Biomechanic
Basics
A beginner's guide to
understanding the
anatomy of lifting
weights
Ben Yanes
Preface
This book is my best attempt at answering the
question "where do I start learning all of this
biomechanics stuff"?
This was the question that I always had when
I first got into lifting, and there was never a
simple answer.
I tried to make this book a good middleground between diving in-depth enough so
that any of you who have a solid foundation
of knowledge would still be somewhat
challenged (and maybe even learn something
new or connect a few dots), but also so that
anyone completely new to this information
could begin to understand it, too. I hope that it
serves as a good resource to refer back to,
regardless of who you are.
As an aside: I never thought I'd be writing an
Ebook like this because I always hated
learning in school. If you hated school too,
cheers! I hope that you enjoy the book and get
something out of it. If you don't, I'm terribly
sorry, but there are no refunds.
PHYSICS
We all took a high school physics class that we
hated, and even if we became personal trainers
or discovered a passion in lifting weights, we
probably never thought about the topic after we
were forced to take a bunch of tests we didn't
care about.
More so than any other topic we can learn
about, though, physics matters (see what I did
there?); like, it matters a hell of a lot.
Why does it matter? Because physics
determines how we interact with the physical
world. Physics is what connects us to our
physical reality, whether or not we realize it.
As you read these words, you're probably
sitting in a position that's comfortable for you (I
hope) - and that's determined by all of the tiny
force equations at every segment through your
spine, arms, hips, femurs and feet.
This is even more relevant when we step into
the weight room, where we're purposefully
magnifying the amount of force on our bodies.
We are, in a sense, magnifying all of the
physics equations that we already interact with
on a daily basis. We do this to create a desired
outcome - one that we find meaningful in some
way - and
to achieve in this as efficiently as possible.
So...physics determines how we interact with
the world and it dictates the outcome of the
exercises that we perform (I wouldn't say it's a
stretch to assume that physics is pretty
meaningful to you, then!).
So what is physics, at a more fundamental
level? Physics is (to repeat myself) how we
interact with our surroundings. The basic unit
of physics - as it relates to exercise - is force.
If you google the definition of force, you'll see
numerous results, most of which conclude
something like: "force is an influence that can
change motion".
Force is the bridge between us and the objects
that we touch. Force is what determines what
moves, how it moves, and how it influences
our bodies (and whether movement occurs at
all!). Force is to the weight room as amino
acids are to protein (forces are the building
blocks of movement).
Let's take this a step further now, so that we
can understand how force actually provides
influence in relation to you.
Force is an abstract concept, meaning that
there's no way to directly measure a force
outside of looking at other properties of it.
For example, we measure force through other
proxies like mass and acceleration (that whole
'force is equal to mass times acceleration'
thing).
The units we use for force in the SI system are
Newtons and Pounds in the US system
(freedom units for the win).
There are three major components to every
force: the direction that the force is influencing
an object, the magnitude with which it
influences an object, and the application or
location on which the force influences that
object.
In order words: direction, application and
magnitude.
When looking at the influence of any force on
the body, we need to look at all three of these
force components. Although there are other
influences force, the scope of this book will
mainly cover these three (if you're curious duration and frequency are also highly
important, but won't be discussed here).
Force interacts with our systems through
something called a moment arm.
A moment arm, by objective definition, is the
perpendicular distance between an axis of
rotation and a direction of force relative to that
axis.
In English: a moment arm is what determines a
force's effect on an object, and how powerfully
that force can create influence. It's the shortest
distance between a line of force and where
motion is occurring.
An axis is a pivot point around which objects
(levers) move. Your elbow is an axis for
forearm movement, your door hinge is an axis
for door movement, and your toilet bowl hinge
is an axis for moving the seat up and down.
So, let's take a look more clearly at what a
moment arm is, what it actually looks like, and
why it's essential in our understanding of
exercise physics.
To repeat myself: a moment arm is
perpendicular distance. Perpendicular just
means 90 degrees from (AKA, shortest
distance), and distance is self-explanatory.
Let's look at an example using the elbow joint:
This is an individual doing a curl (hell yeah!).
In order to understand the concept of a
moment arm, we first need to determine what
the major forces are in this equation, and what
the direction of those forces are.
Because the individual is using a free-weight
implement (a bar), we know that (assuming no
significant swinging during the curl) the forces
imposed on the trainee's body are directly
downward, in-line with the direction of gravity.
All 'free weights' (DBs, plates, barbells, KBs
etc.) are going to act this way.
We can draw a line of force from the weight
directly downward from the individual's hand:
An important caveat here is that
we need to make sure to draw
the line of force from where the
point of application of that
object is, not just wherever the
object is. Notice that I drew the
base of the arrow slightly inward
from where to end of the bar is
(because the individual's hands
are actually not in the same spot
as the end of the bar from the
perspective of this photo).
After we determine the line of force from the
point of application, we need to identify the
primary moving axis of the exercise (we will
dive in-depth on axes later). Note that, although
many other axes are being influenced in this
movement, the elbow is the one that is
primarily being challenged.
The red dot indicates the rough center of the
axis of the elbow. These depictions do not need
to be precisely accurate in order to understand
the exercise (the axis will technically change
slightly throughout the range of motion - but
that's a discussion for another time!).
Next (and last!) we can draw the moment arm
using these two points.
Remember that the moment arm is the
perpendicular distance between the direction of
force (which can change at varying points and
with varying intents on the load) and the axis of
rotation that we're looking at.
Below, the green line represents the moment
arm at this point during the exercise.
We will soon talk about
what this implies - don't
worry!
Let's do a few more examples before moving
on. Repetition is important. This may be
difficult at first to see immediately, but, with
more practice, the relative moment arm lengths
will become apparent without you having to
draw them out on paper.
Use the same process every time: begin by
drawing the direction of the force (do this in
your head before scrolling to the next page!).
Did you get it right?
Now, identify the primary working axis
(assume that this individual is getting a sick
biceps pump).
Did you get it right?
Next, draw in the line from the axis to where it
meets the line of force at a 90-degree angle.
I intentionally chose a picture where the line of
force would not be already perpendicular to the
forearm.
The first photo that we used as an example is
easier to see because the moment arm length
was the same as the forearm's length. In the
example below, the direction of force wasn't
already perpendicular to the forearm, so the
moment arm had to 'exit' the space of the body.
Remember that the moment arm may be the
same as the length of the forearm (in elbow
examples), but, a majority of times it will
not.
Let's do one more for the upper body... this one
will be tricky! Don't underestimate it.
Start by drawing the line of force of the object
(a DB, in this case):
Hopefully you remembered that the line of
force starts from the point of application (his
hand!) and NOT just on the DB.
Draw that axis next!
Finish by drawing the moment arm!
But wait...
The arrow doesn't go down far enough in this
depiction!
