Skeletal muscle anatomy introduction
Summary
TLDRThe video script offers an introductory overview of the human body's skeletal muscles, emphasizing their variety and complexity. It discusses muscles of facial expression, mastication, and the role of muscles in posture and movement. The script delves into the muscles of the head, neck, back, and limbs, highlighting their functions in supporting the body, aiding respiration, and facilitating movement. It also touches on the importance of muscle fiber direction and the interplay between muscles and joints in the body's overall functionality.
Takeaways
- 📚 The human body has a vast number of muscles, far more than bones, which makes understanding them a complex task.
- 💪 Skeletal muscles are the focus of the script, as they are under conscious control and move the skeleton, unlike smooth muscles and cardiac muscles.
- 🤔 The muscles of facial expression are crucial for non-verbal communication and are distinct from other muscles due to their control and innervation.
- 🦷 Mastication muscles, like the masseter, are essential for chewing and are different from facial expression muscles in function and innervation.
- 🔬 The muscles of the neck, such as the sternocleidomastoid and trapezius, play a significant role in head movement and posture.
- 🏋️♂️ The trapezius muscle is multifunctional, affecting both the upper limb and back movements, and has fibers running in various directions.
- 🦴 Back muscles are layered and include superficial muscles that influence upper limb movement, intermediate muscles like erector spinae that support spine posture, and deep muscles that provide proprioception.
- 💨 The diaphragm, a skeletal muscle, plays a key role in respiration by changing the volume within the thorax to facilitate inhalation and exhalation.
- 🧘♀️ Abdominal muscles, including the rectus abdominis and the obliques, are vital for torso movement and maintaining intra-abdominal pressure.
- 🦵 The muscles of the upper limb, such as the deltoid and rotator cuff muscles, are essential for shoulder stability and arm movement.
- 👣 The muscles of the lower limb, particularly the quadriceps and hamstrings, are large and strong to support body weight and facilitate movement at the hip, knee, and ankle joints.
Q & A
What are the main types of muscles in the human body discussed in the script?
-The script primarily discusses skeletal muscles, which are under voluntary control and move the skeleton. It also mentions smooth muscles within organs and blood vessels, and cardiac muscle, which are under autonomic control and not covered in detail in the script.
What is the role of the muscles of facial expression?
-The muscles of facial expression are used for moving the lips, closing the eyes, and making various expressions. They are skeletal muscles that can be consciously controlled.
How does the script differentiate the muscles of mastication from the muscles of facial expression?
-The muscles of mastication, such as the masseter, are involved in moving the jaw for chewing and are distinct from the muscles of facial expression not just in their role but also in their innervation.
What is the significance of the sternocleidomastoid muscle in the script?
-The sternocleidomastoid muscle is significant because it is a superficial muscle involved in flexing the neck and bringing the chin towards the sternum when used bilaterally, and in rotation when used unilaterally.
What is the role of the trapezius muscle as described in the script?
-The trapezius muscle is a superficial muscle of the back and also a muscle of the upper limb. It is involved in holding the head up, moving the scapula, and has different fiber directions allowing for various actions.
How does the script describe the function of the serratus anterior muscle?
-The serratus anterior muscle runs from the ribs to the scapula and is involved in moving the scapula, including rotating and protracting it, as well as helping with breathing by pulling on the ribs.
What is the main function of the intercostal muscles according to the script?
-The main function of the intercostal muscles is to form a pressure barrel, allowing the lungs to be moved by the muscles and bones, thus facilitating the change in volume inside the thorax for breathing.
How does the script explain the importance of the diaphragm?
-The diaphragm is a skeletal muscle with a dome shape that can be consciously controlled. When contracted, it flattens, increasing the volume in the thorax and allowing the lungs to fill with air, playing a crucial role in respiration.
What is the role of the quadriceps femoris muscle group in the lower limb as described in the script?
-The quadriceps femoris muscle group is responsible for extending the knee joint. The rectus femoris part of this group also crosses the hip joint, allowing it to flex the hip and extend the knee.
