Ankle/Foot Biomechanics Book Info!

Question 1

Describe the plafond aspect of the tibia

Answer 1

• inferior articular surface of distal tibia
• articulates with talus
• saddle-shaped
• AP = concave
• ML = convex
• bears 90% of load thru ankle

Question 2

third malleolus

Answer 2

the posterior margin of the distal tibial. projects distally beyond the superior surface of the talus. contributes to the stability of the ankle joint.

Question 3

normal tibial torsion angle?

Answer 3

20-40 degrees laterally/externally (causes medially malleolus to be oriented anteriorly in relation to lateral malleolus)

Question 4

Pott’s fracture

Answer 4

fracture of distal tibia and fibula

Question 5

Calcaneus bone

Answer 5

sparse cancellous bone allows area to fill with blood to help absorb shock during impact

Question 6

Functions of calcaneus

Answer 6

sustains large impact forces, long MA for achilles tendon, transmits body weight from hind to forefoot

Question 7

aspect of calcaneus in contact with ground

Answer 7

distal aspect of posterior surface of calcaneus is the only area of the bone that is in contact with the ground during weight bearing (IC)

Question 8

Sinus Tarsi

Answer 8

depression on lateral aspect of dorsum of foot
palpate neck of talus and anterior talofibular ligaments in this area
large venous plexus located here commonly torn due to ankle sprain

Question 9

Navicular

Answer 9

concave posterior surface articulates with head of talus

articulates with cuneiforms anteriorly

Question 10

Cuneiforms

Answer 10

keystones, form transverse arch of foot

Question 11

hindfoot

Answer 11

calcaneus and talus

Question 12

midfoot

Answer 12

remaining tarsal bones

Question 13

forefoot

Answer 13

metatarsals and phalanges

Question 14

Rays

Answer 14

motion segments of digits
1 = MT of great toe and medial cuneiform
2-5 etc

Question 15

high ankle sprain

Answer 15

sprain of distal TFJ (occurs due to pronation)

Question 16

dorsiflexion of foot is what motion in regards to tibia

Answer 16

anterior tibial translation

Question 17

ICOR

Answer 17

moves posteriorly with PF, anteriorly with DF, medially with INV

Question 18

ankle axis

Answer 18

oblique – passes from M to L in posterior and inferior direction

Question 19

Subtalar joint

Answer 19

all 3 articulating facets of calcaneus and talus
translates motion from tibia to foot and foot to tibia
triplanar motion

Question 20

Calcaneocuboid joint

Answer 20

saddle joint

Question 21

Tarsal coalition

Answer 21

abnormal connection between tarsal bones

decreased mobility at tarsal bones and excess ankle mobility

Question 22

Turf toe

Answer 22

hyperextension of MTPJ of great toes

can also rupture sesamoid bones

Question 23

Midstance

Answer 23

supination of foot

Question 24

Medial longitudinal arch is made up of which bones?

Answer 24

calcaneus, talus, medial cuneiform, navicular, 1st MT bone

Question 25

Lateral longitudinal arch is made up of which bones?

Answer 25

calcaneus, cuboid, 5th MT bone

Question 26

Pes planus

Answer 26

more knee and soft tissue injuries

Question 27

Pes cavus

Answer 27

more ankle and bony injuries

Question 28

Varus deformity of hindfoot (calcaneus) (oriented medially)

Answer 28

more pronation needed for arch to contact ground

Question 29

Calcaneus

Answer 29

provides larger MA for PF muscles, which increases their mechanical advantage
the higher up you go on your toes, the smaller the GRF becomes, which means your PF’s have to produce less force.
When standing on tip toes, JRF in ankle is 2x BW

Question 30

GRF when standing on one leg

Answer 30

GRF = BW

Question 31

when do peak ankle joint forces occur during gait?

Answer 31

occur with plantar flexion