Week 3 - Muscles Of The Pelvic Region Flashcards
What does the superficial gluteal region comprise of?
- gluteus Maximus
- gluteus medius
Origin of the gluteus Maximus
- Sacrotuberous ligament
- Posterior gluteal line
Insertion of the gluteus Maximus ?
- gluteal tuberosity
- iliotibial band
Origin of the gluteus medius ?
- anterior gluteal line
- inferior gluteal line
Insertion of the gluteus medius?
- greater trochanter
What does the deep gluteal region comprise of?
- the cut edges of the gluteus max
- the cut edges of the gluteus med
- gluteus minimus
- the 6 lateral rotators
What are the 6 lateral hip rotators?
1- Piriformis
2- Gemellus superior
3- Obturator internus
4- Gemellus inferior
5- Obturator externus
6- Quadratus Femoris
What is the origin of the piriformis
Anterior surface of the sacrum, gluteal surface of ilium
What is the insertion of the piriformis ?
The apex of the greater trochanter of the femur
What are actions of the piriformis muscle
Thigh external rotation, thigh abduction from flexed hip, stabilises head of femur in acetabulum
Origin of the gemellus superior
Ischial spine
Insertion of the gemellus superior
Medial surface of the greater trochanter of the femur (via tendon of obturator internus)
Actions of the gemellus superior
Thigh external rotation, thigh abduction (from flexed hip), stabilises head of femur in acetabulum
Origin of obturator internus
Posterior surface of the obturator membrane
Insertion of obturator internus
Medial surface of the greater trochanter of the femur
Actions of the obturator internus muscle
External rotation of extended thigh, abduction of flexed thigh, stabilisation of hip joint
Origin of gemellus inferior
Ischial tuberosity
Insertion of gemellus inferior
Medial surface of the greater trochanter of the femur, via tendon of obturator internus
Actions of gemellus inferior muscle
Thigh external rotation, thigh abduction from flexed hip, stabilises head of femur in acetabulum
Origin of the obturator externus
Anterior surface of obturator membrane, bony boundaries of obturator foramen
Insertion of obturator external muscle
Trochanteric fossa of femur
Actions of the obturator externus
Thigh external rotation, thigh abduction from flexed hip, stabilises head of femur in acetabulum
Origin of quadratus femoris
Ischial tuberosity
Insertion of quadratus femoris muscle
Intertrochanteric crest of femur
Actions of the quadratus femoris muscle
Thigh external rotation, stabilises head of femur in acetabulum
What is the sciatic nerve
It is a loose binding of two functional nerves - the common peroneal/fibular nerve and the tibial nerve. It is the largest nerve in the human body
Origin of the sciatic nerve
Under the piriformis
- it leaves the pelvis via the greater sciatic foramen and enters into the posterior thigh
Application of the sciatic nerve
Clinicians are taught to perform buttock injection high rather than lower as they will less likely accidentally jab the sciatic nerve. If a nerve is jabbed with a needle it is more likely to become inflamed or irritated as contraction of the muscle through which it passes rubs/compresses the nerve
Superior and inferior gluteal vessels and nerves
- their names derive from their relation to piriformis
- they have been removed on most prosecutions
Where does the gluteal nerves arise
The lumbosacral region
Where do the gluteal nerves exit
They exit the pelvis through the greater sciatic formamen and pass the piriformis muscle
- the superior gluteal nerve passes over the muscle
- the inferior gluteal nerve passes under the muscle
- after leaving the pelvis, they terminated by giving off branches to innervate the gluteal muscles
What is the tensor fascia latae
It isa fuse form muscle located in the lateral aspect of the thigh. It belongs to the muscle of the gluteal region along with the gluteus max, med and min muscles
Origin of the TFL
Outer lip of the anterior iliac crest, ASIS
Insertion of the TFL
Lateral condole of tibia, via the iliotibial tract
Actions of the TFL
Thigh internal rotation at the hip joint, weak thigh abduction at the hip joint, leg external rotation at the knee joint, weak leg flexion/extension at the knee joint. It stabilises the hip and knee joints
What is the iliotibial tract (ITB)
It is a thickened band of deep fascia that runs down the laterals surface of the thigh. It is formed from the deep fascia of the thigh, the fascia lata and receives the distal aspects of gluteus max and TFL muscles
Origin of ITB
Iliac crest, lateral part of the hip joint capsule and the TFL
Insertion of the ITB
Tubercle of ITB (Gerdy’s tubercle),
Actions of ITB
Lateral stabilisation of hip and knee
- hip flexion, extension, abduction, lateral rotation, medial rotation (through the action of gluteus max and TFL)
What is the ischial tuberosity ?
