Lower Anatomy (origin and insertion)

Gluteus Maximus

Actions: Hip extension, lateral rotation of the hip

Origin: post. sacrum and coccyx, post-to-post gluteal line, sacrotuberous ligament

Insertion: deep ¼ of fibres insert on the gluteal tuberosity of the femur, superficial ¾ of the fibres insert on the iliotibial Band

Innervation/ Arterial Supply: Inferior gluteal nerve (L5, S1 and S2), inferior and superior gluteal arteries

Glute Medius

Actions: Hip abduction (ant. fibres: assists with medial rotation of the hip, post. fibres: assist with extension and lateral rotation of the hip)

Origin: Gluteal surface between the ant/post gluteal lines

Insertion: greater trochanter of the lateral surface of the hip

Innervation/ Arterial Supply: Superior Gluteal Nerve (L4-S1), superior gluteal artery

Gluteus Minimus

Actions: Hip abduction, assists with medial rotation and flexion of the hip

Origin: Gluteal surface between the ant/inferior gluteal lines

Insertion: Greater trochanter of the anterior border of the femur

Innervation/ Arterial Supply: Superior Gluteal Nerve (L4-S1) Superior Gluteal Artery

Piriformis

Actions: Lateral rotation of the hip, abduction with the hip flexed, stabilizes the femoral head in the acetabulum.

Origin: Anterior-lateral Sacrum Sacrotuberous ligament

Insertion: Superior border of the greater trochanter

Innervation/ Arterial Supply: Nerve to the Piriformis (S1, S2), Branches off the superior gluteal, inferior gluteal, and internal pudendal arteries

Obturator Externus

Actions: Stabilizes the head of the femur, lateral rotation of the femur in the hip

Origin: anterior margin of the obturator foramen and inner 2/3 of the obturator membrane. Superior and inferior pubic Rami

Insertion: trochanteric fossa of the femur

Innervation/ Arterial Supply: obturator nerve- posterior branch: L2-L4, obturator Artery medial circumflex femoral artery

Obturator Internus

Actions: Lateral rotation of the hip, assists in hip abduction when hip is flexed. stabilization of the femoral head in the acetabulum.

Origin: Posterior edge of the obturator foramen and membrane. posterior aspect of the ischium.

Insertion: medial surface of the greater trochanter of the femur

Innervation/ Arterial Supply: Nerve to the obturator internus and superior gemellus (L5, S1, S2), Branches off the superior gluteal, inferior gluteal and internal pudendal arteries.

Superior Gemellus

Actions: lateral rotation of the hip, hip abduction when the hip is flexed, helps stabilize the femoral head in the acetabulum.

Origin: Dorsal surface of the ischial spine

Insertion: greater trochanter of the femur via the tendon of the obturator internus

Innervation/ Arterial Supply: Nerve to the obturator internus & superior gemellus (L5, S1, S2), Branches off the superior gluteal, inferior gluteal and internal pudendal arteries.

Inferior Gemellus

Actions: Lateral rotation of the hip. Hip abduction when the hip is flexed. Helps stabilize the femoral head in the acetabulum

Origin: Superior aspect of the ischial tuberosity.

Insertion: Greater trochanter of the femur via the tendon of  obturator internus

Innervation/ Arterial Supply: Nerve to quadratus femoris (L4, L5, S1)

Quadratus Femoris

Actions: Lateral (external) rotation of the thigh at the hip joint. Stabilizes the femoral head in the acetabulum

Origin: Lateral border of the ischial tuberosity

Insertion: Quadrate tubercle on the intertrochanteric crest of the femur. Inferior to the greater trochanter.

Innervation/ Arterial Supply: Nerve quadratus femoris (L4, L5, S1)

Biceps Femoris

Actions: Hip extension, Hip lateral rotation, Knee flexion, Knee lateral rotation, Posterior Pelvic Tilt

Origin: post/ inferior ischial tuberosity, distal sacrotuberous ligament

Insertion: Head of the fibula, lateral condyle of the tibia, Lateral collateral ligament

Innervation/ Arterial Supply: Sciatic L4-S3 (Tibial Division)

Semitendinosus

Action: Knee flexion, medial knee rotation, Hip extension, medial hip rotation, posterior pelvic tilt