Alright, so I kind-of tricked you. In this
instance, all you have to do is extend the line of
force down further (yes, you can do that,
because this is just about direction, not
magnitude - more on magnitude later).
Like this!
Now there's a clear line for you to draw in that
moment arm.
Remember that the moment arm is always
perpendicular in relation to force direction;
just make sure you extend the lines of force
when you need to!
Like this!
Now let's do a lower-body example where we'll
look at two primary joints instead of one.
Use the same exact thought process: direction
of force; axis; extend the force if needed;
moment arm(s). The next slide will show all of
the answers for this photo.
Notice that I drew the line of force with an
application through the middle of the foot. This
is somewhat arbitrary, but generally speaking,
this isn't about being as precise as possible (and
using specific numbers and math etc.) but more
so about gathering general data to tell us more
about the exercise.
So, what does all of this moment arm stuff
actually mean, and why is it important?
To understand the answer to that question, we
need to understand the idea of torque.
From a mechanical standpoint, you can't
'torque' your knee like most people on social
media are saying. Torque is a property of force,
not a force on it's own. Forces alone can't 'twist'
- they can only act in straight lines.
In layman's terms: torque represents what a
force's ability is to produce movement.
Torque is equal to the product of a moment arm
and the force (weight, in lifting) you're using
(T=F x MA). Let's go over some real examples.
Imagine you're doing a lateral raise with 10
pound DBs and that the primary moving axis is
the shoulder.
10lbs
10lbs
Now, go through the same process that we've
gone through multiple times. Make sure to
draw out the relevant axis, then the direction of
force and moment arm to that axis. Below is
the final product:
10lbs
3 ft
Now, we can calculate the torque of the
resistance (the DB) acting on the shoulder
using the following equation (I am not
including units as they are not hyper relevant to
this discussion):
T = F x MA
10 x 3 = 30
Now, let's compare the 30 units of force in the
first example to the same exercise with the
same 10-pound DB being used, but at a
different point in the exercise:
10lbs
Don't forget to
1ft
extend that
force direction
both ways!
10lbs
Let's assume
the tiny green
line is = 1ft
here for the
sake of easy
math.
Now calculate resistance torque:
T = F x MA
10 x 1 = 10
Below represents the relative differences in
moment arm (within the SAME EXERCISE) at
both the bottom and top positions.
Notice that the moment arm at the top position
of the lateral raise (the longer moment arm) is
about 3 times longer than at the bottom
position, and that the outcome of resistance
torque in each position is 3 times different (10
units of force compared to 30).
So...within the same exercise, a 10-pound DB
changed its impact of resistance torque on the
shoulder by 3 times the amount! A 10-pound
DB, therefore, is not just a 10-pound DB. How
the DB influences you depends on all of the
factors we've discussed so far.
So far, we've discussed some of the basic
physics concepts that help us determine what
forces exist, which joints they're acting on, and
what the significance of that influence on the
body is.
Now, we're going to continue to look into this
idea of the moment arm, only inside of the
body as opposed to outside of it.
Up to this point, what we've gone over from a
moment arm perspective has all been in relation
to the objects that are external to the body: how
the DBs, the machines and the barbells all act
on us.
Now, we're going to discuss how these
concepts come into play INSIDE of the body:
enter the internal moment arm.
An internal moment arm is the same as an
external moment arm in principle, but has
opposite affects in terms of its application.
Here's what I mean:
When an external moment arm is longer (like at
the top of a DB lateral raise compared to the
bottom), the amount of resistance acting on us
is HIGHER. When an internal moment arm is
longer (like when a majority of muscles are in a
mid-lengthened position), our capacity to
produce force is higher.
The longer that a moment arm gets (whether
internal OR external), the more it increases the
amount of torque (remember that T=F x MA)
in a scenario; whether or not that works for or
against us depends on internal or external
circumstances. Here's a visual example:
Think about the above image as two that are
overlapping, both of which are of someone
doing a curl (i.e. pretend that the person has a
DB in their hand and that the direction of force
is pointing downward toward the bottom of the
page).
Now, let's illustrate what the line of pull of the
biceps are, in relationship to how they act on
the bones they attach to.
Notice that I also drew in the axis of rotation at
the elbow, too. This process should look very
familiar to you by now. Draw in the moment
arm from the line of force that I already drew;
the principles are the same, but now we've just
applied them inside the body.
The green line represents the moment arm that
the biceps have to act on the forearm in the
lower position of elbow flexion (i.e the lower
version of the forearm in greater elbow
extension):
@ben_yanes
Notice that, although there are two lines of
force (one going from the forearm up, one
from the shoulder down), the location I drew
the moment arm is on the moving segment
(the lighter segment of bone will be the one
that moves much more significantly).
Although the force on the shoulder is relevant,
for the purposes of this discussion, we are
focusing on the forces applied at the forearm.
Below I've drawn out the direction of force
from the forearm that's higher up (more elbow
flexion) and also the moment arm in relation to
that position. Notice how I've extended the line
of force downward as shown in previous
examples so that I could find a line
perpendicular to the axis of the elbow.
n_yanes
#2
#1
The lines below represent the relative moment
arm lengths of the biceps (pulling the elbow
into flexion) in position #1 versus #2. Notice
that the moment arm length decreases
significantly from the first to second position,
meaning that the biceps have LESS leverage to
create elbow flexion the shorter that they
become. This means that the biceps have a
higher capacity to produce elbow rotation in
their mid-lengthened position because their
torque-producing capabilities (muscular
torque capabilities) are higher toward position
#1.
#1
#2
Knowing what we know now about internal
versus external moment arms, we can
understand how changing joint position affects
both the external influence of the weight on the
individual as well as the torque-producing
capabilities of the muscles acting around joints.
External Moment
Arms
Internal Moment
Arms
I like to think about this relationship as a seesaw or tug-of-war between internal and
external moment arms and the resultant
resistance (external) and muscular (internal)
torques that they produce.
Every exercise that we choose in the gym can
be seen this way: as a battle and balance
between internal and external torques between
objects, joints & the surrounding contractile
tissues.
Tom Purvis of RTS (I highly recommend
checking out his work) likens this 'battle'
between internal and external forces to a tugof-war; not only between muscles working
around the same joint but also between those
muscles and all forces externally.
Internal Moment
Arms + force
External Moment
Arms + force
Torque
These are pivotal concepts to grasp when
attempting to understand the anatomy of lifting.
Understanding this relationship will always
change across exercises and even within the
same exercise across different portions of the
range of motion; which is why understanding
these as principles and not fact across all
scenarios is also of high importance. In the next
chapter, we will begin the discussion of range
of motion.
RANGE OF MOTION:
Are you #teamfullROM? Do you try to use as
much range of motion as possible across every
exercise? Do you think more range of motion is
better? Or that more range is, in some
fundamental way, more optimal for every goal?