What are the hamstring muscles and what do they do according to the script?
-The hamstring muscles are in the posterior compartment of the thigh and cross both the knee and hip joints. They can extend the hip by bringing the lower limb back when it's out in front, and flex the knee by bringing the heel up to the butt.
How does the script describe the importance of the gluteus maximus muscle?
-The gluteus maximus is a large muscle that crosses the hip joint and is a powerful extensor of the hip. It plays a crucial role in standing up from a seated position by extending the hip joint.
Outlines
📚 Introduction to Skeletal Muscles
The script begins with an introduction to the complexity of the human body's muscles, which are more numerous and varied than bones. The narrator emphasizes the focus on skeletal muscles, which are under voluntary control and move the skeleton, as opposed to smooth muscles and cardiac muscles that are under autonomic control. The facial muscles, including those of mastication and expression, are highlighted for their distinct roles and innervation. The importance of posture and the muscles' role in supporting the head against gravity are discussed, with a note on the potential for muscle fatigue due to poor posture.
💪 Muscles of the Neck and Back
This paragraph delves into the muscles of the neck and back, starting with the splenius muscles that wrap around others and the scalene muscles that assist in breathing. The sternocleidomastoid and trapezius muscles are highlighted for their roles in neck flexion, rotation, and upper limb movement. The script explains the multi-layered nature of back muscles, including the superficial muscles involved in upper limb movement, the intermediate erector spinae that support the spine, and the deep muscles that provide proprioceptive feedback and potentially cause pain if misaligned.
🏃♂️ Muscles of the Torso and Limbs
The narrator describes the muscular structure of the torso, emphasizing the intercostal and abdominal muscles that form a protective barrier around internal organs and assist in breathing and torso movement. The pelvic floor muscles are mentioned as part of this muscular system. The limbs are introduced, with a focus on the scapula and its associated muscles like serratus anterior and latissimus dorsi, which are crucial for scapular movement and upper limb function. Pectoralis major and minor are also discussed for their roles in adduction and stabilization of the upper limb.
🤲 Upper Limb Muscles and Their Functions
This section provides a detailed overview of the upper limb muscles, starting with the deltoid muscle that suspends the limb and aids in shoulder movement. The rotator cuff muscles are introduced for their role in stabilizing the shoulder joint. The script continues with the muscles of the arm that facilitate elbow flexion and extension, wrist and finger movement, and the intricate actions of the hand that allow for fine dexterity and various forms of grip.
🚶♂️ Lower Limb Muscles and Their Actions
The paragraph focuses on the lower limb muscles, which are larger due to their role in supporting body weight during movement. The hip joint muscles, including the quadriceps femoris for knee extension and the hamstrings for hip extension and knee flexion, are detailed. The adductors and abductors of the hip are mentioned, along with the gluteal muscles that assist in standing up from a seated position. The muscles of the leg that cross the ankle joint and their roles in dorsiflexion, plantar flexion, inversion, and eversion are also discussed.
🌟 Overview of Skeletal Muscles and Their Importance
The final paragraph wraps up the introduction to the skeletal muscles, highlighting their variety, complexity, and the multitude of joints they cross. The importance of innovation and blood supply for muscle function is briefly mentioned. The script concludes with a light-hearted reference to the start of the academic year and an invitation to viewers to join for more detailed explorations of individual muscle groups in future videos.
Mindmap
Keywords
💡Skeletal Muscles
💡Autonomic Control
💡Mastoid Process
💡Trapezius Muscle
💡Serratus Posterior
💡Erector Spinae
💡Intercostal Muscles
💡Diaphragm
💡Pelvic Floor Muscles
💡Quadriceps Femoris
💡Hamstrings
Highlights
Introduction to the complex and numerous muscles of the human body, emphasizing the selectivity required due to their vast number.
Differentiation between skeletal muscles, which are under voluntary control, and smooth muscles and cardiac muscles, which are under autonomic control.
Explanation of the muscles of facial expression and their role in moving the lips, closing the eyes, and making expressions.