Origin: Ischial Tuberosity (post- inferior)

Insertion: Pes Anserine (medial surface of proximal patella), deep fascia of the leg

Innervation/ Arterial Supply: Sciatic L4-S3 (tibial Branch)

Semimembranosus

Action: knee medial rotation, knee flexion, Hip medial rotation, Hip Extension, Posterior Pelvic tilt

Origin: ischial tuberosity (most inferior)

Insertion: Medial condyle of the tibia (posteromedial aspect)

Innervation/ Arterial Supply: Sciatic L4-S3 (tibial branch)

Iliacus

Action: Hip flexion, stabilizes the hip joint and lumbar spine, anterior pelvic tilt, (bilaterally: trunk flexion/ Unilaterally: side flexion)

Origin: Superior 2/3 of the iliac fossa and lip of the iliac crest. Anterior sacroiliac ligament, ala of the sacrum

Insertion: lesser trochanter (fuses with tendon of psoas major)

Innervation/ Arterial Supply: Femoral L2-L4

Psoas Major

Action: Hip flexion, stabilizes hip joint and lumbar spine, anterior pelvic tilt, bilaterally: trunk flexion/ Unilaterally: side flexion

Origin: T12-L5, Anterior surface of the transverse processes, Lateral edge of vertebral bodies, Intervertebral discs

Insertion: lesser trochanter

Innervation/ Arterial Supply: anterior rami of L1-L4

Tensor fascia Latae

Action: Hip flexion/ abduction/ medial rotation (synergist to gluteus medius and iliopsoas)

Origin: ASIS (lateral surface), Anterior aspect of the lateral lip of the iliac crest

Insertion: iliotibial band

Innervation/ Arterial Supply: superior gluteal L4-S1

Sartorius

Action: Flexion, abduction, External rotation (FABER), knee flexion and medial rotation

Origin: ASIS (superior ½ notch)

Insertion: Pes Anserine (medial proximal tibia)

Innervation/ Arterial Supply: Femoral L2-L4

Rectus Femoris

Action: Extension of the knee, flexion of the hip

Origin: AIIS

Insertion: Tibial tuberosity (via the proximal patella and patellar ligament)

Innervation/ Arterial Supply: Femoral L2-L4

Vastus Lateralis

Action: Extension of the knee

Origin: lateral lip of the linea aspera, gluteal tuberosity, greater trochanter (ant/inferior border), intertrochanteric line, lateral intermuscular septum

Insertion: Tibial tuberosity (via the proximal patella and patellar ligament)

Innervation/ Arterial Supply: femoral L2-L4

Vastus Medialis

Action: Extension of the knee

Origin: Medial lip of the linea aspera, introtrochanteric line (distal 1/2), medial supracondylar line and medial intermuscular septum.

Insertion: Tibial tuberosity (via the proximal patella and patellar ligament)

Innervation/ Arterial Supply: Femoral L2-L4

Adductor Magnus

Action:

• Adductor part: hip adduction, hip medial rotation and flexion

• Hamstring Part: Hip abduction, hip lateral rotation and extension

Origin:

• Adductor part: Ischiopubic ramus

• Hamstring Part: ischial tuberosity

Insertion:

• Adductor part: medial lip of linea aspera, medial supracondylar line/

• Hamstring part: Adductor tubercle

Innervation/ Arterial Supply:

• Adductor Part: obturator L2-4

• Hamstring Part: Sciatic L4-S3

Adductor Longus

Action: Hip adduction, hip flexion and medial rotation

Origin: body of pubis (inferior to pubic tubercle)

Insertion: Middle 1/3 of the medical lip of the linea aspera

Innervation: Obturator L2-4

Adductor Brevis

Action: hip adduction, hip medial rotation and flexion

Origin: Body of the pubis, inferior to pubis rami

Insertion: distal 2/3 of pectineal line. proximal ½ of the medial lip of linea aspera

Innervation: Obturator L2-4

Pectineus

Action: Hip adduction and flexion, hip medial rotation

Origin: Superior pubic ramus, iliopubic eminence

Insertion: pectineal line of the femur

Innervation: femoral L2-4

Gracilis

Action: Hip adduction/ medial rotation, knee flexion, medial rotation of the flexed knee

