Foot And Ankle Flashcards
What makes up the hindfoot (rear foot) region of the foot?
Hindfoot (rear foot)
-Calaneus
- Talus
What makes up the midfoot region of the foot?
Midfoot
- Navicular
- Cuboid
- Cuneiforms
What makes up the forefoot region of the foot?
Forefoot
- 5 metatarsals
- Phalanges
What are the motions of the ankle/foot?
- Dorsiflexion and Plantarflexion
- Inversion: plantar surface moves toward midline
- Eversion: plantar surface moves away from midline
- Abuction: distal aspect of segment moves away from midline
- Adduction: distal aspect of segment moves toward midline
What are the composite motions for supination (NWBing)
Supination- coupled plantarflexion, inversion, and adduction
What are the composite motions for Pronation (NWBing)
Pronation: coupled dorsiflexion, eversion, and abduction
What is the axis of the talocrural joint in neutral?
In neutral:
Axis passes through lateral malleolus, body of talus and medial malleolus
Lateral malleolus and fibular facet of talus are more distal and posterior than tibial counterparts
-> creates oblique axis
Lateral malleolus sits more posteriorly due to normal tibial torsion
How does the talocrural joint functionally move in open chain DF and PF?
Open chain DF
- Foot moves upward and slightly lateral to lower leg
- Foot appears to turn longitudinally away from midline
Open chain PF
- Foot moves down and slightly medial to lower leg
- Appears to turn longitudinally toward midline
** How does the talocrural joint move in WBing DF and PF
WBing DF
- Tibia and fibula move toward and medial to foot
- Lower leg rotates medically in transverse plane
WBing PF
- Tibia and fibula move away from and lateral to foot
- Lower leg rotates laterally in transverse plane
What does the Deltoid ligament do?
Resists eversion at talocrural, subtalar, and talonavicular jts
What does the anterior talofibular ligament do?
(Lateral ligament) Restricts combined motion of plantarflexion with inversion or adduction
*****What does the calcaneofibular ligament do
Restricts inversion or varus stress of the talocrural and subtalar joints (its like a lateral collateral ligament)
*****What does the posterior talofibular ligament do
Provides stability to the talus within the joint and restrict abduction during dorsiflexion
**What is tibial torsion
Accounts for “normal” toe-out position of foot in standing
-> similar to that of femur, but typically in opposite direction
Lateral tibial torsion increases from birth until 10yrs
-> ankle jt axis becomes positioned more laterally as torsion increases
Normative values are variable
-> ~20 degrees of lateral torsion (adults)
***Characteristics of the proximal tibiofibular jt
- plane, synovial jt
- Variability of jt surfaces
-> most common: convex tibial facet and concave fibular facet - Capsule reinforced by anterior and posterior tibiofibular ligaments
Characteristics of the distal tibiofibular jt
- syndesmosis b/w concave facet of tibia and convex facet of fibula
- tibia and fibula separated by fibroadispose tissue
- anterior and posterior tibiofibular ligaments and interosseous membrane provide support
What does the Calceneofibular ligament limit?
Limits excessive inversion
What does the tibiocalcaneal fibers of the deltoid ligament limit?
Limits excessive eversion
What does the Interosseous (talocalcaneal) ligament do?
Binds talus with calcaneus; limits extremes of all motions (esp. inversion)
What does the Cervical ligament do?
Binds talus with calcaneus; limits extremes of all motions (esp. inversion)