Discussion on the muscles of mastication, particularly the masseter, and their distinct innervation from facial expression muscles.
Importance of the neck muscles in supporting the head and maintaining posture, especially in the context of modern lifestyle and technology use.
Identification of the sternocleidomastoid and trapezius muscles as key players in neck and upper limb movements.
Description of the back muscles, emphasizing their layered structure and the role of the erector spinae in maintaining an upright posture.
Highlighting the role of the diaphragm as a skeletal muscle involved in respiration and its unique dome shape.
Overview of the abdominal muscles, including the external oblique, internal oblique, transversus abdominis, and rectus abdominis, and their functions in torso movement and support.
Introduction to the muscles of the pelvis and the importance of the pelvic floor muscles in supporting the body's core.
Discussion of the serratus anterior and latissimus dorsi muscles and their roles in scapula movement and upper limb support.
Explanation of the pectoralis major and minor muscles and their involvement in the movement of the upper limb and chest.
Description of the deltoid muscle's role in the suspension of the upper limb and its multi-penate structure.
Overview of the muscles involved in the movement of the forearm, wrist, and hand, emphasizing the importance of grip and dexterity.
Introduction to the muscles of the lower limb, focusing on their size and function in supporting body weight during movement.
Detailing the quadriceps femoris muscle group's role in knee extension and the rectus femoris's dual role at the hip and knee joints.
Explanation of the hamstring muscles' function in hip extension and knee flexion, and their importance in posture and movement.
Highlighting the gluteus maximus muscle's role as a powerful hip extensor, essential for rising from a seated position.
Description of the muscles involved in ankle movement, including the gastrocnemius and soleus for plantar flexion, and their importance in balance and stability.
Concluding remarks on the complexity and importance of the skeletal muscles, their interconnections, and their role in everyday activities.
Transcripts
hi
um I am going to introduce to you the
muscles of the body
this is a daunting task there are lots
of muscles in the body I've done some
introductory videos about the skeleton
hey there's only 206 bones and most of
those duplicated that's easy but there
are a lot of muscles
so I have to be selective in what I talk
about otherwise we'll be here for
literally dozens of hours
um so I'm going to we'll start at the
top head neck consider the trunk the
back and then look at the limbs think
about the joints think about how the
muscles are grouped the actions that
they do
um and try to be very introductory and
not get carried carried away
[Music]
we'll start up here with the head
um
there are muscles of the scalp
but these are the muscles of facial
expression that you use for moving your
lips and closing your eyes and making
Expressions here these are all skeletal
muscles that you can control and that's
an important thing while I'm introducing
the muscles of the body I'm introducing
the skeletal muscles the the the muscles
that we can think about moving and move
muscles that move the skeleton there are
other muscles there are smooth muscle
within organs and blood vessels and what
have you which I'm not going to talk
about which we don't think about that we
can't control they're under autonomic
control and the muscle of the heart the
cardiac muscle that's also under
autonomic control so we're thinking
about skeletal muscle
um the other muscles of the face are the
muscles of mastication this is masseter
here
these move the jaw
in different directions so that we can
chew uh they're distinct from the
muscles of facial expression not just
because of their role but also their
innervation
we actually have some
fairly good muscles that can move the
ear
but you need to practice quite a lot to
be able to move your ear but you can do
it now as we move around posteriorly
because we are upright bipedal animals
this has all evolved quite differently
to other animals and a lot of the
muscles here are important in keeping
our
well keeping our head up so we can gaze
forward
um with modern living satter computers
if you have a bad posture the head's a
very very heavy thing so these muscles
are quite strong in holding the head up
so if we have bad posture if we're
looking down a lot or in an awkward
position these muscles can get fatigued
overused and very tired so there are a
number of muscles under here and the
other thing about muscles is that we
need to consider what joints they cross
when we think about what actions they
might perform and some of these so these
