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Altered Length Tension Relationships

Altered Length Tension Relationships (ALTREs) are an important concept in the field of biomechanics. They describe the mechanical behaviour of skeletal muscles in the context of their anatomical length and the tension experienced within them. ALTREs explore the relationship between muscle length and tension, which can be modified by changes in the structure and function of the muscle, as well as external influences. ALTREs are important for understanding how the body moves and how it adapts when

Transcript

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I'll draw this diagram like this
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again. We do need to be careful with
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wording and every once in a while you hear me correct something you say,
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it's not because I really care about your grammar, I don't, but every once in a while
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we need to be careful how we word things, because I hear people go, 'long and weak'
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and then they go, 'short and tight,' or 'short and strong'. They'll say something
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that doesn't quite make sense. So what you should know,
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let's say this is my hip, I keep going back to this example, it's a good example,
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this is my pelvis, this is my femur, these are my hip flexors, and this
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is my what? If this was the backside what would this be? Glutes. So this is long, and this is
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short, we've got that. Usually, not always, we're going to see some examples where
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this doesn't happen, long also means under active, and short usually is
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overactive. So, rather than short and strong, it's just over active. Now, generally
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speaking short muscles are about a third stronger than long muscles, but they're
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still weaker than they should be. The only reason they're a third stronger is
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because they're involved in everything. They get a little bit more conditioned than
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these, but they're both weak. In some rare instances what you will find
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is, there is long
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and overactive. Those are some troublesome muscles. Take your hamstrings for
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example. They get long. They get pulled long by an anterior pelvic tilt.
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You feel like your hamstrings are involved in everything if you get jacked
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up in your lower leg or your hip. Your hamstrings will not shut down. So we
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can't exactly say that your hamstrings are long and under active, it all
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has to do with neural stuff. That's cool?
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We're actually going to leave this up here as we go through these because it'll be a
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good example to keep coming back to. Have you ever heard the term hypertonic and
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hypotonic. Another couple of vocabulary words you'll want to write down. Hypertonic means
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overactive. So you can put
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hypertonic here,
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and this would be hypotonic. -The only way you could have a a long
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muscle and it be overactive is if it's neurologically overactive, it could never be
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mechanically overactive. Is there a difference? I don't know if anything is ever mechanically
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overactive or interactive. So what's the what's the root
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word of hypotonic and hypertonic. Tonic. Tonic refers to what?
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Tone. Tone itself as a neural thing. So all that's controlled by
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the nervous system. It has to do with something called our gamma
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system. So we basically have two different types of fibers that come out
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of our CNS, or rather our spinal cord, to our muscular system. One set is
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to contract our muscles, another set goes to our muscle spindles, and those muscle
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spindles through another feedback mechanism, control how toned we are.
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So this whole thing is all neural. Even if it's something that's under active, its neural. I
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just answered your question. But there's overactive or under active, long or short,
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the overactive, under activity part, that's all neural control. How many
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of you have heard of reciprocal inhibition? So,
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one of the reasons this is under active is because of reciprocal inhibition. So
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follow my logic here, if this becomes short, short muscles have a propensity to
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become overactive, that gamma system is charged. Well once the muscle turns on
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what is it supposed to do to it's functional antagonist? It's
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supposed to turn this off. Well if this is overactive it's always turned on,
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so that means this is always turned off. It starts creating a
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vicious cycle really fast. Now, one thing I do want you to understand about
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reciprocal inhibition that I think gets a little mistaught in out industry, it's not
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on-off. It's toned up, and toned down. Are you with me there? So just because this
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is overactive, doesn't mean this can't fire at all. It won't fire as much if
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this is a little tight. A little tight, a little off. Really tight, really
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off. Like it's on a dimmer switch, not a flicker switch.
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-Which one do you go to first? Which one happens first? -I had the
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conversation a couple of months ago because my experience is tight hip flexors, I did foam rolling and stretching,
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after I start with activating the glutes, then my hip flexors just released. He said because of synergistic dominance I would not be able to fire my glutes, but it was my own experience I
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was able to. That confused me.
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So there's a couple of
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arguments here, that we can somehow activate our way out of flexibility
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issues, and I know there's some schools of thought that would think that that's
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fine. With a really stubborn muscle, you might try to do a little bit of
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activation work and there are some other techniques that you could do and then go into
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your flexibility training. Generally speaking, this is like a
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general rule to set down before we start looking at more
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complicated ways of doing things. If you don't have the range of motion, you can't
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activate yourself into it. It doesn't mean that you can't fire your glute. Like
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I said, this is tone up, tone down, not turn off. If I only have, let's say, optimal
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hip extension is 15 degrees, so just past that neutral position, but
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let's say my hip flexor only lets me get to here. When I go to activate my glute
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I'm only activating it to 0 degrees. I don't have the other 15 degrees. There's no way to get there. My hip flexor
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is just going to stop me because it isn't long enough. So then we go back
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to another rule. Do you remember isometrics got really popular about a
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decade ago? What's the problem with isometric training?
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You actually would only end up strengthening the muscle at a certain angle.
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You only get about 15 degrees sway at a joint that
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you actually get an increase in strength out of, and then the rest of the range is
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not strengthened by an isometric. It's like, yeah this strengthens your
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biceps to hold a really heavy weight right here, but it really only
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strengthens your biceps right here. If I do my activation work and not my
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flexibility work first, I strengthen my glute through the range of motion I
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already had, but where do I need to strengthen my glute? In the range of motion
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I lost. Because until I strengthen my glute there, I won't keep it. I won't use it. I
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won't feel comfortable in that new position. So generally speaking this is
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one of the reasons why I think flexibility from the corrective
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standpoint is probably the most important component. We have to get our
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range of motion back before we're going to get optimal strengthening, which you
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still have to do to get a permanent change in our posture. Does that make sense?
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So, synergistic dominance, which we've already been referring to, this is kind
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of a circular conversation, these six definitions are all embedded in
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each other. So this is short,
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reciprocally inhibiting this, being our glute. So this is our hip flexor, this
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is our glute. Well, if I need to do a hip extension, and I don't have a glute, am I just
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not going to do hip extension anymore? Hip extension is kind of important to daily
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activity, right? How are you going to get out of that chair without hip extension?
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You still need something to be able to do hip extension.
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So what are we going to do? We're going to call in our synergists.
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Which, in this case, is going to be who? Hamstring, specifically your biceps
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femoris. The big overactive synergist for the glute max
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is biceps femoris. So we've got this coming in, and once it becomes the
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overactive synergist and you start training that way, what's going to
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happen to the neural drive of that muscle? It's going to start toning up.
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So we've got hip flexors, toned up, hamstrings, toned up, glutes toned down.
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We're starting to create a pretty jacked up relationship. Then realize too, and
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I know you have seen this in your clients, this isn't just stronger, this
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also fires faster, fires before it's supposed to, maybe fires in movements
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that it's not related, like you try to go into hip flexion and your hamstrings fire.
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That stuff happens. When we stay toned down, it's not just weaker,
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it's also a timing thing. So it not only fires less hard, it fires late which is
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part of the problem here too. That just keeps leading to the deconditioning. I go to
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do a squat and my hamstrings fire first, and then my glutes kind of come along for as