foot biomechanics inc gait cycle Flashcards Preview

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Flashcards in foot biomechanics inc gait cycle Deck (20):
1

What does the subtalar joint consist of and what is its motion?

  • Calcaneus
  • Talus

Motion

  • Inversion/eversion
  • No role in plantar flexion/dorsoflexion

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2

What does the midfoot consist of and what is its motion?

  • Intercuneiform
  • naviculocuneiform joint
  • Tarsalmetarsal joint ( lisfranc)
  • divided into 3 colums
    • Medial 
      • First MT
      • Medial Cuneiform
      • Navicular
    • Middle Column 
      • 2/3 MT
      • middle cuneiform
      • Lateral cuneiform
    • Lateral 
      • 4/5Th MT
      • Cuboid

Motion

  • Lateral column is the most mobile
    • allows for flexibility whne walking on uneven ground
  • Middle Column is the least mobile
    • Allows for rigidity during push -off
  • Medial column carried most of load when standing

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3

What does chopart joint consist of and what is tis motion?

  • Talonavicular
  • Calcaneocuboid

Motion

  • Inversion of subtalar joint locks the Transverse Tarsal joint
    • allows for stable hindfoot/midfoot for toe off 
  • Eversion of subtalar joint unlocks the transverse tarsal joint
    • allows for supple foot to accomodate ground just after heel strike
  • Plantar aponeurosis is primary structure of load/force transfer between hindfoot and forefoot during stance

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4

What does the forefoot consist of?

  • Metarsal phalangeal joints
  • proximal phalangeal joints
  • distal interphalangeal joints
  • 2nd MT experiences more stress during gait
    • most common MT to have STRESS FRACTURE

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5

What does one gait cycle measure?

  • From heel strike to heel strike

6

Define a stride ?

  • One full gait cycle
    • From heel- strike to heel- strike

7

What is a stride made up of ?

  • A Stance phase
  • A swing phase

8

What is the stance phase? How much of the gait cycle does it occupy?

  • Period of time the foot is ON the ground
  • 60% of one gait cycle is spent in stance
  • Heel strike to toe off 

9

What is the swing phase?

  • The period of time the foot is OFF the ground moving forward
  • Toe off to heel strike 
  • 40% one gait cyle is spent in swing

10

What is walking?

  • A period of double limb support in addition to always having one foot in contact with the ground throughout the gait cycle

11

What is ground reaction force during walking and running ?

  • 1.5 walking
  • 3-4 times in running

12

What is the centre of gravity of the body?

  • 5cm anterior to S2 Vertebral body
  • displaced 5cm vertically and horizontally during adult male step

13

Describe the phases of the stance phase of the gait cycle and muscle involvement?

 

'I like my tea presweetened'

  • Inital contact= HEEL STRIKE
    • when foot contact ground
    •  tibialis anterior- eccentric contraction - lengthens- controls rate of decent of foot- loss = slap foot. Hip extensors contract, quads contract eccentrically
    • Hindfoot - everted, unlocked- absorb ground- Transverse tarsal axes are parallel & flexible
       

  • Loading responde ( double limb support)
    • Occurs after inital contact until elevation of opposite limb
    • ankle dorsiflexors - tibialis anterior contract eccentrically to control planar flexion
    • Quads contract to stabilise knee and counteract flexion moment
    •  
  • Mid Stance
    • From elevation of opposite limb until both ankles are aligned in coronal plane
    • Hip extensors and quads undergo concentric contraction- controls progeession of body over foot- effected in quads weakness -pt leans forwarad to put centre og gravity anterior of knee-> knee hyperextension
  • Terminal Stance ( single leg stance)
    • from ankle are aligned to until opposite to when heel strikes in controlateral limb
    • Toe flexors contribute
    • gastron/ soleus complex- concentric ( shortening)
  • ​Pre- swing ( second double limb stance)
    • from initial contact of opposite limb to just prior to elevation of ipislateral limb
    • HIp flexors contract to propel limb

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14

What is the windlass mechanism ? When does it occur ? What else occurs during this time?

  1. Plantar fascia attached to medial plantar plane to pipj ( past mtpj)
  2. Pt tightens as mtp extend and toes dosiflex. This pulls tarsal bones together locking them in place. Occurs in stance phase from heel strike to toe off.
  3. Post tibialis fires and supinates the hind foot-> the transverse tarsal joint/ chopart locks and provides a rigid lever ready for toe off

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15

What happens in foot drop?

  • Loss of anterior tibialis due to peroneal neve palsy
  • heel strike- foot cannot be lowered controlled so 'slaps ground- no eccentric  contraction of tibilalis anterior
  • during swing phase- weakness in tibialis anterior -> steppage gait as hip flexors and knee flexors have to increase to clear foot from ground

16

What muscle are involved in the swing phase?

Anterior tibialis - concentric contracture ( shortening) to clear foot

17

Describe the stages of the swing phase of gait cycle?

  • 'In My Teapot'
  • quads silent in swing phase
  • Inital contact-Toe off
    • from elevation of limb to point of max knee flexion
    • hip flexors contract
    • Inversion of calcaneus locks transverse tarsal joints
    • weakness of hamstrong/hip flexors affect swing phase- limit limb advancement
  • Mid swing ( foot clearance)
    • Following knee flexion to point where tibia is vertical
    • ankle dorsiflexion contract to ensure foot clearance
  • Terminal swing
    • from point where tibia is vertical to just prior to inital contact
    • hamstring muscles decelerate forward of thigh

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18

What is the antiaagonist to tibialis anterior?

  • Peroneus LONGUS
  • Superifical peroneal nerve


  • It plantarflexes and everts cf TA which dorsiflexes ad inverts 

19

What is the antagonist to tibialis posterior?

  • Peroneus Brevis

20

Decribe the anatomy of tibialis abterior?

  • origin- Gerdy's tubercle, lateral condyle of tibia
  • insertion 1st cuneiform and base of 1st MT
  • innervation= deep peroneal nerve
  •  

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