The Muscular System - Muscles of the Body: Lower Body Musculature

Question 1

What muscles make up the quads?

Answer 1

Rectus femoris, vastus medialis, vastus laterals, and vastus intermedius

Question 2

What does the quadricep muscles do?

Answer 2

The quadricep muscles are used to extend the lower leg and stabilize the knee. The rectus femoris also acts to flex the hip

Question 3

Where does the vastus medialis originate from?

Answer 3

Originates from the intertrochanteric line and pectineal line of the femur, down to the medial lip linea aspera and the medial supracondylar line.

Question 4

Where does the vastus medialis insert?

Answer 4

Inserts on the medial border of the patella and the patellar ligament via the quadricep tendon

Question 5

What are the functions of the vastus medialis?

Answer 5

Extension and stabilization of the knee

Question 6

Where does the vastus lateralis originate from?

Answer 6

It begins on the greater trochanter and the intertrochanteric line, to the gluteal tuberosity and the lateral aspect of the linea aspera.

Question 7

Where does the vastus lateralis insert?

Answer 7

Lateral aspect of the patella and the quadriceps tendon into the patellar ligament.

Question 8

What are the functions of the vastus lateralis?

Answer 8

To extend and stabilize the knee.

Question 9

Where does the vastus intermedius originate from?

Answer 9

Originating from the upper two-thirds of anterior and lateral surfaces of the femur.

Question 10

What are the functions of the vastus intermedius?

Answer 10

Knee extension

Question 11

Where does the vastus intermedius insert?

Answer 11

Inserting via the Quadriceps tendon and then inserts into the patellar ligament, which interest into the tibial tuberosity

Question 12

Where does the tibialis anterior originate from?

Answer 12

The lateral condyle and upper half of the lateral surface of the body of the tibia and interosseous membrane.

Question 13

Where does the tibialis anterior insert?

Answer 13

Medial and under the surface of the first cuneiform bone, and the base of the first metatarsal bone.

Question 14

What is the function of the tibialis anterior?

Answer 14

Dorsiflexion, foot inversion, and assists in maintaining the medial arch of the foot.

Question 15

Where does the tibialis posterior originate from?

Answer 15

The posterior surface of the tibia and fibula

Question 16

Where does the tibialis posterior insert?

Answer 16

It inserts into the tuberosity of the navicular bone, the three cuniform bones, the cuboid bone, and the base of metatarsal bones 2 -4

Question 17

What are the actions of the tibialis posterior?

Answer 17

Plantar flexion, foot inversion, and assists in supporting the medial arch of the foot

Question 18

Where does the Soleus muscle originate from?

Answer 18

The head and the upper posterior surface of the fibula, the soleal line and extends on the medial border of the tibia.

Question 19

Where does the Soleus muscle insert?

Answer 19

Inserts on the posterior surface of the calcaneus via the calcaneal tendon

Question 20

What are the actions of the Soleus Muscle?

Answer 20

Plantar flexion of the talocrural joint and lower leg stabilization.

Question 21

What muscles make up the tricep surae?

Answer 21

Soleus and Gastrucnemius

Question 22

Where do the lateral head and the medial head of the gastrocnemius muscle originate from?

Answer 22

The lateral head originates from the posterolateral aspect of the lateral condyle of the femur.

The medial head originates from the posterior surface of the medial femoral condyle, and the popliteal surface of the femoral shaft

Question 23

Where does the gastrocnemius muscle insert?

Answer 23

The posterior surface of the calcaneus via the calcaneal tendon

Question 24

What are the actions of the gastrocnemius muscle?

Answer 24

Plantar flexion of the talocrural joint, flexion of the knee, and stabilization.

Question 25

Where is the peroneus longus muscle located?

Answer 25

Fibularis (peroneus) longus is a long muscle located superficially on the lateral side of the lower leg

Question 26

Where does the peroneus longus muscle originate from?

