Dislocating a Thumb to Escape Handcuffs: FightWrite™
About five years ago, I sat on a panel at a writer’s conference to discuss injuries. Medical professionals andI answered writer questions about injuries as well as their care and healing time. One writer asked a question that made us all pause, mouths open like trout on hooks, then narrow our eyes and silently look at one another. We simply didn’t know. Could a character escape handcuffs by dislocating a thumb?
(Critiquing a Fight Scene From Start to Finish: FightWrite™)
I did a bit of research after the fact and wrote about it all on FightWrite. And let me tell ya what, there are a disturbing number of people who want to know the answer to that question. That post blew up and still gets the majority of my traffic daily. What you have here is a shortened, but still complete answer. And that answer is…(ehem)…mostly no, but also, yes, sometimes.
The Problem Is Lower Than You Think
First, yes, it is possible to escape handcuffs by dislocating the thumb. The problem is that the joint you need to dislocate is not the joint most people think. If you look at the pic of the x-ray, you will see an X. That is the metacarpophalangeal joint, also known as the MCP. It is not terribly difficult to dislocate. I’ve done it and though it’s uncomfortable, it wasn’t, for me, excruciating.
The MCP is a hinge joint. It moves like a door. While dislocating it does impact the width of the hand, escaping the handcuff does not hinge upon that hinge joint. The hand can slide out without that middle joint being dislocated. The true key to the escape lies beneath the MCP.
The Big Problem Is Fairly Small
To get the cuff up to the middle thumb joint, you must first dislocate the carpometacarpal. The CMC joint, circled on the picture, is where the thumb gets all its mobility. If you look at your palm, that small, meaty bit below the thumb and just above the wrist is why handcuffs work. That joint acts as a ridge that a well tightened cuff cannot slide over.
So, why not just dislocate that first thumb joint? Well, it’s hard as heck to do! It has many more structures holding it in place. Dislocating it is not common and often associated with a blunt force trauma such as a fall. I’m not sure one could simply dislocate the CMC with strength alone, and managing to fall just right to dislocate that first, well-supported joint, but not damage the surrounding bones of the wrist would be a heck of a thing to pull off.
Unless…
The Unless
Once you dislocate any joint, it is easier to dislocate until the supporting structures heal. Because connective tissue has little blood supply, healing takes forever plus a week, and then you still better wear a brace. I heard a PT assistant say that it takes nine months to make a human but a decade to heal a sprained ankle. As some who has enough ankle braces to suit a centipede, I can tell you that she wasn’t wrong.
The more connective tissue is compromised by injury, the more elastic it becomes. That means, the more you dislocate something, the easier it is to dislocate it again. It’s a self-feeding monster. So, if your story character has dislocated that first thumb joint many times, they could possibly dislocate it on their own with just their free hand. Is that likely? No. Possible? Yes. The problem is if that tissue is so lax that your character can displace that joint that easily, that connective tissue may not hold that CMC thumb joint in place well enough for the thumb to do its job well. Remember, it’s that first joint that give the thumb its mobility.
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Most Likely Scenario
The greatest possibility for dislocation of that deep, first joint of the thumb lies with characters who have a condition that compromises the connective tissue. When I first wrote about dislocating a thumb to escape handcuffs on FightWrite, a reader with Ehlers-Danlos syndrome wrote to me saying she could absolutely pull it off. Ehlers-Danlos affects all connective tissue making it too pliable. So, dislocation of any bone is far easier for those with the disorder.
She went on to say that although she could escape the cuffs she wouldn’t get too far or be too tough a fight once caught. Ehlers-Danlos comprises overall health. As she wrote, “… someone with EDS might have trouble escaping after getting out of the cuffs, that's going to be due to a drop in blood pressure on standing up (POTS), lack of coordination (EDS causes problems with proprioception and a lot of us are clumsy), pain from loose joints, or most likely other dislocations. Most people who can dislocate on command are also vulnerable to dislocating when they DON'T want to as well."
Just Let It Be
So, there you have it. Can you dislocate the thumb to escape handcuffs? Well, saying “yes” isn’t as reasonable as saying that it is possible. And there’s a lot of things that are possible that just ain’t likely. If your character ends up in cuffs, leave their thumbs be.
Until the next round with FightWrite® on the WD Blog, get blood on your pages!