um these muscles of the neck up here
we'll consider when we look at the
muscles of the back in a moment there
are also some splenius muscles splenius
means bandage they wrap around the other
muscles but there are also muscles of
the neck like these scalene muscles here
that run between the vertebrae and the
ribs
so they can lift up the ribs when you
take a deep breath
you'll feel these muscles Contracting
your neck as they're helping lift the
rib cage up and helping you inhale there
are two muscles of the neck that I would
like to point out though this one here
is sternocleidomastoid
this is the mastoid process here
posterior to the ear this is the
clavicle that's the clydo bit and the
sternum is here so sternocleidomastoid
it's a superficial muscle it's very
prominent it stands out it's involved in
if you've used if you use both sides
together
you Flex the neck you bring the chin
towards the sternum if you use them
individually then they're involved in
rotation the other big muscle is this
one here trapezius
now trapezius so here we can see
trapezius here it's been removed but if
you had the two trapezius muscles it
would make a trapezium shape now
trapezius is a very interesting muscle
it's a superficial muscle of the back
but it's also a muscle of the Upper Limb
um so this is the back it's superficial
it's covering the other muscles of the
back it runs up to the neck so it's
important in holding the head up it runs
out to this bone here this is the
scapula and to the clavicle so it's
involved in moving the scapula now the
scapula's job is to support the Upper
Limb so if we have a muscle that moves
the scapula then
it's moving supporting stabilizing the
Upper Limb it has a roll in the Upper
Limb and then it also runs down here to
the back and we have different fibers
running in different directions and
we'll see this in a number of muscles
some muscles are very straightforward
and they're just long things and they
contract in one axis and that's it the
sun muscles have fibers running in
different directions so different parts
of a muscle can contract independently
of the other parts and cause different
actions
uh so that's trapezius these are the
deeper muscles of the back here
hmm the back
we have many vertebral bones
forming the vertebral column the back
each one of those vertebrae can move
relative to the next vertebrae and we
join up all those little movements and
we can make quite big movements and
there are multiple layers of back
muscles so they're very superficial
muscles of the back
are actually involved as I say in the
Upper Limb look here if you take
trapezius off you can see the rhomboids
the rhomboids link the scapula to the
vertebrae so they can you can squeeze
your shoulder blades together you can
retract your scapulae with your rhomboid
muscles we have muscles here running
from the vertebrae to the ribs so
they're involved in moving the ribs
helping you push air out there's a this
is serratus posterior inferior there's
another deep set deep to these guys up
here which is serratus posterior
Superior
um which lift the ribs up so these
muscles are either
lifting the ribs and helping you bring
air in or
pulling the ribs down and helping you
push air out
so we have muscles that remove the ribs
relative to the vertebrae and then we
have this band of muscle here this this
intermediate layer and this is the
erector spiny muscle group you can
probably palpate this on your own back
erector spiny so this erects the spine
so if you're bent over these bands of
muscle help lift you back up again and
whilst that is a group of muscles it has
individual muscles or muscle bands
running from different parts of the back
to other parts of the back of the the
ribs and other parts of the back so it
gets broken up into muscles of many many
many different names
and then and this extends up into the
neck and then when you take off that
intermediate group of muscles you find
the Deep muscles and there are muscles
in between the vertebrae there are deep
muscles and deeper muscles and very very
deep muscles and lots of little muscles
there are lots of muscles in the back
and the deeper muscles are very small
they run between vertebrae and they
probably have a more proprioceptive role
sensing where each vertebra is relative
to the other vertebra and giving you
um giving your brain information about
that and maybe giving you pain if the
vertebra is being pulled inappropriately
and causing you to stop moving your back
and lie on a firm surface but it's these
larger muscles here these larger
superficial muscles that are probably
moving the back and also oh yeah
these muscles
the trunk
is made out of muscles and Bone but
muscles
so
um if you want to make a nice strong
container to keep all your organs in
muscles are pretty good building block
in the thorax we see the ribs and we see
