matthew_walker_knot-slack
You may feel this way at the end of this article

Here’s slightly more information than you technically need to start rope bottoming, but I’m the kind of person who remembers things much better if I know the details, so they are for anyone else who feels the same way.

So, the big bad wolf of rope bondage would appear to be nerve damage. Everyone talks about it, many people have experienced it, but very few people really understand it. In my experience in the rope scene, if someone thinks they understand how nerves work (and don’t have medical or specialized biological training), they really don’t. I don’t say this to sound high and mighty or condescending, but it’s simply a fact that nerves are a confusing topic. They’re not intuitive, at all. It took a few years of studying anatomy in college before I felt that I had a handle on them with any confidence. So, my aim here is not to transmit years of anatomy training in one blog post, but to give you very specific tools and just what you need to know as a rope bottom, and hopefully a little bit of background to help it make sense.

But first, disclaimer: While I specialize in anatomy, I am not a doctor, medical professional, or any type of clinician or provider of first aid. If you experience any lasting problem due to rope bondage (or anything else), please speak to your doctor. Also, everyone is literally different. Just as your face looks different from everyone else’s, your insides are also pretty different from everyone else’s. What is true for some other people may not be true for you, and so I beg you to still exercise personal responsibility and risk awareness in consensual kink–reading this post and all the other ones will not make you immune to nerve injury. In fact, a great deal of the information I’ll be giving will be a post-scene evaluation to help you and your top figure out what happened after a nerve incident. In my opinion, as a rope bottom you need to treat nerve injury not as a matter of “if” but a matter of “when.”

And a separate disclaimer for medical professionals: I realize that this is highly, highly simplified and there will be caveats to every statement. However, there is a huge lack of accessible, understandable information about this stuff for lay people, and that is my primary audience here. Information overload isn’t helpful.

What are Nerves? Why are they important?

This may sound like a silly question, but I venture to guess that many people can’t specifically answer this off-hand. To me, the most simple way of defining what a nerve is is to say this: They are what connects our brain to the outside world.

500px-te-nervous_system_diagram-svg“Hitting a nerve” is usually associated with pain, and I think this leads to a misconception that nerves only serve to tell us we’re hurt. Nerves do help us feel pain, but they help us feel other things too–all of your senses (touch, taste, smell, hearing, sight, and a few other ones that aren’t as commonly known) are carried by nerves. Going back to my definition, this is the part of the role that nerves play, bringing data from the outside world to our brain. Remember, our brains are cloistered in our skulls, so they need some way for information to get in–the nerves allow this to happen. But this part, the sensory part, is only half of the story with nerves.

Nerves are actually a two-way street. Not only do our brains need a way for information to get in, so that they can crunch the data and figure out how best to deal with it, but they then need to be able to communicate to the rest of our bodies. Usually, if the brain wants to accomplish something, it does this by telling some muscles to contract. An example: Opening a door. Through a mix of many senses, primarily  through sight and touch, we locate the doorknob on a door we wish to open. We reach out (using muscles in our arms and shoulders), put our hands on the door knob (and we know we’ve done this because we can feel the knob, which is information that will be carried to the brain), and closing our hands on the knob and turning it, again, accomplished by muscles in our hands and arms. How we decide that we want to open the door is waaay out of the scope of this article, but the example does show the interplay of input to the brain (seeing the doorknob, feeling it) and output from the brain (moving our muscles to put our hands in the right place and turning it the right way). And the flow of information to and from the brain is pretty much constant, and always being adjusted for the situation.

So why does all of that matter? First, to explain why they’re important. Second, and more specifically to our aims here, to explain why we look for two main types of signs of nerve injury–that is, sensory loss and motor loss.

Where are the Nerves?

The simple answer: Everywhere. The more accurate answer is far more complicated. This is where things get really hairy, so I hope I’ve made this understandable at least this far. Again, going back to my point that nerves carry information to and from the brain. They do this in relatively consistent ways, thankfully.

illu_nerve_structure
Don’t worry about the terminology here, it’s not really relevant. Just notice that it  looks kind of like a cable.

I like to think of a nerve as a an insulated cable, like an HDMI cable or something. A cable is a bunch of wires bundled together in a sleeve to insulate and protect them, and it has two ends because it’s carrying power or information between two places. HDMI cables carry video as well as audio, and they happen to work in two directions, which is why I like to use them for this example. Similarly, nerves are actually a bundle of axons, which are long, thin extensions which, for our intents and purposes, are carrying information.

afferent_psf
Think of afferent as input/sensory, and efferent as output/motor

Each axon (or wire in our analogy) carries information in one direction, but in nerves, since there are many axons, there can be axons pointing both ways and so some nerves carry sensory as well as motor information (input and output from the brain). Two way street. Some nerves are exclusively sensory, meaning that their “wires” only carry information to the spinal cord/brain, and others are only motor, meaning that they only carry directions to the muscles, but many are mixed.

brachial_plexus_armenian
Don’t mind the labels. This is the brachial plexus.