When it comes to range of motion, what we're
really considering in the context of lifting
weights is the range of the muscle or group of
muscles that we're trying to train.
Hopefully, whenever you're selecting an
exercise, you have a general idea of what you're
trying to accomplish with that exercise. It
doesn't have to be as specific as what
subdivision of every muscle and in what length
it's being trained, but it should be something
that vaguely resembles a train of thought
related to the outcome.
Let's use the example of the lateral raise that
we pictured earlier to illustrate the idea of
resistance torque and its importance.
With the lateral raise, hopefully your primary
goal is to train the middle deltoid. Before
beginning to load any exercise, what I like to
do first is determine which path of motion
makes the most sense to load the tissue.
Because this chapter isn't meant to be a thesis
on middle delt mechanics, we'll assume (for
now) that a lateral raise done in the scapular
plane is an efficient exercise to train the middle
deltoid.
Consider the idea of torque again - more
specifically, the resistance torque that the
middle deltoid has to overcome when doing a
lateral raise (recall that we determined the
movement would be mechanically more
difficult toward the top of the range of a lateral
raise as compared to the bottom, assuming no
weight tossing):
11ft
ft
10lbs
10lbs
3 ft
As we showed earlier, the resistance torque we
need to overcome at the top of the range
(around 90 degrees of flexion + abduction) was
about three times more significant in terms of
its magnitude of resistance as compared to at
the bottom of the range.
So what happens if we keep pushing the range
higher? In your own head first, imagine
someone with their arms over their heads like
they're doing the YMCA; imagine the moment
arm to the shoulder in that position, and ask
yourself whether it would be greater, less than,
or equal to the moment arms at lower angles of
flexion. The following image will display the
physics:
Knowing what you know now - re-visit the
questions posed on the first page of this section,
and reflect on your answers before - your
answers may be a bit different!
The general point to be made around range of
motion is this: more range of motion just for
the sake of it is wasted time and energy. More
range of motion isn't and shouldn't be the goal
when it comes to actually training our muscles,
because more range does not imply more
stimulus - in many cases, it may imply the
opposite.
Take the example of the lateral raise - one done
at the angles wherein the moment arms are
longer (we'll say between 30-120 degrees of
flexion + abduction) and one done with 'full
range', where the arms come down all the way
to the sides and then above the head in the most
flexed position of the joint.
Which do you think challenges the middle
deltoid more? The version of the exercise
where the resistance torque falls to nearly zero
for half of the range, or the version where the
resistance torque is constantly high?
Don't take this to mean that the Y raise with
dumbbells is inherently bad or evil - rather, this
is simply one example to use that
illustrates how 'more range of motion' can be
deceiving when not looked at across specific
contexts and individuals.
If you took the path of motion of a Y raise and
instead used cables or resistance bands, the
outcome of that exercise could be completely
different from the DB variation. Instead of
having a moment arm of near-zero at the top of
the range, you could set yourself up so that, at
the top position, the resistance torque could be
at its greatest - meaning that the moment arm
could be longest at the top (whether or not
you'd actually want to have the torque greatest
at the top is part of a different discussion
entirely).
The goal (when it comes to training muscle)
shouldn't be to train full range of motion, but
rather full range of challenge.
This is another concept I've taken from Tom
Purvis (of RTS) which illustrates this idea of
understanding and applying basic physics to
exercise very well.
If you're re-considering everything you've ever
learned by this point, GOOD. That's what this
book is here to do! Challenging your beliefs
and being willing to change them at the
presentation of new, more accurate information
is what this information is ultimately meant to
do.
MACHINES
Machines are a topic of contention in the
fitness industry because people don't
understand how they work. On one hand,
they're either too simple to bother to analyze,
and on the other, they're too 'non-functional,
complex or unnecessary for the majority of
people.
Machines are tools that provide force to the
body, much like any other tool in the gym;
that's it. They're not good or bad without the
context of the goal, who you're working with,
and whether or not the individual is prepared
for or set up for the motion that the machine
provides.
Although there are many different kinds of
machines, all of them provide force through a
foot plate, a handle, or a pad in order to load a
specific plane or planes of motion (much more
on planes later!).
Some machines, like a leg-extension, for
example, provide force through only one
direction. Others, like a free-motion functional
trainer (cable machine) can provide force
through any plane relative to your body. Some
machines also fall in the middle of this
spectrum, wherein the specific plane loaded is
limited in one sense but can be used in multiple
ways. An example
of this is in something like a leg press, where
the machine only moves through one direction,
but the individual using the machine can
choose to vary their stance such that the motion
at the hip (and subsequently muscular stimulus)
is altered.
Since we are just covering the basics in this
book, I'm going to stick to general information
about machines, how many of them function,
and how we can alter their use to our
advantage.
We've all probably heard of the term 'resistance
profile' at some point; but what is a resistance
profile, and, more importantly, why is it
important?
Resistance profiles are the machine-equivalents
of a strength curve. Technically speaking, a
strength curve represents the amount of force
that we can generate from a muscular
standpoint throughout the range of a joint, and
a resistance profile represents the same, just
inside of a machine (and its force-producing
effects on you).
Every machine has a built-in resistance profile
(some of which can be altered, many of which
can't), whether you know it or not (many
resistance profiles are built horribly and work
against us).
So why is a resistance profile important? A
resistance profile is important because it's what
determines how much force a machine
produces against us throughout a range of
motion. In other words, it determines how
difficult an exercise is - be it a row, a curl, an
extension, a squat etc. - at every point
throughout that range for an individual.
Many machines are built with pulley systems,
just like you'd see in any cable machine.
Credit: Google Images
The moment arms produced by a rotating
pulley work no differently than in any of the
examples discussed thus far. In the image
shown above, the pulley rotates clock-wise in
such a way that allows for the resistance to
'drop off' as the individual moves through
elbow flexion.
Many pulleys are not shaped this way and are
circular. The advantage of having an
asymmetrical pulley (like the one above) is
the fact that the machine accommodates for the
amount of strength that the elbow flexors can
produce at every point.
Recall that, based on the strength curve of the
biceps/elbow flexors, the amount of muscular
torque that we are capable of producing will
decrease as we approach full elbow flexion.
In accordance with this: any well-designed
preacher curl machine will alter its resistance
against the individual as they move through the
curling motion (the very bottom & top are deloaded relative to the middle, which is
appropriate).
The ability for an individual to match the
strength of the machine and muscle is what
creates a 'matched' resistance profile; i.e., an
exercise wherein the amount of muscular
torque-producing capability is matched by how
much the machine is acting against the
individual.
