Muscle Origins, Insertions, and Actions of the Lower Limb

What is the origin of the Gluteus Maximus?

Thoracolumbar fascia; Gluteal fossa of the iliac wing; Sacrotuberous ligament; Posterior and inferior sacrum and coccyx.

What is the insertion of the Gluteus Maximus?

Gluteal tuberosity of the femur; iliotibial band.

What are the actions of the Gluteus Maximus?

Extension of thigh; external rotation of thigh; abduction of thigh.

What is the innervation of the Gluteus Maximus?

Inferior gluteal nerve.

What is the origin of the Gluteus Medius?

Gluteal fossa of the iliac wing.

Where does the Gluteus Medius insert?

Greater trochanter of the femur.

What is the primary action of the Gluteus Medius?

Abduction of the thigh.

What is the action of the anterior fibres of the Gluteus Medius?

Internal rotation of the thigh.

What is the action of the posterior fibres of the Gluteus Medius?

External rotation of the thigh at the hip.

What is the role of the Gluteus Medius when working as a whole?

Stabilizer of the pelvis.

What nerve innervates the Gluteus Medius?

Superior gluteal nerve.

What is the origin of the Gluteus Minimus?

Gluteal fossa of the iliac wing.

Where does the Gluteus Minimus insert?

Greater trochanter of the femur.

What is the primary action of the Gluteus Minimus?

Abduction of the thigh.

What is the action of the anterior portion of the Gluteus Minimus?

Internal rotation of the thigh.

What nerve innervates the Gluteus Minimus?

Superior gluteal nerve.

What is the origin of the Tensor Fascia Latae?

Anterior superior iliac spine.

What is the insertion of the Tensor Fascia Latae?

Iliotibial tract.

What are the actions of the Tensor Fascia Latae?

Abduction, flexion and internal rotation of the thigh

What nerve innervates the Tensor Fascia Latae?

Superior gluteal nerve.

What is the origin of the Piriformis muscle?

Anterior surface of the sacrum.

Where does the Piriformis muscle insert?

Greater trochanter of the femur.

What is the action of the Piriformis muscle?

External rotation of the thigh; Abduction of the thigh.

What innervates the Piriformis muscle?

Branches of the sacral plexus.

What is the origin of the Superior Gemellus?

Spine of the ischium

Where does the Superior Gemellus insert?

Greater trochanter of the femur

What is the action of the Superior Gemellus?

External rotation of the thigh; Abduction of the thigh

What innervates the Superior Gemellus?

Branches of the sacral plexus

What is the origin of the Obturator Internus?

Posterior surface of obturator membrane.

Where does the Obturator Internus insert?

Greater trochanter of the femur; Trochanteric fossa.

What is the action of the Obturator Internus?

External rotation of the thigh.

What is the innervation of the Obturator Internus?

Branches of the sacral plexus.

What is the origin of the Inferior Gemellus?

Tuberosity of the ischium

What is the insertion of the Inferior Gemellus?

Greater trochanter of the femur

What is the action of the Inferior Gemellus?

External rotation of the thigh; Abduction of the thigh

What is the innervation of the Inferior Gemellus?

Branches of the sacral plexus

What is the origin of the Obturator Externus?

Anterior surface of obturator membrane.

Where does the Obturator Externus insert?

Trochanteric fossa.

What is the action of the Obturator Externus?

External rotation of the thigh; Adduction of the thigh.

What nerve innervates the Obturator Externus?

Obturator nerve.

What is the origin of the Quadratus Femoris?

Tuberosity of the ischium

Where does the Quadratus Femoris insert?

Intertrochanteric crest of the femur

What is the action of the Quadratus Femoris?

External rotation of the thigh; Adduction of the thigh

What is the innervation of the Quadratus Femoris?

Nerve to the quadratus femoris

What is the origin of the long head of the Biceps Femoris?

Tuberosity of the ischium

What is the origin of the short head of the Biceps Femoris?

Linea aspera of the femur

What is the insertion of the Biceps Femoris?

Head of fibula; Lateral condyle of tibia

What actions are performed by both heads of the Biceps Femoris?

Flexion of the leg; External rotation of the flexed leg

What additional action does the long head of the Biceps Femoris perform?

Extension of the thigh

What nerve innervates the long head of the Biceps Femoris?

