Lecture 3 Anterior and Medial Thigh Flashcards
Cutaneous nerves of the anterior and medial thigh
- Lateral femoral cutaneous nerve (L2 & L3)
- Anterior (intermediate and medial) cutaneous branches of the femoral nerve (L2-L4)
- Cutaneous branch of the obturator nerve (L2)
- Saphenous nerve (L3, L4)
Where does the cutaneous branch of the obturator nerve innervate?
The inner thigh.
Where does the lateral femoral cutaneous nerve innervate?
Lateral upper thigh.
What spinal nerves form the femoral nerve?
L2-L4
What spinal nerves form the obturator nerve?
L2-L4
What spinal nerves form the sciatic nerve?
L4-S3
What spinal nerves form the tibial nerve?
L4-S3.
What spinal nerves form the Common Fibular Nerve?
The common fibular nerve is a branch of the sciatic nerve.
It is formed by spinal nerves L4-S2.
What does the femoral nerve innervate?
All anterior thigh muscles.
What does the obturator nerve innervate?
All medial thigh muscles.
What does the sciatic nerve innervate?
All posterior thigh muscles.
What does the patellar reflex test?
Patellar reflex tests spinal cord segments L2-L4 and the femoral nerve.
Absensce of the patellar reflex is called Westphals sign.
What does the calcaneal tendon reflex test?
S1 and S2 nerve roots.
What are the anterior muscles of the thigh?
IPSQ
- Iliopsoas m.
- Pectineus m.
- Sartoruis m.
- Quadriceps femoris m.
What muscles make up the iliopsoas muscles?
- Psoas major m.
- Iliacus m.
They both act the same!
What muscles make up the quadriceps femoris m.?
- Vastus lateralis m
- Rectus femoris m
- Vastus medialis m
- Vastus intermedius m.
Iliopsoas m. prominent feature
MAIN FLEXOR OF THE THIGH
Iliopsoas m Innervation
- Iliacus m: femoral nerve
2. Psoas major and psoas minor m: ventral rami of L1-L3
Iliopsoas m Action
- Laterally flex vertebral column
- Balance and flex trunk
- Flex the thigh when acting with the iliacus m.
Iliopectineal bursa
Sits directly on the anterior portion of the hip joint, and acts as a bursa for the Iliopsoas M. Lies underneath Iliopsoas.
Can become inflamed leading to groin pain.
Sartorius m. prominent feature
- Longest muscle
- Most superficial anterior muscle.
- Tailor sit muscle
Sartorius m.
Origin:
Insertion:
Originates: ASIS (anterior superior iliac spine)
Inserts: Pes anserine of the tibia
(near the medial epicondyle of the tibia)
Sartorius m.
Innervation:
Action:
Innervation: femoral nerve
Action:
- Flex thigh
- Flex leg
- Abduct thigh
- Laterally rotate the thigh
What is pes anserinus?
Pes anserinus is located on the tibia. It is a common insertion point for
- Sartorius m.
- Gracilis m. (medial thigh)
- Semintendinosus m. (posterior thigh)
What innervates the gracilis m.?
Obturator nerve
What innervates the semitendinosus m?
Sciatic nerve
What bursa are located at this common insertion point?
- Bursa of semimembranous
- Anserine bursa
- Bursa deep to iliotibial band (lateral side)
Quadriceps Femoris Muscles
- Vastus lateralis m
- Rectus femoris m.
- Vastus medialis m.
- Vastus intermedius m.
Quadriceps Femoris Muscles
Origin:
Insertion:
- Origin:
Rectus femoris m. originates on the AIIS (anterior inferior iliac spine)
Vastus muscles originate at the shaft of the femus
- Insertion: tibial tuberosity
Quadriceps femoris muscles
Innervation:
Action:
Innervation: Femoral nerve
Action: CHIEF EXTENSORS OF THE LEG
-Vasti extend the leg at the knee
-Rectus femoris m [extends the leg at the knee] and [flexes the thigh].
Osgood-Schlatter Disease
During running and jumping activities, a child’s quadriceps can pull on the Patellar tendon causing a slight (incomplete) avulsion of the Tibial Tuberosity. Osteogenesis can lead to a bony growth at the location of the avulsion.
How does the body try to fix osgood-schlatter disease?
