WEBTOON advanced Importance of understanding structure-legs, feet
GCC academy
Hello, this is Webtoon artist Uksoo
Today we're going to cover the anatomy of the lower body, legs, and feet
Legs in Webtoon drawings
is like the back
Actually, it doesn't show that much
If it does appear, there must be a clear intention or purpose
Often requires detailed elements
At the same time, I don't draw much, so I'm not used to drawing
It's something like that
But to me, I like drawing legs
It's much more fun and enjoyable
to express beautiful curves in the lower body than in the upper body
Anyway, today
Let's look at the anatomy of the legs and feet
and when drawing these
Let's see if we can apply it
As before, we start with the bones
We'll cover muscles and other features
However, in the case of the foot, we will not cover the anatomy of the bones and muscles
The feet, rather than about anatomical detail,
I think it's more important to understand the structural form
So let me explain with some examples of feet
and explain the necessary parts
Muscles and bones of the legs
First, let's look at the leg bones
As in the arm area, there were synovial and free bones
The leg bones are also the shin bones
and free leg bones
The pelvic bone is the synovial bone
The free leg bones are specifically the femur,
tibia, fibula,
And here's the cute kneecap (patella)
The legs are somehow simpler than the arms
First of all, the pelvis is the joint of the legs
Because we covered it in the last body section
Let's take a quick look and move on
The pelvic bone is composed of the hip bone
and the sacrum located in the center
These two form a shape similar to
a washbasin
The hollow point on the buttock side of the pelvis
is where the gluteus maximus, the widest part of the hip bone, attaches
This is a point that stands out especially in women
It's a good landmark to depict when emphasizing sexual appeal
Now, let's talk about the free leg bone
Let's take a look at them one by one
Let's look at the femur first
It's often called the femur
The femur is the largest and longest bone in the human body
It is said to have the length About 44cm on average for adults
of about 44cm on average for adults
If a body with only partial bones is found
If you have the femur, using that as a reference
It is said that you can estimate the height while they were alive
In movies, you see primitive people swinging bones
while shouting
In many cases, the bone being held is the thigh of some animal
Because it is the largest and strongest bone
This bone is the foundation of the lower body and supports the weight of the upper body
Because it has to hold on to large muscles responsible
of powerful movements of the lower body
It has become very large in size
The head of the femur
is fitted into the acetabulum of the pelvic bone
Allowing forward, backward, left, right, up and down movement of the legs
In the case of the neck, which connects the body and the head of the femur,
On average, it is bent at around 120 degrees
The bones in a straight line are not directly connected to the joints
A protruding femoral neck
has a structure connected to the head
This is a structure that allows for more diverse maneuvers
At the same time, it is caught between the femur and the pelvic bone
Therefore there may be limitations to exercise
It is similar to the structure of the shoulder blade and humerus
The way the femur is raised towards the head
is the same with arms
It can't be lifted properly from the side
What did we do when we were to lift our arms all the way up?
Yes, I said to put your arms out in front and then go up
The same goes for the exercise of the femur
To prevent the femoral head from becoming engulfed in a large tubercle
Just put the legs forward and go up
In men, the greater trochanter of the femur
becomes an important landmark
This large protrusion is located at the center of the lateral gluteus maximus
of a sunken shape
This is the part where the bones are relatively exposed
So, it emphasizes well-trained, solid muscles
When you want to express a man's sexual attractiveness
That's a good point to emphasize
Now let's look at the tibia and fibula on the calf side
The shinbone, or tibia, is the bone that connects the ankle and the knee
It supports body weight and absorbs shock
and converts the absorbed shock into the power of a leap
It plays a variety of roles
It can be seen as a key point showing the boundary line
between the flexor and extensor of the calf
The tibia is not buried in the middle of the muscles
It's a structure that is almost completely exposed on the front of the calf
When it comes to so-called joint cracking
You could say it's the bone that's referred to when saying that joint
If you're hit here, the bone will be hit right through
How much would it hurt
Meanwhile, the tibia is responsible for the inner malleolus
Setting limits to lateral ankle motion
In simple terms, it prevents ankle twisting
Next is the calf bone
It's called the fibula
This fibula is next to the tibia
It is a bone that plays an auxiliary role
Unlike the radius and ulna, which are responsible for the rotational movement of the wrist
by pushing forward and backward
The tibia and fibula do not have such a rotational function
If the legs rotate
Only the femur on the thigh side
would just swivel in the pelvis
The fibula is not that thick and its presence is weak
It serves to distribute the load
This part is also something we talked about when dealing with the ulna and radius bones of the arm
The tibia and fibula also have this double bone structure
It disperses the shock received from the ground when landing
Conversely, this can be converted into momentum
The fibula is the opposite side of the tibia
That is, it is in charge of the side malleolus part
It limits the lateral movement of the ankle
The calf area is mostly made up of these two bones
I guess you could say it functions as a set
At this point, I'll summarize the malleolus bones
The malleolus bone is what we call the peach bone
This is the part
It refers to the protruding bone part on the side
and this area on the inside of the ankle joint
It is primarily responsible for the up and down movement of the ankle
They are also performing side operations
Turning your ankle inward or outward
is also possible because of this
But if you look closely, the height of the inner and outer malleoli is different
This is simple to remember
Try bending your ankle right now
Which way does your ankle more?
