L4: TFA Rehab and Prosthetic Feet Flashcards
1
Q
OBJECTIVES:
A
- ID and special considerations and barriers during rehab of pts w/ a TFA
- Understand the proper alignment and fit of various transfemoral prosthetics to maximize gait and function
- Understand the concept of the TKA line and how its location effects each individual LE joint and subsequent control of the transfemoral prosthetic devices
- ID various prosth. foot components and the advantages and disadv’s of each
2
Q
Prosth. Feet
Classifications:
A
-
NON-articulating
- SACH (Solid Ankle Cushioned Heel)
-
Articulating
- Single and Multiaxial (like a joystick)
-
Elastic Heels
- SAFE (Stationary Ankle Flexibility Endoskeletal)
-
Dynamic Response or Energy Storing
- Seattle
- Flex Foot
- Carbon Copy
3
Q
Dead giveaway for the Multi-Axial foot
A
O-Ring
4
Q
This is the foot they have on at first
A
SACH foot
Solid Ankle Cushioned Heel
5
Q
SACH Foot
*Non-articulating foot
ADVs vs. Disadvs
A
- ADVs
- NO moving parts: durable→ little maint.
- Excellent for shock absorb.
- Low $
- Good for temporary prostheses
- Disadvs
- Lack of flex.→ partic for uneven surfaces
- NOT approp. for incd rates of walking or active indiv’s
6
Q
Good foot for temp. prosth.
A
SACH
*also good shock absorb
7
Q
Single Axis Feet
A
-
Allow 15degs PF (CC)
- compress of rubber bumper post. to axis of prosth.
- rate of PF controlled by bumpers density in LR
-
Allow 5-7degs DF (CC)
- anterior bumper compress. slowing forward mvmt of prosthetic shank
- Incd sag. plane motion
8
Q
Single Axis Feet
Allows _______ degs PF (CC)
Allows _____degs DF (CC)
A
15degs PF
5-7degs DF
9
Q
@ what stage of gait is at leas 5-7degs DF MOST needed?
A
MSt→TSt
ECC closed chain DF controlling tibia moving on fixed foot
10
Q
Single Axis Feet
ADVs vs Disadvs
A
- ADVs
- Stable foot flat pos. earlier in stance
- INCd knee stability reducing knee flex moment
- moves wt. line ANT quicker– less likely to buckle
- Quick adjs to durometer (compression of bumpers)
- Disadvs
- Heavier vs SACH
- more parts=more repairs
11
Q
Multi-axis/Articulating Designed Feet
**Inv/Eversion→ computerized OR split toe foot
A
- Bumpers BUT allows for motions in transv and coronal (frontal) planes→ In Add. to sagittal
- Incd inversion, eversion, rotational motion and control
- → better accommodation to changing walk surf’s
- Allows foot to absorb torque forces that would normally translate proximally to RL
12
Q
Mulit-Axis Feet
*think more Inv/Ev and Rotation — absorbs forces
ADVs vs Disadvs
A
-
ADVs
- Accommodate to changing terrain
- Reduce torque forces to RL
- Quick adj. to durometer to accommodate indivs wt and function lvl
-
Disadvs
- LESS stable vs nonaxial
- **More deg of freedom===LESS stability
- More parts=more maint.
- heavier
- LESS stable vs nonaxial
13
Q
Rule of Thumb:
MORE degs of freedom======
A
LESS stability!!!!!
14
Q
Elastic Keel Feet
A
- Elastic keel gradually incs tension from heel strike thru MSt to push-off
- *similar to anatomical feet
- Foot loaded in TSt, inc’ing tension on “plantar bands” placed in keel— creates rigid lever for smooth trans. to swing
15
Q
Elastic Keel Feet
*think “Plantar bands” one!
ADVs vs Disadvs
A
-
Adv’s
- SMOOTHER gait pattern bc no mech. rocker motions during Stance
- Flex. of keel eases tasks like stair negot. and inc walking
- Simple design
-
Disadvs
- “spongy feel” → not liked by more active users
16
Q
Prosthetic feet usually progress to THIS….
