Sprain and Strain
Photo by downtown gal (unmodified)
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Casting or Splinting of the Wrist or Hand
When an injury occurs to the wrist or hand, immobilization (prevention of movement) of these structures is often required. This allows tissues to heal while reducing the risk of making the injury worse. Splints are commonly used to protect the tendons and ligaments of the wrist and hand, while casts are commonly used when one or more bones have broken. (Broken fingers may require a splint rather than a cast.)
The image below shows you a splint used to immobilize the wrist, hand, and fingers. This person is likely suffering from significant tendon damage in one or more muscles that control the wrist and fingers. Like any tissue, tendons need time for inflammation to calm down and any damage to heal. Temporary immobilization with a splint can be used to give tendons time to heal.
Hand Splint by Emmat Davis (unmodified)
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The next image shows a wrist immobilized by a plaster cast. This person probably broke one or more of the carpal bones or bones of the forearm. Fractured bones must be kept stable for them to heal properly. If the fracture was displaced, surgery was almost certainly performed to align the bones. If the fracture was nondisplaced, immobilization is still usually required to avoid the risk that the ends of the broken bone will shift. According to the Johns Hopkins Institute, broken wrists usually require casting for up to six weeks.
Wrist Cast
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Unfortunately, any type of immobilization will lead to weakness of the forearm and hand muscles. Once a splint or cast is no longer in use, a physical or occupational therapist, trained in the rehabilitation of the wrist and hand, will evaluate their strength. This will sometimes be done using a hand dynamometer such as the HandexerTM.
The PT or OT will then design a treatment plan that the patient should follow exactly to avoid re-injury. Any significant pain or tingling during treatment, or while performing a home exercise program, should immediately be brought to the attention of a PT or OT. Because hands are so complex, no one should try to exercise “through the pain.” Instead, the painful activity should be stopped, and professional advice sought.
Arthritis of the Hand
The word “arthritis” means inflammation of the joint. The two most common types of arthritis are osteoarthritis and rheumatoid arthritis. Osteoarthritis occurs more often than rheumatoid arthritis. It causes the cartilage at the ends of bones to gradually wear away. The ends of those bones may respond by growing extra bone tissue to keep the bone from deteriorating. This extra bone tissue can lead to pain and limitation of movement.
This image shows you a hand affected by osteoarthritis. You can see that the ends of the metacarpals and phalanges are affected. Osteoarthritis can also affect the joints between the metacarpals and carpals and between the individual carpal bones.
Osteoarthritis
SMART-Servier Medical Art, part of Laboratoires Servier (unmodified)
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Rheumatoid arthritis is less common than osteoarthritis but usually causes more pain and dysfunction. The body’s immune system attacks tissues of the joints, often starting with the joints of the hands and feet. The lining of the joints becomes inflamed, causing severe pain. The joints can become so damaged, that deformities of the structures of the hands occur. You can see these deformities in the image below. Unsurprisingly, rheumatoid arthritis hurts both hand strength and function.
SMART-Servier Medical Art, part of Laboratoires Servier (unmodified)
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Conclusion
Loss of wrist and hand strength has many causes. This article has focused on some of the most common ones. You can read about other causes of wrist and hand weakness on this site.
Disclaimer: This article was written for educational purposes only. Any concerns about the health of your wrists and hands should be brought to the attention of your doctor or a hand specialist.
About the Author
Holly Trimble, PT, DPT earned three degrees in physical therapy, including a doctorate, and a master’s degree in biology. She worked as a physical therapist for fifteen years and taught college-level anatomy and physiology for sixteen years. Dr. Trimble currently writes and teaches health and science courses for Ed2go, Inc.
