foot & ankle. anatomy anatomy - medial anatomy - lateral

Foot & Ankle

Anatomy

Anatomy - Medial

Anatomy - Lateral

Talocrural Joint

Subtalar Pronation – Closed Chain

Subtalar Pronation – Closed Chain

Subtalar Supination – Closed Chain

Subtalar Pronation & Supination Model – Closed Chain

Gait Review

Subtalar Pronation & Supination during Gait

Transverse Tarsal/Midtarsal/Chopart’s Joint

CalcaneocuboidJoint

TalonavicularJoint

Midtarsal Joint

PronationSTJ unlocks MTJ

SupinationSTJ locks up MTJ

Midtarsal Joint Motion - Closed Chain

Pronation Neutral Supination

Abnormal Biomechanics

Breakdown of CTReduced muscle efficiencyChange in muscle functionPoor alignment – Osseous DeformityDysfunction and PathologyReduced ability to attenuate GRFs

Pronation

Closed ChainCalcaneus

eversion (valgus)Talus adduction

(IR - vertical axis)Talus

plantarflexionTibial IR

Normal Pronation in GaitNormal Range:6 - 100

Excessive:130+

Abormal Pronation in Gait

Excessive in magnitudeExcessive in durationOccurs at wrong time

Causes:Intrinsic deformitiesExtrinsic deformities

RF/Subtalar Joint Varus

Inversion deformity of calcaneus

No change in relationship of RF on FF

EtiologyCongenital/developmental failure of talus to derotate

RF/Subtalar Joint Varus – Compensated ST Varus

RF/Subtalar Joint Varus – Compensated ST Varus

Forefoot Varus

Most CommonInsufficiency of 1st rayDorsiflexed/hypermobile

1st rayCongenital deformityInversion of forefoot

(metatarsals) relative to rearfoot in STJ neutral

Forefoot Varus

Forefoot Varus - Compensated

Forefoot Varus (Compensated) - Pathomechanics

During WA - excessive pronation to get 1st ray on ground

Max. pronation occurs @ HOPronation remains thru propulsionFoot never becomes rigid leverInstability

Forefoot Varus - Compensation

Prolonged / excessive pronationCalcaneal valgusUnlocking of forefoot during

propulsionInsufficient pulley system

Forefoot Varus - Pathology

Hypermobile 1st rayExcessive forces on 2nd METProlonged / excessive tibial torsion

and/or IRExcessive anteversion of hip

Forefoot Varus - Uncompensated

Forefoot Varus - Uncompensated

Rigid FootLateral ankle sprainsS.I. Joint DysfunctionITB Dysfunction

Subtalar Varus and Compensated Forefoot Varus

FF Varusacquired soft tissue contracture at

MTJ20 compensatory pronation for a STJ

varus

Subtalar Varus and Compensated Forefoot Varus

Subtalar Varus and Forefoot Varus, Compensated

Ankle Joint Equinus

Fixed limitation of DF @ TCJ< 100 of DF when in STJ neutral and knee

/Etiologytight gastrocnemiusspasticity flattened dome of talusFx, arthritis, trauma

Ankle Joint Equinus

Ankle Joint Equinus - Compensated

Ankle Joint Equinus - Pathomechanics

pronation 20 to DFloss of ankle rockertibia unable to move anterior to talus

tibia and talus move anterior to calcaneus

DF of RF at FF and prolonged pronation during

propulsion

Compensated Ankle Joint Equinus

Excessive STJ pronationCalcaneal valgus/eversionInefficient pulleysDF of RF on FF

Uncompensated Ankle Joint Equinus

Genu RecurvatumEarly heel riseExcessive abduction and ER of LE