layers of muscle in between the
intercostal muscles and the main
function here sure those intercostal
muscles can pull on the ribs and move
them but the main purpose of those
intercostal muscles is to form a
pressure Barrel a wall so that the lungs
inside can be moved by the muscles and
the bones you can change the volume
inside the thorax and if you increase
the volume inside the thorax you
decrease the pressure
air is drawn in through the Airways and
if you
decrease the volume inside the thorax
you push the air out and what we can't
see here if I took this off you'd find
the diaphragm so the diaphragm is also a
skeletal muscle and it's a dome inside
here do I want to take
there it is here's the diaphragm this
Dome up here
and this is a skeletal muscle you can
choose to control it and if you contract
it it flattens it pulls down all this
squishy stuff gets pushed out but the
volume here increases and the lungs
filled with air so the diaphragm is also
a skeletal muscle
and as we continue
inferior to the ribs and down to the
pelvis that's all covered with muscle
so the body wall is made up of mostly
three layers of muscle we have three
layers of intercostal muscle
three layers of abdominal muscle out
here you see how these fibers are
running in this direction we have the
external oblique muscles and then deep
to that we have the internal oblique
muscles their fibers are running in the
opposite direction and then deep to that
you have a third layer of muscle
transversus abdominis whose muscle
fibers run in that direction run
transversely and then in the midline we
also have the six pack we have rectus
abdominis running from the pelvis up to
the sternum and the the inferior ribs
here
[Music]
um
and when I said that
the big muscles move the back well
these are big strong muscles and these
the directions the muscle fibers run in
means that you can move your torso right
if you're moving your torso you're
moving your vertebrae so the abdominal
muscle wall is important at holding your
viscera in at resisting the
intra-abdominal and intrathoracic
pressure changes and also in movement of
the Torso
um down in the pelvis there is a pelvic
floor so
um the levator A9 muscle group and then
also support all of this inferiorly with
the pelvic floor muscles also skeletal
muscles you can
you can contract your pelvic floor right
you can choose to do that so it's glutal
muscle
um
now that's most of the Torso muscles but
now we can see the the limbs are hanging
from this
we mentioned the scapula back here
let me go this way around I take the arm
off
you can see
this muscle here
this is a it has a serrated appearance
this muscle because it has lots of slips
of muscle attaching to the ribs and this
is serratus anterior
goes along with this serratus posterior
muscle now serratus anterior is a big
beefy muscle running from the ribs
to the scapula so it's also involved in
moving the scapula rotating the scapula
protracting the scapula around the body
wall
but also it can pull on the ribs it's a
big muscle that can pull on the ribs and
help you breathe if you hold on to
something if you fix these bones in
place with your Upper Limb
big muscle here latissimus dorsi
so this big it's a back muscle runs
around laterally it's coming from fascia
and bones and vertebrae here and it runs
around to the humerus and this is the um
the climber's muscle this is the
swinging around in trees muscle this is
the muscle that lets you do a pull-up
it's so big because you can lift your
body weight with the pair of these
working together if you're really strong
you can do a one arm pull-up then you
just need one of them but not many
people can do that latissimus dorsi so
you can see how we've got muscles of the
back which are very much muscles of the
Upper Limb
serratus anterior latissimus dorsi if I
put the arm back on
okay
um here's pectoralis major
so this is a major bustle of the chest
but it's actually a muscle of the Upper
Limb it's running from sternum
clavicle out to the humerus this is a
muscle that's gonna
um well
see we get into the weeds already
the pectoralis major can
adduct the humerus and rotate the
humerus that's another thing we need to
think about with bones when we have like
a ball and socket joint like we have at
the glenohumeral Joint the humerus can
rotate
right
um and the way the muscles attached to
the bone will determine whether they can
take part in that rotation and how they
might take apart pectoralis major take
that off and you see pectoralis minor
running from the ribs up to the tip of
the shoulder
um so if trapezius you can use to shrug
your shoulders pectoralis minor you can
use to pull the tip of your shoulders
back down again
talking of trapezius
see we keep coming back to some of these
major muscles but
um here's trapezius you see how these
fibers are running from the axial