Origin: medial aspect of the inferior pubic ramus, inferior ½ of symphysis pubis

Insertion: Pes anserine (medial proximal tibia)

Innervation: Obturator L2-4

Tibialis Anterior

Action: Dorsiflexion, inversion, supports medial longitudinal arch of the foot

Origin: Lateral condyle, lateral surface of tibia (proximal half), Anterior surface of interosseous membrane

Insertion: medial & plantar surfaces of medial (first) cuneiform & base of 1st metatarsal

Innervation: L4-S2, Deep peroneal (fibular) nerve

Extensor Digitorum Longus

Action: Extension of toes 2-5 at PIP, DIP and MTP joints, dorsiflexion

Origin: Lateral tibial condyle, interosseous membrane. proximal ½ of anterior shaft of fibula

Insertion: via dorsal digital expansions to base of middle and distal phalanges of toes 2-5

Innervation: L4-S2, deep peroneal (fibular) nerve

Extensor Hallicus Longus

Action: extends to the big toe at the IP and MTP joints, aids in dorsiflexion, aids in inversion

Origin: Middle of anteromedial fibula, interosseous membrane

Insertion: Dorsal aspect of base of distal phalanx of great toe vis extensor hood (dorsal digital expansion)

Innervation: L4-S2, deep peroneal (fibular) nerve

Fibularis Longus

Action: eversion at subtalar joint, plantarflexion

Origin: head of fibula, proximal 2/3 of fibula, anterior intermuscular septum

Insertion: lateral side of the base of the 1st metatarsal, lateral side of the medial cuneiform

Innervation: L4-S2, superficial peroneal (fibular) nerve

Fibularis brevis

Action: Extension, aids in plantar flexion

Origin: Distal 2/3 of lateral fibula

Insertion: tuberosity on base of 5th metatarsal

Innervation: L4-S2, Superficial peroneal (fibular) nerve

Gastrocnemius

Action: plantar flexion, knee flexion

Origin:

• Medial O: medial femoral condyle

• Lateral O: Lateral femoral condyle

Insertion: posterior calcaneus via the achilles tendon

Innervation: L4-S3, tibial nerve

Soleus

Action: Plantar flexion

Origin: posterior head of fibula, proximal 1/3 of the post. fibula, middle 1/3 of medial border of tibia and soleal line of tibia

Insertion: Posterior calcaneus via the Achilles tendon

Innervation: L4-S3, tibial nerve

Plantaris

Action: assists in knee flexion, assists in plantar flexion

Origin: popliteal surface of femur, distal lateral supracondylar line of femur

Insertion: posterior calcaneus via the achillies tendon

Innervation: L4-S3, tibial nerve

Popliteus

Action:

• Open Chain (NWB): Flexion of knee & laterally rotates the tibia

• Closed Chain (WB): flexion of knee and medial rotation of femur

Origin: Anterior aspect of lateral femoral condyle, lateral meniscus of knee

Insertion: Posterior proximal tibia (superior to soleal line)

Innervation: L4-S3, tibial nerve

Tibialis Posterior

Action: inversion, assists with plantar flexion

Origin: Proximal 2/3 of medial fibula, proximal posterolateral surface of tibia, posterior surface of interosseous membrane

Insertion: Navicular tuberosity, expansions to sustentaculum tali., medial cuneiform, cuboid, bases of MT 2-4

Innervation: L4-S3, tibial nerve

Flexor Digitorum Longus

Action: Flexion of toes 2-5 at DIP, PIP and MTP joints, plantar flexion, assists in inversion

Origin: Posteromedial tibia (immediately below soleal line)

Insertion: Bases of the distal phalanges of digits 2-5

Innervation: L4-S3, tibial nerve

Flexor Hallucis Longus

Action: Flexion of big toe, assists in plantar flexion

Origin: Distal 2/3 of posterior surface of fibula, distal interosseous membrane, transverse intermuscular septum

Insertion: base of distal phalanx of big toe

Innervation: L4-S3, tibial nerve

Extensor Digitorum Brevis

Action: Extends toes (at the MTP Joint). Assists in extension of IP joints

Origin: anterior aspect of the dorsal calcaneus (lateral to sinus taris) Lateral talocalcaneal ligament, inferior extensor retinaculum

Insertion: forms 4 tendon and inserts to 4 digits via the EDL. Base of the proximal phalanx of big toe, dorsal digital expansion of toes 2-4.

