Ankle and Foot ComplexAnkle and Foot ComplexFunctions:Functions:Stability demands:Stability demands:• Provide stable base of support for body in weight Provide stable base of support for body in weight

bearing activities without undue muscle or energy bearing activities without undue muscle or energy expenditureexpenditure

• Acts a rigid lever for effective push off phase of gait Acts a rigid lever for effective push off phase of gait cyclecycle

Mobility demands:Mobility demands:• Dampen the rotations imposed by proximal jointsDampen the rotations imposed by proximal joints• Being flexible enough to absorb the shock of Being flexible enough to absorb the shock of

superimposed body weight superimposed body weight • Permitting the foot to adapt to changing terrainPermitting the foot to adapt to changing terrain

• The foot and ankle consists of 28 bones The foot and ankle consists of 28 bones with 25 complex jointswith 25 complex joints

• It can be divided into It can be divided into

a.a. Hind Foot:Talus & calcaneumHind Foot:Talus & calcaneum

b.b. Mid Foot:Navicular,cuboid & 3 cunieformMid Foot:Navicular,cuboid & 3 cunieform

c.c. Forefoot:Metatarsals Forefoot:Metatarsals

& phalanges& phalanges

Ankle Joint:Ankle Joint:• Synovial joint with 1Synovial joint with 1 of freedom,most of freedom,most

congruent jointcongruent joint• Articulation between talus and distal tibia Articulation between talus and distal tibia

and fibulaand fibulaArticular surface:Articular surface:• Proximal segment is Proximal segment is

composed of concave composed of concave surface of tibia and surface of tibia and tibial and fibular tibial and fibular malleoli – mortisemalleoli – mortise

• Distal segment is formed by the body of Distal segment is formed by the body of talus – has 3 articular surfaces lateral , talus – has 3 articular surfaces lateral , medial and trochlear/superior facetsmedial and trochlear/superior facets

Ligaments:Ligaments:• Capsule is thin and weak anteriorly and Capsule is thin and weak anteriorly and

posteriorlyposteriorly• Two major ligaments maintain contact and Two major ligaments maintain contact and

congruence of the mortise and talus and congruence of the mortise and talus and control medial- lateral joint stabilitycontrol medial- lateral joint stability

i.i. Medial collateral ligament-Medial collateral ligament- • Deltoid ligamentDeltoid ligament• Has superficial and deep fibersHas superficial and deep fibers• Controls medial distraction stress, checks Controls medial distraction stress, checks

motion at extremes of rangemotion at extremes of range

ii.ii. Lateral collateral ligament-Lateral collateral ligament- • Consists of Consists of Anterior &Anterior &

posterior talofibular lig.,posterior talofibular lig.,

calcaneofibularcalcaneofibular ligament ligament• Helps control varus stresses and checks Helps control varus stresses and checks

extremes rangeextremes range• Anterior talofibular ligament is the weakest Anterior talofibular ligament is the weakest

& most commonly torn followed by & most commonly torn followed by calcaneofibularcalcaneofibular

• Posterior talofibular ligament is strongestPosterior talofibular ligament is strongest

Function :Function :• Ankle has 1Ankle has 1 of freedom – dorsi flexion/ of freedom – dorsi flexion/

plantar flexionplantar flexion

Other motions areOther motions are • Talar tilt (Inversion/ Eversion) in the frontal Talar tilt (Inversion/ Eversion) in the frontal

plane, A-P axisplane, A-P axis• Talar rotation (Abduction/adduction) occurs Talar rotation (Abduction/adduction) occurs

in the transverse plane/vertical axisin the transverse plane/vertical axis

ROMROM:: • Dorsiflexion from neutral : 0 - 20°Dorsiflexion from neutral : 0 - 20°• Plantar flexion from neutral :0-30° to 50°Plantar flexion from neutral :0-30° to 50°

Sub Talar Joint (Talocalcaneal)Sub Talar Joint (Talocalcaneal) • Composite joint formed by three separate Composite joint formed by three separate

articulations between talus superiorly and articulations between talus superiorly and calcaneum inferiorlycalcaneum inferiorly

• Consists of anterior, middle & posterior Consists of anterior, middle & posterior articulationsarticulations

• Together, three surfaces provide a triplanar Together, three surfaces provide a triplanar movement around a single joint axismovement around a single joint axis

