Sprained Thumb Overview

Without our thumbs, performing everyday tasks like typing, texting, and grasping objects would quickly become a nightmare. If you're suffering from a sprained thumb, you know how important that first digit really is. Besides the loss of functionality, the pain and stiffness put a definite damper on daily life. The good news is there are many effective at-home and professional treatments, depending on the severity of your sprain. Use this guide to learn more about thumb sprains and their causes and symptoms.

What is a Sprained Thumb?

A sprained thumb is defined as damage to the ligaments (and potentially surrounding connective tissue) to one or more of the three joints in the thumb. These three joints include the carpometacarpal joint (where your wrist and thumb meet), the metacarpophalangeal joint (the knobbiest part of the thumb), and the interphalangeal joint (the last joint in the thumb).  The most common ligament to sprain is the ulnar collateral ligament that provides lateral stability to the middle joint.

Types of Sprained Thumb Joints

Sprained thumb joints come in two broad categories, each with their own symptoms and causes. Understanding your sprain begins with knowing the difference between the two categories.

• Hyperextension Sprained Thumb

  Hyperextension describes a sprained thumb ligament caused by backwards motion, away from the inside of the palm. This often occurs with a fall, an accidental force to the hand, or when participating in sports.

• Hyperflexion Sprained Thumb

  Hyperflexion is caused by a forceful or repetitive motion toward the inside of the palm. This might include repetitive typing or texting, or more commonly a high impact force while gripping a ball, ski pole, or steering wheel.

Sprained Thumb Grades

A thumb injury can be separated into three different grades to determine severity.  These include:

• Grade 1 (mild)

  Ligaments of the thumb are stretched but not torn. Symptoms, such as pain, swelling, bruising, and weakness, are mild and decrease quickly.  

• Grade 2 (moderate)

  The ligament(s) in the thumb are partially torn. This causes significantly more pain and can compromise stability and function in the thumb.

• Grade 3 (severe)

  The ligament(s) are completely torn. This requires immediate medical attention due to concerns with stability and possible fracture. Casting or surgery may be required. Symptoms experienced will be severe and limit quality of life.

Sprained Thumb vs. Broken Thumb

Ultimately, an X-ray is the only way to formally determine if a thumb is broken (fractured) or sprained, so be sure to see your doctor for a professional diagnosis if you’re feeling unsure or your quality of life has been drastically affected.

A sprained thumb is an injury to the ligaments and other soft tissues between the joints, whereas a broken thumb involves damage to the bone itself.  Additionally, with high impact injuries, a thumb can of course be both sprained and fractured.

With either injury, the symptoms largely depend on the severity. Thus, if your symptoms are manageable (mild to moderate pain) and there is no visible deformation in the thumb you may consider starting with home treatment.

On the other hand, if your symptoms are more severe, you heard a crack, or your thumb appears to be out of alignment, seek medical care quickly. 

Causes of a Sprained Thumb

A sprained thumb ligament is often caused by any activity that puts the thumb at risk for high impact. Some of the most common causes of injury include falling on an outstretched hand, ball sports (baseball, basketball, football, etc.), or high fall risk sports like skiing. Occasionally, high repetitive moves can sprain the thumb. However moves like texting, typing, cooking, and driving more likely lead to issues with the tendons (such as tendonitis).

Additionally, pre-existing conditions can make an individual more susceptible to such injuries.

Arthritis

As we age, the soft tissues that hold our joints together can weaken without proper care or overuse, causing arthritis pain and stiffness. While distressing in its own right, arthritis also makes the joints of older adults more fragile and easily sprained.

Unexpected Falls

Certain health complications and environments can make us more susceptible to falls. People that experience vestibular issues (like vertigo), have poor overall endurance, or poor general balance are at a higher risk of falling and injuring their thumb (and other parts of their body).

Inflammatory Disease

Diseases that are inflammatory in nature, such as diabetes, rheumatoid arthritis, and celiacs disease can predispose the body to injury. When tissue quality is compromised, high use areas like the thumb are at risk of injury.

Sprained Thumb Symptoms

The signs of a sprained thumb are often clear, immediate, and easily identifiable. Symptoms can last days or weeks depending on the severity of the sprain.

• Mild to severe pain

  The mildest cases feel similar to a pulled or strained muscle, and severe cases can feel like a broken bone.

• Bruising

  You'll notice a characteristic bruise around the thumb joint that may spread to the hand if severe.

• Stiffness

  Tasks such as writing, typing, or texting will become difficult if thumb mobility is compromised.

• Swelling

  A comparison with your uninjured hand will reveal mild to severe swelling.

What Does a Sprained Thumb Look Like?

Using visual cues, you can identify a thumb sprain quickly and easily. You'll typically see some form of bruising and swelling in the area around the joint.  Alternatively, a broken bone won’t necessarily show any symptoms specifically surrounding the joint itself.

Sprained Thumb Test

Lower grade sprains can often be managed at home. If you are experiencing moderate to severe symptoms and are unsure what type of injury you have sustained, consult your doctor. They will be able to perform a ligament stress test, request any necessary imaging, and prescribe the correct treatment for your injury.

Sprained Thumb Recovery Time

Sprained thumb recovery can vary depending on a few factors, including your age, pre-existing conditions affecting your health, and the severity of your injury. In most cases, a sprained thumb will heal completely four to six weeks after the initial damage.

If your sprained thumb is not healing within this timeframe, seek medical attention as soon as you can. It is possible that your sprain was initially misdiagnosed, or that the sprain led to additional complications, which needs to be more thoroughly addressed.

Understanding, identifying, and treating a sprained thumb ligament early on will speed your recovery and allow you to get back to your active life as soon as possible.