L4 Part 1: Functional Foot Orthoses (FFOs) Flashcards
Objectives: Make sure you know them ALL!!!
aka Exam Items***
1. Define functional foot orthosis (FFO)
- Define goals and mechanisms of FFOs based on Root’s theories
- Describe 5 criteria for abnormal pronation
- Understand how orthotic rx relates to presence, or absence, of compensatory motion
- Describe the basics of foot orthotic rx, including materials, length, supplemental materials, and wear schedule
- Compare and contrast custom and prefab’d foot orthoses
- Rx in-shoe orthoses for common foot pathos, such as Rearfoot Varus and Forefoot Varus
**SEE CASES IN CANVAS-THERE’S 2!!!!!!!
Functional Foot Orthosis (FFO)
Defined:
*Know underlined stuff!!!!
- Orthopedic device designed to promote structural integrity** of joints of the foot and lower limb by **resisting the GRFs** that cause **abnormal skeletal motion** during the **stance phase of gait
- Theory→ control motion==> DEC pain
A functional foot orthosis is an ortho device designed to __________ of the joints of the foot and lower limb by _________ that cause _________ during the _____ phase of gait
- Promote structural integrity
- Resisting the GRFs
- Abnormal skeletal motion
- Stance
Primary Goal of FFO:
*know _underlined stuf_f!!!
CONTROL abnormal foot functioning during stance
Mechanisms of a FFO: How does it work to control abnormal foot function?
3 things it DOES DO:
- Controlling excessive STJ and MTJ motion
- DEcelerating pronation
- *think post-tib
- Allowing STJ to function closer to its neutral position @ MSt
Mechanisms of an FFO:
3 things it DOES NOT DO:
- Do NOT support the MLA
- Do NOT provide cushioning and shock absorb.
- Do NOT adhere to the outside of a shoe
Conceptual Framework of a FFO
STN position→ according to Root:
- Pt of maximal congruence in articulation of talus and navicular
- Minimizes stress to surrounding tissues
- @ IC→ most eff. pos. for mm function and attenuation of impact forces
- Point where foot converts FROM mobile adapter TO a rigid lever
- *just BEFORE TSt when STJ is neutral and MTJ is fully locked
Conceptual framework of FFO is based on ___________
Normal alignment
“Normal” Alignment
According to Root
In loaded STN position
what does this look like/entail?
- Bisected lower leg is parallel w/ bisected calcaneus
- Plane of metatarsal heads perpendicular to bisected calcaneus
- Distal ⅓ of lower leg perpendicular to floor
Real-life challenges to operating under assumption that STN Pos=”Normal” alignment?
Pronation is important for adapting to surfaces, so diff to maintain “normal” STN pos.
What is “Normal” Pronation values?
4-6 degs
5 Criteria for Abnormal Pronation:
IMPORTANT!!!!!
- STJ pronation > normal 4-6degs
- Foot pronates @ wrong time→ disrupts normal seq. of events during CKC motion
- Pronation is recurrent, w/ ea step contributing to repetitive microtrauma to MSK structures
- *post-tib tendonitis
- Pronation happens @ loc. other than STJ
- Unnecessary destructive compensatory motion occurs in other planes of motion of STJ
Summary of FFO Basics
Purpose of FFO?
- Restore normal foot alignment and promote STN pos.
Summary of FFO Basics
In order to decide if pt needs FFO:
Examine foot-ankle alignment and STN position, as well as dynamic gait analysis
REVIEW LEG-HEEL ALIGNMENT TESTING AND STN!!!!!
NORMAL RF varus angle?
0-8 deg.
***KNOW THIS!!!
Normal RF Varus angle is 0-8degs
If they are outside of this…. you want to correct for 50%!!!!
EXAMPLE
If they are at 10degs of RF Varus…. you want to correct for 50% of this…..
So, get them to 5 degrees!!!!!
RF Varus
Describe and pics
- STJ is neutral, BUT RF to leg angle is in varus (towards midline) direction
*NOTE: Normal RF varus== 0-8degs
RF Valgus
Describe and pics
- STJ is neutral, BUT RF to leg angle is in valgus (toward lateral) direction
STJ Neutral, but RF to leg angle is in Varus (toward midline)
RF varus
STJ is neutral, but RF to leg angle is in valgus (towards lateral)
RF valgus
If a pt has leg-heel (Rearfoot) VaRus when in STJ neutral, the pt will likely compensate in weight bearing by excessively _________________
PRONATING to get plantar surface of medial side of calcaneus in contact w/ ground (in WB)
Leg-heel RF VaRus… pt excessively PRONATES to get plantar surface of medial side calcaneus to ground (in WB)
This compensatory PRONATION includes 2 other things:
-
Motion @ STJ
- video slide 13
- MAY include motion @ 1st MTJ
- video slide 13
RF Varus compensation
Think….
Excess. PRONATING to get plantar surface of medial side of calcaneus in contact w/ ground
RF VaRus
What would you expect to see during gait if pt did NOT compensate?
Landing on outside border of foot
video slide 14***
Check the shoes!!!!!
Orthotic Rx component
Orthosis Length
Orthotic Rx:
Orthosis Length
3 lengths:
- ¾ length→ shortest
- ends just prox to metatarsal heads
- rearfoot deformity
- Sulcus length→ medium
- ends @ sulcus bw ball of foot/toes
-
Full length→ longest→ reqd for ANY forefoot correction
- distal end of toes
Orthosis length
Use for rearfoot correction
¾ length
Orthosis length
Required for any Forefoot correction*********
FULL LENGTH*******
Orthotic postings for RF and FF Deformities
RECOGNIZE THEM ALL!!!!
SEE PICS
Name the correction
Balanced FF VaRus
Name the correction
Balanced hindfoot (RF) vaRus
*flexible pronating deformity
*posterior view
Name the correction
Balanced Forefoot valGus