• Function at the weight bearing sub talar joint Function at the weight bearing sub talar joint is to dampen the rotational forces imposed is to dampen the rotational forces imposed by the body weight while maintaining by the body weight while maintaining contact of foot with supporting surfacecontact of foot with supporting surface

Tarsal tunnel:Tarsal tunnel:• Between the posterior articulation and the Between the posterior articulation and the

anterior and middle articulations there is a anterior and middle articulations there is a bony tunnel formed by a sulcus in the bony tunnel formed by a sulcus in the inferior talus and superior calcaneuminferior talus and superior calcaneum

• Contents of the tunnel are Tibialis Posterior, Contents of the tunnel are Tibialis Posterior, Flexor Digitorum Longus,Posterior Tibial Flexor Digitorum Longus,Posterior Tibial artery,Posterior Tibial Nerve,Flexor Hallucis artery,Posterior Tibial Nerve,Flexor Hallucis LongusLongus

Ligaments:Ligaments:

1.1. Calcaneofibular ligamentCalcaneofibular ligament

2.2. Cervical ligamentCervical ligament

3.3. Interosseus talocalcaneal ligamentInterosseus talocalcaneal ligament

Non weight bearing subtalar joint motion:Non weight bearing subtalar joint motion:• Supination/pronation of subtalar joint can Supination/pronation of subtalar joint can

be described by motion of its distal non be described by motion of its distal non weight bearing segment –calcaneumweight bearing segment –calcaneum

• Supination=Adduction+Inversion+Plantar Supination=Adduction+Inversion+Plantar flexionflexion

• Pronation=Abduction+Eversion+Dorsi Pronation=Abduction+Eversion+Dorsi flexionflexion

• If the calcaneum is observed posteriorly the If the calcaneum is observed posteriorly the component of inversion/eversion can be component of inversion/eversion can be observedobserved

• In eversion the medial angulation between In eversion the medial angulation between the long axis of the tibia and an axis the long axis of the tibia and an axis through the tuberosity of the calcaneum through the tuberosity of the calcaneum

Eversion=CalcaneovalgusEversion=Calcaneovalgus

• In inversion the medial angulation between In inversion the medial angulation between the long axis of the tibia and an axis the long axis of the tibia and an axis through the tuberosity of the calcaneum through the tuberosity of the calcaneum ..

Inversion=CalcaneovarusInversion=Calcaneovarus

Neutral calcaneum

Calcaneal valgus (eversion)

Calcaneal varus (inversion)

Calcaneal positions

Weight bearing subtalar joint motion:Weight bearing subtalar joint motion:• The most critical functions of the foot occur in The most critical functions of the foot occur in

weight bearing, and when the foot is weight weight bearing, and when the foot is weight bearing, there is effectively a closed chain formed bearing, there is effectively a closed chain formed for the lower extremityfor the lower extremity

• Consequently the kinetics and kinematics of this Consequently the kinetics and kinematics of this joint will be affected by proximal and distal jointsjoint will be affected by proximal and distal joints

• Calcaneum is not free to move Calcaneum is not free to move • It can only evert (valgus) and invert (varus)It can only evert (valgus) and invert (varus)• These movements cannot occur in isolation, the These movements cannot occur in isolation, the

proximal segment of the joint moves but in the proximal segment of the joint moves but in the opposite directionopposite direction

• Motions of supination/pronation are absorbed Motions of supination/pronation are absorbed by the tibiofibular mortiseby the tibiofibular mortise

• Tibia remains unaffected by Tibia remains unaffected by supination/pronationsupination/pronation

• In this case the talus carries the super In this case the talus carries the super imposed body weight along with itimposed body weight along with it

• Subtalar supinationSubtalar supinationleg moves laterallyleg moves laterally• Subtalar pronationSubtalar pronationleg moves mediallyleg moves medially

• Sub talar joint acts as a mitered hinge Sub talar joint acts as a mitered hinge between leg and footbetween leg and foot

• Medial rotation of the leg proximally Medial rotation of the leg proximally imposes pronation on the distally located imposes pronation on the distally located foot foot

• Lateral rotation of the leg proximally Lateral rotation of the leg proximally imposes supination on the distally located imposes supination on the distally located foot foot