It is a large round protrusion at the inferoposterior aspect for the ischium. It is where the weight of the body is held when seated.
What attaches onto the ischial tuberosity
Sacrotuberous ligament, gluteal muscles (inferior gemellus, quadratus femoris), adductor Magnus, posterior thigh muscles (biceps femoris, semitendinosis, semi membranous)
What does the ischial tuberoisty help to locate
The sciatic nerve - which descends through the pelvis between the ischial tuberosity and the greater trochanter of femur
What is the sacrotuberous ligament
It is a thick fibrous band that extends from the posterior ilium, lateral sacrum and coccyx to the ischial tuberosity.
What is the function of the sacrotuberous ligament
Stabilisation of the sacroiliac joint and strengthening the connection between bony pelvis and the vertebral column
What is the greater trochanter of the femur
It is a prominent, palpable bony projection located on the upper lateral aspect of the proximal femur
Functions of the greater trochanter
It is an attachment site for muscles that move and stabilise the hip joint
- particularly those muscles that are responsible for abducting and rotating the thigh
- serves as an attachment point for hip ligaments which contribute to the stability and integrity of the hip joint
What is the inguinal ligament
It is a band of connective tissue that extends from the ASIS of the ilium to the pubic tubercle on the pubic bone
Attachment of the inguinal ligament
- ASIS
- Pubic tubercle
Extension of the inguinal ligament
- lacunar ligament
- pectineal ligament
Function of the inguinal ligament
- attach external oblique muscle to the pelvis
- protect structure passing between the pelvis and thigh/external genitalia
- forms boundary of femoral triangle and inguinal canal
What is the inguinal canal
It is a passage in the lower anterior abdominal wall, located just above the inguinal ligament
What is the obturator nerve
It is one of the largest branches of the lumbar plexus and is a mix of nerves which arise from the anterior rami of spinal nerves L2-L4
What is the function of the obturator nerve
To provide motor innervation to all the middle muscles of the thigh (hip adductors) expect from the hamstring part of the adductor Magnus
Where does the obturator nerve exit through
Obturator canal in the pelvic cavity
What is the obturator canal formed
By the obturator membrane and obturator groove
Origin of psoas major muscle
- transverse processes of all the lumbar vertebrae
- vertebral bodies of T12-L5
Insertion of psoas major
Lesser trochanter of the femur as iliopsoas tendon
Actions of psoas major muscle
Flexion of thigh/trunk at hip joint, lateral rotation of the thigh at hip joint, lateral flexion of trunk at the hip joint
What is the iliopsoas muscle
It is a large compound muscle of the inner hip
What is the iliopsoas muscle composed of
Iliacus and psoas major muscle
What is the extensive origin for the iliopsoas
The psoas major portion originates from the 12th thoracic and all 5 lumbar vertebrae and the iliacus portion arises from the iliac fossa of the pelvis. Their fibres merge into a single muscle belly around the pelvis brim
Insertion of iliopsoas
It ends in a tendon that inserts onto the lesser trochanter of the femur
What does the iliopsoas tendons of insertion sometimes form?
Grooves on the superior pubic ramus
Actions of the iliopsoas muscle
It is the main flexor of the hip joint. There is also external rotation of the thigh and flexion of the trunk at the hip joint. And lateral flexion of the trunk (psoas major only). Due to its proximal attachments, the psoas major can also produce additional movements of the lumbar vertebral column
What muscle of iliacus and psoas major is medial
Psoas major
What is the psoas minor
It is very tiny and weak so it is functionally significant
Do all specimens have a psoas minor?