Innervation: L4-S2, Deep peroneal (fibular) nerve

Abductor Hallucis

Action: Abducts big toe (MTP joint), assists with the flexion of the big toe (MTP joint), Assists with adduction of forefoot

Origin: calcaneal tuberosity (medial process), flexor retinaculum, plantar aponeurosis

Insertion: base of proximal phalanx of the great toe (medal Side) into the tendon of the FHB, medial sesammoid bone

Innervation: L4, L5, medial plantar nerve

Flexor Digitorum Brevis

Action: Flexes toes (PIP of toes 2-5), assists flexion of the MTP joints

Origin: Calcaneal tuberosity (medial Process), plantar aponeurosis

Insertion: divides into 4 tendons, divides into 2 at the base of proximal phalanx to wrap dorsally around the FDL, inserts at the middle phalanx of toes 2-5

Innervation: Medial plantar nerve (S1, S2)

Abductor Digi minimi

Action: Abducts little toe (MTP joint), Flexes the little toe (MTP joint)

Origin: Calcaneal tuberosity (medial & lateral process), plantar aponeurosis

Insertion: Base of proximal phalanx of the little toe (lateral side), blends with FDMD

Innervation: Lateral plantar nerve (S1, S2)

Quadratus Plantae

Action: Modifies line of pull of FDL, assists in flexion of DIP joints of toes 2-5

Origin:

• Medial head: medial calcaneus of long plantar ligament

• Lateral Head: Lateral calcaneus, lateral border of long plantar ligament

Insertion: Lateral side of FDL tendon

Innervation: Lateral plantar nerve (S1, S2)

Lumbricals

Action: Extension of PIP and DIP of toes 2-5, Flexion of MTP of toes 2-5

Origin: tendon of FDL

Insertion: medial aspects of EDL tendons via extensor hoods, dorsal surfcae of proximal phalanges

Innervation:

• 1st lumbrical: medial plantar nerve (L4, L5)

• 2nd lumbrical: lateral plantar nerve 9S1, S2)

Flexor Hallucis Brevis

Action: Flexion of big toe (MTP joint)

Origin:

• Lateral Head: plantar surface of cuboid & lateral cuniform

• Medial Head: tendon of tibialis posterior

Insertion: base of the proximal phalanx of the big toe (via 2 tendons- to medial and lateral sides)

Innervation: Medial Plantar nerve (L4, L5)

Adductor Hallucis

Action: Adduct big toe, flexion of MTP joint of big toe (weak), helps to maintain the transverse arch

Origin:

• Oblique head: plantar surface of base of MT 2-4 Fibularis (peroneus) longus tendon, long plantar ligament

• Transverse Head: transverse metatarsal ligament of toes 3-5

Insertion: common tendon of the FHB to base of the proximal phalanx of great toes (lateral side), Lateral sesmoid bone

Innervation: Lateral plantar nerve (S1, S2), deep branch

Flexor Digiti minimi Brevis

Action: Flexion of the little toe (MTP joint)

Origin: plantar surface of the base of the 5th metatarsal. Long plantar ligament, tendon of the fibularis (peroneus) longus

Insertion: base of the proximal phalanx of toe 5 (lateral side)

Innervation: Lateral plantar nerve (S1, S2) superficial branch

Plantar Interossei

Action: adduction of toes 3-5 (towards toe 2), assists with flexion of toes (MTP joint), assists with extension of PIP and DIP of toes 3-5

Origin: 3 muscles bellies; medial surface of MT 3-5 (base and shaft)

Insertion: medial surface of proximal phalanx of toes 3-5 EDL via Extensor hoods

Innervation: Lateral Plantar nerve (S1, S2)

Dorsal Interossei

Action: abduction of toes 2-4, assists with flexion of toes (MTP joint), assists with extension of PIP and DIP of toes 2-4

Origin: 4 muscles bellies; each with 2 heads, adjacent MT bones (shaft)

Insertion:

• 1st interosseous; medial aspect of proximal phalanx of 2nd toe

• 2nd-4th interosseous: lateral aspect of toes 2-4 via extensor hoods

Innervation: lateral plantar nerve (S1, S2)