Extensor Digitorum Longus

Extensor digitorum longus (often shortened to EDL) is found in the front of the lower leg, in the outer more muscle bound compartment.

Origin

• Lateral condyle of the tibia
• Head and anterior surface of the fibula
• Interosseous membrane (between tibia and fibia)

Insertion

• Dorsal (top) surface of the middle and end phalanges of the four outer toes.

Actions

• Extends toes 
• Dorsiflexion
• Eversion

Daily uses

• Walking upstairs and making sure the toes clear the steps

Extensor Hallucis Longus

The extensor hallucis longus is the only muscle responaible for extending (pulling back) the big toe.

Origin

• Middle 2/3 of the inner surface of the front of the fibula

Insertion

• Distal phalanx of the big toe

Actions

• Extension of the big toe
  
• Dorsiflexion
  
• Inversion

Daily uses

• Walking up the stairs it pulls the big toe up to clear the step

Flexor Digitorum Longus

Flexor Digitorum Longus causes the toes to grip and mold to the floors surface which is vital in maintaining balance on rough surfaces. The image opposite shows the tendons passing under the foot. Walking barefoot on an uneven surface is an excellent exercise for this muscle.

Origin

• Lower 2/3 of the posterior surface of the tibia

Insertion

• Plantar (bottom) aspect of the base of the distal (furthest) phalanges of each of the four toes

Actions

• Plantarflexion
  
• Inversion
  
• Flexion of the toes

Daily uses

• Gripping with the toes

Flexor Hallucis Longus

Flexor Hallucis Longus bends the big toe when you curl up your foot. It is called 'Hallucis' as the word Hallux means great or big toe in latin. This muscle also supports the longitudinal arch of the foot.

Origin

• Lower 2/3 of the posterior surface of the fibula

Insertion

• Plantar (sole of the foot) aspect of the base of the distal (furthest) phalange of the big toe

Actions

• Flexion of the big toe 
• Inversion
• Plantarflexion

Daily uses

• Pushing off the surface in walking

Gastrocnemius

Gastrocnemius is the largest and most superficial of the calf muscles. Together the Gastrocnemius,Soleus and Plantaris are known as Triceps Surae. The Gastrocnemius is the main propellant in walking and running.

Origin

• Lower posterior surface of the femur above the medial condyle
  
• Lateral condyle of the femur

Insertion

• Posterior surface of the calcaneus via the achilles tendon

Actions

• Plantar flexion

Daily uses

• Standing on tip toes

Peroneus Longus

Peroneus Longus is one of the peroneal muscles which pass down the outside of the lower leg and evert (turn out) the foot. These muscles are sometimes referred to as fibularis longus and brevis due to their attchments on the fibula.

Origin

• Head of fibula
  
• Upper 2/3 of fibula

Insertion

• Base of underside of first metatarsal
  
• Undersurfaces of cuneiforms

Actions

• Eversion
  
• Plantarflexion

Daily uses

• Walking on uneven surfaces

Peroneus Brevis

Peroneus Brevis is one of the peroneal muscles which pass down the outside of the lower leg and evert (turn outwards) the foot. These muscles are sometimes referred to as Fibularis brevis and longus due to their attchments on the fibula.

Origin

• Lower 2/3 of the lateral surface of the fibula

Insertion

• Base of the 5th metatarsal

Actions

• Eversion
  
• Plantarflexion

Daily uses

• Walking on uneven surfaces

Plantaris

Origin: Inferior aspect of lateral supracondylar line of distal femur

Insertion: Middle 1/3 of the posterior calcaneal surface, just medial to Achilles tendon

Action:  Plantar flexor of ankle; also flexes knee

Popliteus

Popliteus is a small muscle which is often described as the key of the knee joint. It unlocks the knee joint by rotating the femur at the beginning of knee flexion to allow full knee flexion to occur.

Origin

• Lateral condyle of the femur

Insertion

• Upper posterior surface of the tibia, above the soleal (popliteal) line

Actions

• Knee flexion
  
• Internal rotation of the knee when it is flexed

Daily uses

• Walking

Soleus 

Soleus is a large large muscle, deep toGastrocnemius. Together the Gastrocnemius, Soleus and Plantaris are known as Triceps Surae. Soleus is used constantly in standing to maintain an upright position.

Tibialis Anterior 

Tibialis anterior forms the main fleshy part of the outside of the shin.

Tibialis Posterior 

The Tibialis Posterior is the deepest of all the calf muscles. It helps to support the arch of the foot.

Vastus Intermedius 

Vastus Intermedius is located deep in the thigh underneath the Rectus Femoris muscle.

Vastus Lateralis 

Vastus Lateralis is the most lateral (outer) of the four quadriceps muscles and is felt on the outside top of the thigh.

Vastus Medialis 

Vastus Medialis is the most medially (inner) located of the quadricep muscles. The portion of the muscle just above the knee is known as VMO (vastus medialis oblique). This is important in stabilising theknee joint and often becomes inhibited following injury.

Origin

• Intertrochanteric line (between the greater and lesser trochanters of the femur)
• Medial lip of the linea aspera of the femur

Insertion

• Patella via the quadriceps tendon and then the tibial tuberosity via the patella tendon

Actions

• Knee extension

Daily uses

• Cycling
• Walking up stairs