9 - Gluteal Region and Posterior Thigh Flashcards
What is valgus knee alignment?
Knees go inwards. Feet wider apart than knees
What is varus knee alignment?
Knees go outwards “var is ze pig?” Bow legged with increases gap between knees. Smaller joint space on medial side/worn down cartilage and menisci like after running.
What are the boundaries of the gluteal region?
Iliac crest to the gluteal folds created by the inferior gluteal muscles
Why is the hip bone described as a innominate bone?
No-name bone. Is formed from the fusion of the ischium, ilium and pubis
What makes up the pelvis?
The hip bone, sacrum and coccyx
Important features/landmarks on the hip bone
iliac crest ilium ASIS AIIS ischial spine (most posterior - numb in child birth as lots of nerves) pubic tubercle (points anterior) inferior/superior pubic rami iliac spine (between ASIS and AIIS) ischium pubis
What are the two major ligaments that bind the hip bones to the pelvis?
The sacrospinous ligament (anterior) and sacrotuberous ligament (longer and more posterior)
The ligaments divide the sciatic notch into 2 smaller spaces - what are these?
Greater Sciatic Foramen
- vessels enter the lower limb/gluteal region i.e. sciatic nerve
Lesser Sciatic Foramen
- vessels return to the pelvis/peroneal region to the midline
Sacrospinous Ligament?
Sacrum (inferior) > Ischial Spine
Sacrotuberous Ligament?
Sacrum (superior) > ischial tuberosity
What forms the Greater Sciatic Foramen?
The sacrotuberous ligament
What forms the lesser sciatic foramen?
The sacrospinous ligament
How many gluteal muscles are there and what are they?
9 muscles Superficial: Gluteus Maximus Deep: Gluteus Medius Gluteus Minimus Short External Rotators: Piriformis Obturator Externus Superior Gemelli Inferior Gemelli Quadratus Femoris
Tensor Fascia Lata
Gluteus Maximus
- most superficial and biggest in body
- when you sit down it slides forward so you sit on ischial tuberosity not glut
O = Upper ilium, posterior sacrum, coccyx and sacrotuberous ligament
I = Illiotibial Band and Gluteal Tuberosity on posterior Femur
> thigh extension
> INFERIOR gluteal nerve
What are the 3 bursa associated with gluteus maximus?
- Trochanteric Bursa
> Most superior on the greater trochanter
> Get inflammed and painful in elderly - Ischial Bursa
> Over the ischial tuberosity
> Rubs every you sit. Often problems in cyclist - Gluteofemoral Bursa
> Is lateral between the ITB insertion and vastus lateralis (clear plane here)
> balloons filled with fluid to help with lubrication with movement and structures gliding over each other
Gluteus Medius and Minimus
O: Upper iliac crest
I: Greater Trochanter
> Gluteus medius and minimus come off superior to maximus hence supplied by the Superior Gluteal Nerve
> Hip ABDuction which holds the pelvis level rather than moving from side to side even when on one foot
> Have different fibre orientation to gluteus maximus. Are almost vertical compared to maximus which is more oblique
> fascia plane between them and maximus
Tensor Fascia Lata
O: ASIS and iliac crest I: ITB > abducts thigh and stabiliser > Superior Gluteal Nerve See anteriorly but is a gluteal muscle
What are the short external rotator muscles, what do they do and what is their nerve supply?
- Piriformis (pear shaped)
- Superior Gemelli
- Inferior Gemelli
- Obturator Internus (inbetween the 2 gemelli)
- Quadratus Femoris
> They are inferior to gluteus minimus and medius and externally rotate the thigh (ballet muscles)
> Nerves off of the sacral plexus
Piriformis
Pear shaped. Landmark. O: Sacrum I: Greater Trochanter > Sacral plexus > externally rotates thigh
All the gluteal muscles insert onto the greater trochanter except 2/3… what are they?
Gluteus Maximus - ITB laterally and gluteal tuberosity on posterior upper femur
Quadratus Femoris - intertrochanteric CREST of the femur
Tensor Fascia Lata - ITB
What gluteal muscles act as a three headed muscle and where do they originate and insert?