By closing the gap with new bone growth. However, it results in a bony lump.
Tendons of all 4 quadricep femoris muscles unit to form what?
Quadriceps tendon.
Above the knee, it is called the patellar tendon (bone-muscle).
Below the knee, it changes its name to the patellar ligament (because ligament is bone-bone)
Bursa in the knee
Suprapatellar bursa is a bursa that is continuous with the joint. It slides as the patella slides during extension and flexion.
Why does the rectus femoris flex the thigh?
Because it attaches to the pelvic bone (AIIS).
What are the superficial medial muscles of the thigh?
- Pectineus M.
- Adductor Longus M.
- Adductor Brevis M.
- Gracilis M.
What action do all superficial medial muscles have in common?
They are adductors.
What are the deep muscles of the medial thigh?
- Obturator externus m.
2. Adductor magnus m.
Pectineus M
Origin:
Insertion:
Origin: pecten line of the pubis
Insertion: Pectineal line of the femur (inferior to the lesser trochanter)
Pectineus M
Innervation:
Action:
Femoral nerve (sometimes, obturator nerve will innervate.
- Adduct thigh
- Flex the thigh
Adductor Longus M
Origin:
Insertion:
Origin: body of the pubis, inferior to the pubic crest
Insertion: Middle 1/3 of linea aspera
Adductor Longus M
Innervation:
Function:
Innervation: Anterior division of the obturator nerve (L2-L4)
- Adduct thigh
- Flex thigh
Adductor Brevis M
Origin:
Insertion:
Origin: body of the pubis and inferior public ramus
Insertion: proximal linea aspera
Adductor Brevis M
Innervation:
Function:
Innervation: Anterior division of the obturator nerve
Function:
Adduct thigh
Flex thigh
Gracilis M. Prominent Feature
Long and straplike.
It is the only adductor to cross the knee joint.
Gracilis M.
Origin
Insertion
Origin: Body of the pubis and inferior public ramus.
Insertion: Medial aspect of the proximal end of the tibia (Pes anserine)
Gracilis M.
Innervation:
Action:
Innervation: Anterior division of the obturator n.
Action:
- Adduct thigh
- Flex leg.
- Medially rotate the leg/
Where is your groin?
Your groin is the junction between the trunk and thigh.
What can happen if you pull your groin?
You can strain, stretch and tear the proximal attachments of thigh adductor and flexor muscles.
Obturator Externus M.
Origin:
Insertion:
Lies deep to the pectineus.
Origin: External margin of the obturator foramen
Insertion: Trochanteric fossa
Obturator Externus M.
Innervation:
Function:
Innervation: Obturator nerve
Function: Laterally rotates the thigh.
Adductor Magnus M prominent feature
Largest adductor muscle.
The superior part lies deep to the adductor brevis m.
Parts of the adductor magnus muscle
- Adductor portion
2. Hamstring portion
Adductor Magnus M
Origin
Adductor portion originates at the [ischiopubic ramus].
Hamstring portion originates at the [ischial tuberosity].
What nerves inervate the three muscles of the pes anserinus?
- Femoral N.
- Anterior division of the obturator n.
- Tibial division of the sciatic n.
Calcaneal tendon reflex test should result in what?
Should result in plantar flexion.
It tests the S1 and S2 sacral contributions of the sciatic nerve.
Pes anserinus
the common insertion point for 3 tendons of 3 muscles:
S,G,T
All quadricep muscles unite form what?
- Patellar tendon
After it crosses the knee, it becomes the patellar ligament.
What is the largest adductor muscle?
Adductor magnus m.
What is the adductor hiatus?
The space in between the adductor and hamstring portion of the adductor magnus m.
When you “pull your groin”, this often involves what muscles?
- Adductor and flexor muscles
- Often times, your adductor longus m. is involved.
In sports, these muscles are in a tug of war and can easily be strained.
How do we seperate the compartments of the thigh?
- Medial intermuscular septa
2. Lateral intermuscular septa
Medial intermuscular septa seperates what?
The anterior and medial compartments
Lateral intermuscular septa
Separates the anterior and posterior compartments of the thigh.
Becomes continuous with the IT band
How do we seperate the medial and posterior muscles of the thigh?
they are not seperated.
main job of anterior compartment
extend
main job of medial compartment
adduct
main job of posterior compartment
flex