Muscles of the Lower Limb

Muscles of Gluteal region

• Gluteus Maximus Muscle

          This is the largest and superficial muscle of the body mainly responsible for the prominence of Gluteal region.

Origin:
          Outer surface of ileum behind the posterior Gluteal line, coccyx and sacrum

Insertion:
          Ileotibial tract and gluteal tuberosity

Innervation:
          Inferior Gluteal nerve

Function:
          Extension and laterally rotation of thigh at hip joint and also extension of the knee joint through ileotibial tract

• Gluteus Minimus Muscle

Origin:
          Outer surface of ileum b/w middle Gluteal line and inferior Gluteal line

Insertion:
          Anterior border of greater tronchanter of femur

Innervation:
          Superior gluteal nerve

Function:
          Abducts and medially rotates the thigh at hip joint

• Gluteus Medius Muscle

Origin:
          Outer surface of ileum between iliac crest above and middle gluteal line below

Insertion:
          Lateral surface of greater tronchanter

Innervation:
          Superior gluteal nerve

Function:
          Abducts the thigh and anterior fibers medially rotate the thigh at hip joint

• Tensor Fasciae Latae Muscle

Origin:
          Iliac crest b/w ASIS and iliac tubercle

Insertion:
          Ileotibial tract

Innervation:
          Superior gluteal nerve

Function:
           Assists gluteus maximus in extending the knee through ileotibial tract and also abducts the thigh along with medius and minimus muscles

• Piriformis Muscle

Origin:
          Anterior surface of the 2nd, 3rd and 4th sacral vertebrae in pelvis

Insertion:
          Upper border of greater tronchanter of femur

Innervation:
          1st and 2nd sacral nerves

Function:
          Lateral rotation of the thigh at hip joint

• Obturator Internus Muscle

Origin:
          Inner surface of Obturator membrane

Insertion:
          Upper border of greater tronchanter
Innervation:
          Obturator internus from sacral plexus

Function:
          Lateral rotation of the thigh at hip joint

• Gamellus Superior Muscle

Origin:
          Spine of ischium

Insertion:
          Upper border of greater tronchanter of femur

Innervation:
          Obturator internus from sacral plexus

Function:
          Lateral rotation of thigh at hip joint

• Gamellus Inferior Muscle

Origin:
          Upper margin of ischial tuberosity

Insertion:
          Upper border of greater tronchanter of femur

Innervation:
          Sacral plexus

Function:
          Lateral rotation of thigh at hip joint

• Quadratus Femoris Muscle

Origin:
          Lateral border of ischial tuberosity

Insertion:
          Quadrate tubercle of femur

Innervation:
          Sacral plexus

Function:
          Lateral rotation of thigh at hip joint

Muscle of Anterior compartment of Thigh

• Sartorius Muscle

Origin:
           ASIS (Anterior Superior Iliac Spine)

Insertion:
          Upper medial border of tibia

Innervation:
          Femoral nerve

Function:
          Flexes, abducts and laterally rotates the thigh at hip joint. It flexes and medially rotates the leg at the knee joint.

• Iliacus Muscle

Origin:
          Iliac fossa within abdomen

Insertion:
          Lesser tronchanter of femur

Innervation:
          Femoral nerve

Function:
         Flexes the thigh on abdomen and abdomen on thigh as sitting up from lying

• Psoas Muscle

Origin:
          Transverse processes and intervertebral discs of T12 to L5

Insertion:
          Lesser tronchanter of femur

Innervation:
          Lumber plexus

Function:
          Flexion of thigh on abdomen and abdomen on thigh as in sitting up from lying

• Pectineus Muscle

Origin:
          Superior ramus of pubic bone

Insertion:
          Upper border of linea aspera

Innervation:
          Femoral nerve

Function:
          Flexion and adduction of thigh at hip joint

• Quadriceps Femoris Muscle

          It is consist of the following four parts having same quadriceps tendon which inserts on patella forming patellar ligament. Patellar ligament in turn inserts on the tibial tuberosity.

Rectus Femoris

Origin:
   Straight head:
          ASIS

   Reflected head:

          Ileum above acetabulum

Insertion:
          Inserts on patella as quadriceps tendon which in turn inserts on tibial tuberosity

Innervation:
          Femoral nerve

Function:
          Flexion of thigh at hip joint and extension of hip at knee joint

Vastus Medialis

Origin:
          Upper medial shaft of femur

Insertion:
          Quadriceps tendon
Innervation:
          Femoral nerve

Function:
          Extension of leg at knee joint


Vastus Lateralis

Origin:
          Upper lateral shaft of femur

Insertion:
          Quadriceps tendon

Innervation:
          Femoral nerve

Function:
          Extension of leg at knee joint



Vastus Medius

Origin:
          Anterior and lateral shaft of femur

Insertion:
          Quadriceps tendon

Innervat:ion:
          Femoral nerve

Function:
          Extension of leg at knee joint

Muscles of Posterior compartment of Thigh
          These muscles are also called as Hamstring muscles
Biceps Femoris Muscle
Origin:
   Long head:
          Ischial tuberosity

   Short head:
          Linea aspera

Insertion:
          Head of fibula

Innervation:
          Sciatic nerve

Function:
          Extension of thigh at hip joint and flexion along with lateral rotation of leg at knee joint


Semitendinosus Muscle

Origin:
          Ischial tuberosity

 Insertion:

            Upper medial surface of shaft of tibia

Innervation:
   Tibial portion of sciatic nerve
Function:
          Extension of thigh at hip joint; Flexion and medial rotation of leg at knee joint

Semimembranosus Muscle

Origin:
          Ischial tuberosity

Insertion:
          Medial condyle of tibia

Innervation:
          Tibial portion of sciatic nerve

Function:
          Extension of thigh at hip joint; flexion and medial rotation of leg at knee joint