***What is the function of the Subtalar joint?
3 articulations with alternating convex-concave facets
- Limit joint mobility
- Creates triplanar motion around oblique joint axis
- Motion is complex twisting or screw like motion
-> Pronation/supination
Posterior calcaneal facet is convex
Middle and anterior facets of the calcaneus are concave
What are the Couple motions of the Subtalar in NWBing supination and pronation
Supination
- Calcaneal inversion (calcaneal varus)
- Calcaneal adduction
- Calcaneal plantarflexion
Pronation
- Calcaneal eversion (calcaneal valgus)
- Calcaneal abduction
- Calcaneal dorsiflexion
What are the Couple motions of the Subtalar in WBing supination and pronation
Supination
- Calcaneal inversion (or varus)
- Talar abduction (or lateral rotation)
- Talar dorsiflexion
- Tibiofibular lateral rotation
-> Causes Talar abduction
-> carries mortise laterally, producing ER of lower leg
DF and abduction of talus is observed in elevation of medial longitudinal arch and convexity on the dorsal lateral midfoot
Pronation
- Calcaneal eversion (or valgus)
- Talar adduction (or medial rotation)
- Talar plantarflexion
- Tibiofibular medial rotation
-> Causes Talar adduction
-> Body of talus rotates medially, brings lower leg into IR
PF and adduction of talus is observed in the lowering of medial longitudinal arch and convexity of the plantar medial midfoot
What makes up the Transverse Tarsal joint
Compound jt btwn rearfoot and midfoot
- Talonavicular jt
- Calcaneocuboid jt
- Involved in pronation and supination
- Anatomically and functionally related to subtalar jt
- Plays major role in compensatory motions to adjust to variations in ground surface
Describe pronation of the foot when the calcaneus is fixed and free
- With calcaneus fixed, pronation occurs primarily at midfoot
- With calcaneus free, pronation occurs as sum of motion from rearfoot and midfoot
Describe supination of the foot when the calcaneus is fixed and free
- With calcaneus fixed, supination occurs primarily at midfoot
- When calcaneus is free, supination occurs as sum as motion from rearfoot and midfoot
What are the capsular reinforcements of the Talonavicular joint
Inferiorly: plantar calcaneonavicular ligament (spring ligament)
- Spans gap b/w calcaneus and navicular immediately below Talar
Supports the head of talus and talonavicular joint, Major passive stabilizer of medial longitudinal arch
Medially: Deltoid ligament
Laterally: bifurcate ligaments
Joint looks like it is on dorsal side of foot
What are the capsular reinforcements for the calcaneocuboid joint
Laterally: lateral band of bifurcate ligament (calcaneocuboid ligament)
Dorsal: dorsal calcaneocuboid ligament
Inferiorly: plantar calcaneocuboid (short plantar) and long plantar ligaments
extrinsic muscles of foot provide support for transverse tarsal joint
What does the long plantar ligament do?
- Spans calcaneus and cuboid and extends distally to bases of 2nd, 3rd, and 4th metatarsals
- Supports transverse tarsal joint and lateral longitudinal arch
*** What does the tarsometatarsal joint do?
Contributes to hollowing and flattening of plantar surface of the foot
In WBing
- Contributes to transverse tarsal joint
-> Regulates position of forefoot in relation to WBing surface
- If transverse tarsal jt motion is adequate to compensate for hindfoot position -> significant TMT jt motion is not needed
- If hindfoot position is at end ROM or transverse tarsal jt is unable to fully compensate…
-> TMT jts may rotate to provide further adjustment of forefoot (pronation or supination twist)
What is supination twist?
Extreme pronation at subtalar joint causes…
- ADD and PF of talus
- EV of calcaneus
- Pronations at transverse tarsal joint (due to navicular being forced down by talus)
TMT jts must have COUNTERACTING SUPINATION TWIST to keep forefoot on the ground
What is pronation twist?
Extreme supination at subtalar joints causes…
- ABD and DF of talus
- INV of calcaneus
- Supination of transverse tarsal joint
TMT joints need a counteracting pronation twist to keep forefoot on ground
What is Metatarsal Break?
