Biomechanics test 2 (THE FOOT)

Joints of the foot?

Subtalar, midtarsal, tarsometatarsal, metatarsophalangeal, interphalangeal, rays of forefoot.

DEE?

Pronation (dorsiflexion, external rotation, eversion)

PII?

supination (plantarflexion, internal rotation, inversion)

Motion at ankle joint?

flexion/extension

Rotation is ?

is a combination of motions

Major motion at subtalar is?

inversion and eversion

Subtalar joint is a ?

triplanar axis

Subtalar joint pronation ? (calcaneus moving on subtalar )

�eversion mainly
�abduction (external rotation) --->happens at transverse plane
�dorsiflexion

Subtalar joint supination? (calcaneus moving on subtalar)

�inversion mainly
�adduction (internal rotation)
�plantarflexion

Degrees of motion of Subtalar joint at sagittal plane?

16-20 degrees (the least movement occurs here)

Degrees of motion of subtalar joint at frontal plane?

40-45 degrees

Degrees of motion of subtalar joint at transverse plane?

45-50 degrees

Open chain pronation of subtalar joint? (calcaneus moving on talus)

�calcaneal eversion
�calcaneal abduction (external rotation)
�calcaneal dorsiflexion

Open chain supination of subtalar joint?

�calcaneal inversion
�calcaneal adduction (internal rotation)
�calcaneal plantarflexion

Closed chain pronation of subtalar joint? (Heel strike to Foot Flat)

�calcaneal eversion (valgus)
�talar adduction (medial rotation)
�talar plantarflexion
�tibial/fibular internal (medial) rotation

Closed chain supination (FF to MS) of subtalar joint?

�Calcaneal inversion (varus)
�talar abduction (lateral rotation)
�talar dorsiflexion
�tibial/fibular external (lateral) rotation

Reasons of over supination (subtalar stability)?

� Laxity in calcaneofibular ligament
� Laxity in lateral talocalcaneal ligament
� Weakness of fibularis longus and brevis

Reasons of over pronation (subtalar stability)?

� Laxity in tibiocalcaneal part of the deltoid ligament
� Laxity in medial talocalcaneal ligament
� Laxity in interosseous talocalcaneal ligament
� Weakness of posterior tibialis, flexor
digitorum longus and flexor hallucis longus

When walking calcaneus and talus move due to ?

GRF (ground force reaction)

Knee unlocking is driven by?

external rotation

Midtarsal joint?

Longitudinal axis
�inversion and eversion
Oblique or transverse axis
�dorsiflexion, plantarflexion
�abduction (external rotation)
�adduction (internal rotation)
Pronation
�eversion
�abduction (ER)
�dorsiflexion
Supination
�inversion
�adduction (IR)
�plant

Whatever midfoot is doing.......?

Hindfoot is doing

Midtarsal movements are controlled by?

subtalar joint movements

Hindfoot (subtalar) pronation ?

�midtarsal joint pronates
�longitudinal and oblique axes become more parallel
�midfoot is mobile and able to adjust to surface irregularities
�heel strike (initial swing) the subtalar and mid tarsal joints are pronated

Hindfoot (subtalar) supination?

�midtarsal joint is supinated
�longitudinal and oblique axes becoming more crossed
�midfoot movements are restricted providing a solid support base of to transfer weight from the hindfoot to the forefoot.
�subtarsal and midtarsal joints are supinated thro

Forefoot (ray 1 movement)?

Pronation
�mainly dorsiflexion
�inversion
�slight adduction (IR)
Supination
�mainly plantar flexion
�eversion
�slight abduction (ER)

Forefoot (ray 5 movement) ?

Pronation
�mainly dorsiflexion
�eversion
�slight abduction (ER)
Supination
�mainly plantar flexion
�inversion
�slight adduction (IR)

Forefoot (supination twist)? don't miss on the test

�rays 1 and 2 dorsiflex
�rays 4 and 5 plantar flex
�forefoot inverts

Forefoot (pronation twist) ?

�rays 1 and 2 plantar flex
�rays 4 and 5 dorsiflex
�forefoot everts and externally rotates

Forefoot stays opposite direction of mid and hindfoot because?

it balances it

If forefoot follows mid and hindfoot you will?

roll your foot.

The 3rd metatarsal ?

doesn't do anything

Excessive hindfoot (subtalar) pronation?

�midfoot and forefoot compensate by supination.
****they need to have compensation

Excessive hindfoot (subtalar) supination?

�no compensation at midfoot
�EXCESSIVE FOREFOOT PRONATION (GIVE THIS ANSWER ON TEST)

Forces on the foot?

Standing (compression)
�60.5% across heel
�7.8% by midfoot
�28.2% by forefoot
�3.6 by toes

During walking what are the two strongest forces?

HO and FF

Forces on the foot?

Greatest loads
�heel to the talonavicular to the naviculocuneiform to the first (1st metatarsal head)
Least loads
�heel to the cuboid to fifth metatarsal head

Plantar fascia ?

�Windlass mechanism---mechanics of foot from HO to TO
�need about 90 degrees to run but 60 degrees to walk

Pronators of foot? (only important one)

Fibularis longus
�supinator of ankle
Fibularis brevis
�supinator of ankle

Supinators of foot (only important ones)

Anterior tibialis
�pronator of ankle
Extensor hallucis longus (weak)
�pronator of ankle