skeleton from that vertebral column out
to
the scapula and the clavicle and then we
have this muscle this is the deltoid
muscle look it's got lots of groups of
fibers running in slightly different
directions it's a multi-penate muscle
and then the humerus the lower limb
is attached to the deltoid muscle and
what we've got is we've got the
suspensory arrangement then the limbs
are quite heavy the Upper Limb is is a
heavy thing
so the weight of the limb is suspended
largely through the deltoid muscle there
are other muscles involved up to this
bony points and then the weight is
transferred through trapezius up to the
axial skeleton can you see that that
suspension Arrangement so the deltoid
muscle will move you know it'll
um abduct uh Flex extend the humerus of
the glenohumeral joint but his other big
job is actually holding that joint in
there together when you're carrying
something heavy it's holding that Upper
Limb
into the scapula
deep to all of that if you take deltoid
off well actually there's deltoid there
but you have um the rotator cuff muscles
so a smaller deeper muscles running from
the scapula to the humerus helping us
rotate the humerus but also helping hold
that joint together hoping helping
stabilize The Joint when we do things
like this when we stick our arm out when
we do these movements that we take for
granted
um there's deltoid and then of course we
move out to
uh the Upper Limb itself so if that's
the shoulder joint here's the elbow
joint and there's the wrist
on this side the anterior side of the
arm the brachium we have elbow flexors
like biceps
and then deep to that we have brachialis
and coracobrachialis and if they cross
the elbow joint then they can Flex the
elbow and they're also crossing the
shoulder joints they're also taking part
in movements of the humerus relative to
the shoulder joint
and then on the other side we have the
triceps muscle
so because the elbow is a hinge joint
the muscles on this side Flex the hinge
joint and the triceps brachii muscle on
this side extends the hinge joint and as
we move past the elbow everything gets a
lot more complicated
um we have muscles that are running to
the fingers that give us the power of
grip so most many of the muscles in the
anterior compartment of the forearm
forearm give us the power of grip
um but with the forearm we can also
pronate and supinate pronate and
supinates we have a number of muscles
involved with that including biceps
actually
and then we have muscles that are
running to the wrist so not only do we
Flex our fingers but we also Flex the
wrist
so we have flexors of the wrist the the
carpi muscles
and then when you get into the hand
these muscles are also important they're
smaller but these are the muscles that
give us the dexterity that we take for
granted
uh these little muscles in here the the
thumb has its own set of muscles the
thumb is very special very useful for us
with various forms of grip but those
other little movements of the hand of
the fingers that we use we're using the
muscles in the forearm but we're also
using the small muscles in the hand to
give us that fine dexterity and if we
have muscles on this side doing those
jobs then we have muscles on the
opposite side so these muscles will
extend the wrist extend the fingers
and so on so that's the Upper Limb oh
yeah
with the lower limb we have the hip
joint we have the knee joint and then
the ankle and the foot
um and these muscles are very big
they're big because they're supporting
most of the body weight when we're
walking when we're getting up from a
chair when we're going upstairs when
we're running jumping whatever
so these muscles are much larger and
when we walk with every step that we
take
we stand on one leg
so a number of these muscles have to
support us while we're stood on one foot
with every step that we take and keep
the pelvis level to give us that
efficient gait that we use
so these muscles are big so the hip
joint is a ball and socket joint now in
this anterior compartment of the thigh
the the big muscle bulk is the
quadriceps femoris muscle group and most
of that muscle only crosses the knee
joint this is the patella and the
patella is a sesame bone in the tendon
of that muscle and the tendon inserts
into the tibia here so this muscle
extends the knee joint which is a hinge
joint you go from a flexed knee to a
straight knee uh with the the rectus
with the quadriceps femoris muscle group
now one part of that this midline part
here the rectus femoris muscle also
crosses the hip which means that it can
act at the hip and at the knee so you
can Flex the hip that is raise your knee
towards your chest using rectus femoris
and quadriceps then extends the knee
from a bent position
we also see Sartorius here
and then there are some other bits and
Bobs now the medial compartment these
muscles in here these are the adductor
