subtalar joint

Question 1

articulation

Answer 1

formed by 3 separate plane articulations

b/w the talus superiorly and the calcaneus inferiorly

together they will provide triplaner movement around a single joint axis

Question 2

what is normal ROM and fxining of this joint critical for

Answer 2

dampening the rotational forces imposed by the body weight while maintaining contact of the foot with the supporting surface

Question 3

what does the talocalcaneal joint prevent

Answer 3

unwanted movements

Question 4

3 articular facets

Answer 4

posterior

anterior and medial

Question 5

posterior facet

Answer 5

concave on convex

largest of the 3 facets

concave talus articulating w/ a convex facet on the body of the calcaneus

has its own joint capsule

Question 6

anterior and medial facet

Answer 6

convex facets on the inferior body and neck of the talus and 2 concave facets on the calcaneus

2 articulations will share a joint capsule w/ the talonavicular joint

Question 7

subtalar joint ligaments

Answer 7

very stable joint with strong ligamentous support

4 major ligaments

Question 8

4 major ligs of the subtalar joint

Answer 8

interosseous talocalcaneal lig

ligamentum cervicis

posterior talocalcaneal ligaments

lateral talocalcaneal ligaments

Question 9

arthrokinematics

Answer 9

complex twisting or screw like motion

can continue only until the posterior and anterior and middle facets can no longer accommodate the simultaneous and opposite motions

posterior facet –> glide is in the same direction

anterior and middle facets –> glide is in the opposite directions

Question 10

arthrokinematics motion

Answer 10

rotation

_d/t the different shapes of the articular facets

Question 11

result of complex arthrokinematics

Answer 11

triplanar motion of the talus around a single oblique joint axis

Question 12

subtalar joint is a

Answer 12

uni-axial joint w/ 1 degree of freedom

allows for supination and pronation

Question 13

supination and pronation

Answer 13

component motions w/ movement in each of the 3 planes

component motions DO NOT OCCUR INDEPENDENTLY

Question 14

subtalar joint can

Answer 14

ABD/ADD

invert/evert

PF/DF

but will always happen together

Question 15

OKC movements

Answer 15

talus is fixed and the calcaneus and the more distal segments of the foot move on it

Question 16

OKC supination

Answer 16

combination of

ADD (around a vertical axis)

inversion (around an A-P axis)

PF (around a frontal axis)

Question 17

what bone moves in OKC supination

Answer 17

calcaneus and distal segments of the foot

Question 18

calcaneus is in what position during OKC supination

Answer 18

varus

Question 19

OKC pronation

Answer 19

combo of

ABD (around a vertical axis)

eversion (around an A-P axis)

DF (around a frontal axis)

Question 20

what bone is moving during OKC pronation

Answer 20

calcaneus and the distal segments of the foot

Question 21

what position is the calcaneus in during OKC pronation

Answer 21

valgus

Question 22

pronation was once called

Answer 22

eversion

Question 23

supination was once called

Answer 23

inversion

Question 24

axis of motion OKC

Answer 24

orientation of the axis is inclined

42 degrees upward and anterior from the transverse plane

inclined medially 16 degrees from the sagittal plane

Question 25

subtalar neutral OKC

Answer 25

point in which the calcaneus will invert twice as many degrees as it will evert

Question 26

CKC arthro

Answer 26

calcaneus is fixed but is capable of some inversion and eversion with the foot on the group cannot DF/PF or ABD/ADD (Completed by the talus)

Question 27

CKC supination

Answer 27

calcaneus will invert talus will ABD (ER) and DF

Question 28

CKC pronation

Answer 28

calcaneus will every talus will ADD (IR) and PF

Question 29

talar ABD/ADD is sometimes referred to as

Answer 29

IR (ADD), medial rotation ER (ABD), lateral rotation d/t occurring on the vertical axis

Question 30

if the mortise moves (CKC)

Answer 30

the talus moves most congruent joint in the body

Question 31

in WB positions...

Answer 31

the lower leg and the subtalar joint are mechanically linked motion of the lower leg will influence the subtalar joint motions of the subtalar joint will influence movement at the lower leg

Question 32

lateral rotary force is imposed on the leg

Answer 32

lateral motion of the tibia carries the ankle mortise and the trochlea of the talus laterally if the talus laterally rotates (ABD), then the other component motions must occur when the talus ABDs, it will also DF and the calcaneus will invert (occur simultaneously)

Question 33

what if the subtalar joint is forced into pronation by uneven terrain

Answer 33

talar PF and ADD calcaneal eversion the ankle mortise is carried with the subtalar joint and will result in medial rotation of the tibia

Question 34

what can the subtalar joint do d/t the mechanical link

Answer 34

absorb lateral and medial rotary forces/movements with pronation and supination

Question 35

does the mechanical link exist in OKC

Answer 35

no

Question 36

calcaneal movement

Answer 36

easily measured 10 degrees of eversion 20 degrees of inversion

Question 37

supination ROM

Answer 37

limited by the ligamentum cervicis considered the closed packed position lig tension is the greatest draws articulating surfaces together

Question 38

pronation ROM

Answer 38

limited by interosseous talocalcaneal ligament position of mobility for the foot