It's inside
That means the inner malleolus is further up
If you memorize it like this, it will be easier to understand
Lastly, the cute and precious kneecap of the leg
It is also called the patella
It's small so it's easy to ignore
The knee joint itself is by no means something to be ignored
The knee is the largest joint in the human body
While receiving the greatest power
At the same time, as long as we don't stop moving
it is a joint area that is always used
You could also say that it is a part that can easily break down
You could say the kneecap is a bone that's been created
to prevent injuries and functional decline of the knee joint
and at the same time, to deliver power effectively
This bone lies between the joint space of the femur and tibia
It is placed inside the tendon
The kneecap itself is not independently exposed
As mentioned earlier, between the thigh muscles and the tibia
It is wrapped in fascia
If the large muscles of the thigh were to lift the tibia using only the tendons,
It takes a lot of strength
At that time, this knee part gets in the gap between the joints
It plays a role in making things easier
in the transmission of power to thigh muscles
If you look at the picture, you can see the change in the position of the kneecap
Now that you understand the anatomy of the knee,
Then how should we draw it?
The knee joint, like the tibia, is generally
Because the bones are directly exposed to the skin
Understanding the shape of bones makes it easier to depict
There is a kneecap in the center of the femoral joint
Around it are the femoral and tibial joints
in a surrounding shape
And you can draw the protruding part with a line
Or simply, it can be described with these two lines
We looked at the bones of the legs so far,
femur, tibia, fibula, and kneecap
You get the feeling that it has a simple structure
compared to other parts, comparatively
That's because the simpler it is, the easier it is to support great power
and because it breaks down less often
Because the legs support our torso
and it is a valuable part that allows movement
Okay, now let's learn about the leg muscles
The legs are one of the large parts of the body
It plays a pivotal role in our movement
While talking about movement previously, the overall flow
In other words, the continuity of the S line was emphasized
As the flow moves from the bones of the leg to the muscles,
It becomes more and more evident
Before we get into specific muscles,
Let's go over the overall flow of the leg
The part you should pay close attention to is
the flow that deviates diagonally from each joint
The flow of the knee bends in the opposite direction from the flow of the ankle
This flow also matches the split flow of the quadriceps femoris muscle
And then again going up, the angle of the femoral neck
Bends at the opposite angle to the knee
Through this changing flow, the leg
Creates a fun S-line
The side is the same
The leg that you might have thought would fall straight down
While the massive thigh muscle, an extensor muscle, protrudes from the upper part
In the calf is a pulling muscle
which protrudes to the back and shows its presence
This creates a true S-line
If you know this flow, that would be a great help
when you draw the outline
Okay, now let's get into
how each muscle in the leg is connected to the bone,
How they exercise, and finally
which line they fall in
First, let's look at the muscles on the front of the thigh
The main muscles are the quadriceps femoris and the sartorius muscle
And then there's the adductor muscles
First of all, let's talk about the quadriceps femoris muscle
It's very sturdy
The quadriceps femoris is activated when we sit down and stand up
Also like when you climb stairs
It plays a pivotal role in leg extension exercises
This muscle is attached to the femur
It is responsible for the extension movement of the knee joint
As its name suggests, the quadriceps femoris
consists of four muscles
There are the vastus medialis and lateralis muscle on the left and right respectively
The rectus femoris muscle crosses the middle of it
If there are four branches, why do I only say three?