Many people that utilize a machine with a wellmatched resistance profile report that the
machine feels 'smooth', and this is because
muscle is challenged appropriately relative to
its strength-producing capabilities through
every point in the range. Although not every
well-designed machine will fit every person
well, the ones that are designed to match
the strength of the muscle(s) being challenged
are typically the ones that feel best for most
people.
If you've ever used a machine that has an
'unmatched' resistance profile - i.e. a machine
that acts against you with greater resistance
torque when you're weaker and a lesser
resistance torque when you're stronger - it feels
'clunky' and unnatural. Whenever using
'unmatched' resistance profiles, the individual
has a greater tendency to cheat using inertial
effects to move the weight (tossing it,
generating momentum with other tissues etc.).
The example of the preacher curl machine
matching the strength-producing capabilities of
the elbow flexors is a perfect example to use
when discussing the concept of 'full range of
challenge' discussed in the previous section.
The easiest way to provide a full range
challenge is to match the strength of a muscle
against a resistance that is equally challenging
at every point through the range. This provides
the most efficient stimulus for the target tissue,
as no reps (and no portion within them) are
'wasted'.
If you've ever seen a machine that uses a
weight stack (pin-loaded machines), pulleys are
being used. Not all machines utilize pulleys
exclusively, however!
Machines like leg-presses, chest presses, rows
and many others utilize plate-loading as the
mechanism through which resistance is created.
Although every machine is different in some
way, all of them function off of the same
physics principles that have been discussed so
far.
Pictured above is a plate-loaded pulldown
machine made by Prime Fitness. If you take a
look at the weight sleeve, you'll notice that
there are three different locations that you can
choose to add weight to the machine.
Because plate-loaded machines utilize 'freeweight', we use gravity as our force-direction;
i.e. we can analyze the resistance
profile and how it would change based on
forces pointing directly downard toward the
floor below the machine.
Picture someone adding plates to the highest
weight sleeve, sleeve #3. Draw the line of force
directly down from the sleeve and picture the
moment arm as a result in the static bottom
position. Use the exact same process that you
used to draw out the moment arms in all
previous examples (inside of the body and
external to it):
This is the
axis
Now, take note of that distance, and draw out
the same moment arms for the other two
sleeves, sleeves #1 and #2:
Bonus info: as this machine
moves, it will move in an
arc, not a straight line. This
makes drawing the moment
arms slightly more
complex, but the same in
principle. If you're
interested in this concept,
google 'tangential forces' for
more info.
I felt a need to
include this caveat
for the sake of
illustrating that this
image is not in
motion and is oversimplified to a
degree.
Take note of how different the moment arms
are between each sleeve and where the entire
lever is rotating around.
The top weight sleeve provides a much longer
moment arm to the pivot point in the bottom
position. As the individual pulls on the handles,
the machine will rotate up and back and that
top sleeve will move closer to the axis of
rotation. Because the sleeve will move closer to
the axis, the moment arm will decrease.
This effectively means that, if you put weight
on the top sleeve, the load against you has a
greater resistance torque in the bottom as
compared to the top.
Putting weight on the bottommost sleeve will
do the exact opposite; picture how the pivot
point and lowest weight sleeve would move
farther away from one another as the axis
rotates, making the weight gradually heavier as
the individual pulls (this means it would
become harder as the individual approached the
short position).
This conversation is not based on which load
placement would be 'better' in absolute, but
rather is meant to demonstrate how plate loaded
machines with multiple options for loading can
influence the outcome of the movement
differently. Many machines that are plate
loaded only have one sleeve to load, but all
of the principles of moment arm and resistance
torque remain the same when looking at those.
Other machines, such as a 45° hyperextension,
use the structure of the individual as the levers
of the movement as opposed to something
intrinsic to the machine.
Of course, both the levers of the individual
using the machine and the machine are
important, however both should be looked at
individually and analyzed individually before
looking at the picture as a whole to understand
how the two interact. If you want to figure out
where a machine is heaviest, go to failure under
control and you'll find out. :)
Machines that have more adjustability are
advantageous in being able to fit the structure
of more total people. The problem with a
greater amount of adjustability is that most
machines are made to be in commercial gyms
where general population individuals train.
Most non-trainers (and many trainers
themselves) aren't aware of how to use more
adjustability. Many machines, for this reason,
intentionally lack adjustability and attempt to
fit the structure of the average person. Many
machines won’t fit people perfectly without
some degree of manipulation of the machine.
This is true both from a structural standpoint
and a path of motion standpoint.
Because these structural considerations will
change from machine to machine (and personperson!), we will not be able to get into the
specifics of every machine. However, some
general principles can be applied to commonly
used machines:
1) Much like anything else, machines are
neither good nor bad. They either fit the context
of the goal, or they don’t. Some machines may
work better for some people (for some goals)
but you cannot call a machine good in absolute
without the context of the greater picture (much
like everything else we've discussed). Use the
machine that fits you well (or that you can
adjust to fit you well) only if it suits your goals
and needs in training.
2) Align the path of motion of your arm or leg
in the direction that is being loaded. When
using any machine, you want to work within
the range of the machine that the person can
actively control without it. An easy way to
figure this out is to reproduce the path of
motion that the machine provides without
actually contacting it. If you are comfortable
working within this range using only your
bodyweight while matching the path of motion
of the machine, it is likely that you will be able
to comfortably and progressively load the
machine over time. If you find that performing
the motion without any added load causes
discomfort or too many secondary
rotational mechanics (not loaded in the plane of
the machine), then that particular machine may
not be best to use long-term. This is not an
absolute rule, but rather a general guideline to
follow if you’re looking to analyze the
mechanics of any machine and how they fit
you. Adding handles to a row machine that are
free moving can be extremely beneficial for
this reason.
3) Although the resistance profile of every
machine may not align well with the strength
curve of the target muscle(s), there are ways to
utilize inertial effects so that the muscular and
resistance torques are more closely matched.
For example, if you are using a row machine
that gets harder as you pull (where you're
weaker), it may behoove you to utilize a bit of
momentum-based intent at the beginning of the
pull, so that the short position becomes
relatively easier.
4) Using a bilateral machine unilaterally can
completely change the way that you interact
with a machine. When doing a movement
unilaterally, you gain the ability to adjust the
orientation of your arm or leg much more
easily than if you were to fix yourself into place
with both hands or feet. Doing this is
essentially the same as adding more degrees of
adjustability to whatever machine you're using.
An example of this that I often employ is using
a row or press machine unilaterally while I
adjust how I sit in the machine/how my torso or
hips are oriented relative to my upper
extremity. Making these seemingly minor
adjustments to where you can comfortably
pull/press/extend/flex can make the exercise a
completely new one for you.
Cable-only machines:
Using regular cable pulleys - like a prime
functional trainer - is a fantastic way to create
more adjustability with a multitude of upper
body exercises. Because the circular pulleys
only redirect force (and don't make a separate
profile on their own like the asymmetrical one
earlier), it is incredibly easy to set up lines of
force where you want them, relative to the joint
angle that you want to load.
