Muscles Of Foot

INTRODUCTION :
  • The muscles acting on the foot can be classified into extrinsic muscles, those originating on the anterior or posterior aspect of the lower leg, and intrinsic muscles, originating on the dorsal (top) or plantar (base) aspects of the foot.
TYPES:
EXTRINSIC MUSCLES
  • All muscles originating on the lower leg except the popliteus muscle are attached to the bones of the foot.
  • The tibia and fibula and the interosseous membrane separate these muscles into anterior and posterior groups, in their turn subdivided into subgroups and layers.
  • Anterior group
Extensor group:
MUSCLE ORIGIN INSERTION ACTION
Tibialis Anterior Proximal half of tibiaInterosseous membrane near tarsometatarsal joint of 1st digit Non-weight-bearing leg tibialis anterior flexes the foot dorsally and lift its medial edge (supination).
Weight-bearing leg it brings the leg towards the back of the foot, like in rapid walking
Extensor digitorum longus Lateral tibial condyle
Along the fibula
Second to fifth digits and proximally on the fifth metatarsal. Similar to the tibialis anterior Dorsiflexes the digits.
Extensor hallucis longus Medially on the fibula first digit Dorsiflexes the big toe and also acts on the ankle in the unstressed leg
Weight-bearing leg it acts similar to the tibialis anterior.
2. Peroneal group:
MUSCLE ORIGIN INSERTION ACTION
Peroneus Longus Proximal aspect of Fibula 1st tarsometatarsal joint
Lateral margin of plantar surface of 1st cuneiform
Pronator
Plantor flexion
Evertor of ankle
Acts like a bowstring that braces the transverse arch of the foot.
Peroneus Brevis Proximal aspect of fibula below
P. Longus
Proximal part of 5th metatarsal PronatorPlantor flexion
Posterior group
  • Superficial layer
MUSCLE ORIGIN INSERTION ACTION
Triceps Surae
Soleus(peripheral heart) Gastrocnemius
Soleus
(peripheral heart)
Gastrocnemius Proximal dorsal parts of tibia & fibula
Proximal to condyle on femur
Plantaris Femur Medial to Achilles' tendon Plantar flexion
During walking it not only lifts the heel, but also flexes the knee,
assisted by the plantaris.
2. Deep layer :
MUSCLE ORIGIN INSERTION ACTION
Tibialis Posterior Interosseous membrane & adjoining bones
Passes deep to flexor retinaculum
Tarsall bone except talus Non-weight-bearing leg, it produces plantar flexion and supination
weight-bearing leg,
it proximates the heel to the calf.
Flexor hallucis longus Back of the fibula
(i.e. on the lateral side)
Extends distally down to the flexor retinaculum where it
passes over to the medial side to stretch across the sole to the distal phalanx of the first digit.
Plantar flex and invert the foot
Flex the great toe and helps supinate the ankle
Popliteus Lateral femoral epicondyle
(intracapsular)
Posterior surface of the tibia,
just proximal to the soleal line
Does not act on the foot
Unlocker of knee flexor of knee
INTRINSIC MUSCLES:
  • There are three groups of muscles in the sole of foot, those of the first and last digits, and a central group:
Muscles Of Big Toe:
MUSCLE ORIGINN INSERTION ACTION
Abductor hallucis Calcaneus of 1st digit 2 head insert proximal & distal to 1st metatarsal Abductor & Weak flexor
Maintain arch of foot
Flexor hallucis brevis
( sesamoid bone present in its tendon)
Medial cuneiform bone 2 head insert proximal & distal to 1st metatarsal Plantar flexor
(crucial for ballet dance)
Adductor hallucis oblique head:central part of midfoot
Transverse head:metatarsophalangeal joints of digits five to three
Lateral sesamoid bone of the first digit Tensor of the plantar arches andalso adducts the
big toe and then might plantar flex the proximal phal
2. Muscles of the little toe:
MUSCLE ORIGIN INSERTION ACTION
Abductor digiti minimi calcaneus proximal phalanx of the fifth digit Form the lateral margin of the foot
Support the arch of the foot and to plantar flex the fifth digit
flexor digiti minimi Base of the fifth metatarsal Attach to hook of hamate
Together with abductor on the first phalanx.
Support the arch of the foot and to plantar flex the fifth digit
Opponens digiti minimi cuboid bone Fifth metatarsal bone. Support the arch of the foot and to plantar flex the fifth digit
3. Central muscle group:
MUSCLE ORIGIN INSERTION ACTION
Lumbricals(4) Medial side of the tendons of flexor digitorum longus Medial margins of the proximal phalanges Plantar flexors at the metatarsophalangeal joints
Quadratus plantae 2 slips from the lateral and medial margins of the calcaneus Lateral margin of the flexor digitorum tendon Plantar flexors at the metatarsophalangeal joints
Flexor digitorum brevis Inferiorly on the calcaneus Middle phalanges of digits two to four Flexes the middle phalanges
Dorsal and plantar interossei Between the toes, the stretch from the metatarsals Proximal phalanges of digits two to five Plantar interossei adducts
Dorsal interossei abducts
Plantar flexors at the metatarsophalangeal joints
Exam Question
  • Sesamoid bone present in tendon of Flexor hallucis brevis
  • Lumbricals Originates from tendons of flexor digitorum profundus
  • Popliteus is the unlocker of knee
  • Peroneus longus is the Evertor of ankle inserted into the medial cuneiform
  • Gastrocnemius Muscle is used in normal walk during DIstance and swing
  • Tibialis posterior muscle passes deep to the flexor retinaculum
  • Tibialis posterior is inserted into all tarsus bones except talus
  • Peroneus brevis is inserted into proximal part of 5th metatarsal
  • Gastrocnemius & plantaris acts both on knee & ankle
  • Muscles causing dorsiflexion of foot are Extensor digitorum longus, Extensor hallucis longus & Tibialis anterior
  • Planter flaxion is brought about by Plantaris, FHL & Soleus
  • Action of tibialis anterior is that in Non-weight-bearing leg tibialis anterior flexes the foot dorsally and lift its medial edge (supination) & in Weight-bearing leg it brings the leg towards the back of the foot, like in rapid walking
  • Tibilais anterior causes inversion of foot
  • Soleus is k/as peripheral heart
  • Flexor digiti minimi muscle is attached to hook of hamate
  • Action of popliteus muscle unlock knee, flex knee
Don't Forget to Solve all the previous Year Question asked on Muscles Of Foot