A
Dynamic-Response Feet
17
Q
Dynamic-Response Feet
A
-
Need to absorb and store forces during Loading and release these forces in PSw/push-off
- running/jumping
- Mats used in keel combined stiff and flex.
-
Stiffer keel=== LOSS of inv/ev.
- split toe advancements
-
More force on forefoot (running)== greater the material compresses === more energy is stored
- Carbon-graphite material
18
Q
What is crucial for prosth. foot Rx???
A
PLOF!!!
What are they going to be doing? Where? Prev activity lvl???
19
Q
Dynamic-Response Feets
Advs vs. Disadvs
A
-
ADVs
- BEST option for high demand acts.
- Accommodates quickly to changing grades of terrain and speeds
- Made to order specific to user
-
Disadvs
- Mat. used to make foot stronger often produces feeling of being stiff and unaccommodating
- $$$
20
Q
Dynamic-Response Feets
VIDEOS!!!
A
SEE VIDEOS WHEN STUDYING!!!
SLIDE 16
21
Q
Prosthetic Feet→ Role during Stance phase
Initial Contact
A
Absorb shock*
22
Q
Prosthetic Feet→ Role during Stance phase
Initial Contact
Cushioned heel→ SACH
Softer heels vs. Firmer heels
A
Role→ absorb shock
-
Softer heels
- lighter pts
- allows quicker foot flat stability
- more knee stability
-
Firmer heels
- heavier pts
- slows transfer of wt. midfoot and forefoot
23
Q
Prosthetic Feet→ Role during Stance phase
Initial Contact
A
*Absorb shock
- Compression of heel simulates ecc. contract. of DF towards foot flat
- Provides for a normal knee flex moment as gait progresses to LR
24
Q
Prosthetic Feet→ Role during Stance phase
Midstance
A
*Accommodation of terrain
25
Prosthetic Feet→ **Role during Stance phase**
## Footnote
**_Midstance_**
\*accommodation of terrain
* Accomplished to varying degs by **diff types of ankle-foot componentry:**
* non-artic, single-axis, multi-axis, etc..
* **Transition from PF→ DF as shank/pylon moves over a _fixed foot_ (ankle rocker)**
* Accomplished in prosthesis by **flex. of keel**
26
Prosthetic Feet→ **Role during Stance phase**
**_Midstance_**
Transition from PF to DF moving over fixed foot (ankle rocker)
**Accomplished in prosth. foot how?**
Flex. of keel
27
Prosthetic Feet→ **Role during Stance phase**
## Footnote
**_Terminal stance to Preswing_**
* Provides **simultaneous TSt support and toe rocker moment w/ _flexible keel_**
* Reduces force to **sound side** aiding in **balance and smooth transfer of wt.**
* Control of **heel rise (TSt)** during the **toe rocker in TSt** and **progression onto forefoot**
* see other card how this accomplished\*\*\*\*
* Depending on material and/or energy storing capability of material in foot **is how eff. push-off is**
* Sligh **spring action** that simulates **rapid knee flex (**limb shortening during PSw)
28
Prosthetic Feet→ **Role during Stance phase**
**Tst→PSw**
Control of heel rise during the **toe rocker in TSt** and **progression onto forefoot**
**How is this accomplished in prosth. foot?**
\*Accomplished by **LENGTH of keel**
* **Keel too SHORT→** EARLY heel rise and PREMATURE knee flexion (**buckling)**
* **Keel too LONG→** DELAY heel rise and knee EXT moment occurs
29
Control of heel rise during toe rocker in TST and progression to forefoot
## Footnote
**If Keel too SHORT ===**
EARLY heel rise
Premature knee flex.