Most pulleys also accommodate for minute
changes in joint rotation because many pulleys
rotate around two axes. Subtle rotations in
internal or external motion, for instance, may
be needed during presses and pulls. Most
machines, on their own, do not account for
these subtle rotations unless they have freemoving handles and/or adjustable paths of
motion.
One of the main drawbacks of using cables can
be adding external stability in certain
circumstances where it may be needed (like
during heavy cable rows or presses).
Using machines AND cables in tandem is a
great way to extract the benefits of both
modalities while not incurring too much of the
downsides to either in isolation. This is yet
another reason not to limit yourself to one or a
few modalities. Often times, many modalities
used together can optimize results most.
JOINT STRUCTURE
When we observe motion occurring from a
superficial perspective, what we see moving are
the levers of the body. Examples of these are
the forearm, the femur, the tibia etc. all in
different scenarios. This isn't where motion
actually occurs, though. Enter the discussion of
joints!
Joints are the junctions of bones, where all
movement is ultimately created. The primary
joints that we'll be discussing are all synovial
joints: lubricated pivots points that allow all of
the major muscle groups (that we'll later
discuss) to act around.
Synovial joints are super cool. They're layered
with a connective tissue called hyaline
cartilage, which is primarily composed of a
protein called collagen. This cartilage is
incredibly smooth and allows bones to slide
along one another (not with actual bone-bone
contact) to provide a surface for smooth
articular motion.
Hyaline cartilage is what provides nutrition to
the bone (when the joint gets compressed and
decompressed) in tandem with the synovial
fluid that's released into the joint capsule by the
synovial membrane. This is an incredible
mechanism that allows the body to lubricate
and create its own nutrition to keep our joints
healthy long-term. If you've ever heard the
phrase "motion is lotion" - well, it quite
literally is. Motion is what allows for the
hyaline to release nutrition to the surrounding
connective tissues, even though it itself is
devoid of blood vessels and nerves.
Joint
Capsule
Hyaline
(articular)
Cartilage
Image Credit: Kenhub.com
There are a few major synovial joint types
that's we'll be discussing in this book: hinge,
ball and socket, and pivot joints. There are
multiple other kinds of synovial joints that we
will not get into in this book, but just be aware
that more exist. We are discussing these 3
because they are the joint-types that the major
muscle groups we'll be discussing act around.
For each joint, we'll discuss two major
components:
1) Degrees of freedom that the joint has:
how many planes of motion does the joint
move in?
We can imagine a plane of motion with an
analogy: windshield wipers on a car have a
point from with they pivot. The wipers
themselves are the moving segments (bone)
and the plane that the wipers move on is the
glass itself. We can imagine this in relation to
every single joint in the body.
2) Examples of the joint type. There will be
multiple examples to draw upon for each joint
type, although we'll focus on just one for each
category. Keep in mind that all specific joints
that fall under each category of joint type will
move in a very similar way (i.e. the shoulder
and hip are both ball and socket and their
motion qualities are similar to some degree).
Image Credit: Kenhub.com
Hinge Joint:
Degrees of freedom: 1
Example: tibiofemoral
joint (part of the knee)
The knee technically
operates in two planes
(google 'screw-home
mechanism' if you're
interested in that), but for
all intents and purposes,
the knee acts around the
medial-lateral (side to
side) axis. The structure
of the knee does not allow
for side-side movement
and as a consequence it
does not have contractile
tissue that stabilizes it in
the medial-lateral plane.
The knee only pivots in
one direction.
Ball and Socket Joint:
Degrees of freedom: 3
Example: glenohumeral
joint (part of the shoulder
complex)
The GH joint operates
with three degrees of
freedom, meaning that it
can move in the sagittal,
frontal and transverse
planes and combinations
of all three of them (there
are an infinite number of
planes in reality!). This
allows it to be a very
mobile but not very
structurally stable joint.
Image Credit: Kenhub.com
Pivot Joint
Degrees of freedom: 1
Example: radioulnar
joint
Image Credit: Kenhub.com
Pivot joints do exactly
what they sound like they
do, which is to pivot
around an axis much like
in the photo above. The
radioulnar joint is
probably the easiest to
conceptualize this motion
visually, and is what
allows for pronation and
supination of the forearm
to occur (this is what
visually looks like people
turning their palms up
and down as the arms are
fixed).
Now that we know the basic types of joints and
their degrees of freedom, we need to talk about
joint structure.
Joint structure determines what ranges of
mobility we have available to us. If you've ever
heard the phrase 'structure determines function',
this is what it's meant to illustrate; that there are
structural constraints and physical bony
limitations within which we all have an ability
to contract. Let's look into a few examples.
An obvious example to visualize are the end
ranges of knee extension and flexion:
When the knee bends fully, the
constraints that the hamstrings
and calves create (upon contact)
stop the knee from flexing any
more. We could consider this a
structural endpoint wherein
contractile tissue abuts.
Image Credit: Kenhub.com
Something similar may occur
when the knee extends but for a
different reason. In this
instance, the joint end-range
may be reached because the
tibia can no longer continue to
translate forward as it abuts the
front/bottom of the femur. This
is another example of a
structural constraint in range
that may be due more so to
bony limitation as opposed to
tissue that lies more superficial.
Let's look at another
example in the pelvis.
Shown to the left is
frontal plane abduction
of the hip. Can you
imagine what may stop
this motion from
occuring?
Image Credit: Kenhub.com
Image Credit: Kenhub.com
Looking at the structure of the pelvis, take
note of what bony landmarks stick out to you,
and which ones will tend to abut one another
with every joint motion.
In the example of hip abduction above, the
greater trochanter will at some point
approximate the lateral aspect of the ileum
bone (shown with arrows). This will provide a
structural end range that is in bony contact
rather than superficial tissues touching one
another. Of course, both will play a role, but
these are all just considerations to make in the
context of observing joint range.
Now let's consider the fact that every
individual that trains is an N of 1, meaning
that their structure (bony landmarks, the size
of them, the shape of them, size of muscle
tissue, structure of other soft tissues etc.) will be
individual to them. Doesn't it seem silly now to
think that everyone should be able to achieve
certain arbitrary joint range standards? What if
the structure prevents the individual from
achieving 180 degrees of shoulder (overhead)
flexion? What if, by attempting to increase these
end ranges, we're actually creating more issues
than we're solving?
This is where I strongly question modalities like
static passive stretching which are meant to
increase joint range devoid of the contractile
capabilities of the individual. If you or your
client have specific structures and/or
osteoarthritic changes that actually make
pushing more range a potential danger to the
system, then you're violating the joints that
you're trying to take care of in the first place.