Refers to hinge or break occurring at MTP jts as heel rises
- Occurs as MTP extension around single oblique running through metatarsal heads
- Area of higher stress during gait
Talocrural Jt. Arthrokinematics: Open Chain DF and PF
VCO
DF: Talus rolls anteriorly, slides posteriorly on calcaneus
PF: Talus rolls posteriorly, slides anteriorly on calcaneus
Talus is convex and calcaneus is concave
Subtalar Jt. Arthrokinematics Open Chain: Supination and Pronation
VCO: motion of calcaneus on talus (posterior articulation)
Supination with INV: calcaneus rolls medially, slides laterally on talus
Pronation with EV: calcaneus rolls laterally, slides medially on talus
Metatarsophalangeal and Interphalangeal Jt. Arthrokinematics Open Chain: Flexion and Extension
Flexion: phalanges roll and slide in the plantar direction
Extension: phalanges roll and slide dorsally
Transverse Tarsal Jt. Arthrokinematics: PF and DF
CVS
PF: plantar roll and slide
DF: dorsal roll and slide
What is calcaneovalgus?
Increase in MEDIAL angle b/w calcaneus and posterior leg
Medial angle 185 degrees or greater
(Standing on medial side of foot, lateral side coming off the ground)
Calcaneovalgus= rearfoot valgus= hindfoot valgus
What is calcaneovarus?
Decrease in MEDIAL angle b/w calcaneus and posterior leg
Medial angle 175 degrees or less
(Standing on lateral side of foot, medial side coming off the ground)
Calcaneovarus= rearfoot varus= hindfoot varus
What is Pes Cavus?
- Supinated foot
- High arch
(High arch makes a cave)
What is Pes planus ?
- Flat foot or hyperpronated foot
- Low arch
Me ;(
What is forefoot varus and valgus?
Identified in NWBing position
(Calcaneus in subtalar neutral position)
- Examine if forefoot is deviated from a line bisecting the calcaneus
-> Forefoot varus: calcaneus going laterally, toes going in medially
-> Forefoot valgus: calcaneus going medially, toes going laterally
Characteristics of arches of the foot (children)
Enhances dynamic function of the foot
- Usually not present at birth
-> Develop with progression of WBing - Flattened longitudinal arches are seen in children less than 5 yrs old
-> Majority of children will develop a normal arch by age 6
Characteristics of Longitudinal Arches
(Medial longitudinal arch (MLA) and Lateral Longitudinal Arch (LLA))
-Talus: KEYSTONE OF MLA
-Cuboid: KEYSTONE OF LLA
All weight transferred from body to heel and forefoot must pass through talus
Characteristics of Transverse arch
- Easiet to visualize in midfoot at level of tarsometatarsal joints
- MIDDLE cuneiform: KEYSTONE OF TRANSVERSE ARCH
What are the functions of the plantar arches?
Mobility and Stability
Mobility
- Plantar arches muscle be flexible enough to allow the foot to…
-> Absorb the impact of WBing forces
-> Reduce/dampen superimposed rotational motions
-> Adapt to changes in the supporting surface
Stability
- Arches must allow…
-> Distribution of weight through the foot for proper WBing
-> Conversion of a flexible foot to a rigid lever
How do bones of the foot contribute to arches of the foot?
Shape and arrangement of bones partially contributes to stability of arches
- Wedge shape of midtarsal bones provides inherent stability to transverse arch
- Inclination of calcaneus and 1st metarsal contribute to stability of medial longitudinal arches (esp in standing)
Arches would collapse w/out additional support from ligaments and muscles
What are key PASSIVE supports to MLA and LLA
MLA
SPRING LIGAMENT
-> MOST IMPORTANT STATIC STABILIZER
- Interosseous talocalcaneal ligament
- Deltoid ligament
LLA
- long and short plantar ligaments
What muscles play a role in DYNAMIC arch support?