Tibial nerve

What nerve innervates the short head of the Biceps Femoris?

Common peroneal nerve

What is the origin of the Semitendinosus muscle?

Tuberosity of the ischium; Sacrotuberous ligament.

Where does the Semitendinosus muscle insert?

Pes anserinus (proximal tibia).

What is the action of the Semitendinosus muscle?

Flexion of the leg; Internal rotation of flexed leg; Extension of the thigh.

What is the innervation of the Semitendinosus muscle?

Tibial nerve.

What is the origin of the Semimembranosus muscle?

Tuberosity of the ischium.

What is the insertion point of the Semimembranosus muscle?

Dorsal surface of the medial condyle of the tibia.

What are the actions of the Semimembranosus muscle?

Flexion of the leg; Internal rotation of flexed leg; Extension of the thigh.

What is the innervation of the Semimembranosus muscle?

Tibial nerve.

What is the origin of the Psoas Major?

Transverse processes, L1-L5.

Where does the Psoas Major insert?

Lesser trochanter of the femur.

What is the primary action of the Psoas Major?

Flexion of the thigh, Flexion of the trunk (e.g., from supine).

What innervates the Psoas Major?

Branches 1-4 of lumbar plexus.

What is the origin of the Iliacus muscle?

Iliac fossa

Where does the Iliacus muscle insert?

Lesser trochanter of the femur

What is the action of the Iliacus muscle?

Flexion of the thigh, Flexion of the trunk (e.g., from supine)

What nerve innervates the Iliacus muscle?

Femoral nerve

What is the origin of the Sartorius muscle?

Anterior superior iliac spine.

Where does the Sartorius muscle insert?

Medial aspect of the tibia via pes anserinus.

What are the actions of the Sartorius muscle?

Flexion of the thigh; Flexion of the leg; External rotation of thigh; Internal rotation of the leg.

What is the innervation of the Sartorius muscle?

Femoral nerve.

What is the origin of the Rectus Femoris?

Anterior inferior iliac spine

What is the insertion point of the Rectus Femoris?

Patella, tibial tuberosity

What is the action of the Rectus Femoris?

Extension of the leg, Flexion of the thigh

What nerve innervates the Rectus Femoris?

Femoral nerve

What is the origin of the Vastus Lateralis?

Linea aspera of the femur; Greater trochanter of the femur.

Where does the Vastus Lateralis insert?

Patella, tibial tuberosity.

What is the action of the Vastus Lateralis?

Extension of the leg.

What nerve innervates the Vastus Lateralis?

Femoral nerve.

What is the origin of the Vastus Medialis?

Linea aspera of the femur; Intertrochanteric line.

What is the insertion of the Vastus Medialis?

Patella, tibial tuberosity.

What is the action of the Vastus Medialis?

Extension of the leg.

What is the innervation of the Vastus Medialis?

Femoral nerve.

Vastus Intermedius

Origin: Body of femur. Insertion: Patella, tibial tuberosity. Action: Extension of the leg. Innervation: Femoral nerve.

What is the origin of the Pectineus muscle?

Pectineal line of the pubic bone.

Where does the Pectineus muscle insert?

Pectineal line of the femur.

What is the action of the Pectineus muscle?

Adduction of the thigh; external rotation of the thigh.

What nerve innervates the Pectineus muscle?

Femoral nerve.

What is the origin of the Adductor Brevis?

Body of the pubic bone; Inferior pubic ramus.

Where does the Adductor Brevis insert?

Linea aspera of the femur.

What is the primary action of the Adductor Brevis?

Adduction of the thigh.

What are the rotational actions of the Adductor Brevis depending on the position of the femur?

Internal rotation when flexed; external rotation when extended.

What nerve innervates the Adductor Brevis?

Obturator nerve.

What is the origin of the Adductor Longus?

Body of the pubic bone.

What is the insertion of the Adductor Longus?

Linea aspera of the femur.

What is the action of the Adductor Longus?

Adduction of the thigh; External rotation of the thigh.

What is the innervation of the Adductor Longus?

Obturator nerve.

What is the origin of the hamstring portion of the Adductor Magnus?

Ischial tuberosity

What is the origin of the adductor portion of the Adductor Magnus?

Ischio-pubic ramus

What is the insertion of the hamstring portion of the Adductor Magnus?

Adductor tubercle of femur