The vastus intermedius muscle is hidden behind the rectus femoris
This muscle is responsible for the presence of the front of the thigh
As I mentioned earlier, due to the difference in height between the inside and the outside
This is where the interesting diagonal flow is created
When this muscle is developed, similar to the biceps and triceps of the arm
It may give the impression of a muscular lower body
Next, let's talk about
the sartorius muscle
The sartorius muscles is the thin, long muscle located on the inner thigh
This muscle is slightly laterally
curved to wrap around the thigh
And it extends to the inside of the knee
It is mainly responsible for the movement of
bending the legs inward
Guys, remember this muscle
The sartorius muscle is one of the main points
used to depict the thigh
The adductor muscles are located inside this muscle
There are several muscles on the lateral side that are extensors
And also on the inner thigh contour
The sartorius muscle plays a crucial role in holding the curve
And inside the border, it has a relatively flat three-dimensional feel
The outer side shows a sturdy and protruding shape
of the quadriceps femoris muscle
It shows the boundary between these two
The muscles located on the inner side of the sartorius muscle are called
the adductor group
The adductor group is largely made up of four major muscles
adductor magnus muscle, gracilis muscle,
adductor brevis muscle and pectineus muscle are those
This muscle group primarily performs leg-pull movements
The part worth noting is the gracilis muscle
Starting from the pubic bone of the pelvis,
It goes inside the knee like the sartorius muscle
This is the muscle that reveals its presence when the legs are spread
Next, let's learn about the muscles on the side and back of the thigh
The rectus femoris muscle, or hamstring
is the main muscle that describes the back of the thigh
It is a muscle that is mainly responsible for the flexion movement of the calf
It consists of the biceps femoris, semimembranosus, and semitendinosus muscles
These muscles each originate from the ischial tuberosity
Each is divided into the left and right calf joints and connected
The combination of these muscles forms the hamstring at the ankle joint
This part is sunken only with muscle
By filling this with fat
The hamstring that we know behind the knee is completed
Now let's move on to the muscles on the side of the thigh
Here are the tensor fasciae latae and the iliotibial band
Also the small, middle, and large gluteus muscles
That is, the gluteus minimus, gluteus medius, and gluteus maximus muscles are located there
Simply put, it's the buttock muscles
It would be easier to understand it as the gluteal muscle
Actually, this part, the gluteus maximus
covers a wide area of ​​the buttocks
so the rear area is also included rather than just the side
These muscles are mainly used to spread the legs or stand,
or to walk while maintaining that posture
The iliotibial band binds the tensor fasciae latae and the gluteus maximus
It is a band of muscles that provides volume to the sides and back of the pelvis
This band has the quadriceps femoris muscle on the front
In the back is the hamstrings
which makes it the boudary of these two
Now let's move to the back
I mentioned the gluteus maximus a little while ago
This is the muscle that depicts the protruding volume in the buttocks area
I told you that the greater trochanter of the femur in men
is what shapes the hollow part
on the side of the thigh
This point is where the gluteus maximus, medius, and minimus
gather to meet the fascia
So it has a
relatively sunken shape
If you look at it with muscle on
You can see that part definitely standing out
Okay, now let's go down to the calves
It is the frontal muscle of the calf
This part consists of the anterior tibialis, the fibularis muscles,
and the extensor digitorum muscle
These muscles are mainly in charge of lifting the top of the foot
and the toes
The anterior tibialis starts just below the knee
from the beginning of the tibia
and falls towards the big toe
And this muscle, along with the extensor digitorum
Creates a gentle protrusion on the front of the calf
At the same time, lifting the top of the foot activates this muscle
The front of the calf becomes more prominent
On the other hand, the fubularis is divided into three types
which are fibularis longus, brevis, and tertitus
All starting from the back of the tibia
extend down the heel bone
Lastly, the extensor digitorum also starts from the upper part of the tibia
Each one sits towards the toes
and performs its function when you spread your toes
Like the sartorius muscle of the thigh, the front of the calf
The tibia plays that role
The inner side of the tibia is the extensor muscles of the toes,
and the lateral side is where the flexor muscles are located
Finally, let's look at the back muscles of the calf
The main muscles are
the triceps surae muscle
A strong tendon runs from the end of those muscles to the heel
is the calcaneal tendon
The Achilles tendon is connected
First of all, the triceps surae muscle
are the soleus and gastrocnemius muscles
It is separated like this and has two layers
First, the soleus muscle is located in the inner layer below
Above it, the gastrocnemius muscle wraps around it
Also, a famous fascia at the end of the gastrocnemius muscle
extends all the way to the heel
It's the Achilles heel
These tendons allow us to walk and run