\***Buckling**
30
Control of heel rise during toe rocker in TST and progression to forefoot
## Footnote
**If Keel too LONG**
DELAY in heel rise
Knee EXT moment
31
Prosthetic Feet: **Role during Stance Phase**
## Footnote
**SACH foot and heel compression**
**IC→ MSt**
Durometer (resist. to compression) of heel cushion
32
Prosthetic Feet: **Role during Stance Phase**
## Footnote
**Single axis foot**
**IC→LR**
Durometer of heel and PF stop or bumper
33
Prosthetic Feet: **Role during Stance Phase**
## Footnote
**Single Axis Foot**
**LR→TSt**
DF bumper and firmness of keel
34
**Medicare→ Prosthetic Feet**
**K-lvls**
\*REMEMER ALL CHILDREN ARE K4'S!!!!!!!!!!
35
Prosthetic Feet
## Footnote
**Medicare K-lvls**
**K0**
**Nonambulatory**
* Cannot ambulate or transfer safely w/out assist.
* Prosth. does not enhance QoL or mobility
* Components: NONE
36
Prosthetic Feet
## Footnote
**Medicare K-lvls**
**K1**
**Lmtd or unlmtd household ambulation**
* Can use prosth. for transfers or ambulation on LEVEL surfs @ fixed cadence
* Components:
* SACH
* Single Axis
37
Prosthetic Feet
## Footnote
**Medicare K-lvls**
**K2**
**Limited community ambulation**
* Can traverse LOW lvl environmental barriers such as curbs, stairs, uneven surfs
* Components:
* SACH
* Flex (elastic) keel
* Single Axis
* Multi-axial
38
Prosthetic Feet
## Footnote
**Medicare K-lvls**
**K3**
**Community Ambulation**
* Can amb. w/ variable cadence and traverse MOST environmental barriers.
* Has vocational, therapeutic, or ex. activities that demand prosth. use beyond simple loco.
* Components:
* SACH
* Flex (elastic) keel
* Single axis
* Multiaxial
* Energy storing (dynamic resp.)
39
Prosthetic Feet
## Footnote
**Medicare K-lvls**
**K4**
**\*all children/athletes are K4!!!**
**Higher Activity**
* Child, active adult, or athlete who exceeds basic amb skills including high impact, stress, or energy lvls
* **Components:**
* Any foot approp. for the indiv's activity lvl
40
What happens if a TTA, non-articulated foot gets measured for a ¾ inch heel **but wears a 2in heel while @ work?**
## Footnote
**@ Knee joint angle and muscle activity?**
* Knee joint angle→ **Flexion**
* Muscle activity→ **more quads to offset flexion**
41
What happens if a TTA, non-articulated foot gets measured for a ¾ inch heel **but wears a 2in heel while @ work?**
## Footnote
**@ Hip joint angle and muscle activity?**
* Hip joint angle→ **Flexion**
* Muscle activity→ **More glutes to offset flexion**
42
Rule of thumb:
## Footnote
**Pylon must ALWAYS be what?????**
VERTICAL TO GROUND!!!
43
Heel ht changes and effect on knee
## Footnote
**Most prosth feet designed for \_\_\_\_\_\_\_**
Standard ¾ in heel
44
Heel ht changes and effect on knee
## Footnote
**DEC heel height does what????**
* Creates EXT moment @ knee
* Leads to **excessively stable knee**
45
Heel ht changes and effect on knee
## Footnote
**INC heel ht does what????**
* Creates **FLEX moment @ knee**
* **Leads to INstability of prosth. knee**
46
Heel ht changes and effect on knee
## Footnote
**Special prosth. feet made esp. for shoes w/ high heels\*\*\*\***
see pics
47