Adductor Magnus (hamstring portion)

Origin:
          Ischial tuberosity

Insertion:
          Adductor tubercle of femur

Innervation:
          Sciatic nerve

Function:
          Extension of thigh at hip joint



Muscles of Medial compartment of Thigh

• Gracilis Muscle

Origin:

          Inferior ramus of pubis and ramus of ischium

Insertion:

          Upper medial border of tibia

Innervation:

          Obturator nerve

Function:

          Adduction of thigh at hip joint and flexion of leg at knee joint

• Adductor Brevis Muscle

Origin:

          Inferior ramus of pubis

Insertion:

          Linea aspera

Innervation:

          Obturator nerve

Function:

          Adduction of thigh at hip joint

• Adductor Longus Muscle

Origin:

          Body and inferior ramus of pubis

Insertion:

          Linea aspera

Innervation:

          Obturator nerve

Function:

          Adduction of thigh at hip joint

• Adductor Magnus Muscle

Origin:
          Inferior ramus of pubis, ramus of ischium and ischial tuberosity

Insertion:
   Adductor part:
          Linea aspera

   Hamstring part:
          Adductor tubercle

Innervation:
   Adductor portion:
          Obturator nerve

   Hamstring portion:
          Sciatic nerve

Function:
   Adductor portion:
          Adduction of thigh at hip joint

   Hamstring portion:
          Extension of leg at knee joint

• Obturator Externus Muscle

Origin:
          Outer surface of Obturator membrane

Insertion:
          Medial border of greater tronchanter

Innervation:
          Obturator nerve

Function:
          Lateral rotation of thigh at hip joint



Muscles of Anterior compartment of Leg

• Tibialis Anterior Muscle

Origin:

          Shaft of tibia and interosseous membrane

Insertion:

          Medial cuneiform and base of 1st metatarsal

Innervation:

          Deep peroneal nerve

Function:
          Extension of foot at ankle joint; inversion of foot at subtalar and transverse tarsal joints; holds up medial longitudinal arch of the foot

• Extensor Digitorum Longus Muscle

Origin:

          Anterior surface of shaft of fibula

Insertion:

          Extensor expansion of lateral four toes

Innervation:
          Deep peroneal nerve

Function:
          Extension of toes and extension of foot at ankle joint

• Peroneus Tertius Muscle

Origin:
          Anterior surface of shaft of fibula

Insertion:
          Base of distal phalanx of fifth toe

Innervation:

          Deep peroneal nerve

Function:

          Extension of foot at ankle joint; eversion of foot at subtalar joint and extension of 5th toe

• Extensor Hallucis Longus Muscle

Origin:
          Anterior surface of shaft of fibula

Insertion:
          Distal phalanx of big toe

Innervation:
          Deep peroneal nerve

Function:
          Extension of foot at ankle joint and extension o big toe

• Extensor Digitorum Brevis Muscle

Origin:

          Calcaneum

Insertion:

          Proximal phalanx of great toe, 2nd, 3rd and 4th toes

Innervation:
          Deep peroneal nerve

Function:
          Extension of toes except the 5th

Muscles of Lateral compartment of Leg

• Peroneus Longus Muscle

Origin:
          Lateral surface of shaft of fibula

Insertion:
          Medial cuneiform and base of 1st metatarsal

Innervation:

          Superficial peroneal nerve

Function:
          Plantar flexion of ankle joint and also support the medial longitudinal arch of foot

• Peroneus Brevis Muscle

Origin:
          Lateral surface of shaft fibula

Insertion:
          Base of 5th metatarsal bone

Innervation:
          Superficial peroneal nerve

Function:
          Plantar flexion of ankle joint and longitudinal arch of the foot

Muscles of Posterior compartment of Leg

Superficial Group

• Gastrocnemius Muscle

Origin:
   Lateral head:
          Lateral condyle of femur

   Medial head:
          Medial condyle of femur

Insertion:

          Achilles tendon which in turn inserts on the posterior surface of calcaneum

Innervation:
          Tibial portion of sciatic nerve

Function:
          Flexion of the knee joint and plantar flexion of the ankle joint

• Plantaris Muscle

Origin:
          Just above the supracondylar ridge of femur
Insertion:

          Achilles tendon

Innervation:
          Tibial nerve (branch of sciatic nerve)

Function:
          Flexion of leg at knee joint and plantar flexion of foot at ankle joint

• Soleus Muscle

Origin:
          Shaft of tibia (soleal line) and fibula
Insertion:
          Achilles tendon

Innervation:
          Tibial nerve

Function:
          Plantar flexion of ankle joint


Deep Group

• Popliteus Muscle

Origin:
          Lateral surface of lateral condyle of femur

Insertion:
          Just above soleal line on posterior surface of tibia

Innervation:

          Tibial nerve

Function:
          Flexion and medial rotation of leg at knee joint

• Flexor Hallucis Longus Muscle

Origin:

          Posterior surface of fibula

Insertion:
          Base of distal phalanx of big toe

Innervation:
          Tibial nerve

Function:
          Flexion of big toe and flexion of ankle joint

• Flexor Digitorum Longus Muscle

Origin:

          Posterior surface of shaft of tibia

Insertion:

          Distal phalanges of lateral four toes

Innervation:
          Tibial nerve

Function:

          Flexion of lateral four toes and flexion of ankle joint

• Tibialis Posterior Muscle

Origin:

          Posterior surface of shaft of tibia fibula and interosseous membrane

Insertion:

          Navicular and other adjoining bones (neighboring)

Innervation:
          Tibial nerve

Function:
          Plantar flexion of ankle joint, support the transverse arch and inverts foot at subtalar and transverse tarsal joint