1. ALIGNMENT AND FINE TUNING OF AFO’S UTILIZING THE STRATHCLYDE APPROACH AND THE DYNAMIC RESPONSE ANKLE FOOT ORTHOSIS
By: Davin Heyd CO

2. Our industry is on the advent of a Paradigm shift on a couple of fronts
Research proven techniques
Objective outcomes – pay for performance will be reality

3. Our focus has been wrong!
Too much attention on achieving 90 degrees at the ankle
Not paying attention to the foot biomechanics and their alignment
Not looking at the entire body too much individual segment focus
Forcing everything!

4. We must re-assess our approach
There is not a supporting body of evidence w regards to our historical approach to LE management
In fact, research show that 90 neutral is actually unstable and detrimental if we are forcing that Alignment
Owen 2008, Webber 1990/91

5. Now!
use what the patient has, Align, relax, control, and balance our patient to the floor.
This is a completely new approach

6. Structure Modeling until bone maturation infancy-14 years for girls
Infancy-16 years for boys
“Prevent over-stretching of ligaments.”
Deformation of bone modeling

7. Structure
Effective stretch to gastroc-soleus complex occurs when subtalar and midtarsal joints “ARE” properly aligned.

8. Structure Interdependent on each other
Talus Alignment : the alignment of the talus requires effective mechanical base levers.
Hindfoot alignment (stabilize subtalar jt.)
Forefoot alignment (adduct midtarsal jt., supination/pronation)
Interdependent on each other

9. Fixed DF angle Caused by tight heel chord
Initial Contact
Fixed DF angle Caused by tight heel chord
Rigid Lever Arm

10. Forward motion and weight dictates end result
Mid-Stance
Forward motion and weight dictates end result
In this case:
destructive collapse at the midfoot
Could also see:
Knee hyperextension
Early heel rise and up on toes ? ?

11. Terminal Stance
Wide stance with abducted forefoot and externally rotated leg
Why?
Shorten the lever arm to bring the foot through
COMPENSATION!

12. FORCE NOTHING! Tardieus 1987
Warned against precipitating painful spasm by over stretching the muscle fibers in the coarse of casting
Excessive elongation, particularly at high rate, can produce soft tissue strains or complete rupture
David S. Butler 1991
Nerves become embedded in tonically – recruited muscles so when the muscle is forcefully stretched so is the nerve contributing to the spasms

13. Physical Assessment Determining functional ROM Calcaneal Alignment.
Determine Forefoot alignment to attain vertical heel
Determine first Catch / R1

14. OWEN 74 Children independent ambulators in AFOs
Prescription tuned on video vector generator gait laboratory
Ankle angle (PF,DF, or Plantar-grade) did not effect end result
All ended up being tuned to an inclined angle – 8-14ْْ
Alignment produced stability in both Normal and Pathological gait
Centers knee joint directly over the middle of the foot
Author suggests starting at 10-12ْ

15. OWEN Shank Angle to Floor
Defined : Angle of the shank (tibia) relative to the horizontal surface when standing in AFOs with heels down and weight equally distributed between heel and toe.
Inclined = if shank is inclined forward from vertical
Reclined = if shank is reclined from vertical
Vertical = 0ْْ
*Angle of the Ankle, it refers to: Plantar Flexion, Dorsiflexion, and Plantar grade

16. Perry
Control of the kinematics of the shank (tibia) relative to the vertical is essential in normal gait
Our patients are
here

17. OWEN Gastrocnemius (GN) is a tri-jointed musculotendinous unit (MTU) crossing the knee, ankle and subtalar joint. It reaches its maximal length twice in the gait cycle (GC):
At initial contact, the knee is extended, the ankle plantigrade, the subtalar joint supinated and the MTU has been lengthening passively during terminal swing
At 40% GC in terminal stance (TST), the knee reaches maximal stance extension, the ankle is in some dorsiflexion, the subtalar joint neutral and the MTU is lengthening actively
Passive Stretch
Active Stretch

18. OWEN
Setting the Angle of the Ankle in the AFO (AA-AFO) without regard to the tri-jointed requirements of the GN can result in insufficient length being available to allow knee extension during the GC. In addition, an overstretched GN in TST will reduce the possibility of MTU force production. The lever arm ratio between the ankle and the knee at 40% GC is 3:2, so small changes in the ankle angle are amplified at the knee.

