Gluteal muscles (anatomy)

alright hello everybody today we're

going this way around because I did my

ultra marathon on the weekend and my

legs still hurt and this week's topic is

partly because of that but largely

because in a recent exam students seem

to get their understanding of the

gluteal muscles a little bit

ass-backwards if you'll excuse the pun

so we're going down here to the gluteal

region I've looked at the muscles that

the large muscles of the hip and the

small muscles of the hip in the past

today I'm doing three muscles gluteus

maximus gluteus medius and gluteus

minimus we're gonna talk about what they

attach to what happens when they

contract what their jobs are what their

innovation is and then the thing I

really want to get clear is what happens

if they don't work properly I think it's

pretty straightforward I'm just gonna

try and keep it super clear alright I'm

not entirely sure this was the best idea

it's my leg still so now I got I didn't

think this through did I anyway gluteus

maximus so the shape of the buttocks is

largely formed by gluteus maximus it's a

really big muscle which tells you is

therefore power powerful movements and

the reason is so powerful is because

it's it aids in lifting our entire body

weight this is the gluteal cleft between

the two gluteal bits as the vertical bit

and the gluteal fold is the horizontal

bit beneath the gluteal bits the

buttocks right what could see the

gluteus maximus then well gluteus

maximus it's coming from so this is the

pelvis this is the ilium nice this is

the posterior bit of what we're looking

at here this is the ilium right ilium


and then pubis around here so gluteus

maximus then is clearly coming from the

ilium part of the pelvis now if you've

got a really good ilium like I'm really

not not you but if you've got a skeleton

with a really good in

you can see anterior posterior inferior

gluteal lines little lines on here right

will show you where the muscles attach

some of these is a good skeleton is a

very expensive skeleton I'm not seeing

those lines and mouth looking a real

alien to see them anywho it also

attaches to the sacrum and your base the

coccyx right so it's coming it's

attached with all of these bones down

here and then is running across the hip

joint to the femur now if this is the

diathesis here this big lump is the

greater trochanter this is the little -

cancer there just then here we haven't

really got one there's a gluteal

tuberosity a little little knobbly bit

some of the fibers of gluteus maximus

insert into the femur this is the

posterior femur that the gluteal

tuberosity but most of the fibers don't

most of the fibers inserts into the

flash' what I mean is that is that the

the lower limb is covered in a layer of

fairly tough deep fascia holds

everything in place right keeps the

muscles in groups and that fascia is

thickened laterally here's the hip the

knees down then there this is the Meo

tibial tract or the iliotibial band so

it goes from the ilium all the way down

to the tibia down here

now this elio tibial try to really a

tibial band something else that one is

care about because if it gets too tight

the tensor fasciae latae pulls on

another muscle causes a bit any pain see

your phone roll right anyway the reason

it's here is to give some stability to

the lower limb when you're standing

walking in that sort of thing but all it

is is a thickening of the fashio

of the fasciae latae of the lower limb

of the of the thigh here so we see as

this band largely when you're deciding

is like thinner here and thicker it's

you kind of cut it out if you look

pretty make you stand out now my point

is that most of the fibers of gluteus

maximus insert into the iliotibial tract

into the deep fascia of the leg salutis

maximus crosses the hip joint

is very good at helping you stand up and

when I had to do them was to raise

almost all of my body weight up so

extension of the hip joint right so this

is flexion of the thigh at the hip joint

so this is that is extension of the

thigh at the hip joint or hamstrings are

good at that

gluteus maximus is is also good so when

you walk you're mostly using your

hamstrings not really your glutes the

gluteus maximus is like is like your

turbo boost it's like your extra jet it

gives you that extra power when you need

to extend your hip joint and it's

particularly powerful when you're

extending from a flexed position or

partially flexed position most notably

when we're getting out of a chair right

so when you sat in the chair your hip

joint is flexed you at 90 degrees right

so when you stand up shouldn't need to

use your arms oh then you're engaging

gluteus maximus and going from going

from a flexed hip to an extended hip

course when you sit down when you're

lowering yourself gluteus maximus is

also lowering you slowly against gravity

so that's gluteus maximus great when

you're getting our chairs running

sprinting jumping climbing going up

stairs that's all think that's what

gluteus maximus is for all right now

gluteus maximus is innervated by the

inferior gluteal nerve there are two

gluteal nerves as an inferior gluteal

nerve and the superior gluteal nerve

remember our backers like Heraclitus

maximus it's big but it's it's the

inferior most muscle of the gluteal

muscles take gluteus maximus off here we