Prosthetic Feet
## Footnote
**Connection bw ____ and \_\_\_\_\_**
Prosth. and ground
48
Prosthetic Feet
## Footnote
**Classified by \_\_\_\_\_\_\_\_\_**
Motions they allow or simulate
49
Prosthetic Feet
## Footnote
**PT provides ________ and _____ to prosthetist**
Current lvl of function and goals
50
Prosthetic Feet
## Footnote
**Initial fabrication ("Bench Alignment") designed for _____ to ______ inch heel**
½ to ¾ inch heel
51
Prosthetic Feet
## Footnote
**Advancements in new materials for the keel:**
INCs in **flexibility** and **responsiveness of foot**
52
Prosthetic Feet
## Footnote
**Advancements in _ankle components:_**
Mvmt in **3 planes of anatomical ankle motion**
Sag, Frontal, Transv
53
Prosth. Feets Examples
see pics and types
54
Prosthetic feet
## Footnote
**NEW GENERATION VIDEOS!!!**
See vids slide 27
55
Knee Stability: **TFAs**
**3 factors that _influence knee stability_ during _Stance:_**
1. **Individual, volitional control using _muscular power_**
1. Ex. **Hip EXT IC→ MSt**
2. **Alignment of knee jt** w/ respect to **wt. line**
3. Inherent **mech. stability of knee unit** chosen
56
Knee Stability
## Footnote
**Ideally, alignment of 1.\_\_\_\_\_\_\_, 2.\_\_\_\_\_\_\_, 3.\_\_\_\_\_\_\_ is one that allows individual to optimally use muscle w/ min. amt of alignment stability and still consistently stabilize knee**
1. Socket
2. Knee
3. Ankle
\***Tradeoff bw/ _stability_ and _mobility_ w/in design**
57
Trochanteric Knee Ankle (TKA) Line: **Prosthetic term**
## Footnote
**A TKA line that passes _IN FRONT OF KNEE JOINT AXIS:_==\>**
Inherently **STABLE** Knee
* Incs **EXTRINSIC** knee stability (**bench alignment bias)**
* LESS **muscle (quads)** needed
* LESS **responsive knee during stance**
* **Indicated for those w/ SHORTER RLs, poor mm control, K1/K2's**
58
Trochanteric Knee Ankle (TKA) Line: **Prosthetic term**
## Footnote
**A TKA line that passes _IN FRONT OF KNEE JOINT AXIS:_==\>**
**Indicated for who?**
Inherently STABLE knee
* **Indicated for those w/ SHORTER RLs, poor muscular control, K1/K2's**
59
Trochanteric Knee Ankle (TKA) Line: **Prosthetic term**
## Footnote
**A TKA line that passes _IN FRONT OF KNEE JOINT AXIS:_==\>**
**TKA-Anterior**
see pics and EXPLAIN
60
What is the **Bench Alignment?**
Initial design of prosth.→ how its given to the pt @ first
“Shoe right off the shelf”
61
Trochanteric Knee Ankle (TKA) Line: **Prosthetic term**
## Footnote
**A TKA line that passes _BEHIND THE KNEE JOINT AXIS:_==\>**
Higher lvl patient
* LESS stable and **more mm req.**
* EASIER transition to flexion reqd during swing
* **more resp. into/out of subphases**
* **_Timing of mm contraction_→ more important**
* **Indicated for:** those w/ good strength, proprio, longer RLs
62
Trochanteric Knee Ankle (TKA) Line: **Prosthetic term**
## Footnote
**A TKA line that passes _BEHIND THE KNEE JOINT AXIS:_==\>**
**Indicated for?**
Higher lvl patient
* Good strength, proprio, LONGER RLs
63
TKA Line **ANTERIOR**
## Footnote
**Think….**
* MORE stable
* SHORTER RLs
* Less mm control needed
* K1/K2
64
TKA Line **POSTERIOR**
## Footnote
**Think….**
* HIGHER lvl pts.
