Lecture 24 - Muscles Of The Thigh

Question 1

What are the 3 compartments of the muscles of the thigh?

Answer 1

• anterior
• posterior
• medial

Question 2

How many muscles are in the anterior compartment? What are they?

Answer 2

• 5 muscles total
• rectus femoris
• Vastus lateralis/medialis/intermedius
• sartorius
• all share a common innervation via the femoral nerve

Question 3

What is the origin/insertion/innveration/main action of the rectus femoris?

Answer 3

• O: 2 Heads, Straight Head - Anterior Inferior Iliac Spine, Curved Head - Superior Acetabulum
• I: Tibial tuberosity via the patellar tendon
• Inn: Femoral nerve
• MA: Knee extension & hip flexion

Question 4

What is the origin/insertion/innveration/main action of the Vastus lateralis?

Answer 4

• O: Linea aspera & greater trochanter
• I: Tibial tuberosity via the patellar tendon
• Inn: Femoral nerve
• MA: Knee extension

Question 5

What is the origin/insertion/innveration/main action of the Vastus medialis?

Answer 5

• O: Linea aspera & intertrochanteric line
• I: Tibial tuberosity via the patellar tendon
• Inn: Femoral nerve
• MA: Knee extension

Question 6

What is the origin/insertion/innveration/main action of the Vastus intermedius?

Answer 6

• O: Anterior & lateral surfaces of the femur
• I: Tibial tuberosity via the patellar tendon
• Inn: Femoral nerve
• MA: Knee extension

Question 7

What is the origin/insertion/innveration/main action of the sartorius?

Answer 7

• O: Anterior Superior iliac Spine
• I: Medial proximal tibia
• Inn: Femoral nerve
• MA: Hip flexion, abduction, external rotation & Knee flexion
• note: also longest muscle in the body

Question 8

What is the posterior compartment of the muscles of the thigh?

Answer 8

• Known as the hamstrings
• Three 2-jointed muscles that cross both the hip & knee
• Common origin is the ischial tuberosity & all innervated by the sciatic nerve

Question 9

What are the 3 muscles of the posterior compartment?

Answer 9

• biceps femoris
• semimembranosus
• semitendinosus

Question 10

What is the origin/insertion/innveration/main action of the biceps Femoris?

Answer 10

• O: 2 Heads, Long Head - Ischial tuberosity, Short Head - Linea aspera
• I: Head of the fibula
• Inn: Sciatic nerve
• MA: Hip extension, knee flexion, lateral rotation of a FLEXED knee

Question 11

What is the origin/insertion/innveration/main action of the semimembranosus?

Answer 11

• O: Ischial tuberosity
• I: Posteromedial tibial condyle
• Inn: Sciatic nerve
• MA: Hip Extension, knee flexion, medial rotation of a FLEXED knee

Question 12

What is the origin/insertion/innveration/main action of the semitendinosus?

Answer 12

• O: Ischial tuberosity
• I: Medial surface of proximal tibia
• Inn: Sciatic nerve
• MA: Hip extension, knee flexion, medial rotation of a FLEXED knee

Question 13

What is the medial compartment of the muscles of the thigh?

Answer 13

• Comprised of 5 muscles
• All cross the hip joint: Only one (gracilis) also crosses the knee joint
• Collectively referred to as the hip adductors

Question 14

What are the 5 muscles of the medial compartment of the muscles of the thigh?

Answer 14

• Gracilis
• pectineus
• adductor brevis
• adductor longus
• adductor Magnus (smaller & larger portion)

Question 15

What is the origin/insertion/innveration/main action of the gracilis?

Answer 15

• O: Body of Pubis
• I: Just below the medial tibial condyle (posterior to sartorius)
• Inn: Obturator nerve
• MA: Hip adduction

Question 16

What is the origin/insertion/innveration/main action of the pectineus?

Answer 16

• O: Superior Pubic Ramus
• I: Pectineal line of the femur
• Inn: Femoral nerve
• MA: Hip adduction

Question 17

What is the origin/insertion/innveration/main action of the adductor brevis?

Answer 17

• O: Body of pubis & inferior pubic ramus
• I: Proximal linea aspera & pectineal line
• Inn: Obturator nerve
• MA: Hip adduction

Question 18

What is the origin/insertion/innveration/main action of the adductor longus?

Answer 18

• O: Body of Pubis
• I: Middle 1/3 linea aspera
• Inn: Obturator nerve
• MA: Hip adduction

Question 19

What is the origin/insertion/innveration/main action of the adductor Magnus (smaller adductor portion)?

Answer 19

• O: Ischiopubic ramus
• I: Medial supracondylar ridge & linea aspera of the femur
• Inn: Obturator nerve
• MA: Hip adduction

Question 20

What is the origin/insertion/innveration/main action of the adductor Magnus (larger hamstrings portion)?

Answer 20

• O: Ischial Tuberosity
• I: Adductor tubercle of femur
• Inn: Sciatic nerve
• MA: Powerful hip adduction

Question 21

What is the intermuscular septum?

Answer 21

• connective tissue that extends from the superficial fascia deep into a muscle groups to separate one muscle from another

Question 22

What is the fascia of the thigh?

Answer 22

• Sleeve of connective tissue surrounding the muscles of the thigh
• Responsible for maintaining the shape of the thigh & enhancing the mechanical function of the muscles of the thigh
• Thicker proximally & laterally, also thicker around the knee for support

Question 23

What are the femoral triangle boundaries?

Answer 23

• Base: Inguinal ligament
• Medial: Adductor Longus
• Lateral: Sartorius
• Floor (lateral to medial): Iliopsoas, Pectineus, & Adductor Longus

Question 24

What are the femoral triangle contents?

Answer 24

• From lateral to medial:
• Femoral nerve
• Femoral artery
• Femoral vein
• Lymphatic vessels

Question 25

What is the pes anserine group?

Answer 25

• Medial group of 3 muscles crossing the knee
• One muscle from each compartment:

  - Anterior=Sartorius
  - Medial = Gracilis
  - Posterior = Semitendinosus

• Order (anterior to posterior) – “Say Grace before Tea”