19. Owen
“The Shank Angle to Floor (SAF) measure of an AFO-Footwear Combination is the prime determinant of gait rather than the AA-AFO.” -An appropriate SAF for normal gait can be achieved with a dorsiflexed, plantigrade or plantarflexed AA-AFO. -The use of plantarflexion may be essential. -Using a plantarflexed AA-AFO does not necessarily lead to MTU shortening and may increase MTU length.

20. Utilization of Hinged AFO:
One or more of the “contraindications” or “conditions making hinged AFOs irrelevant” apply in most children with Neurological conditions, so the use of hinged AFOs is limited - OWEN

21. Contraindications: Tendency to mid foot instability (Webber 1990/1991)
Insufficient passive ROM of DF with knee extended (GN length)
Risk of excessive DF at mid stance and terminal stance – insufficient control of the shank by calf muscles - (lack of stability and over lengthening of soleus)
Too much tone to allow normal stance phase ankle DF-incline of shank during 2nd rocker will not occur to over come this inclination of the shank needs to be increased making the hinge irrelavant

22. Functions other than gait:
Squating to play or pick things up
Stair climbing
Sitting and standing up from a chair
Traditionally felt that SA AFOs prevent these functions
If the knee joint is aligned over the center of the foot, it is possible to squat and climb stairs with a SAAFO

23. AFO design An AFO should be designed to provide:
Optimum cutaneous and propreoceptive input through the foot and ankle
Enhance the biomechanics of load bearing joint alignment through the knee and hips during the stance phase of gait, and to thereby
Optimize the postural, weight shift, and movement training process
(Owen 2008, Butler PB et al 2007, Major 1995)

24. AFO design
The key is to not force alignment, and in the case of an equinous deformity, involves acknowledging and accommodating gastrocnemius hypoextensibility in the AFO and posting the AFO and or shoe as needed to influence the alignment and motion of the load bearing segments in order to optimize the GRF and internal moments at the knee and hip joints
Owen 2008, Bowers et al 2008, Meadows et al 2008, Owen 2005

25. The DRAFO System: Designed around a scientifically proven biomechanical analysis process and functional gait

26. DRAFO System
The DRAFO System Mimics gait biomechanics of normal human locomotion –
The 3 foot rockers are incorporated into the orthosis
2nd rocker achieved by Tibial Alignment
Stabilizes and maintains desired alignment without requiring excessive pressure
Plantar aspect functions like a prosthetic foot

27. Allows 1st Rocker at heel strike Achieves Stability at Heel Strike
Calcaneal Wrap
Locks in the Hindfoot
Allows 1st Rocker at heel strike
Achieves Stability at Heel Strike
Sach heel effect
de-accelerator
De-rotator
Propreoceptor feedback
2nd Rocker
Tibial inclination
3rd Rocker
Forefoot design:
Posting designed to have duel function:
Align forefoot
Manipulate terminal stance
Allows for functional 3rd rocker

28. Standing Alignment Alignment of the center of gravity
So that the weight line goes
through the center of the knee
Which centers over the
middle of the foot provides the
Optimum balance alignment for
both “normal and Pathological”
Gait
Stable alignment
Unstable alignment

30. Validation: Outcomes Measures WHY???
How do we know what we are doing really does what we say it is doing?
Outcomes Measures
WHY???
Hospital Contracts
Insurance Contracts
Institutional Mandates
Prevent misconceptions
State/Federal Mandates
SPARG
Medicare
Everybody else is doing it

31. Practical Outcome Measures
10MWT
6mWT (2mWT)w Heart rate
Standing stability (ABC)
Pediatric Balance test
AOS
Dynamic gait index
Time required
maximum of 15 minutes
Items needed
Stop watch, tape measure, tape
Validation for: Patient, Practitioner, and Reimbursement Resources

32. Thank You