Where the analogy breaks down is that nerves can branch. Not only can they branch, but they can join up with other nerves and form new nerves. They’re not nice and linear like everyone would like (it sure would have made my anatomy classes easier). This branching means that a map of the nerves themselves would look more like a highway map or a subway map, where they intersect each other and recombine. Again, luckily, they do this in a way that usually pretty consistent from person to person (but there are always many exceptions). The brachial plexus (plexus means “network”) is an example of a lot of mixing and weaving happening in a pretty small space, and it is also where many of the important nerves in our arms and shoulders begin.

 

Like I mentioned before, nerves are not very intuitive to understand. They take winding tracks through the body, carrying information in two directions. You’ll often see diagrams like this bandied about on the internet:

500px-gray812and814-svgAnd while they’re very pretty, they’re also pretty confusing. What you see here is a sensory map of the arm and hand. The names are the sensory nerves which carry touch input from each color coded area. The alphanumeric codes on the colored areas (C8, T1, etc) correspond to where the touch information from that area will enter the spinal cord to be carried up to the brain.

So, say someone touched you on the top of your shoulder. The supraclavicular nerves will be the ones carrying the “you’ve been touched!” information to your brain, and it reaches the brain by connecting to the spinal cord at the C3 and C4 levels (The numbers and letters correspond to the segments of the spinal cord, and each segment has one pair of spots on the right and left side for where the nerves plug in. But this isn’t really relevant to us). So what is the point? The point is that specific nerves serve specific areas of our body, and we can figure out (sometimes) where the nerve got injured by what areas go numb, tingly, or painful.

I imagine that that was a lot of information to compute. But luckily there are a lot of cutaneous innervation maps on the internet, so we don’t have to memorize all of them. I mostly want us to be familiar with the concept, and maybe remember a few key ones particularly in our hands.

But Wait, There’s More…(sorry)

I mentioned and attempted to explain the sensory maps, but you should hopefully know by now that there is a second part to this–the motor part. Many nerves are carrying these sensory fibers to various parts of our bodies, but they are often carrying motor fibers to similar parts of the body, and these fibers are connecting to muscles.

forearm_muscles_back_superficial

There are a shitload of muscles in our arms. This is just the back of the forearm, which conveniently is primarily supplied by branches of the radial nerve, which is the subject of most concern in rope bondage. You definitely don’t need to know all of these muscles, just realize that they work kind of like marionette strings. If they attach on the back of the hand, they will pull it back when they contract, and if they attach on the back of the fingers, they will straighten out the fingers. This is what many of the muscles supplied by the radial nerve do, and this is why we get wrist drop when the radial nerve is compressed too much in the upper arm.

The motor nerve fibers, again, carry the directions from the brain: If the brain wants us to straighten our wrists and/or fingers, it will send signals via the radial nerve (which then branches into things such as the posterior interosseous nerve, a motor nerve), to contract those particular muscles which will straighten out our arms and hands. If something goes wrong with the nerves, like too much pressure, this signal doesn’t make it to the muscles and we can’t straighten out our wrists and/or fingers.
And remember, many nerves are carrying sensory and motor information at the same time, the radial nerve being one of these. If you compress the radial nerve pretty high up in the arm, you’re cutting off that signal to the motor fibers in the posterior interosseous nerve, and the sensory fibers in the superficial branch of the radial nerve, and so you can get tingles, numbness, or pain, as well as weakness or loss of wrist and finger straightening. And a huuuuuge point to take home: Since nerves are like cables, just because you see the problem where the cable ends, doesn’t mean that’s where it got cut! Just as if I cut a cable that is providing power to my TV, if I cut it very close to the wall, I will see the TV shut off. There’s nothing wrong with the TV, the cause is much closer to the outlet than where I’m seeing the problem. But in this case, I actually prefer the analogy of the hose. If you have a 50 foot hose and you’re looking at the end of it, where the water should be coming out but isn’t, you should know that the blockage or kink can be anywhere between that end and the spigot, and it’s probably not right where you’re seeing the problem. When a nerve is injured, we usually notice the symptoms further away from the spine than where the injury happened.

I think I’ve written more than enough to get most people’s heads spinning, so I’m going to wrap this up here.