muscles there are a number of adductor
muscles the big one being Magnus the
lung one being longest the short one
being brevis
and those adduct the lower limb at the
hip joint and that is so if you are
adduct you bring the lower limb back to
the body if you abduct you take the
lower limb away from the body so the
abductors sorry the hip adductors bring
the legs back together gracilis is in
there as well
and if we turn around and we see the
hamstrings here this is the posterior
compartment we have a pair of muscles
here
semitendinosis and semimembranosus and
biceps femoris laterally these muscles
also cross the knee and the hip joint so
they can extend the hip joint
that is take the lower limb out behind
you or if your hip is flexed that is
your knee is out in front of you then
these muscles these hamstring muscles
can bring
the
lower limb back to an extended position
and they can also Flex the knee joint so
if these muscles shorten you'll bring
your heel up to your butt you'll Flex
the knee joint bend the knee joint so
those are the hamstrings and then we
have the gluteal region so this muscle
here is gluteus maximus big muscle and
it's running across the hip joint and
it's also a powerful extensor of the hip
so if you're sat in a chair and then you
stand up again
when you're sat in the chair your hip is
flexed and then when you stand up you'll
use gluteus maximus and the hamstrings
to extend
your hip joint and get up from that
chair
and then from the knee joint to the
ankle joint
we again have muscle compartments we
have this posterior compartment this
lateral compartment
and these anterior compartment and we're
moving the ankle joint so to lift the
toes towards your shin would be
dorsiflexion this is the dorsal foot the
dorsal surface to stand on your tiptoes
would be plantar flexion
and we can see that it's these muscles
back here these muscles of the posterior
compartment we can see gastrocnemius
deep to that we have Soleus so those are
plantar flexors that cross the ankle
joint and attach to the heel the
calcaneus bone here is sticking out to
give the mechanical advantage to the
ankle joint which is a little bit more
anterior
so these are big muscles that we can use
to stand on tiptoes to lift our entire
body weight to stabilize the foot when
we're walking to stabilize the foot on
uneven ground and uneven surfaces and
deep to those muscles we have muscles
that run around
the arches of the foot and run into the
sole of the foot which will
like the muscles of the forearm Flex the
toes Flex the big toe and help us with
our stability on the ground and also
stabilize the ankle joint
inversion is to bring your your soul so
it's facing inwards eversion is to bring
the soul of your foot so it's facing
outwards and those muscles that pass
immediately will help with inversion
that's the posterior compartment the
anterior compartment kind of does the
opposite so these muscles are running
across the ankle so they will help with
dorsiflexion bringing your toes to your
shins and also extending your toes with
your toes are flexed then the muscles in
the anterior compartment like extensor
digitorum longness
will help extend the toes and then also
um
muscles there are crossing the ankle
joint and help will help with inversion
and then that lateral compartment we
have the fibularis muscles because the
fibular bone is out here and those
fibularis muscles are running around the
ankle laterally and will help with
eversion all of those muscles are
working together
to help stabilize us
as we're stood over that foot
on a maybe less than perfect surface but
even if it is a flat surface you know
it's like you stand on on on one foot
one legged
right
a little bit wobbly it's
it's all of these muscles working
together to balance us and stabilize us
and then when we get into the foot
just like in the hand there are a lot of
small muscles which help with fine
movements of the toes which are maybe
less important to us than the fine
movements of the hand which are so
important for day-to-day living and then
in the sole of the foot there are layers
layers of muscles supporting all of this
oh okay
that was a lot of muscles
how's that that's an introduction to the
skeletal muscles of the human body there
are a lot they do a lot of things they
cross a lot of joints there's a lot of
detail in there the innovation's
important the blood supply is important
if you want to know more I have many
more videos in more detail about
individual Parts but I hope I hope
that was a useful warm-up speaking of
warm-ups
I don't know if you can hear but it
sounds like the uh
the freshest party is starting to warm
up students are coming back it's that
that time of the year where we
introduced students to new knowledge
right see you next week
[Music]
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