can see at least gluteus medius this

might be gluteus minimus here are those

not labeled as such but gluteus medius

and minimus then see how they're higher

up so they were innovated by the

superior gluteal nerve inferior gluteal


right gluteus medius and minimus are

also running from the ilium but they're

both running to the greater trochanter

of the femur the greater trochanter of

the femur is this lovely big bony bit

here roast they're running across from

the ilium so the greater trochanter of

the femur the media sees is more

superficial and minimus is deep now what

this means is there is that again

they're not actually powerful extensors

they're powerful abductors of the hip

joint so if they run across from there

because the greater trochanter is look

this is lateral is sticking out to the

side here because they pull out there

they're actually quite good at pulling

on the great circuit trochanter and

pulling the femur out away from the

midline so gluteus medius and minimus

are powerful abductors of the thigh at

the hip joint so you pull on the greater

trochanter the femur gets pulled away

from the midline so this is abduction of

the hip

so for gluteus medius and minimus bunk

right that's a production of the hip so

abduction of the thigh at the hip and if

you think about it because of that if

you if you think about this choice if

the if the hip join then is partially

flexed because we're running across this

joints the greater trochanter if you put

on the greater trochanter you'll also

get some medial rotation of the hip

joints they're quite good at medial

rotation of the femur at the hip gluteus

maximus does the opposite it can help in

lateral rotation again but it's you know

it's when you flex like this way so

gluteus booty's Maximus or powerful

extensors of the hip gluteus medius and

minimus powerful abductors of the hip

why is all this important well it's

because we're bipedal animals and we

walk and every time said this before but

every time we take a step we take one

foot off the ground so that means that

every time you take one foot off the


and hey look I can take my foot off the

ground and put it back on again and the

pelvis stays level

this is gluteus medius and minimus on

this side because I'm taking this four

off the ground they're contracting and

keeping my pelvis level if gluteus

medius and minimus don't contract my

pelvis drops and if I try and bring my

foot back down

oh it's Gus on the floor that's the

concept that students seem to be

struggling with so if the superior

gluteal nerve is damaged or maybe the l5

root which is part of the superior

gluteal nerve but if you if the l5 nerve

root was damaged you see foot drop and

other things as well right

so just consider damage to the superior

gluteal nerve it could happen through

trauma through like hip replacement

surgery hip fracture or like an

intramuscular arrangement and

intramuscular injection injection is the

body would do the wrong place right that

was a superior gluteal nerve if you want

to test to see if gluteus medius and

minimus are working you just ask move

I've run a hundred K so I'm wobbly you

ask the person to stand on one leg and

you look for the stability and you look

for the pelvis staying level if gluteus

medius and minimus a week they will

struggle to keep the pelvis level right

what this means is for you if you have a

weakness in gluteus medius and minimus

it means that that as you take that foot

off the ground the pelvis drops so the

foot doesn't swing through so you have

to compensate and what we typically see

is Trendelenburg sign the Trendelenburg

sign is when you ask somebody to stand

on one leg the pelvis drops to the other

side and that's a sign the gluteus

medius and minimus are weak for some

reason so you see the person then

leaning out see if you lean over that

way if you lean your body way over the

side with the pathology over the weak

side your body way you can lift the hip

on our side and you can swing your foot

through you might see also see a

swinging gait and a swinging gait then

is the pelvis drops and you swing the

foot out to the outside right see pelvis

drops swing the foot out around or you

might see a high stepping gate so the

pelvis drops so you bring the knee

forward more to compensate to get the

foot through so high step is gate

swinging gate Trendelenburg sign those

are all the signs that the pelvis isn't

staying level when you take one foot off

the ground

if the pelvis isn't staying level then

that's gluteus medius and gluteus

minimus and maybe the superior gluteal

nerve or something like that all right

so Trendelenburg sign is hip dropping to

the opposite side to the weakness and

then even a waddling gait gluteal gait

high step each gate swinging gate all

those sorts of things that's it that's

all I wanted to do because it's Maximus

extensor of the hip powerful when the

thigh is flexed to the hip gluteus

medius and minimus abductors of the hip

their job is to keep the pelvis level

when you take the leg on the opposite

side to the muscle off the floor so if

the weakness is on one side it's the

foot on the other side that's gonna drag

or something strange is gonna happen to

it those are the key points right

another cup of tea cup of teas a

recovery drink of choice right I'll be

fine this time next week see you next