No, it is absent in about half the specimens
Does the psoas major have an action on the hip?
No, because it doesn’t cross the hip joint as it inserts on the superior pubic ramus.
What are the 5 hip adductors
- gracilis
- adductor longus
- pettiness
- adductor brevis
- adductor magnus
How to identify the 5 hip adductors
- from medial to lateral you can see gracilis, adductor longus and then pectineus
- behind gracilis and adductor log us os adductor Magnus
- behind adductor longus and pectineus is adductor brevis
What is the gracilis muscle ?
Gracilis muscle is a long and slender muscle located in the medial (adductor) compartment of the thigh. It is the most superficial hip adductor
Origin of the gracilis
Anterior body of pubis, inferior pubic ramus, ischial ramus
Insertion of gracilis ?
Medial surface of proximal tibia (via pes anserinus)
Actions of the Gracilis
Thigh flexion and abduction and the hip joint and leg flexion and internal rotation at the knee joint
What is the adductor longus muscle?
It is a large, fan-shaped muscle located in the medial aspect of the thigh.
What is the primary function of the adductor longus
To adduct the thigh at the hip joint
Origin of adductor longus muscle
Body of pubis, inferior to pubic crest and lateral to the pubic symphysis
Insertion of adductor longus
Middle third of linea aspera of femur (medial lip)
Actions of the adductor longus muscle
Hip joint: Thigh flexion, Thigh adduction, Thigh external rotation and Pelvis stabilization
What is the pectineus
It is a flat muscle found in the superomedial part of the anterior thigh.
Origin of pectineus
Superior pubic ramus (pectineal line of pubis)
Insertion of pectineus
Pectineal line of femur, linea aspera of femur
Actions of pectineus muscle ?
Hip joint: Thigh flexion, thigh adduction, thigh external rotation, thigh internal rotation; pelvis stabilization
What is the adductor brevis muscle ?
It is a flat, triangular muscle that is found in the inner thigh.
Origin of the adductor brevis
Anterior body of pubis, inferior pubic ramus
Insertion of the adductor brevis
Linea aspera of femur (medial lip)
Actions of adductor brevis
Hip joint: thigh flexion, thigh adduction, thigh external rotation and pelvis stabilization
What is the adductor Magnus muscle ?
is a large triangular muscle of the lower limb, with its apex situated on the hip bone, and its base on the linea aspera of the femur. It has two seperate muscles - a true adductor part and an ex-hamstring part. The uppermost part is called adductor minimus
Origin of adductor Magnus
Adductor part: Inferior pubic ramus, ischial ramus
Ischiocondylar part: Ischial tuberosity
Insertion of the adductor Magnus
Adductor part: Gluteal tuberosity, linea aspera (medial lip), medial supracondylar line
Ischiocondylar part: Adductor tubercle of femur
Actions of the adductor Magnus muscle
Adductor part: Hip joint - Thigh flexion, thigh adduction, thigh external rotation
Hamstring part: Hip joint - Thigh extension, thigh internal rotation
Entire muscle: Pelvis stabilization
Where is there often another muscle between?
Adductor brevis and minimus
What is the adductor hiatus ?
It is the space between the two parts of adductor Magnus. The femoral vessels pass from the front of the thigh to behind the the knee through this gap.
What is the rectus femoris
It is one of the four quadriceps muscles. It also acts across the hip
Origin of rectus femoris
From the pelvis at the AIIS
Insertion of the rectus femoris muscle
Patella via the quadriceps femoris tendon
Actions of the rectus femoris
Extends the knee, flexes the hip
What is the sartorius
It is the longest muscle in the human body. Together with the quadriceps femoris, it belongs to the anterior muscles of the thigh.
Origin of the sartorius
Anterior superior iliac spine (ASIS)
Insertion of sartorius
Proximal end of tibia below medial condyle (via pes anserinus)
Actions of the sartorius
Hip joint: thigh flexion, thigh abduction, thigh external rotation
Knee joint: leg flexion, leg internal rotation