If you look closely, the inside is empty
So it's filled with many blood vessels and flesh
The two muscle masses split in this gastrocnemius muscle
gives a great silhouette to the back of the calf
The long Achilles tendon extending below it
Adds a three-dimensional feel to the concave part of the ankle
So far we have looked at the muscles of the legs
Just like arms, legs are also made up of many different layers
Now let's take another look at it these complex layers
as a group
First, let's look at the legs from the front
From the front view, you can see the
border beginning at the iliac crest
connecting to the inguinal ligament
As mentioned earlier, you could say that this boundary
is the basic line that separates the legs and the torso
This part is tied together
In the thigh area, the sartorius muscle becomes the standard
The border between the quadriceps femoris and the adductor muscles is clearly visible
Let's lump these two areas together like this
And on the outermost front and back
The tensor fasciae latae and gluteus maximus are tied together
to form the iliotibial band
This is the muscle that lifts the leg to the side
So it's on the outside
Let's look at this muscle group again
I have already explained a lot about the knee area before
Let's move on by grouping them together
If you go towards the calf, the tibia becomes the standard
In the case of the front, in the inside is the triceps surae muscle
mainly located at the back
It's a group
And on the side, there are the ankle
and toe extensor muscles
This is also one group
Let's look at the back
The first thing that stands out is the gluteus muscles
It's a group
Below that are the hamstrings
which come down to the popliteal fossa
This is also one group
You didn't forget the iliotibial band on the side, right?
Already included in a group
And inside
The adductor muscles on the inside and the triceps femoris below it
were also grouped already
Below that is the popliteal fossa
Going down
There is also triceps surae muscle group
Okay, now we've divided all the areas
Based on these areas
I think you can see the leg area
a little more easily
So far we have covered all the anatomy of the leg
Thank you for your hard work
Now it's time to move on to the feet
Before that, like the carrying angle,
Did you know that there are differences in the leg based on gender?
The Q angle of the leg or
the quadriceps angle
Strictly speaking, it refers to the difference in angle between men and women
This angle is an important anatomical point that deals with the degree
to which the femur and knee are bent
It is mainly understood based on the quadriceps femoris muscle
The English initials of that muscle are taken to call it the Q angle
This angle also caused by the difference in size and shape of
the pelvis of men and women
Because of women's wide pelvis
The femurs are spread apart more in women than in men
However, the position of the knees does not differ much between men and women
This is where the difference in angles comes into play
For men, the fall is relatively straight from the pelvis
having an 11-character shape
For women, because the bending of the femur
down to the knees is large
It will show a Y shape
In a standing position, the Q angle of a woman is usually
around 15 to 20 degrees
Men are said to show around 10 to 15 degrees
Due to this Q angle, women often appears as a shape with legs together
compared to men
The interesting part is the Q angle's
Effects on leg joint movement
As you can see, men fold their legs closer together in a straight line
Women have calves that go to the outer thighs
So you can see the tendency to go out
In this case, in terms of efficient transmission of power
Women are at a disadvantage
Because the legs move in a direction that deviates
from the direction they want to go
You can see this difference even when you do squats
Men have a relatively small Q angle when doing squats
So stable exercise of the quadriceps femoris is possible
On the other hand, in the case of women, due to the Q angle
To do a straight squat
The knee receives more force from the outside
which will make them face difficulties
This Q angle also creates differences in the poses of men and women
Especially for women, when running or standing
There are many cases of posing
with the thighs together and calves turned outward
Sitting in a W position
is also used as a pose of women sitting
This Q angle, similar to carrying angle
I guess you could say it's a depiction point based on biological differences
Shape of the foot
Okay, now it's the last stop of real anatomy
Foot
Let's take a look at the feet
Feet are the part that we really don't draw much
When drawing a full body, most people wear shoes
Even though they are barefoot characters, they are often captured from far away
Detailed descriptions of feet are often abbreviated
Out of sight, out of mind, that's it
It's familiar to us, but
feet are not at all friendly for drawing
The shape of the foot is so complex
because our feet bear the weight of our body
and because not only the function of standing upright but also walking,
a difficult task on a completely different level from that of quadruped animals,
is given to it
Basically, tt will be easy to understand if you look at the shape of the foot
as a complex arch shape
The front part has toes
The outside of the foot touches the ground in an arch-like shape, then a dome-like shape
And a heel at the back
How did it turn out like this?
