Trigger thumb is a very common condition. As an orthopedic physical therapist, I have treated this condition many times. There are trigger thumb exercises, as well as several other strategies, that can aid in recovery. Read on to learn more about trigger thumb. Let’s start with anatomy!
Tell me about tendons?
To understand what causes trigger thumb, you will need to understand a little bit about the anatomy of the hand. Tendons attach muscle to bone. There are tendons that run the length of the fingers and thumb. They extend from the base of the thumb to the tip. These tendons attach muscles from the forearms to the fingers and the thumb.
The tendons on the palmar side of the hand are flexor tendons. The tendons move the fingers and thumb into flexion or bending. This is the action of making a fist. The tendons on the other side of the fingers are extensor tendons. They straighten the fingers and thumb from a bent position.
The tendons are covered in a tubular structure called a tendon sheath. This sheath separates the tendon from its surrounding structures and allows it to glide smoothly.
What are the pulleys?
There are bands of tissue that are referred to as pulleys. These bands of tissues hold the flexor tendons firmly on the finger and thumb bones. There are several of these pulleys to secure the flexor tendons as the fingers and thumb bend and straighten.
What is trigger thumb?
Trigger thumb occurs when there is locking or catching in the thumb when you bend and straighten it. The ring finger and thumb are the most likely to be affected. It is called trigger finger when it is affecting the fingers. The medical term for trigger finger and trigger thumb is stenosing tenosynovitis.
Trigger thumb is caused by an inflammation of one of the pulleys on the thumb. This is most likely the A1 pulley at the base of the thumb. The A1 pulley thickens and narrows due to inflammation. This makes it harder for the tendon to glide through it. Subsequently, the tendon will become inflamed and could develop a small nodule. This nodule causes a catching, popping, or locking in the thumb as it passes through the pulley. The thumb could get stuck in a bent position and require the use of the other hand to straighten.
The initial inflammation in the thumb is idiopathic meaning that the cause is unknown. However, it could also occur after extensive use of the hands, especially with pinching or grasping. Examples of this could include carrying shopping bags for an extended period, rock climbing, or writing for long periods of time.
What are the symptoms of trigger thumb?
There are several symptoms associated with trigger thumb. These include:
- Pain in the affected thumb
- Increased pain when bending the thumb
- Stiffness and swelling of the thumb (especially in the morning)
- Nodule (tender lump) at the base of the thumb
- Painful clicking or catching
- Inability or difficulty straightening the thumb
- Symptoms usually start gradually
- Symptoms are usually worse after period of inactivity
- Symptoms typically improve when gently using the hands throughout the day
Are there risk factors for trigger thumb?
There are a few risk factors for trigger thumb. These include:
- Age – Trigger finger and thumb is more common in adults. It typically occurs between the ages of 40-50. However, children can develop trigger thumb.
- Gender – Trigger thumb is more common in females than males. It also tends to occur in the dominant hand.
- Medical conditions – Some medical conditions may increase the risk of developing trigger thumb. These include:
- Rheumatoid arthritis
- Diabetes
- Psoriatic arthritis
- Hypothyroidism
Who should I see?
- Physical therapy – Physical therapy can help decrease pain and inflammation with techniques including manual therapy and dry needling. PT can evaluate and address abnormal joint mobility, instability, muscle weakness, and muscle tone. Specific exercises will be prescribed to help mobilize the tendon and decrease irritation in the area. Your PT can help you modify the action that is causing the inflammation to prevent it from reoccurring.
- Orthopedic hand specialist – An orthopedic hand specialist might be necessary if the condition is not responding to physical therapy. Your physician can prescribe medication and/or give a steroid injection to decrease the inflammation. Surgery is an option if all conservative measures fail, or your finger is stuck in position. Surgery would involve release of the A1 pulley.
What can I do?
- Relative rest – Resting the area to decrease further pain and damage from occurring is one of the best ways to treat trigger thumb. Basically, stay away from the activities that are causing irritation. This gives the area time to heal. If you keep doing what is causing the injury, it is not going to get better. This might include not participating in your sport or changing how you perform a task or job.
- Ice – Ice can help decrease pain and symptoms at the thumb. Ice the painful area for 15 to 20 minutes at a time. I would recommend using an ice pack several times per day if the pain is constant or is preventing you from participating in an activity. Ice immediately after activity.
- Trigger thumb splint – Because the thumb is the most stiff, painful, and swollen in the morning, it would be beneficial to sleep in a thumb splint. This decreases the stress on the tendon and A1 pulley during sleep when our hands can be put in all sorts of crazy positions. It will also help decrease the swelling and pain in the morning.
- Exercises for trigger thumb
- Tendon glides – These are a series of different finger and thumb movements designed to improve the mobility of the flexor tendons. See the video below for how to perform this exercise.
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- Thumb active range of motion – These are a series of exercises designed to move the thumb in all of its different directions and to keep the joints from becoming stiff. See the video below for how to perform these exercises.
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- Digit blocking – This type of exercise is designed to decrease stiffness of the joint and improve gliding of the tendon. See the video below for how to perform these exercises.
In review
- The tendons on the palmar side of the hand are flexor tendons.
- The tendons move the fingers into flexion or bending.
- There are bands of tissue that are referred to as pulleys.
- These bands of tissues hold the flexor tendons firmly on the finger and thumb bones.
- Trigger thumb occurs when there is locking or catching in the thumb when you bend and straighten it.
- Trigger thumb is caused by an inflammation of one of the pulleys on the thumb.
- This is most likely the A1 pulley at the base of the thumb.
- The initial inflammation typically occurs after extensive use of the hands, especially with pinching or grasping.
- Symptoms include pain, swelling, catching, and locking of the thumb.
- Physical therapy can help decrease the inflammation, pain, and swelling.
- An orthopedic hand specialist might be needed if the condition does not respond to physical therapy.
- There are things that you can do.
- Relative rest
- Ice
- Finger splint
- Exercises
- Tendon glides
- Finger AROM
- Digit blocking
As always, If you have questions about the content of this post or any other musculoskeletal questions, please e-mail me.
Additional resources
https://www.ncbi.nlm.nih.gov/books/NBK441854/
https://www.physio-pedia.com/Trigger_Finger