Street Medic Wikia (beta), the online resource for street medics that anyone can edit Since the arrests in NYC last week, the principle complaint I have heard from folks is that their thumbs and/or fingertips are still numb. What treatment and course of action can we be recommending for them. So far it seems that one of the medics has told them to go to a doctor to document it, which is good advice.
Here's my medical review of so-called "Handcuff Neuropathy" (or more technically Cheiralgia Paresthetica, a superficial radial nerve branch compression mononeuropathy, or some such gobbledegook):
How prevalent is this problem? Edit
Nerve damage resulting in pain, numbness or abnormal touch sensations caused by even brief periods of handcuff restraint is more common than generally believed. It's been called a "widespread problem" based on data from the Chicago penal system. A neurologist in the NYC prison system describes it as a "common occurrence." Studies suggest that it may occur in as many as 1 in 20 people taken into police custody.
What's the typical presentation? Edit
The person typically experiences pain around the thumb while tight handcuffs are in place. The pain decreases when the handcuffs are removed, but there is residual altered or decreased sensation over the edge of the hand between the base of the thumb and the wrist. It can also extend to the back of the hand below the first two fingers (forefinger and middle finger), and/or the back of the thumb and the backs of those fingers. There's a decent diagram of the typical region affected at  This is a description of the most common type of handcuff nerve injury, the bruising of a nerve called the "superficial radial nerve." The reason this nerve is the one most frequently bruised is because of it's vulnerable location as it crosses along the end of the radius, the thumb-side bone in the forearm. For Medic Trivial Pursuit purposes, the first case described of a compression injury to this nerve was reported in 1922 (some guy was wearing his watch too tight). The first report of a similar injury due to tight handcuffing was described in 1978.
Is it serious? Edit
Luckily, this "superficial radial" nerve is purely a sensory nerve, meaning that it doesn't control any muscles, it just picks up touch and temperature sensation. So in this most common manifestation of handcuff nerve injury, one doesn't have to worry about losing function. In fact, assuming the nerve is not reinjured, the vast majority of these cases clear up completely on their own.
What causes it? Edit
The damage is thought to be from the direct compression, cramming the nerve against the adjacent bone. If cuffs are kept on for hours, lack of circulation to the area may also injure the nerves by starving them of oxygen. In most cases, just the insulation around the nerve is damaged, which slows or blocks the conduction of the electrical nerve impulses and results in decreased or altered touch sensation.
When is it going to get better? Edit
If the nerve is fine and the insulation is just damaged, the symptoms can clear up in as few as 3 weeks. If the nerve itself is bruised, then the nerve from that point on tends to die off and has to regrow. Nerves grow at about a millimeter a day (or about an inch per month). So if the weird or numb sensation goes all the way from your wrist to the tip of your thumb, it could be 4 or 5 months (4 or 5 inches) before the nerve grows all the way back and normal sensation is restored. Typically it takes between 2 to 3 months, but can take as long as 3 years. The "prognosis" for return of normal sensation oft quoted in the medical literature is "1-12 months."
Is there anything I can do to help prevent it? Edit
Nerve damage can be a product of one's own struggling as much as it can be from too-tight handcuffs, so we may want to caution others against thrashing around. Evidently, police officers are instructed not to remove or adjust handcuffs until a "safe controlled environment is reached". So while one's complaints of overtight cuffs may be ignored, if only for future legal purposes it's probably worth it to describe your symptoms and ask for them to be loosened. One can also ask to have cuffs "double-locked" which entails the cop applying a special pin to the cuffs which prevents the cuffs from accidentally getting ratcheted any tighter.
How about cops just not putting them on too tight? Well, as one medical journal article concluded in typical apolitical fatalistic BS medical ." [There's a lot missing here!]
What as medics should we do if we come across this? Edit
I think the most important thing we can do is to make sure something more serious isn't going on (and then offer reassurance if that's the case). There are two major nerves other than the radial that go to the hand. Rarely, they too can be damaged by tight cuffs. This could potentially be disabling because these other nerves control muscles in the hand and damage could result in severe motor dysfunction (such as weakness or muscle wasting). So it's very important for us to test for any muscle weakness in the hand, thumb or fingers. If the person says it feels weak or you detect weakness, the person may need special splints and/or physical rehab and so should get it checked out further.
Another serious sign to look out for is total numbness, total anesthesia in a certain area. When the nerve insulation is just damaged or the nerve is just bruised, the sensation may be off, weird, tingly, burning, different, decreased, "numb-ish," but not totally numb. If there no feeling at all in any particular area to light touch, then that indicates a nerve has probably been cut totally through and the sensation in that area may actually never recover.
We also want to make sure the symptoms are not arising from nerve damage higher up in the spine or arm. If someone gets in a car accident, for example and is handcuffed and then ends up complaining of thumb or forefinger numbness, one might just attribute it to the handcuffs and tell the person that it's basically harmless and it will go away on it's own. Meanwhile, what may be happening is that the symptoms may actually be arising from a spinal injury sustained in the crash. So the thing to do is see if there is any sensory loss on the pad side of the thumb, or in the upper 2/3 of the forearm. Either of these would indicate that the nerve damage is probably located in the neck, not the wrist, so make sure to examine these areas with a light touch to see if it extends onto the "front" side of the thumb or up the forearm.
Wrist fractures can also be caused by violent handcuffing and cause similar symptoms, so if there is any bony tenderness one should consider getting the person's wrist X-rayed.
Can I sue the hell out of them? Edit
There have actually been cases in which people have gotten serious settlements for handcuff-induced nerve damage. Despite the potential for being annoying, though, the typical altered or decreased sensation been deemed "harmless," and "functionally unimportant." Some people, however, instead experience pain in the area, pain which may be severe and prolonged. There was this one case in Scotland, for example, where a police officer was awarded £108,000 in damages against his own force after hurting his wrist in a training course on the use of handcuffs. The pain from the nerve damage evidently affected his ability to garden and write and led to his early retirement.
In terms of documentation, you may want to take a pen or marker and draw the borders of the affected area and photograph it so you can see how it changes over time. If you're interested in perhaps taking the case to court, I expect you would want a medical professional to document the injury as well. There is a test called a "nerve conduction study" that can be done to objectively prove that there was damage to the nerve.
What a nerve conduction study entails is having a few flat metal disc electrodes applied to your skin with tape or a special paste. A shock-emitting electrode is then placed directly over the nerve to be studied and repeated, brief electrical pulses are administered to the nerve to see if it's conducting the electrical impulse properly. The whole test shouldn't take more than 15 minutes. This testing isn't dangerous--only a very low-voltage electrical current is used and each electrical pulse is very brief (less than a millisecond)--but can evidently be quite uncomfortable . Each shock feels like a brief burning pain, a tingling sensation, and a twitching of the muscle each time the electrical pulse is applied. Though invaluable as court evidence, nerve conduction studies are not medically necessary for typical handcuff nerve damage cases.