Dr. Mitch Broser
The Anatomical Snuffbox refers to a box-like indentation at the base of the thumb. It originally got its name from people using this area for the inhalation of powdered tobacco, aka snuff. Today, some have expanded into using their snuffboxes for other purposes. In my world, many people find this area to become a problem, either acutely after an accident, or gradually over time. This small area is home to multiple anatomical structures, making it a challenging or confusing area to assess and to diagnosis. Let’s understand all of the structures of the snuffbox so we can have a better understanding where problems can happen.
Give yourself a thumbs up with your right hand to see your snuffbox (plus you deserve a thumbs up for reading, learning and getting better). From this view, the inside (palm side) edge is made up of your Abductor Pollicis Longus (APL) and Extensor Pollicis Brevis (EPB) tendons, while the outside (back of hand) edge is your tendon of Extensor Pollicis Longus (EPL). The top of the box is the base of your 1st metacarpal and the bottom of the box is the end of your radius.
The floor of your anatomical snuffbox is made up of the scaphoid and lunate bones, which are 2 of your 8 small wrist bones, called your carpal bones. The tendons of your Extensor Carpi Radialis Longus (ECRL) and Extensor Carpi Radialis Brevis (ECRB) pass through this are, along with branches of your radial nerve, radial artery and cephalic vein.
As we can now see, there a lot of different things in this area that can go wrong! A thorough examination by a skilled practitioner is the best way to determine what the issue may be and how to best treat or manage it. However, there are a few basic things you can keep in mind:
- Any fall or impact-bracing with your arm straight and immediate pain within the anatomical snuffbox and a sign of a scaphoid fracture. Imaging and prescription medication may be needed.
- A gradual onset of pain around the anatomical snuffbox with a history of repetitive wrist motion such as drumming, cooking or playing racket sports, along with symptom exacerbated with hand or wrist movement may be a sign of a tendinopathy (ex. tendonitis) of the APL, EPB and EPL. This is typically amenable to manual therapy and exercise rehabilitation
- Numbness, tingling, loss of sensation or pain travelling into the thumb and first 2 fingers suggest issues of the nerves, arteries and veins inside the snuffbox, but could also be issues higher up the arm or even the neck. A detailed assessment and possibly referral to a specialist may be needed to understand if the issue is at the wrist, arm or neck.
All 3 of these basic scenarios require a visit to your trusted practitioner for proper assessment, diagnosis, and management (manual therapy, exercise rehab or referral to another healthcare practitioner). Having a better understanding of this anatomy will help you make better decisions when you start to feel pain or experience issues in your snuffbox. At the very least, the word “snuffbox” is just entertaining to say – plus you learned something new today. (make sure to write in your Better Everyday Cahier!)
That’s e-snuff.