Let's go into more detail
Memorization will also become easier
We are animals that walk on two feet
If you just stand there
Flat feet wouldn't be bad either
But the problem lies in walking and running
The ground we move on isn't just flat
It's full of all kinds of difficult obstacles and slopes
In such cases, flat feet rather
give us trouble to deal with various types
of surfaces
So we have an arch shaped
miraculous design that we evolved into
By evolving in this way,
Not only can we respond to various surfaces,
Due to the nature of the arch structure
we also get additional spring-like jumping power
It's commonly called flat feet
It's not for nothing that these people have a hard time running
There are all these ergonomic reasons for this
It's actually hard to run
And for a stable upright position
The outer part evolves into a semi-dome shape that touches the ground
As the area touching the ground on the sides increases,
When standing on two feet
we have become able to stand without shaking
The shape of the arch is the same even when viewed from the front
The toes will stick along this line
And the heel
As the feet are in a forward position overall,
we need something to support it
That's the heel
Although it is in charge of the back of the arch
When drawing a standing foot, the stability of the entire foot
lies here
So I actually tend to draw
the degree of protrusion of the heel from the ankle
a little more exaggerated than it actually is
The heel is like this at the back of the foot
It is in the area that is tilted to the side
Now the toes
It is also the area that needs to support our center of gravity
the most when we stand upright, too
First of all, how should we draw the toes themselves?
Do you remember the last joint of your finger on the arm?
The toes will be easier to understand
if you think the last joint of the fingers
are cut off and pasted
However, toenails are smaller than fingernails
Keep that part in mind a little more
For the big toe
Compared to the other four toes
I think it would be better to draw it much bigger and with more volume
Next, let's look at the flow of the toe positions
I said that the flow of the toes when viewed from the front is in the shape of an arch
So what about the flow of the toes seen from above?
S-line including the big toe
and the branches that extend out along the flow become your four toes
If you look at this flow, you can see the overall line of the foot
The heel is tilted to the side
The void in the arch, and the flow of the toes
We have been looking at the movement of the feet so far
How is it? Isn't the movement really amazing?
As I mentioned earlier, in the case of feet
I won't go into specifics about bones and muscles
Let me explain the necessary parts
by explaining several examples
First, here is the foot from the side, viewed from the inside
It moves forward from the ankle to the instep
And then there's the big toe
At this angle, if you draw up to the big toe,
You can consider it almost finished
The heel also sticks out
This concave part is
the empty space where the Achilles tendon passes,
a heel tendon descending from the gastrocnemius muscle
The contour of the sole
is a hollow arch
There is a curve where the adductor pollicis and flexor pollicis muscles
combine in the big toe
There is also a protruding curvature of the plantar tendon at the heel
In between, a concave arch is created
This is the foot viewed from the outside
The overall silhouette is the same, right?
However, since it is the sole that supports the ground,
The sole of the foot takes on a flatter appearance than the inside
And starting from the little toe
You have to draw the overlapping toes up to the big toe
The depiction of the Achilles tendon on the heel is still there
I've covered everything about the lower body
It was a simpler structure than the arm, but it was by no means easy
You've all worked really hard so far
Next time is finally the last lecture
Let's take some time to assemble each part of the body
we have looked at so far
And at the same time, we will look at several other tips
Thank you for your hard work
Thank you
Bones and muscles of the leg The femur is large because it supports the weight of the upper body and is responsible for movement of the lower body
The tibia is mostly exposed at the front of the calf Though thin, it helps distribute the load
The malleolus protrudes on both sides of the joint The kneecap sits in the joint space, surrounded by the femur and tibia
The quadriceps femoris muscle of the leg attaches to the femur and is responsible for flexing the knee joint
The sartorius muscle is a thin, long inner thigh muscle that shapes the thigh contour and divides the adductor area
The hamstrings flex the calf and shape the thigh’s back The iliotibial band links muscles, adding volume to the pelvis
Front calf muscles: tibialis anterior, posterior, extensor digitorum Back calf muscles: triceps surae muscle linked to Achilles tendon
For stable standing, the foot forms an arch or dome, with the heel providing overall stability
The heel tilts laterally at the back, while the toes form an arch, following an S-line flow from the big toe