Answer 26

Head of the fibula, proximal 2/3 of the lateral surface of the fibula, and the intermuscular septa

Question 27

Where does the peroneus longus muscle insert?

Answer 27

The medial cuneiform bone and the first metatarsal bone.

Question 28

What are the actions in the peroneus longus muscle?

Answer 28

Plantar flexion of the talocrural joint(ankle joint), foot eversion, and support the longitudinal and transverse arches of the foot.

Question 29

Where is the peroneus brevis located?

Answer 29

On the lateral and inferior aspect of the lower leg.

Question 30

Where does the peroneus brevis muscle originate from?

Answer 30

Distal 2/3 of the lateral surface of fibula, and the anterior intermuscular septum

Question 31

Where does the peroneus brevis muscle insert?

Answer 31

Tuberosity of the 5th metatarsal

Question 32

What are the actions in the peroneus brevis muscle?

Answer 32

Plantar flexion of the talocrural joint(ankle joint) & foot eversion

Question 33

Where does the gluteus medius originate from?

Answer 33

Gluteal surface of ilium

Question 34

Where does the gluteus medius insert?

Answer 34

Lateral aspect of greater trochanter of femur

Question 35

What are the actions of the gluteus medius muscle?

Answer 35

Abduction, extension, internal rotation of thigh, external rotation, and pelvic stabilization

Question 36

Where does the gluteus minimus originate from?

Answer 36

Gluteal surface of ilium

Question 37

Where does the gluteus minimus insert?

Answer 37

Anterior aspect of greater trochanter of femur

Question 38

What are the actions of the gluteus minimus muscle?

Answer 38

Abduction, extension, internal rotation of thigh, external rotation, and pelvic stabilization

Question 39

What happens when the gluteus medius is underactive?

Answer 39

When the glute medius is weak, the quadratus lumborum on the opposing side often becomes overactive to stabilize the pelvis since the glute medius isn’t assisting in pelvic stabilization. This often causes low back pain.

Question 40

Where does the tensor fascia latae originate from?

Answer 40

Anterior superior iliac spine, outer lip of
iliac crest

Question 41

Where does the tensor fascia latae insert?

Answer 41

The iliotibial tract

Question 42

What are the actions of the tensor fascia latae muscle?

Answer 42

Hip extension and abduction, internal rotation of the thigh, external rotation of the leg, and hip and knee joint stabilization

Question 43

Where does the piriformis muscle originate from?

Answer 43

Anterior surface of the sacrum (between the S2 and S4), Gluteal surface of ilium.

Question 44

Where does the piriformis muscle insert?

Answer 44

Inserts on the apex of the greater trochanter of the femur.

Question 45

What are the functions of the piriformis?

Answer 45

External rotation of the thigh, thigh abduction, and stabilizes the head of the femur in the acetabulum.

Question 46

What happens when the piriformis becomes tight?

Answer 46

When the piriformis tightens, the sciatic nerve may become compressed and induce sciatica (pain that originates at the gluteals and often travels down the leg via the sciatic nerve). This is also called piriformis syndrome.

Question 47

Where does the popliteus muscle originate from?

Answer 47

Lateral condyle of the femur and posterior horn of the lateral meniscus of the knee joint.

Question 48

Where does the popliteus muscle insert?

Answer 48

On the posterior surface of the proximal tibia.

Question 49

What are the actions of the popliteus muscle?

Answer 49

To unlock the knee, stabilize and flex the knee joint. It also assists with the internal rotation of the tibia.

Question 50

Where does the sartorius muscle originate from?

Answer 50

Anterior superior iliac spine

Question 51

Where does the sartorius muscle insert?

Answer 51

The proximal end of the tibia below the medial condyle via the pes anserinus.

Question 52

What are the actions of the sartoruis muscle?

Answer 52

This muscle acts to flex, abduct, and externally rotate the hip. It also aids in knee flexion.