foot


⚙ FUNCTIONS OF THE FOOT & ANKLE



  • Provides a stable base of support

  • Acts as a rigid lever for push-off

  • Absorbs shock from body weight

  • Conforms to uneven/irregular terrain

  • Important for:

    • Sensation

    • Proprioception

    • Balance


  • Adjusts line of gravity in standing

  • Provides propulsion and restraint in walking






🦴 BONES OF THE FOOT






Tarsal Bones (7 total)



  • Talus

  • Calcaneus

  • Navicular

  • Cuboid

  • Cuneiforms:

    • Medial

    • Intermediate

    • Lateral







Metatarsals



  • 5 long bones






Phalanges (14 total)



  • Great toe:

    • Proximal

    • Distal


  • Other toes:

    • Proximal

    • Middle

    • Distal







🔍 INDIVIDUAL BONES






Talus



  • Body has 3 articular facets:

    • Superior (trochlea)

    • Medial

    • Lateral


  • Articulates with:

    • Tibia

    • Malleoli




Shape:


  • Convex (anterior–posterior)

  • Concave (side-to-side) → pulley shaped



Function:


  • Wedge shape prevents posterior displacement during jumping/stopping






Calcaneus



  • Largest tarsal bone



Features:


  • Posterior rough surface for:

    • Tendocalcaneus (Achilles tendon) attachment







Navicular



  • Located:

    • Anterior to talus

    • Medial to medial malleolus




Features:


  • Prominent medial tuberosity

  • Posterior surface:

    • Concave → articulates with talus


  • 3 anterior facets:

    • Articulate with cuneiforms







Cuboid



Articulations:


  • Posterior:

    • Calcaneus (calcaneocuboid joint)


  • Medial:

    • Lateral cuneiform (cuneocuboid joint)


  • Anterior:

    • 4th & 5th metatarsals (TMT joint)







Cuneiforms



  • All articulate with:

    • Navicular

    • Each other




Specific articulations:


  • Medial → MT 1

  • Intermediate → MT 2

  • Lateral → MT 3 + cuboid






Metatarsals



  • Bases:

    • MT 1–3 → cuneiforms

    • MT 4–5 → cuboid


  • Bases articulate with each other






🦴 JOINTS OF THE FOOT & ANKLE






Superior Tibiofibular Joint



  • Type: Synovial plane



Articulation:


  • Fibular head + lateral tibial condyle



Ligaments:


  • Anterior & posterior fibular head ligaments



Movement:


  • Small rotations during:

    • Dorsiflexion

    • Plantarflexion


  • Slight gliding






Interosseous Membrane



  • Strong fibrous sheet between tibia & fibula



Functions:


  • Muscle attachment

  • Separates:

    • Anterior compartment

    • Posterior compartment







Inferior Tibiofibular Joint



  • Type: Fibrous syndesmosis



Articulation:


  • Fibula (medial aspect)

  • Tibial fibular notch



Ligaments:


  • Anterior inferior tibiofibular

  • Posterior inferior tibiofibular

  • Transverse tibiofibular






Talocrural Joint (Ankle Joint)



  • Type: Synovial hinge

  • Uniaxial (1 DOF)



Plane/axis:


  • Sagittal plane

  • Frontal axis



Movements:


  • Dorsiflexion

  • Plantarflexion



Position:


  • Neutral = plantigrade standing






Subtalar Joint



  • Between:

    • Talus

    • Calcaneus


  • Type: Synovial (plane / modified saddle)



Movement:


  • Inversion

  • Eversion






Midtarsal Joints



  • S-shaped joint



Includes:


  • Talocalcaneonavicular

  • Calcaneocuboid



Function:


  • Works with subtalar joint



Combined movement:


  • Pronation

  • Supination






Other Foot Joints




Tarsometatarsal (TMT)



  • Synovial plane






Metatarsophalangeal (MTP)



  • Synovial ellipsoid



Movements:


  • Flexion / Extension

  • Abduction / Adduction






Interphalangeal (PIP & DIP)



  • Synovial hinge



Movement:


  • Flexion / Extension






📝 Exam Question



Q: Type of talocrural joint?

→ Synovial hinge joint


Q: Functions (any 4):


  • Stable base

  • Rigid lever

  • Shock absorption

  • Adapts to terrain

  • Balance/proprioception

  • Adjusts gravity line

  • Propulsion/restraint



Q: Movements?

→ Dorsiflexion & plantarflexion






🦶 FOOT & ANKLE – MOVEMENTS & MUSCLES




📚 Intended Learning Outcomes



  • Describe movements

  • Name muscles acting on foot & ankle






🔄 TALOCURAL JOINT MOVEMENTS



  • Dorsiflexion (DF)

  • Plantarflexion (PF)






📏 RANGE OF MOTION




Dorsiflexion



  • 20–30° (knee extended)






💪 MUSCLES – DORSIFLEXION



  • Tibialis anterior

  • Extensor hallucis longus (EHL)

  • Extensor digitorum longus (EDL)






💪 MUSCLES – PLANTARFLEXION



(Implied from lecture structure)


  • Gastrocnemius

  • Soleus

  • Others assist






🔄 SUBTALAR MOVEMENTS



  • Inversion

  • Eversion






💪 MUSCLES – INVERSION



(From standard grouping implied in slides)


  • Tibialis anterior

  • Tibialis posterior






💪 MUSCLES – EVERSION



  • Fibularis (peroneus) muscles






🦶 TOE MOVEMENTS






Metatarsophalangeal (MTP) Joints



  • Flexion

  • Extension

  • Abduction

  • Adduction






Interphalangeal Joints (PIP & DIP)



  • Flexion

  • Extension






📝 Exam Question



Q: Muscles for dorsiflexion?


  • Tibialis anterior

  • Extensor hallucis longus

  • Extensor digitorum longus





Q: Normal DF range?


  • 20–30°






✅ OVERALL SUMMARY



  • Main ankle joint = talocrural (hinge)

  • Movement split:

    • DF/PF → talocrural

    • Inversion/eversion → subtalar


  • Combined = pronation/supination

  • Foot designed for:

    • Stability + mobility balance