Rearfoot deformity

Question 1

Rearfoot deformity

Answer 1

position of the rearfoot (calcaneus) relative to the floor when the subtalar joint is in neutral position
NCSP

Question 2

Rearfoot deformity or NCSP formula

Answer 2

Subtalar joint neutral position +Tibial influence

Question 3

STJNP

Answer 3

The FRONTAL PLANE relationship of the leg bisection to the calcaneal bisection while the subtalar joint is neutral position

Question 4

STJNP Is affected by

Answer 4

The shape of the calcaneus
The shape of the talus
The orientation of the STJ itself
(in reality because the way we measure STJNP , the shape/orientation of the ankle joint also affects the measurements )

Question 5

Tibial influence

Answer 5

The Frontal plane relationship of the tibia to the ground while the STJ is in neutral position

Question 6

The pt should be standing in what position while measuring TI?

Answer 6

NCSP

Question 7

Tibial influence affected by

Answer 7

Frontal plane deformities proximal to the STJ

• Tibial varum/valgum
• Genu Varum/Valgum
• and anything that will effect the frontal plane

Question 8

Rearfoot deformity formula

Answer 8

NCSP=STJNP+TI

Question 9

Rearfoot varus

Answer 9

The rearfoot (calcaneous) is inverted with respect to the ground when standing in neutral calcaneal stance position

Question 10

Rearfoot varus is composed of

Answer 10

-STJ varus
AND/OR
-varus TI

Question 11

STJ varus may be caused by

Answer 11

• calcaneal varus
• Talar varus
• Varus orientation of the joint
• inverted tibial plafond ( not a true STJ varus but will appear as an inverted calcaneal bisection)

Question 12

calcaneal varus is due to

Answer 12

Lack of normal ontogeny

medial hypoplasia of the calcaneus or assymetric growth meaning medial and lateral are not growing at the same rate

Question 13

Talar varus is due to

Answer 13

medial hypoplasia of talus

Question 14

Varus TI may be a result of

Answer 14

• tibial varum

- Genu varum

Question 15

Tibial Varum

Answer 15

• bowing of the lower 1/3 of the leg (inadequate ontogenous change )
• pathiphysiological bowing (rickets, etc)
• hypoplasia of medial tibial epiphysis

Question 16

compensation

Answer 16

The way body responds to a deformity or abnormal function

Question 17

How many forms of compensation?

Answer 17

• compensated
• partially compensated
• uncompensated
• overcompensated

Question 18

compensated

Answer 18

GRF are equal across the STJ axis, plantar aspect of the heel and plantar aspect of the foot

Question 19

Partially compensated

Answer 19

• at end ROM , a fully compensted position is unable to reached
• GRF are unable to equialized

Question 20

uncompensated

Answer 20

No motion has occurred to provide compensation

Question 21

Overcompensated

Answer 21

Motion has occurred beyond what was required for full compensation

Question 22

compensation is represented by

Answer 22

RCSP

Question 23

What is RCSP?

Answer 23

RCSP represents STJ position as a result of compensation for deformities in all 3 planes

Question 24

Frontal plane deformities examples

Answer 24

Valgus/Varus

Question 25

Sagittal plane deformities

Answer 25

equinus

Question 26

Transverse plane deformities examples

Answer 26

abducted/adducted

Question 27

What are the possible motions for MTJ

Answer 27

- maximally pronated - supinated - maximally supinated

Question 28

what is the compensation for rearfoot varus

Answer 28

STJ pronation will occur until GRF are equal across the STJ /plantar aspect of the heel/plantar aspect of the foot (look at the notes for clarification)

Question 29

what does isolated rear foot varus mean?

Answer 29

it means the only deformity present is rear foot varus

Question 30

compensation of rearfoot varus in an isolated rearfoot varus?

Answer 30

pronation at STJ occurs until the calcaneal bisection is perpendicular to the ground or until the end of ROM , whichever comes first

Question 31

maximally pronated stance position can be determined

Answer 31

using TI and STJ eversion

Question 32

STJ ROM is measured using

Answer 32

leg bisection

Question 33

Maximally pronated stance position formula

Answer 33

maximally pronates stance position = TI-STJ eversion

Question 34

In a fully compensated rearfoot varus defromity RCSP is

Answer 34

0

Question 35

RCSP represent

Answer 35

rearfoot deformity and also compensation at the STJ

Question 36

STJNP

Answer 36

eversion + inevrsion/3- eversion

Question 37

NCSP

Answer 37

STJNP+TI

Question 38

when the RCSP is 0

Answer 38

Fully compensated rearfoot varus

Question 39

Rearfoot valgus

Answer 39

The rearfoot (calcaneus ) is everted with respect to the ground when standing in NCSP

Question 40

Rearfoot valgus is composed of

Answer 40

-STJ valgus and/or -Valgus tibial influence

Question 41

STJ valgus is rare or common

Answer 41

RARE

Question 42

Valgus TI

Answer 42

Genu valgum | Tibial valgum

Question 43

where will GRF be in RF valgus?

Answer 43

GRF will be on the medial side of the foot , medial to the MTJ and STJ axis providing an external supinatory moment

Question 44

How far would the LMJA compensate

Answer 44

LMJA would be able to supinate 4-6º ( end of ROM) to compensate

Question 45

if the rearfoot valgus deformity is more than 4-6º

Answer 45

The STJ may aslo supinate

Question 46

if the LMJA is supinating for compensation, the forefoot

Answer 46

is unstable

Question 47

Any deformity that puts the STJ in an everted position of greater than 5º will force the STJ

Answer 47

to go to the end of range of pronation

Question 48

The more everted the calcaneal bisection to the ground,

Answer 48

the more inverted the forefoot to the rearfoot