Ankle Biomechanics Flashcards

1
Q

Name some functions of the ankle.

A

Shock Absorption
A rigid lever for push-off
Adapts to uneven terrain

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2
Q

What type of joint is the distal Tibiofibular Joint?

A

Syndesmosis joint

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3
Q

How is the distal Tibiofibular joint connected?

A

Articular capsule

Anterior & Posterior tibiofibular ligaments

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4
Q

What is the Talocrural joint?

A

Articulation between the distal tibia & fibula with the trochlea of the talus

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5
Q

What type of joint is the Talocrural Joint?

A

Uniaxial hinge joint

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6
Q

How many degrees of freedom does the talocrural joint have?

A

1 (Plantar and Dorsal Flexion)

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7
Q

Where is the axis of rotation for the talocrural joint?

A

10 degrees offset in the frontal plane

6 degrees offset in the horizontal plane

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8
Q

What are the 3 fibers for the deltoid ligament?

A

Tibionavicular fibers
Tibiocalcaneal fibers
Tibiotalar fibers

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9
Q

What does the Tibionavicular fibers restrict?

A

(restricts talocrural eversion, PF, & anterior slide of talus)
(restricts talonavicular eversion & abduction

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10
Q

What do the Tibiocalcaneal Fibers restrict?

A

Talocrural and subtalar eversion

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11
Q

What do the Tibiotalar fibers restrict?

A

Talocrural eversion, DF, and posterior slide of the talus

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12
Q

Name some of the lateral ligaments of the talocrural joint

A

Anterior talofibular ligament (ATFL)
Calcaneofibular Ligament
Posterior talofibular ligament

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13
Q

What does the ATFL restrict?

A

Talocrural PF, anterior slide of talus, inversion, and adduction.

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14
Q

What does the Calcaneofibular ligament restrict?

A
Talocrural DF, posterior slide of talus, and inversion
Subtalar inversion (mostly stretched during DF)
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15
Q

What does the posterior talofibular ligament restrict?

A

Talocrural DF, posterior slide of talus, inversion, and abduction

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16
Q

Which ligament is the weakest in the lateral region, and is mostly related to inversion ankle sprains?

A

ATFL

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17
Q

What type of joint is the subtalar joint?

A

Diarthrodial synovial joint

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18
Q

What is the articulations with the Subtalar joint?

A

Calcaneus and talus

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19
Q

What is the main action of the Subtalar joint?

A

Supination (inversion), and pronation (eversion)

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20
Q

What is pronation?

A

Dorsiflexion, Abduction, Eversion

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21
Q

What is supination?

A

Plantarflexion, Adduction, Inversion

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22
Q

What does supination allow?

A

A rigid push-off during gait, (medial sole showing)

23
Q

What does pronation allow?

A

Shock absorption with ground reaction forces (lateral sole showing)

24
Q

What path does the subtalar joint take and where is the axis of rotation?

A

Curvilinear path
Approximately 42 degrees from the horizontal plane
Approximately 23 degrees from the sagittal plane

25
Name the ligaments associated with the subtalar joint
Cervical talocalcaneal ligament | Interosseous talocalcaneal ligament
26
What does the cervical talocalcaneal ligament restrict?
Inversion | binds the calcaneus to the talus
27
What does the interosseous talocalcaneal ligament restrict?
Limits Eversion | binds the calcaneus to the talus
28
What is the articulations with the Transverse Tarsal joint?
Calcaneocubiod & talonavicular joints
29
What type of joint is the Transverse Tarsal joint?
Synovial saddle joint
30
What are the axis of motion in the transverse tarsal joint?
Longitudinal (inversion/eversion) 15 degrees upward from transverse plane, 9 degrees from longitudinal reference Oblique (flexion/extension) 52 degrees upward from transverse plane, 50-57 degrees from the frontal plane
31
What does the spring ligament do?
Supports the medial longitudinal arch | Prevents excessive medial and plantar movement of the talus
32
What does the medial longitudinal arch consist of?
Calcaneous, Talus, Navicular, Cuniforms, and Medial metatarsals
33
What's the keystone of the medial longitudinal arch?
Talonavicular joint?
34
What supports the medial longitudinal arch?
Plantar Fascia, Spring ligament Short & long plantar ligaments tibialis posterior muscle
35
What is Pes planus?
``` dropped arch (overstretched plantar fascia) Commonly connected to overpronation & excess rearfoot varus ```
36
During stance phase, what happens to the arch?
decreased arch, increased rear foot pronation w/ increased weight bearing
37
During the swing phase, what happens to the arch?
Increased arch, decreased rear foot pronation (so supination), w/ decreased weight bearing
38
What happens with over pronation of the foot?
Hip-increased IR, flexion, adduction Knee-Increased valgus stress Rearfoot- increased pronation Mid/Forefoot- supination (inversion)
39
What happens when you correct over pronation?
Better storing of elastic energy (better push off) Able to grip surface better Decreased stress transmission to other joints
40
What type of joint is the tarsometatarsal joint?
Plane synovial joint (gliding movements)
41
Which TMT is most mobile and least mobile?
2nd and 3rd TMT highly immobile | 1st TMT most mobile (helps transfer force at push-off)
42
What type of joint is the MTP joint?
Condyloid synovial joint (biaxial joints) | 2 degrees of freedom
43
What is turf toe?
Hyperextension of first MTP joint
44
What type of joint is the IP joints?
Synovial hinge joint (Concave on Convex) | 1 degree of freedom
45
What is the Plantar Fascia
Fibrous band that goes from medial plantar tuberosity to MTP plantar plates
46
What tightens the plantar fascia?
toe extension
47
What's the windlass effect?
When Plantar fascia is tight, it inverts calcaneous and elevates arch, helps supinate subtalar joint
48
Where's the tarsal tunnel, and what can happen here?
Posterior & inferior to medial malleolus, can cause tibial nerve entrapment
49
What all runs through the tarsal tunnel
``` Tibialis posterior Flexor Digitorum Longus Posterior Tibial Artery & Vein Tibial Nerve Flexor Hallucis Longus ```
50
What doe the intrinsic muscles of the foot do?
Control arch during midstance of gait Help lift the arch during the later phases of gait Stabilize the forefoot during terminal stance
51
What happens during inversion ankle sprain?
Tear of ligaments of ankle (ATFL most common, followed by CFL) Happens with PF & inversion
52
How are ankle sprains graded?
1: Ligament damage, with no instability 2: Ligaments having partial tear, ATFL partial tear, CFL stretches 3: Rupture of of ATFL & CFL ligaments, with partial tear of posterior talofibular & Tibiofibular ligaments
53
What is a foot drop?
Inability to DF foot Damage to fibular nerve, (stroke/brain injury, spine problems, muscle disorders) Treated with bracing, orthotics, physical therapy
54
What is hallux valgus?
``` 1st metatarsal is adducted phalanges abducted hypermobile 1st metatarsal increased pronation of the foot bunions can form ```