Neurodynamics (AKA meat & wire)

Looks like a fun on-ramp group.......welcome!!!

With the amount of new CFSB members  I wanted to share  something that I experienced when I was a Crossfit newbie myself. After all the nagging from my friends who were already members of CFSB, I rallied a group of friends from my soccer team to do on-ramp. During the first few weeks our conversations after the workouts included a lot of complaining of how sore we were. Also how badly we wanted to yell back at Forrest during the WODs. But besides not being able to hold our arms up to blow-dry our hair, we all had another thing in common. We all noticed that our finger tips were going numb during the workout and sometimes lingering for days after. One of my friends actually said that her finger tips were numb for the entire month. Forrest eased our minds by saying that he noticed the same thing during his first month of Crossfit, but that it went away after that. This eased everyones’ mind but mine (because I like to be different), which lead me to one of many research adventures I have been on about Crossfit.

The nervous system is a crazy thing. It’s made up of the brain, spinal cord and all the others nerves that branch out into our arms and legs. Even though there are separate names for all the nerves, they are all connected. TRUE STORY. K-starr uses the analogy of wires surrounded by meat. This may be hard to visualize, or just weird, but it makes sense. Our nerves are the wires and they run through the muscles of our body, AKA meat. When we move our body, our muscles and nerves must move together in order to function properly. However, research shows that nerves can only move about 7mm before they become tight and are stretched.¹ Nerves are not meant to be stretched for long periods of time, so this can eventually lead to irritation or damage to the nerve. Our nerves also have a large supply of blood vessels surrounding them that can be irritated with large, prolonged stretching of the nerves. For example, when you wake up and freak out because you can’t move your arm it’s because you were probably sleeping in a position of neural tension. Your arm actually falls asleep because it loses blood supply from the vessels being stretched/compressed. Similar to when you stretch your shoulder overhead using the band because of the huge connection of nerves located at the front of your armpit called the brachial plexus.

Fun fact: Research has shown that 15% stretch to a nerve leads to 80-100% reduction in the blood supply to the nerve. 10-12% stretch also causes a block of the nerves ability to fire and make a muscle contract. Typical leg and arm movements throughout the day actually put our nerves on stretch around 15%. This is why sitting still for too long is bad……especially with poor posture!¹

...moderate.....

Mild.....

So what’s the point of all this nervy talk? Why is this relevant to CF? Let’s go back to the wire analogy and think about the affects that moving your body has on the nervous system. The length of your nerves is essentially set and contained within your body. The problem is that we have become so sedentary that our nerves are not used to moving a lot throughout the day. This means they become stiff, just like if you don’t move your muscle for a while. So when we move our body, to a certain extent the nerves stop moving and get pulled. So think about the first time in on-ramp when you put your arms over head to set up for an OH squat. Or even just doing pass throughs. What would this do to your nervous system? Since it’s all connected this is going to put a large amount of tension/stretch on your nerves all throughout your body. Especially if this is a new position for your body. There will be even more stretch and even compression on the nerve if you have built up scar tissue/adhesions from injury, decreased flexibility or limited joint mobility. Over time, and with a lot of mobility, this position would be okay and your nerves will accommodate to the larger movements. Our bodies are pretty good at adapting if we treat them right. However, initially the overhead position puts a lot of stress on your nerves that they are not used to and BAM….numbness/tingling in your fingers. On top of the overhead arm position, add in the neural tension from the squat and you can only imagine…..

... and severe possibilities for neural tension

The OH squat is an extreme range of motion movement that usually gets everyones’ nerves flared up, but for some really tight people it may just be a slight overextension of the back that stretches and irritates the nerves. This is why midline stability is super important. Rowing is also another position of possible nerve irritation because of the position of the body. This DOES NOT mean stop moving and avoid these positions all together. This is just a possible explanation for why you may feel weird nerve -like symptoms during or following workouts. However, it’s still important to address so that you don’t end up damaging your nerves. It’s not really fun to lose sensation of your leg/arm in the middle of a workout and not be able to do you best.

Ways to fix neural tension? For that question I will share one of K-Starr’s mobility WOD videos because he does an awesome job of explaining all of this, as well as ways to possibly fix the problem. You want to get the nerves moving, as well as mobilize the “meat” so that the “wires” have a nice environment to move around in. Another place that nerves get caught up in a lot is the thoracic spine, which K-Starr talks about as well. This is where your loving foam roller comes in and saves the day, helping you mobilize your thoracic spine.

The numbness and tingling should eventually go away because of all the mobility education you have at CFSB. If you have some other type of injury you may not want to play around with nerve mobility until you get that checked out. Also go see a doc if the numbness and tingling continues for a while.Sometimes it won’t be in your finger tips, but maybe in the back of your thigh or feet. This is just another great example of why we all need to work on our full-body mobility. We need that balance between mobility and stability. A lot of times the numbness and tingling comes on while stretching or mobilizing. It’s not really the best idea to hang out in these positions for a long time because like I mentioned earlier nerves don’t like to be stretched. So you can try moving in and out of the position or just not pushing so far. It is possible to stretch your nerves and injure them! Nerve re-growth after injury has been compared to slow growing hair, so that’s not something you want sit around for.

* If I just confused the heck out of you, I really encourage you to watch this video to help calrify.

Increase your body awareness and pay attention to numbness/tingling while stretching

Also here’s a fun way to test out your neural tension throughout the day and learn where you are restricted. Pay attention to the positions that your body is in throughout the day and see if you ever get numbness/tingling in your arms or legs. Or even a pulling sensation that just doesn’t really feel like muscle. For example, I know the right side of my body has major neural tension just from testing during school. But I also notice it as I hold certain positions throughout the day. I can only sit with my right leg crossed over my left for a few minutes before my leg gets tingly. And forget about putting my legs up on something while I’m sitting. Or if I carry a heavy bag on my right shoulder for too long my right arm gets tingly. I blame all of my neural tension to being a student for way too long. These may not be relevant to everyone, but just increase your body awareness throughout the day and see what you find. Then you will know what areas to work on!

On a side note, I am excited to say that I have introduced Crossfit to my co-workers out here (and patients when appropriate). I printed out a list of bodyweight travel WODs for them to look at from www.crossfitsouthie.com and they are really excited to try them! I’m happy to have some friends to do workouts with now because my workouts have definitely been less than 100% and semi-boring without the CFSB comrodery. Miss you guys!

Reference:

1. Boyd BS et al. Sciatic nerve during a modified SLR altered after traumatic nerve injury. Journal of Orthopedic Research. 23; 764-770. 2005.

Workout of the day 8/5/2011