Iliopsoas (Psoas major & Iliacus)

• Action– flexion at hip– flexion at lumbar intervertebral joints (psoas

major only)

Gluteus Maximus

• Largest

• Actions– Extends and laterally rotates at hip joint

Gluteus Medius

• 2nd Largest

• Actions– Abduction and medial rotation at hip joint

Gluteus Minimus

• Smallest

• Actions– abducts and medially rotates

• SAME AS MEDIUS

Tensor Fasciae Latae (iliotibial or IT band)

• Action– flexion and medial rotation at hip– lateral support of knee

Piriformis

• Origin– sacrum

• Insertion– femur (greater Trochanter)

• Action– lateral rotation and abduction at hip joint

Quadratus Femoris

• Action– lateral rotation at the hip joint

Adductor Magnus

• Origin– pubis & ischium

• Insertion– femur (linea aspera)

• Action– altogether: adduction at hip joint– superior portion: flexion and medial rotation at hip– inferior part: extension and lateral rotation at hip

Adductor Longus

• Origin– pubis

• Insertion– femur (linea aspera)

• Action – adduction, flexion, and medial rotation at hip

• same for adductor brevis

Adductor Brevis

• Origin– pubis

• Insertion– femur (linea aspera)

• Action– adduction, flexion, and medial rotation at hip

• same for adductor longus

Pectineus

• Origin– Pubis

• Insertion– Femur

• Action– adducts, flexes, and medially rotates at hip

Gracilis

• Origin– pubis

• Insertion– tibia

• Action– flexes at knee, adducts and medially rotates

at hip

Rectus Femoris

• Origin– anterior inferior iliac spine

• Insertion– tibial tuberosity via patellar ligament

• Action– extends at knee, flexes at hip

• part of quadriceps femoris muscle group of anterior thigh

Vastus Lateralis

• Origin– femur

• Insertion– tibial tuberosity via patellar ligament

• Action– extension at knee joint

• part of quadriceps femoris muscle group of anterior thigh

Vastus Medialis

• Origin– Femur

• Insertion– tibial tuberosity via patellar ligament

• Action– extension at knee joint

• part of quadriceps femoris muscle group of anterior thigh

Vastus Intermedius

• Origin– femur

• Insertion– tibial tuberosity via patellar ligament

• Action– extension at knee joint

• part of quadriceps femoris muscle group of anterior thigh

Sartorius

• Origin– Anterior superior iliac spine

• Insertion– tibia

• Action– flexion at knee– flexion and lateral rotation at hip

Biceps Femoris

• Origins– Long Head: ischial tuberosity – Short Head: femur

• Insertion– Long Head: tibia– Short Head: head of fibula

• Action– flexes knee, extends and laterally rotates hip

• Part of Hamstring Muscle group (posterior thigh)

Semimembranosus

• Origin– ischial tuberosity

• Insertion– medial tibia

• Action– flexion at knee, extension and medial rotation

at hip

• Part of Hamstring Muscle group (posterior thigh)

Semitendinosus

• Origin– Ischial Tuberosity

• Insertion– medial tibia

• Action– flexion at knee, extension and medial rotation

at hip

• Part of Hamstring Muscle group (posterior thigh)

Tibialis Anterior

• Action– dorsiflexion (flexion at ankle)– inversion of foot

Peroneals

• peroneus (fibularis) longus• peroneus (fibularis) brevis

• Actions– eversion of foot and plantar flexion (extension

at ankle)

Gastrocnemius

• Origin– femur

• Insertion– calcaneus via achille’s tendon

• Action– plantar flexion (extension at ankle), inversion

of foot, flexion of knee

Soleus

• Origin– fibula & tibia

• Insertion– calcaneus via achille’s tendon

• Action– plantar flexion (extension of ankle)

Popliteus

• Action– medial rotation of tibia (or lateral rotation of

femur)– flexion at knee

Extensor Digitorum Longus

• Action– flexion at joints of toes 2-5

Extensor Hallucis Longus

• Action– Flexion at great toe