We are not meant to move around like cartoons
in every way imaginable. We have specific
structural end-ranges that are build into the
frameworks of our bodies. This is why
improving range of motion should not be a goal,
but rather a consequence of the individual's
ability to work within what they can actively
control and tolerate on any given day.
Attempting to give yourself or your client more
range of joint mobility just for the sake of it is
not doing anyone any favors. This topic alone
could comprise an entire chapter in this book,
but for now, I'll leave it at that (and maybe
finish that thought in an additional book :)).
Joint Motion
Now that we've gone over some of the basics
as it relates to joint structure, let's talk about
motion.
Recall that every joint is the origin of motion
and not the surrounding bony levers.
Although it may appear that the levers that we
translate force through are doing the moving
(such as a an upper leg, upper arm or forearm
etc.), where motion actually occurs is around
an axis that lies somewhere close to the
middle of the joint (there are exceptions to
this).
Before we look into some visuals, let's cover a
bit of terminology. Terminology is an
important aspect of specificity. Specificity is
crucial when it comes to describing motion
because there are many different ways to
describe similar things. For example, I could
say "abduct your hip" and you could do 10
different things. You could abduct it from a
standing or a seated position, from a standing
position but somewhere slightly out in front
of the body or behind it etc.
Anyways - enough rambling!
Axis of rotation: the point around which
bones pivot. An axis is technically a line that
goes through a specific plane, as shown
below:
Image Credit: Kenhub.com
We could also use the term
fulcrum, which is meant to
describe a fixed point
around which rotation can
occur. If you wanted to
only draw the fulcrum on
the image to the right, you'd
simply remove the green
line and keep the circle. I
use fulcrum and axis
interchangeably because
using the two separately
creates confusion at no
benefit to understanding. I
like to use plane of motion
to illustrate where axes are
in different motions
because it's easier to
understand intuitively (as
mentioned earlier - recall
the windshield wiper
analogy).
Plane of motion: from a technical standpoint is
the line perpendicular to the axis of rotation. If it's
complicated to visualize, picture the windshield
analogy again. The 'axis' of the wipers would be
going directly through the glass (entering it at 90
degrees), almost as if it were a pole crashing
through the glass. Another way to think about
plane of motion is to equate it with the direction
of motion. Flex and extend your knee and you'll
see that the plane of motion is parallel with the leg
and that the axis of rotation is perpendicular to
that, going straight through the sides of the knee.
Image Credit: Kenhub.com
Let's look at a few examples now, starting with
hip adduction in the frontal plane. Notice first the
green dots that represent the axis of rotation for
this motion (again, technically a fulcrum, but axis
works just fine) and the plane of motion which
would be perpendicular to that. Before reading on
below, try to visualize the plane of motion.
The plane of motion here would be the direction
your screen is facing. If I could draw a line going
directly through the screen (entering the screen at
90 degrees), that would represent how the axis of
rotation would actually extend. Let's look at
another example:
Image Credit: Kenhub.com
Shown again in green is the axis of rotation for
movement at the knee, which would technically
be going through the screen at 90 degrees if I
could extend it that way. The plane of motion of
this movement being flexion and extension of the
knee would dictate that that plane of motion
would be a line that sits as the screen does (put
your hand on the screen, and that's the plane!).
Hopefully the repetition helps with this. It can be
tricky to see at first, but once you get it, you get it.
Something I would highly recommend is
downloading an app like Complete Anatomy '22
and going through all of the joint motions of there
to see things in 3D.
Let's briefly go over what we've talked about so
far (in no particular order) before we get into the
fun stuff - muscles!
1) Moment Arms - external and internal moment
arms (recall perpendicular distance)
2) Levers - bones! Recall structure as the bedrock
of range of available joint motion/mobility
3) Force (or influence) and its three major
components: direction, magnitude or amount
(which we did not cover extensively),
location/point of application
4) Torque (T= force x moment arm) and the
tug-of-war of internal and external moment arms
and forces
5) Basic Machine Mechanics - pulleys, plate
loaded machines, linear machines
6) Joint Structure - recall structure as the
foundation for function and motion, and that this
differs significantly between individuals (N is
always =1)
7) Joint Motion - axes of rotation, planes of
motion, fulcrums, levers
8) Types of joints - degrees of freedom, planes of
motion
MUSCLES:
We live in a day and age where information about
every muscle in the body is somewhere on some
fitness influencer's page. How many of you think
that those influencers have taken the time to learn
all of the physics concepts we've discussed? How
many of you think that they've sat down and
learned about joint structure before making a post
about doing leg extensions sideways?
Now that we've got a solid foundation of
understanding of the aforementioned topics, we're
now able to dive into muscles. Muscles don't
come first (even though they have for many);
physics and structure do.
Notice that we didn't start off this book by talking
about the fiber orientation of the lateral head of
triceps or the angle of pull of the medial
hamstrings; we talked about all of the things that
are the foundation for being able to look at and
answer questions about those topics on your own.
Too many people today start trying to learn about
muscle action without understanding all of the
physics and joint-related concepts. I was one of
those people too (*sigh*), which is partially why
I'm writing this E-book in the first place - to be
able to give people more of a truly foundational
starting point. It's unfortunate that this is the state
of the industry and how people learn, but makes
perfect sense given that a majority of people are
getting most of their information from social
media.
In principle, all of the topics we've discussed so
far should give you most of the answers you want
as it relates to looking at muscular function and
how to train them - all it takes is repetition of
those concepts applied to different tissues!
In theory, training for strength and hypertrophy
(which, if you're not a powerlifter, are pretty
much the same things FYI), is pretty simple:
1) Take every muscle you train through its
stretched position and then shorten it under load.
Use various exercises to do this.
2) Repeat step #1 with enough volume, exertion
and food.
But in application, it's much trickier than this.
Why? Because to understand all of the elements
of how a muscle acts, we need to understand the
physics and structure concepts, which a majority
of people in this industry (including well-known
coaches, trainers and athletes) do not.
So let's dive into some application (now that I've
gotten that out of my system)!
Fiber Direction:
Fiber direction is pretty easy to understand
intuitively. Every muscle is oriented in such a
way that, when it pulls on the bones it attaches to,
it influences those bones in a manner that differs
from every other muscle. Fiber direction is
influenced by a number of
things, to include (but not limited to): direction of
fibers attaching to origin, direction of fibers
attaching to insertion, other muscles that share
similar origins and or insertions, total length of
the tissue, moving bones between origins and
insertions, non-moving bones between origins and
insertions and many more.
In application, what's most important to recall is
that forces only act in straight lines (remember
that whole conversation around torque and how
you can't torque an object?), they don't act in arcs
of motion as is visibly represented in motion.
