The Anatomy of Carpal Tunnel Syndrome

In this mini episode, Hillary dives into the anatomy of carpal tunnel syndrome. You will learn about the parts of the body that are involved in carpal tunnel syndrome, common causes, symptoms, and solutions. 

The articles below were used as a reference for this episode. 
https://orthoinfo.aaos.org/en/diseases--conditions/carpal-tunnel-syndrome/
https://www.ncbi.nlm.nih.gov/books/NBK546607/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3558235/ https://my.clevelandclinic.org/health/diseases/4005-carpal-tunnel-syndrome

You can connect with Hillary on Instagram @theanatomynerdpodcast or feel free to send her an email at theanatomynerdpodcast@gmail.com 

Transcript

Hello and welcome to The Anatomy Nerd Podcast. I am your host, Hillary. And in this mini episode, we will be nerding out about carpal tunnel syndrome. 

Let’s dive right in, shall we? We will start with the first very obvious question. What is carpal tunnel syndrome? To begin my explanation, I will start by breaking down the name. Carpal is from your carpal bones in your hands. So we are talking about our hands and your wrists. Tunnel is referring to the passageway under the transverse carpal ligament. And syndrome simply means a group of symptoms which consistently occur together, or a condition characterized by a set of associated symptoms. Carpal tunnel syndrome is one of the most common problems affecting the hand.

The next thing that is important to explain is the anatomy of the wrist and the structures involved in carpal tunnel syndrome. This is my favorite part y’all. The anatomy bits. So, the carpal tunnel is a narrow passageway in the wrist, measuring about an inch wide. So, looking at the palm of your hand, about a half of an inch below your palm is the area where the carpal tunnel is located. The bottom of the tunnel is formed by small bones in your wrist called the carpal bones.The top is made of a piece of connective tissue called the transverse carpal ligament, or the flexor retinaculum. Both are used interchangeably. Because this area in your wrist is rigid and small, the carpal tunnel is not able to stretch or increase in size. The median nerve is one of the main nerves in the hand. It runs down the arm, passes through the carpal tunnel at the wrist, and goes into the hand. The nerve provides feeling in the thumb, index, middle, and ring fingers. The median nerve also controls the little muscles around the base of the thumb. Because the median nerve does not innervate the pinky finger, it is typically not affected. Yay for pinky. 

Six long flexor muscles originate in the forearm and have tendon attachments in the hand. The six muscles are the flexor carpi radialis muscle, the flexor carpi ulnaris muscle, the flexor pollicis longus muscle, the flexor digitorum profundus muscle, the flexor digitorum superficialis muscle, and the palmaris longus muscle. These long flexor muscles either flex the fingers or flex the hand at the wrist joint. And all of their tendons travel through the carpal tunnel. 

All in all, there are ten structures that traverse the carpal tunnel. Nine tendons from the muscles we just went over. And the median nerve. That makes ten. 

Okay, so now that we know what structures we are talking about. Let’s dive into what carpal tunnel syndrome is. Carpal tunnel syndrome occurs when the tunnel becomes narrowed or when tissues surrounding the flexor tendons swell. This puts pressure on the median nerve, and the nerve sends signals to your brain that something is wrong. The tissue around the tendons are called the synovium and it helps to lubricate the tendons, making it easier to move your fingers. When the synovium swells, it takes up space in the already pretty narrow carpal tunnel and, over time, crowds the nerve. This increased pressure on the nerve can result in pain, numbness, tingling, and weakness in the hand. 

While there are a handful of things that can cause carpal tunnel syndrome, the most common causes are heredity and repetitive hand use. Both of which we have no control over. Some other things that may cause carpal tunnel syndrome are how you position your hand and wrist when going about certain activities such as typing at a computer or writing. Another thing that can cause it is pregnancy. This is because of hormonal changes during pregnancy that can cause swelling which would contribute to carpal tunnel syndrome. And lastly, health conditions. Diabetes, rheumatoid arthritis, and thyroid gland imbalance are all conditions that are associated with carpal tunnel syndrome.The chance of getting carpal tunnel syndrome may increase with age.

Symptoms of carpal tunnel syndrome may include: Numbness, tingling, burning, and pain—primarily in the thumb and index, middle, and ring fingers. You may also feel pain or a tingling feeling that may travel up the forearm. Another symptom is weakness and clumsiness in the hand—this may make it difficult to perform fine movements such as buttoning your clothes or tying your shoes. And last, dropping things—due to weakness, numbness, or a loss of proprioception, which is your body’s awareness of where your hand is in space.

There are various treatment options, the most common are hand braces and carpal tunnel surgery. If you are one of those poor unfortunate souls who happens to have carpal tunnel syndrome, talk to your doctor to find out what solution might be best for you. 

That is all the information I have for you in this mini episode. If you would like to learn more I have attached the links to the articles I used in the show notes. Or feel free to nerd out with me on instagram @thenanatomynerdpodast. 

Thank you so much for tuning in. Until next time, hasta luego.