* LONGER RLs
* LESS stable, MORE mm requirement
65
TKA Line:
**_Length of RL_ and the resultant weight line determines the _mechanical knee adjustments_ (Ex. inc resistance in hydraulic or pneumatic knees) required:**
**SHORTER vs LONGER RLs**
* SHORTER RLs== **LESS intrinsic control==MORE resistance @ knee**
* LONGER RLs== **MORE intrinsic control==LESS resistance @ knee**
66
TKA Line:
## Footnote
**_Length of RL_ and the resultant weight line determines the _mechanical knee adjustments_ (Ex. inc resistance in hydraulic or pneumatic knees) required:**
**SHORTER RLs**
SHORTER RLs== LESS intrinsic control==MORE resist. @ knee
67
TKA Line:
## Footnote
**_Length of RL_ and the resultant weight line determines the _mechanical knee adjustments_ (Ex. inc resistance in hydraulic or pneumatic knees) required:**
**LONGER RLs**
LONGER RLs==MORE intrinsic control==LESS resistance @ knee
\***bc longer RL they have _more control of knee_!!!**
68
TKA Line
\_\_\_\_\_\_\_\_\_**relationship bw RL length and amt of muscular force needed to control prosth. knee**
INVERSE RELATIONSHIP
\***Longer RL== less amt mm force**
\***Shorter RL== More mm force**
Ex. Hip EXT w/ shorter RL
69
TKA Line
## Footnote
**Distinct ADVANTAGE for knee control w/ _____________ and \_\_\_\_\_\_\_\_\_\_\_\_\_**
LONGER RLs and Knee disartics
\***Longer lever arms _closer_ to knee jt. axis**
70
TKA Line:
## Footnote
**Shorter RLs req. TKA to be ________ to knee or Prosth. knee units w/ HIGH __________ (i.e hydraulic or pneumatic)**
ANTERIOR to knee (**bias towards more _stability);_**
Knee units w/ **high mechanical stability**
71
Shorter RLs
just think you NEED more what?
STABILITY!!!!!! bc they have LESS mm control
72
Initial **transfemoral socket** design set in _________ degrees of **flexion** to pre-set hip EXTs and **minimize anterior pelvic tilt (lordosis) compensation**
5 degrees
\***See pics of design for shorter RL/longer RL vs normal**
73
Shorter RLs typ have _________ prosth control and require (bench) alignment of knee axis to be placed _________ relative to wt. line
DECREASED; ANTERIOR
74
Knee Stability:
**2 extremes of mechanical (extrinsic) knee stability:**
1. Manually locked knee w/ ultimate mech. stability
2. Single axis knee (unlocked/free swinging) w/out any stability
75
Knee Stability:
**2 extremes of mechanical (extrinsic) knee stability:**
1.**Manually locked knee w/ _ultimate mech. stability_**
**Where does mobility come from?**
**Is alignment of knee important still?**
* Mobility comes from **hip**
* Alignment **not important** if **locked**
76
Knee Stability:
## Footnote
**2 extremes of mechanical (extrinsic) knee stability:**
**2.Single Axis knee (unlocked/free swinging) _w/out any stability_**
**Where does stability come from?**
Hip, mechanical ankle
77
Knee Stability:
## Footnote
**2 extremes of mechanical (extrinsic) knee stability:**
**Where do hydraulic and wt. activated knees fall on the _mechanical stability continuum?_**
More dynamic==More freedom
78
Pelvic Stability: **Quadrilateral socket**
## Footnote
**Most stabilization in \_\_\_\_\_\_-\_\_\_\_\_\_\_ direction w/ little to keep femur from drifting laterally**
Ant-Post direction
79
Pelvic Stability: **Quadrilateral socket**
## Footnote
**Most stabilization in Ant-Post direction w/ little to keep femur from drifting laterally**
**What happens @ pelvis as a result?**
Causes pelvis to **drop** when **intact limb is in _swing phase_**
**\*Trendelenberg→ hip drop away from prosth. side**
80
Pelvic Stability: **Quadrilateral Socket**
## Footnote
**Most stabilization in A-P direction w/ little to keep femur from drifting laterally**
**Causes pelvis to drop when intact limb in Sw phase (Trendelenberg)**
**To _compensate_, what does amputee do?**
Amputee will **lurch laterally _towards_ prosth side (opp of Trendelenberg)** to improve control inside socket and clearance of intact side (**during prosth. stance/single limb support phase)**
