Knee & Thigh OIAN

Rectus Femoris

O: Anterior inferior iliac spine (AIIS)

I: Tibial tuberosity (via patella and patellar ligament)

A: Extend the knee; Flex the hip

N: Femoral nerve

Rectus Femoris - Origin

Anterior inferior iliac spine (AIIS)

Rectus Femoris - Insertion

Tibial tuberosity (via patella and patellar ligament)

Rectus Femoris - Action

Extend the knee; Flex the hip

Rectus Femoris - Nerve

Femoral nerve (L2-L4)

Vastus Medialis

O: Medial lip of linea aspera

I: Tibial tuberosity (via patella and patellar ligament)

A: Extend the knee

N: Femoral nerve

Vastus Medialis - Origin

Medial lip of linea aspera

Vastus Medialis - Insertion

Tibial tuberosity (via patella and patellar ligament)

Vastus Medialis - Action

Extend the knee

Vastus Medialis - Nerve

Femoral nerve (L2-L4)

Vastus Lateralis

O: Lateral lip of linea aspera, gluteal tuberosity, and greater trochanter.

I: Tibial tuberosity (via patella and patellar ligament)

A: Extend the knee

N: Femoral nerve (L2-L4)

Vastus Lateralis - Origin

Lateral lip of linea aspera, gluteal tuberosity, and greater trochanter.

Vastus Lateralis - Insertion

Tibial tuberosity (via patella and patellar ligament)

Vastus Lateralis - Action

Extend the knee

Vastus Lateralis - Nerve

Femoral nerve (L2-L4)

Vastus Intermedius

O: Anterior and lateral shaft of the femur

I: Tibial tuberosity (via patella and patellar ligament)

A: Extend the knee

N: Femoral nerve (L2-L4)

Vastus Intermedius - Origin

Anterior and lateral surface of the femur

Vastus Intermedius - Insertion

Tibial tuberosity (via patella and patellar ligament)

Vastus Intermedius - Action

Extend the knee

Vastus Intermedius - Nerve

Femoral nerve (L2-L4)

Biceps Femoris

O: Long head: Ischial Tuberosity; Short head: Lateral lip of linea aspera

I: Head of the fibula

A: Flex the knee; Laterally Rotate the flexed knee; Long head: Extend the hip; Assist with Laterally rotate the hip; Tilt the pelvis posteriorly

N: Long Head: Sciatic nerve (tibial branch) (L5, S1-S3); Short Head: Sciatic nerve (fibular branch) (L5, S1-S2)

Biceps Femoris - Origin

Long head: Ischial Tuberosity; Short head: Lateral lip of linea aspera

Biceps Femoris - Insertion

Head of the fibula

Biceps Femoris - Action

Flex the knee; Laterally rotate the flexed knee;* Long head: Extend the hip; Assist with laterally rotating the hip; Tilt the pelvis posteriorly.

Biceps Femoris - Nerve

Long Head: Sciatic nerve (tibial branch)(L5, S1-S3); Short Head: Sciatic nerve (fibular branch)(L5, S1-S2)

Semimembranosus

O: Ischial Tuberosity

I: Posterior aspect of medial condyle of tibia

A: Flex the knee; Medially rotate the flexed knee; Extend the hip; Assist to medially rotate the hip; Tilt the pelvis posteriorly.

N: Sciatic nerve (tibial branch)(L4-L5, S1-S2)

Semimembranosus - Origin

Ischial tuberosity

Semimembranosus - Insertion

Posterior aspect of medial condyle of tibia

Semimembranosus - Action

Flex the knee; medially rotate the flexed knee; extend the hip; assist to medially rotate the hip; tilt the pelvis posteriorly.

Semitendinosus

O: Ischial tuberosity

I: Proximal, medial shaft of the tibia at pes anserinus tendon

A: Flex the knee; medially rotate the flexed knee; extend the hip; assist to medially rotate the hip; Tilt the pelvis posteriorly

N: Sciatic nerve (tibial branch)(L4-L5, S1-S2)

Semitendinosus - Origin

Ischial tuberosity

Semitendinosus - Insertion

Proximal, medial shaft of the tibia at pes anserinus tendon

Semitendinosus - Action

Flex the knee; medially rotate the flexed knee; extend the hip; assist to medially rotate the hip; tilt the pelvis posteriorly.

Semitendinosus - Nerve

Sciatic nerve (tibial branch)(L4-L5, S1-S2)

Plantaris

O: Lateral supracondylar line of femur

I: Calcaneus via calcaneal tendon

A: Weak plantar flexion of the ankle; Weak flexion of the knee

N: Tibial nerve (L4-L5, S1)

Plantaris - Origin

Lateral supracondylar line of femur

Plantaris - Insertion

Calcaneus via calcaneal tendon

Plantaris - Action

Weak plantar flexion and knee flexion.

Plantaris - Nerve

Tibial nerve (L4-L5, S1)

Popliteus

O: Lateral condyle of the femur

I: Proximal, posterior aspect of tibia

A: Medially rotate the flexed knee; Flex the knee

N: Tibial nerve (L4-L5, S1)

Popliteus - Origin

Lateral condyle of the femur

Popliteus - Insertion

Proximal, posterior aspect of tibia

Popliteus - Action

Medially rotate the flexed knee; Flex the knee

Popliteus - Nerve

Tibial nerve (L4-L5, S1)

Gastrocnemius

O: Condyles of the femur, posterior surfaces

I: Calcaneus via calcaneal tendon

A: Flex the knee; Plantar flex the ankle

N: Tibial nerve (S1-S2)

Gastrocnemius - Origin

Condyles of the femur, posterior surfaces

Gastrocnemius - Insertion

Calcaneus via calcaneal tendon

Gastrocnemius - Action

Flex the knee; Plantar flex the ankle

Gastrocnemius - Nerve

Tibial nerve (S1-S2)