ORIGINS, INSERTIONS AND ACTIONS

1
Ankle Muscles

• ORIGINS, INSERTIONS AND ACTIONS
• BY TAELAR SHELTON, MS, ATC, AT/L

2
Origins of muscles

• Origins are the flixed attachment point of
  muscles in the bone (this bone doesnt move when
  the action of the muscle is performed)

3
Insertions of muslces

• Insertions is the attachment point of the tendon
  into the bone that moves when the action of the
  muscle is performed

4
Actions of muslces

• Actions- what the muscles does

5
Tibialis Anterior

• O- lateral condyle and upper 2/3rds of tibia
• I- by tendon into interior surface of medial
  cuneiform and 1st metatarsal bone
• A- prime mover of dorsiflexion inverts foot
  assists in supporting medial longitudinal arch of
  foot

6
Extensor Digitorum

• O- lateral condyle of the tibia proximal ¾ of
  the fibula interosseous membrane
• I- second and third phalanges of toes 2-5 via
  extensor expansion
• A- dorsiflexes foot prime mover of toe extension

7
Peroneus Brevis

• O- distal fibula shaft
• I- by tendon running behind lateral malleolus to
  insert on the proximal end of the 5th metatarsal
• A- plantar flexes and everts the foot

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Extensor Hallucis Longus

• O- Anteriomedial fibula shaft and interosseous
  membrane
• I- tendon inserts on the distal phalnx of the
  great toe
• A- extension of the great toe dorsiflexion

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Peroneus Tertius

• O- distal anterior surface of the fibula
  interosseous membrane
• I- Tendon passes anterior to lateral malleolus
  and inserts on the dosum of the 5th metatarsal
• A- dorsiflexes and everts the foot

10
Peroneus Longus

• O- head and upper portion of fibula
• I- by long tendon that curves under the foot to
  1st metatarsal and medial cuneiform
• A- plantarflexes and everts foot helps keep foot
  flat on the ground

11
Tibialis Posterior

• O- extensive origin from superior tibia and
  fibula and the interosseous membrane
• I- tendon passes behind medial malleolus and
  under the arch of the foot inserts into several
  tarsals and metatarsals 2-4
• A- prime mover of foot inversion plantar flexes
  ankle, stabilizes medial longitudinal arch

12
Flexor Digitorum

• O- Posterior tibia
• I- tendon runs behind medial malleolus and splits
  to insert into distal phalanages of toes 2-5
• A- plantar flexes and inverts foot flexes toes
  helps foot grip ground

13
Flexor Hallucis Longus

• O- middle part of the shaft of fibula
  interosseous membrane
• I- tendon runs under foot to distal phalanx of
  great toe
• A- plantar flexes and inverts foot flexes great
  toe at all joints push off muscle during walking

14
Popliteus

• O- lateral condyle of femur
• I- proximal tibia
• A- flexes and rotates leg medially to unlock knee
  from full extension when flexion begins

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Plantaris

• O- posterior femur above the lateral condyle
• I- via a long, thin tendon into the calcaneus or
  calcaneal tendon (achilles)
• A- assists in knee flexion and plantar flexion of
  foot

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Soleus

• O- extensive cone shaped origin from the superior
  tibia, fibula and interossous membrane
• I- calcaneus via calcaneal tendon
• A- plantar flexes ankle important locomotor and
  postural muscle during walking, running and
  dancing

17
Gastrocnemius

• O- by two heads from the medial and lateral
  condyles of the femur
• I- calcaneus via calcaneal tendon
• A- Plantar flexes foot when knee is extended can
  flex the knee when the foot is dorsiflexed