81
Pelvic Stability: **Quad socket**
## Footnote
**Most stabilization in A-P direction w/ little to keep femur from drifting laterally**
**Causes pelvis to drop when intact limb in swing (Trendelenberg)**
**Pt will compensate by lurching laterally _towards prosth._ side to improve control inside socket and clearance and clearance of intact side (during prosth.stance/single limb support phase)**
**What ensues?**
**How are these issues corrected?**
* Widened BOS and high energy cost ensues
* **These issues are corrected w/ IRC socket→** holds femur in a _normally ADD'd position_ in stance allowing for:
* **Lvl pelvis**
* **Improved qual of gait**
82
IRC socket holds femur in ________ position
Normally ADDucted position
83
used to correct Trendelenberg and compensations of Trendelenber in Quadrilateral socket
IRC socket
84
TFA: **Gen Prosthetic Considerations**
## Footnote
**Most important influence on functional outcomes and return to IND is the _____ and _____ of socket fit\*\*\***
quality and comfort
85
TFA: **Gen Prosthetic Considerations**
## Footnote
**Quality and comfort of socket fit\*\*\***
**Must comfortably what?**
* Contain **all soft tissue in sitting and standing**
* Provide **adeq. relief for bony prominences**
* Distribute **stabilizing pressures equally**
* Provide **adeq. WB surface** for the **ischial/gluteal region\*\*\***
86
TFA: **Gen Prosthetic Considerations**
## Footnote
**Donning prosth must involve**
**Educating** Pt. AND family
87
TFA: **Gen Prosthetic Considerations**
**Too many cotton plies….**
Talk about this…
* **Too MANY (cotton) plies (RL too thick) → RL will NOT fully descend into socket\*\***
* **Too FEW and limb will descend too far**
* == incd distal pressure/pain OR **medial socket pressure in groin**
## Footnote
**\*\* remember we want TOUCHING but NOT WB!!!**
88
TFA: **Gen Prosthetic Considerations**
## Footnote
**Suction suspension**
More skill involved
* Before valve is replaced must have **total skin contact**
* **Finger in valve to check where limb is\*\*\***
89
TFA: **Gen Prosthetic Considerations**
## Footnote
**Biggest obstacle**
Fluctuating edema/volume
\*inconsit. fit
\*alters quality of gait
90
TFA: **Gen Prosthetic Considerations**
## Footnote
**Convince pt.**
Convince pt. to be faithful w/ pressure/volume mgmt @ home w/ **shrinkers, wrapping.. etc**
## Footnote
**\*for fluctuating edema/volume**
91
TFA: **Gen Prosthetic Considerations**
First few mos w/ no prosth. donned
Use of a **shrinker or elastic wrap CRUCIAL!!!**
\*For fluctuating edema/volume
92
TFA: **Gen Prosthetic Considerations**
## Footnote
**Proper _total contact fit will:_**
* Distribute **socket forces** equally
* Reduce **pressure** over bony proms.
* Promote **venous return**
* Aid in **control** of **edema**
93
TFA: **Gen Prosthetic Considerations**
## Footnote
**Consider SHORTER RLs!**
* Present **suspension probs**
* Result in **DECd Control** of **prosth. knee (Stance)**
* INCd **energy expenditure**
94
TFA: **Gen Prosthetic Considerations**
## Footnote
**Sitting:**
More important to **most TFAs than standing or walking!!**
* **Lower Ant. rim (IRC vs. Quad socket)**
* **Must be able to flex to 90degs @ hip**
* **Standing ← → Sitting will cause _change in negative pressure_**
* MINMIZED by **iso. contraction of the thigh expanding the mm's to maint. negative pressure gradient**
95
\*\*\*TAKE HOME MESSAGE:
* WHO is wearing prosth?→ PLOF, etc.
* What are the GOALS of the pt?→ keep them involved
* What is there OCCUPATION?→ sitting? standing?
* What are there HOBBIES/ACTIVITY LEVEL?
* What is their PERSONALITY?
* **The Ideal Prosthetic Foot:**
* “Looks and feels good”
* Allows for **efficient walking on varying surfs.**
* Achieves an **equal step length** of **both amputated AND intact limbs**
96
VIDEO REVIEW!!!!!!
SLIDE 49\*\*\*\*\*