Superior Gemelli > O: Ischial Spine Obturator Internus > O: Obturator Foramen Inferior Gemelli > O: Ischial Tuberosity The 3 tendons insert together at the greater trochanter > nerves off sacral plexus > externally rotate thigh
Quadratus Femoris
O: Ischial Tuberosity
I: Intertrochaneteric crest of the posterior femur
> nerves off sacral plexus
> externally rotates thigh
What are the posterior thigh (hamstring) muscles, what are their actions and nerve supply?
Biceps Femoris (most lateral) Semitendinosus Semimembranosus Adductor Magnus (hamstring head) > Tibial nerve from the sciatic nerve > Flex the leg
Where do all the hamstring muscles originate from (apart from the short head of biceps femoris?)
The ischial tuberosity
short head of biceps femoris origin is linea aspera
Biceps Femoris
Most Lateral
O: L. head ischial tuberosity
S. head linea aspera
I: Lateral so head of FIBULA
> flexes and externally rotates leg. Extends thigh
tibial n.
Semitendinosus
O: Ischial tuberosity
I: Pes Anserinus
> flex and internally rotates leg. Extends thigh
> tibial n.
Semimembranosus
Deeper and more medial
O: Ischial tuberosity
I: Medial condyle of tibia and joint capsule
> Extend thigh, flex and internally rotate leg
> tibial n.
Adductor Magnus
O = Ischia tuberosity (and inf. pubic ramus)
I = Linea aspera, medial supracondylar ridge and adductor tubercle (femur NOT tibia)
> extends and flexes thigh by different fibres. Adducts thigh.
> tibial n. (and obturator)
How does Piriformis act as a landmark muscle in the gluteal region?
- the superior and inferior gluteal arteries/nerve run superior and inferior to the piriformis muscle supplying G.Med/Mine and G.Max
- there is a neurovascular bundle both inferior and superior
What is the path of the gluteal arteries?
Aorta > CIA > Int. Iliac A. > inf. and sup. gluteal arteries leave the pelvis by the Greater Sciatic Foramen along with the Sup and Inf Gluteal Nerves > the sup and inf gluteal arteries anastomose with the femoral circumflex arteries off Profunda femoris
Where will you find the sciatic nerve?
Inferior to Piriformis. Is the largest nerve in the body thumb or 2 thumbs thick.
Which of the gluteal arteries has a branch and what does it do?
The inferior gluteal artery branches into the Artery of the Sciatic Nerve
What does the Sciatic nerve divide into?
Tibial and common peroneal usually in the distal thigh but can occur much higher - can be injured in surgery if not considered
How does a hamstring injury occur?
- during kicking and running
- can get muscular strains/tears or ischial tuberosity avulsion where you can tear the tendon off or even the tuberosity itself especially in young as the bone hasn’t fused yet
Describe a Trendelenburg Gait
- occurs when you damage gluteus medius and minimus or the supplying superior gluteal nerve
- these muscles hold the pelvis level and stabilise it especially when standing on one leg it stops you falling
- thigh ABduction on the affected side is weakened resulting in the trendelenburg swing gait
- if right side is affected then will lean over to the ride side to compensate falling to the left
- if right side affected then the left leg will drop when lifted/pelvis fall on the non affected side
Which side of the gluteal region is common and safer for intra-muscular injection?
Superior lateral - large muscular area for venous absorption and away from sciatic nerve which is more medial and inferior
Piriformis Syndrome?
When the Sciatic Nerve is compressed by Piriformis causing pain, tingling numbness in buttocks and along sciatic nerve
Where does the sciatic nerve run in a cross section diagram?
Deep to biceps femoris and between adductor magnus (between posterior compartment and medial compartment)
How is the pelvis stabilised?
Gluteus Medius is the major muscle to stabilise the pelivs - abducts the thigh to stabilise during walking/lifted leg. Tensor Fascia Lata also stabilises
