The Muscular System - Muscles of the Body: Lower Body Musculature Flashcards
What muscles make up the quads?
Rectus femoris, vastus medialis, vastus laterals, and vastus intermedius
What does the quadricep muscles do?
The quadricep muscles are used to extend the lower leg and stabilize the knee. The rectus femoris also acts to flex the hip
Where does the vastus medialis originate from?
Originates from the intertrochanteric line and pectineal line of the femur, down to the medial lip linea aspera and the medial supracondylar line.
Where does the vastus medialis insert?
Inserts on the medial border of the patella and the patellar ligament via the quadricep tendon
What are the functions of the vastus medialis?
Extension and stabilization of the knee
Where does the vastus lateralis originate from?
It begins on the greater trochanter and the intertrochanteric line, to the gluteal tuberosity and the lateral aspect of the linea aspera.
Where does the vastus lateralis insert?
Lateral aspect of the patella and the quadriceps tendon into the patellar ligament.
What are the functions of the vastus lateralis?
To extend and stabilize the knee.
Where does the vastus intermedius originate from?
Originating from the upper two-thirds of anterior and lateral surfaces of the femur.
What are the functions of the vastus intermedius?
Knee extension
Where does the vastus intermedius insert?
Inserting via the Quadriceps tendon and then inserts into the patellar ligament, which interest into the tibial tuberosity
Where does the tibialis anterior originate from?
The lateral condyle and upper half of the lateral surface of the body of the tibia and interosseous membrane.
Where does the tibialis anterior insert?
Medial and under the surface of the first cuneiform bone, and the base of the first metatarsal bone.
What is the function of the tibialis anterior?
Dorsiflexion, foot inversion, and assists in maintaining the medial arch of the foot.
Where does the tibialis posterior originate from?
The posterior surface of the tibia and fibula
Where does the tibialis posterior insert?
It inserts into the tuberosity of the navicular bone, the three cuniform bones, the cuboid bone, and the base of metatarsal bones 2 -4
What are the actions of the tibialis posterior?
Plantar flexion, foot inversion, and assists in supporting the medial arch of the foot
Where does the Soleus muscle originate from?
The head and the upper posterior surface of the fibula, the soleal line and extends on the medial border of the tibia.
Where does the Soleus muscle insert?
Inserts on the posterior surface of the calcaneus via the calcaneal tendon
What are the actions of the Soleus Muscle?
Plantar flexion of the talocrural joint and lower leg stabilization.
What muscles make up the tricep surae?
Soleus and Gastrucnemius
Where do the lateral head and the medial head of the gastrocnemius muscle originate from?
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
Where does the gastrocnemius muscle insert?
The posterior surface of the calcaneus via the calcaneal tendon
What are the actions of the gastrocnemius muscle?
Plantar flexion of the talocrural joint, flexion of the knee, and stabilization.
Where is the peroneus longus muscle located?
Fibularis (peroneus) longus is a long muscle located superficially on the lateral side of the lower leg
Where does the peroneus longus muscle originate from?
Head of the fibula, proximal 2/3 of the lateral surface of the fibula, and the intermuscular septa
Where does the peroneus longus muscle insert?
The medial cuneiform bone and the first metatarsal bone.
What are the actions in the peroneus longus muscle?
Plantar flexion of the talocrural joint(ankle joint), foot eversion, and support the longitudinal and transverse arches of the foot.
Where is the peroneus brevis located?
On the lateral and inferior aspect of the lower leg.
Where does the peroneus brevis muscle originate from?
Distal 2/3 of the lateral surface of fibula, and the anterior intermuscular septum
Where does the peroneus brevis muscle insert?
Tuberosity of the 5th metatarsal
What are the actions in the peroneus brevis muscle?
Plantar flexion of the talocrural joint(ankle joint) & foot eversion
Where does the gluteus medius originate from?
Gluteal surface of ilium
Where does the gluteus medius insert?
Lateral aspect of greater trochanter of femur
What are the actions of the gluteus medius muscle?
Abduction, extension, internal rotation of thigh, external rotation, and pelvic stabilization
Where does the gluteus minimus originate from?
Gluteal surface of ilium
Where does the gluteus minimus insert?
Anterior aspect of greater trochanter of femur
What are the actions of the gluteus minimus muscle?
Abduction, extension, internal rotation of thigh, external rotation, and pelvic stabilization
What happens when the gluteus medius is underactive?
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.
Where does the tensor fascia latae originate from?
Anterior superior iliac spine, outer lip of
iliac crest
Where does the tensor fascia latae insert?
The iliotibial tract
What are the actions of the tensor fascia latae muscle?
Hip extension and abduction, internal rotation of the thigh, external rotation of the leg, and hip and knee joint stabilization
Where does the piriformis muscle originate from?
Anterior surface of the sacrum (between the S2 and S4), Gluteal surface of ilium.
Where does the piriformis muscle insert?
Inserts on the apex of the greater trochanter of the femur.
What are the functions of the piriformis?
External rotation of the thigh, thigh abduction, and stabilizes the head of the femur in the acetabulum.
What happens when the piriformis becomes tight?
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.
Where does the popliteus muscle originate from?
Lateral condyle of the femur and posterior horn of the lateral meniscus of the knee joint.
Where does the popliteus muscle insert?
On the posterior surface of the proximal tibia.
What are the actions of the popliteus muscle?
To unlock the knee, stabilize and flex the knee joint. It also assists with the internal rotation of the tibia.
Where does the sartorius muscle originate from?
Anterior superior iliac spine
Where does the sartorius muscle insert?
The proximal end of the tibia below the medial condyle via the pes anserinus.
What are the actions of the sartoruis muscle?
This muscle acts to flex, abduct, and externally rotate the hip. It also aids in knee flexion.