If a group of muscle fibers is distorted in such a
way wherein the belly of the tissue is 'twisted',
when it contracts, it will attempt to create the
shortest distance that it can between attachment
sites. This is synonymous with saying that the
fibers of a particular muscle will attempt to
shorten into a straight line if effectively recruited.
Let's look at a few examples now.
Note that the long head
of triceps (red arrow)
has an origin that lies
medial (closer to the
spine) to the insertion
and that, if you look
closely, the fibers wrap
inward/downward in an
oblique direction as they
insert into the olecranon.
What does this imply?
Image Credit:
Kenhub.com
If we look at the long head of the triceps from
a different angle, this oblique fiber direction
becomes more clear. This is why I mentioned
earlier it's important to learn these things in
3D!
Because the fibers insert down toward the
elbow at an angle, if only the long head were
to contract, the arm would be pulled like this:
Image Credit: Complete
Anatomy '22
If we picture what that line of pull would do
to the upper arm: the long head can function
as a shoulder external rotator (not really in
practice, but in principle it could).
Now, would it be reasonable to say that
ONLY the long head could contract if I
extended by elbow? Of course not - but what
this illustrates is that, even though the fibers
appear to be pulling in a 'curved' direction,
their influence - like all other forces - acts in a
straight line.
In this particular example, if I maintained that
externally rotated position, those distal fibers
of the long head would move more parallel to
the bone, making the arrangement of fibers
such that they're as close to being a straight
line as possible.
Practically speaking, then, if I wanted to 'bias'
the long head of the triceps with an elbow
extension movement, I'd put my shoulder into
an externally rotated position and then I'd hold
that position as I worked through elbow
flexion and extension against load (like in a
single arm cable pushdown).
This is effectively how all biases are created:
the brain chooses the solution that most
efficiently solves the problem. Assuming that
you're talking about the muscles on the correct
side of a joint you're trying to train, your brain
will contract the tissue that's aligned in the
straightest possible orientation between its
attachment sites. Of course, forces also need
to be set up properly, but that's specific to
each exercise.
An analogy I like to think of to teach this:
imagine that you're driving a couple of miles
to the grocery store. You have the option to
take two different routes; one that takes you 2
miles north and then one mile east, or one that
takes you 2.5 miles northeast. Which one
would you take? I'll let you decide :)
Let's look at another example in the upper
extremity in the rear deltoid.
Image Credit:
Kenhub.com
The arrow above points roughly to the middle
of the rear deltoid, of which there are 3
subdivisions.
Imagine moving the humerus from this static
anatomical position and raising it out into
frontal plane abduction (straight out to the
sides). How would fiber orientation shift?
Pictured below is frontal plane abduction of
the arm in a degree of external rotation. Check
out what happens to the rear delt:
Image Credit: Complete
Anatomy '22
Straight line (more
efficient) fibers
*Imagine doing a
DB row with your
arm out to the side
like this. This is
what
would
Bending (less efficient)
fibers
preferentially be
recruited with
forces specficic to
that scenario.
Observe now how the fiber orientation
changes and which portion of the highlighted
segment would be more efficient at pulling the
arm directly back from here. It would be the
fibers that have more of a straight-lined
orientation (the ones that are more lateral on
the scapula)!
Now picture in your head how that orientation
would shift with a shoulder position that was
more adducted (closer to the body).
Hopefully you can imagine how the more
medial portions of the rear delt would be more
efficient at pulling the arm back if the arm
moves closer into the body.
Now, be careful with the application of this
information. These specifics aren't trying to
tell you that you should be so myopic and
nuanced about your training that you should
train every division of every muscle with a
different exercise (impossible to do
anyways!); rather, these examples are purely
meant to illustrate visually how different
portions of a muscle can 1) be biased over
others and 2) how fiber orientation functions
to align the length of the muscle in as straight
a line as possible between attachment sites
(and how all muscles will look to do this).
Let's look at an
example in the lower
body to illustrate a
different point. Take
the quads, for example.
Note that all of the
different fiber
orientations are
oriented in an oblique
(diagonal) direction,
much like the long
head of the triceps
toward the distal end of
the upper arm.
Image Credit:
Kenhub.com
The quads are a muscle group that is multipennate, which is a fancy way of saying
they're oriented diagonally relative to the
length of the bone (femur) they lie on. This
allows more fibers to be packed into the same
amount of space as if those same fibers were
running parallel to the bone. But how are they
going to act on the knee to pull it in a straight
line? The answer is in resultants.
A resultant is the net force of two or more
forces acting on an object. I purposefully
didn't put this in the introductory section so
that I could introduce it here with a visual
example.
Because the knee is a hinge joint with
(practically speaking) one degree of freedom
in the sagittal plane, both the medial and
lateral aspects of the quads will pull on the
patella to create a resultant force (along with
the intermediate quads along the middle of the
femur) that goes directly sagittal.
Can you picture that in your head before I
draw out the diagram? Try to visualize it on
your own before scrolling.
Here's what it looks like:
Image Credit:
Kenhub.com
The net forces from
both the medial and
lateral aspects of the
quads (within the
muscles themselves)
are drawn in red, and
the resultant arrow is
drawn in bright green.
Let's look at another
example of this in the
upper body.
Of course, the upper, middle and lower traps
could all act preferentially, but to illustrate
the concept of resultants, let's assume that
you're doing something similar to a row,
where the scapulae need to move inward
toward the spine. What would the resultant
look like?
Image Credit:
Kenhub.com
Keep in mind this is an over-simplified
illustration meant to demonstrate the point.
The upper traps insert on the clavicle too, but
what I illustrated here were net forces of all
of the upper portions of the trap pulled
toward the head and all of the lower portions
pulling down toward the lower thoracic spine.
The outcome of these two (very theoretical)
lines of pull would be something similar to
the green resultant as shown above.
Now that we've got a solid understanding of
fiber direction and lines of influence, we can
understand - at least, in theory - how to fully
stretch and shorten any muscle, or any
subdivision of any muscle: orient the fibers so
that they're arranged in a way that creates the
most efficient solution for the brain to choose
upon contraction, and then move within that
arc of motion to train the tissue.
In Layman's terms: put the muscle into a
straight line, and then stretch and shorten it
under load. This is much easier said than
done in application, but in the specific muscle
sections, we'll be diving into the basics of
most of the major muscle groups.
Moment Arms:
We discussed early on the concept of a
moment arm: what it is, why it's important
and the basics of its relation to exercise.
Now, we're going to talk more specifically
(and give more examples) about the internal
moment arm.
Recall this idea of torque, and how it
functions as a property of force; one that
determines the effectiveness of a force on
you, or - in the case of this section - the
effectiveness of a muscle in its ability to
move the bones that it attaches to.
Because torque is the product of force and
moment arm, we can say that, in relation to
external torque, the force is the resistance
you're holding or contacting (i.e. a DB, a
barbell, machines, cables etc.).