- TIBIALIS POSTERIOR
-> Major role in MLA SUPPORT - Tibialis anterior
- FIBULARIS LONGUS
-> SUPPORTS TRANSVERSE AND LLA - Flexor digitorum longus
- Fibularis tertius
- Plantar intrinsic muscles
-> Provide support to the arch in static standing and walking
Fibularis longus tendon and tibialis posterior work together to provide stability to 1st ray and maintain foot arches
What is the Plantar Aponeurosis
Relationship b/w plantar aponeurosis and MTP jts contributes to arch support
- Tension in aponeurosis INCREASES when toes are EXTENDED at MTP jts
-> Metatarsal heads act as pulleys as plantar aponeurosis is pulled tighter
-> Occurs in both open and closed chain
As plantar aponeurosis wraps around metatarsal heads and tension increases, the heel and MTP jts are drawn toward each other
-> Raises the arch, contributing to supination of foot (Attachment sites being drawn together)
What is the Windlass Mechanism
When toes are neutral…
- Plantar aponeurosis and intrinsic foot muscles reinforce the longitudinal arch
When toes extend in a heel raise…
- Fascial tension INCREASES and intrinsic muscles contract
- STABILIZES foot to provide more rigid lever for extrinsic muscles to act on
Allows plantar aponeurosis to increase its role in supporting arches as heel rises during metatarsal break
What would increase and decrease tension in the plantar aponeurosis?
- SUPINATION of WBing foot via ER of lower leg or calcaneal varus
-> RELEASES TENSION in planter aponeurosis - PRONATION of WBing foot via IR of lower leg or calcaneal valgus
-> INCREASES TENSION in plantar aponeurosis and can limit MTP joint extension
Distribution of body weight on the foot
Distribution of body weight through foot depends on…
- Shape of the arch
- Location of the LOG at any given moment
Distribution of body weight begins at talus
- Body of the talus receives ALL weight passing through leg
-> 50% or less of weight received by talus passes through POSTERIOR subtalar articulation with calcaneus
-> 50% or more passes ANTERIORLY through talonavicular and calcaneocuboid jts
- about 2x as much weight passes through talonavicular jt due to more medial position of Talar head
Trabeculae of bone
- 100% of force goes to talus then splits…
-> 50% passes posteriorly to calcaneus
-> 50% passes anteriorly to forefoot
Name all of the Talocrural Dorsiflexors
- Tibialis anterior
- Extensor digitorum longus
- Extensor hallucis longus
- Fibularis tertius
Name all the talocrural plantarflexors
- Gastrocnemius
- Soleus
- Plantaris
- Tibialis Posterior
- Flexor hallucis longus
- Flexor Digitorum longus
- Fibularis Longus
- Fibularis brevis
Name all of the Subtalar invertors
- Tibialis anterior
- Tibialis posterior
- Flexor digitorum longus
- Flexor hallucis longus
Name all of the Subtalar evertors
- Fibularis longus
- Fibularis brevis
- Fibularis tertius
- Extensor digitorum longus
What’s stronger Supinators or Pronator
Supinators of the foot are stronger than pronators
- LOG in WBing more often falls MEDIAL to STJ producing a pronation torque
-> Supinators must work to control the pronation moment
What’s stronger dorsiflexors or plantarflexors?
Plantarflexors are stronger than dorsiflexors
- LOG in WBing is most often ANTERIOR to ankle joint axis
-> Plantarflexors work to control dorsiflexion moment
What are the contents of the Tarsal Tunnel?
- Tibialis posterior
- Flexor Digitorum longus
- Tibial Artery
- Tibial Nerve
- Flexor Hallucis longus
-> Goes through sustentacular groove
Tom, Dick, And Nervous Harry
Normal ROM for angle DF and PF
DF: 20 degrees
PF: 50 degrees
Subtalar Eversion and Inversion ROM
Subtalar Eversion: 5-10 degrees
Subtalar Inversion: 35 degrees
ROM for Inversion w/ supination and Eversion with pronation
Inversion with supination: 35 degrees
Eversion with pronation: 15 degrees
Open and close packed position for talocrural jt
Open-pack position: 10-20 degrees of PLANTARFLEXION
Closed packed position: Full DORSIFLEXION
Open and closed pack position for subtalar jt
Open pack position: midway between inversion and eversion
Closed pack position: Full SUPINATION
