WARNING: Trainer Geekery Inside
Last week, my E-brother from another mother, Tony Gentilcore, emailed me in a panick for an opinion on a piece he was writing for T-Nation. First, it’s pretty cool to have people from thousands of miles away asking your opinion on stuff, especially when they have an extensive network of champs of the iron game at their disposal the way Tony has, so I was definitely more than willing to help out. He was asking about Neural Inhibition of the squat pattern, and wound up trimming part of the article and making it into an article and a blog post. You can’t check out the article yet, but the T-Nation website is right over HERE, and the blog post HERE.
I’ll sum up the article Tony wrote to give you an idea of what it’s about. Ahem:
Blah blah blah neural inhibition blah blah blah light sabers blah blah toe touch blah blah I know Eric Cressey
All kidding aside, he did a fantastic job outlining some thought processes that aren’t commonly considered when it comes to performance of the squat, hamstring flexibility, etc, so I have to take my hat off to him for it. Just not today though, it’s too damn cold outside. So in response to his post, I emailed him a follow-up for some suggestions as well as my two cents on the whole topic, and you know what? It’s so damn good I thought I’d throw it out there for everyone to see what a couple of trainers talk about when we’re not talking deadlifts or protein bars. We’re both actually kinda sorta smart, so hopefully we can collab on more of these kind of things and get some craziness going on.
Without further adieu, here’s my response to Tony.
One concept overlooked quite often is the one touched on regarding the length of the muscle being directly related to the number of sarcomeres. Neural tissue is plastic as is muscle tissue. When the ACL is injured, the nerve is damaged as well, and once repaired, the nerve actually can begin to regrow into the full length of the ACL over time, causing some pain and discomfort in the individual, even if there’s nothing technically “wrong” with the ACL as it heals. The nerve can reduce it’s length, just as a muscle can, especially under low load high frequency activities like sitting at a desk, etc where the joint position is held in a relatively immobile position. This would result in a “tight nerve” that when stretched would cause neuralgia referring down the limb (I get this pretty consistently since my back injury, even when it’s healthy and moving well). Traction, where the joint is immobilized following injury, has often shown through CT and MRI scans, the nerve (if it’s big enough to see) becomes actually thinner and shorter as a result, just like the muscle. Makes sense, since the nerve isn’t sending an impulse, so why should it maintain it’s size and malleability??
McGill touches on this with his concept of nerve flossing. If a muscle can become adhesed, then all of the other tissues in the area can become adhesed, including the nerves.
I agree completely with your first statement, that limited mobility can be directly impacted by tissue length, but the key word there is simply “tissue,” a non-differential statement that would also encompass the muscle, fascia, vascular, neural, and lymphatic tissues, each of which could be less than plastic and therefore affect the mobility of the offending movement. Static stretching still involves stress on a muscle with possible passive compression of the vascular and lymphatic components, whereas PNF style stretching (actually closer to active-assisted than PNF, talk to a classically trained physio and they’ll tell you PNF is actually closer to diagonal spiral movement pattern acquisition through open kinetic chain patterns) brings the active involvement of all tissues as the muscle tension generated also activated the above mentioned tissues.
(Word.)
Fascial tissue is peisoelectric, meaning it can carry and generate a charge, so if the nerve tissue is hyper-excited, it will bunch the fascia up like huggies in a babies crack. An over-excited nerve tends to come from an irritated position, like terminal range of motion with non-reciprocal muscle activation (ie. bottom of a squat causes a bottoming-out contraction to prevent further movement into a damaging ROM, similar to a golgi tendon organ that causes a reflex contraction when rapidly stretched).
(Oh yeah, that’s right)
I’ve never liked the explanation that the hamstrings are tight if the hips don’t move properly at the bottom of a squat, since the knee is fully flexed and the hips are commonly in a neutral posiition, it wouldn’t stretch the hamstrings as much as it would the piriformis, which would create tension on the siatic nerve as it exits the siatic foramen of the pelvis, and would therefore inhibit the contraction of the glute muscles, which would limit the mobility of the squat. It seems like a cleaner explanation. I have rediculously tight hamstrings, and I can drop it like it’s hot, so there!!
Well, there you have it folks. Maybe it’s not really your hamstrings that are the culprits for the lack of squat depth after all. If you have any further questions regarding this, check out the post I did on why your hamstrings aren’t to blame for you squatting like an 80 year old HERE, or simply leave a comment below to let me know what you think. Thoughts are best left to discussion, so let’s get one going here!!