The forces internally - and in relation to
internal torques - are how much tension lies
between the muscle belly and wherever it
attaches to. Knowing the precise numbers of
these forces are not what's relevant in this
section, however (or really anywhere besides
research and the application thereof). What IS
relevant in this section are the internal
moment arms we'll be discussing and their
effect on what we're going to call muscular
torque.
So, to summarize in brief: external torque we
can define as resistance torque, and internal
torque we can define as muscular torque. This
section is dedicated to elaborating on what
enhances or diminishes muscular torque: the
internal moment arm.
Recall the illustration early on in the physics
section of an elbow and how we drew out the
internal moment arms at various points
throughout the range of contraction:
@ben_yanes
Also recall how this internal moment arm
from the insertion of the biceps to the axis of
rotation at the elbow changes as the elbow
continues to flex:
And finally how we made a comparison
between the two internal moment arms to
show how, in the more elbow-extended
position, we had a greater internal moment
arm, which meant a greater ability to produce
muscular torque around the elbow joint:
#2
#1
#1
#2
(torque = F x MA - moment arm #1 being
about 30% longer could potentially mean
producing close to 50%+ more muscular
torque)
Hopefully that served as a good refresher for
the concept of internal moment arms. Let's
dive into some other examples!
Everyone wants to bench press with a really
wide grip, but let's look into why that's not
advantageous from a pec-training perspective
(hint: it's because of internal moment arm!).
First, draw out the internal moment arms for
any tissue you're looking it. The angle at
which you look at them will differ based
upon location and structure of the muscle.
Because the pecs are a fan-shaped muscle that
wraps around the ribs, it's easiest to see
moment arms from a sagittal viewpoint. For
simplicity's sake, in this example, we're just
going to choose to look at the sternal division
of the pec.
Image Credit:
Complete Anatomy '22
If you need a refresher on the steps to identify
the internal moment arms, see the
introductory section again on basic physics
before proceeding.
Take note of the moment arm shown (in
green) above. Now let's look at an image that
shows the arm in the 'guillotine' position as
many gym bros call it:
Image Credit:
Complete Anatomy '22
(apologies for the faded deltoid that's in the
way)
Not too great of a moment arm in the moreabducted position, huh? Let's compare the
internal moment arms below (scaled
appropriately):
Wide
Narrow
In this instance, we can conclude that the pecs
(generally speaking) have greater internal
leverage in a relatively adducted position,
where the arm is closer to the side of the body
- as compared to a more abducted position,
where the arms are out wide close to 80+
degrees of abduction.
Internal moment arms are half of what
determines leverage (T = F x MA).
Let's look at another example, but in the
lower body.
As discussed previously, the quads are a
multi-pennate muscle that act on the knee
joint. Although their fiber direction appears to
pull the patella in several different directions
(medial/lateral), the net forces will (under
normal, healthy circumstances) translate the
patella in the sagittal plane as the knee is
meant to flex and extend. Let's take a look at
internal moment arms throughout the range of
knee flexion and extension:
Let's first look at the quadricep's leverage for
knee extension with a knee bent around 90
degrees (keep in mind that this is not full
knee flexion for most people!):
Image Credit:
Complete Anatomy '22
And now in a more relatively knee-extended
position (not fully extended for most!):
Image Credit:
Complete Anatomy '22
And now let's compare the two moment arms
scaled the same way:
More extended
knee
More flexed
knee
Although not drawn perfectly in any of these
pictures, I hope that these moment arm
illustrations are starting to make sense across
the board.
We can see clearly that the moment arm for
knee extension decreases significantly the
shorter that the quadriceps become. This is
what is responsible for the decreasing amount
of muscular torque you're able to produce as
you straighten your knees (amongst a few
other things such as exercise selection,
execution, muscle length etc.).
Now that we've discussed both fiber direction
and internal moment arms, it's time to start
diving specifically into the major muscle
groups that we look to develop in the weight
room. Specific joint structures will be
discussed in greater depth in the following
sections as is necessary to understand each
muscle's function, which is why there hasn't
been an in-depth section up to this point on it.
I've put a lot of thought into how I wanted to
present the muscle mechanics information
and settled on making videos where I could
actually talk and show things in real time.
Plus, you're probably tired of reading at this
point, so it makes sense anyways.
For every major group, I made a
corresponding video that goes over the
specifics of each tissue in tandem with some
information about the joints they surround.
Keep in mind these are meant to illustrate the
basics of a lot of these tissues and that each
video on its own probably could've been an
hour (or more) each. I tried to keep rambling
to a minimum and hopefully everything is
concise.
Below you will find all of the links to each of
the major groups as hyperlinks. Simply click
on whichever group you want to see and
you'll be taken to an unlisted YouTube
upload. I advise going in order from top to
bottom because there are a number of
concepts that I introduce in earlier videos that
I assume as prior knowledge in later ones. I
hope you enjoy.
Calves & Tibialis
Quads
Hamstrings
Glutes
Trunk Muscles
Hip Flexors & Adductors
Pecs & Lats
Delts
Arms & Forearms
Upper Back
Hopefully that all was much easier to see and
hear in real time as opposed to me trying to
describe (in text) all of the minutia that I wanted
to cover for each group. I recommend going
over these videos again at various points or
prior to training sessions of your own so that
you can visualize and feel the motions for
yourself and see where your own ranges align
well for each tissue.
Notice that I didn't get into many specific
exercises for each of the groups, other than
listing a few generally and making reference to
them when discussing relative length biases.
This book is not meant to function as some
cookie-cutter program that's just going to give
you all of the answers to generalized questions
like "what are the best exercises for XYZ
muscle group?".
Rather, this book is meant to function as a means
of providing the tools that you can practice using
on your own. The old adage of 'teach a man to
fish' has high application to these topics in
particular, because once you've honed in your
own thought process on all of this information,
you can use it and apply it to any scenario to
accomplish whatever you want.
Once you've got a good grasp of this information,
you'll be able to set anything up in a way that's
appropriate for yourself or anyone that you're
going to train. You'll quickly come to realize that
every scenario you encounter will be slightly
different in some way, but that that's ok because
it's part of solving the puzzle of each client or of
each exercise within your own training.
Honing the tools here long-term will be where the
results really start to manifest themselves. I hope
this makes sense; and if it doesn't now, it will
eventually with enough repetition.
If you enjoyed this short Ebook or my content in
general and want to support me so that I can
continue to create in this way, please refer it to
friends or share it to your platform so that more
people can pick it up. I ask that you please not
share the PDF with those who haven't actually
purchased it, as these thoughts took a long time to
consolidate and articulate. I really think so many
of the issues we face as an industry as it relates to
exercise comes from not understanding these
fundamentals.
Thank you :)