Anterior thigh muscles

Question 1

What are the attachments, actions and innervation of the illiopsoas ?

Answer 1

• Illiopsoas made up of two muscles the psoas major and the ilium which join to form a tendon.
• Origin : Psoas major - lumbar vertebrae / illiacus - iliac fossa.
• Insert : Lesser trochanter
• Action : flexes the thigh at the hip joint.
• Innervation : Psoas major - L1 - L3 anterior rami / illiacus - femoral nerve.

Question 2

What are the attachments, actions and innervation of the vastus lateralis ?

Answer 2

• One of the 4 quadriceps femoris muscles.
• Origin : lateral lip of the linear aspira and the greater trochanter.
• Insert : patella via the quadriceps tendon.
• Action : Extension at the knee joint and stabilises the patella.
• Innervation : femoral nerve.

Question 3

What are the attachments, actions and innervation of the vastus intermedius ?

Answer 3

• One of the 4 quadriceps muscles
• Origin : the anterior and lateral surface of the femoral shaft.
• Insertion : Patella via the quadriceps tendon.
• Actions : Extension at the knee joint and stabilise the patella.
• Innervation : femoral nerve

Question 4

What are the attachments, actions and innervation of the vastus medialis ?

Answer 4

• One of the 4 quadriceps muscles.
• Origin : Intertrochanteric line and the medial lineal aspera.
• Insert : Patella via the quadriceps tendon.
• Actions : Extension at the knee and stabilise the patella.
• Innervation : femoral nerve

Question 5

What are the attachments, actions and innervation of the rectus femoris ?

Answer 5

• One of the 4 quadriceps muscles.
• origin : Anterior inferior iliac spine and immediately superior illium of the acetabulum.
• Insert : Patella via quadriceps tendon.
• Actions : crosses both the hip and knee joint. So flexion of thigh at hip joint and extension of the knee.
• Innervation - femoral nerve

Question 6

What are the attachments, actions and innervation of the sartorious ?

Answer 6

• Longest muscle in the body, crosses hip and knee joint , superficial and runs in an inferior medial direction.
• Origin : ASIS
• Insertion : superior medial tibia
• Actions: at the hip abduction, lateral rotation and flexion and at knee flexion.
• innervation - femoral nerve

Question 7

What are the attachments, actions and innervation of the pectinous ?

Answer 7

• Origin : pectineal line on anterior surface
• Insert : Pectineal line on the posterior surface just inferior to the less trochanter
• Actions: adduction and flexion at the knee
• Innervation : femoral nerve and the obturator nerve ( a branch ).