Pathology Specific Orthoses Evidence Based Orthotic Therapy: Functional Hallux Limitus Orthotic Therapy for Hallux Valgus and Hallux Rigidus Lawrence Z. Huppin, DPM California School of Podiatric Medicine at Samuel Merritt College
Functional Hallux Limitus Lack of Big Toe Joint Dorsiflexion A Pathology that Can Lead to Pain and Deformity Hallux Rigidus Hallux Valgus Associated with Increased Plantar Fascial Tension and Plantar Fasciitis
Deformity / Result vs. Pathology Deformity / Result Hallux Valgus / Hallux Rigidus, Plantar Fasciitis Pathology Functional Hallux Limitus Where Should Treatment Be Directed?
First Ray Must Plantarflex for Normal 1 st MPJ Function
Functional Hallux Limitus Etiology Increasing Force Under 1 st Metatarsal Significantly less hallux dorsiflexion when the first ray was dorsiflexed by increasing force under first metatarsal head Ground Reactive Forces Against the 1st MPJ Will Prevent 1st Ray Plantarflexion Lack of First Ray Plantarflexion will Cause Limitation of Big Toe Joint Dorsiflexion. 100% of subjects, dorsiflexion is decreased Roukis, et. al. Position of the first ray and Motion of the First MTP. 1996 JAPMA. Vol 86:11
Windlass Function Blocked by Forces Driving the First Ray Up First Ray Prevented From Plantarflexing Hallux Not Able to Dorsiflex Plantar Fascia Tension Increases First MPJ Compression Increases
Functional Hallux Limitus Etiology What foot types cause increased force under the first metatarsal head?
Foot Types That Increase Medial Forefoot Force Everted Calcaneus Everted Forefoot Plantarflexed First Ray Flexible Forefoot Valgus
Foot Types That Increase Medial Forefoot Force Everted Calcaneus
Rearfoot Eversion and Hallux Dorsiflexion Eversion of the Rearfoot will lower the maximal hallux dorsiflexion No Wedge: 85.91 3 Wedge: 68.23 5 Wedge: 58.80 First Ray Dorsiflexion Hallux Dorsiflexion Decreased Harradine, Bevin: The Effect of Rearfoot Eversion on Maximal Hallux Dorsiflexion; 2000
Foot Types That Increase Medial Forefoot Force Everted Forefoot Plantarflexed First Ray Flexible Forefoot Valgus Both Load the First Ray Sooner and with Greater Force
So What? Now That We Know the Etiology of Functional Hallux Valgus, What Can We do for the Patient? Hallux Rigidus Hallux Valgus
Prescribing Orthoses for Functional Hallux Limitus Bring First Ray Down When Casting Orthosis must maintain contact with foot Reduce Rearfoot Eversion Support Everted Forefoot Deformities Decrease Force Under Medial Forefoot Enhance First Ray Plantarflexion
Casting Technique to Treat Functional Hallux Limitus Subtalar Joint Neutral Mid-tarsal Joint Locked Capture Valgus Forefoot Deformity Plantarflex the First Ray
Casting Technique to Treat Functional Hallux Limitus Plantarflex the First Ray
Casting Technique to Treat Functional Hallux Limitus Plantarflex the First Ray and / or Dorsiflex the Hallux
What Happens If You Don t Plantarflex the First Ray When Casting? Excess Varus Captured in Negative Cast Excess Varus Captured in Positive Cast
What Happens If You Don t Plantarflex First Ray When Casting? Excess Varus Captured in Orthosis Greater Talar Tilt Bad Cast/Orthosis Lower Calcaneal Inclination First Ray Dorsiflexion No Orthosis Functional Hallux Limitus Good Cast/Good Orthosis
What Happens If You Don t Plantarflex First Ray When Casting?
The Orthotic Prescription Material Size - Width and Heel Cup Depth Positive Castwork Posts Top Cover Forefoot Extensions Special Additions
Shell Material
Reduce Rearfoot Eversion if Necessary 22 x
Maintain Close Arch Contact Evaluate your orthoses
Physicians and laboratories often fail to achieve close contact 3
Decrease Force Under the Medial Forefoot Reverse Morton s Extension x
Cluffy Wedge
Our Prescription: 160 lb man. Pain in 1st MPJ with running. Mild dorsal exostosis. 3 degrees everted Casting: First Ray Plantarflexed Material: Semi-rigid Polypropylene Width: Wide Heel Cup Height: 18mm Positive Cast Modifications: 4mm Medial Heel Skive 4 degrees inversion Posting: 0/0 Rearfoot Post Covers: EVA to Sulcus. Glued Posterior Only Accommodation: Reverse Morton s Extension Shoe: Brooks Addiction VI
Studies Influence of functional orthoses on the ROM in stance and gait of the first MTP joint Stance Gait
Stance Study Methods: 27 Subjects N= 49 feet 11 males 16 females Greater than 50 dorsiflexion NWB* Less than 14 dorsiflexion in stance * No trauma/arthritis Weight Max= 285 lbs. Min= 105 lbs. Ave= 167 lbs. Heel Position 5 inverted 4 perpendicular 40 everted Ave. heel eve= 5.6 * Study definition of Functional Hallux Limitus
WB goniometer measurement Casted with 1 st ray plantarflexed Poly functional- min fill 2mm Kirby skive 14 mm heel cup Wide width Rear post 4/4 Materials
RESULTS Weight bearing dorsiflexion without orthosis Greatest DF= 14 Least DF= 4 Mean DF= 9.8 Weight bearing dorsiflexion with orthosis Greatest DF= 28 Least DF= 12 Mean DF= 18.6
Results: Percentage (%) increase of DF 49 feet ALL increased the ROM of 1 st MTPJ 8/49 or 16% more than 200% ROM 19/49 or 39% more than 100% ROM 42/49 or 86% more than 50% ROM 49/49 or 100% more than 10% ROM Greatest increase= from 6 to 28 Least increase= from 12 to 14
Data Summary Dorsiflexion Motion Mean Weight bearing (no orthotic) 9.8 Weight bearing (with orthotic) 18.61 Ave. Degree Increase in DF 8.78 Ave. % increase 109%
Gait Study Methods: 18 Subjects N= 36 feet 8 males 10 females Greater than 50 dorsiflexion NWB* Less than 14 dorsiflexion in stance * No trauma/arthritis Weight Max= 280 lbs. Min= 105 lbs. Ave= 160 lbs. * Study definition of Functional Hallux Limitus
Tekscan/F Scan 7 steps- removed 1 st and last steps Hallux evaluated for maximum pressure from heel lift to toe off
Assumption Decrease in hallux pressure at heel off = increase in 1 st MTPJ motion Greater 1st MTPJ motion = less pressure under hallux
Without orthotic With orthotic Tekscan
Without orthotic With orthotic Tekscan
RESULTS Hallux peak pressures Without orthotics Greatest = 27.92 PSI With orthotics Greatest = 27.02 PSI Least = 9.06 PSI Least = 8.33 PSI Mean= 18.50 PSI Mean= 15.85 PSI
RESULTS Decrease in hallux pressure Greatest 10.38 PSI (49%) Least 0.31 PSI ( 2%) Mean 2.65 PSI (14.7%)
Results: Percentage (%) decreased hallux pressure 36 feet ALL decreased hallux pressure at heel lift 2/36 or 6% more than 30% 7/36 or 19% more than 20% 23/36 or 64% more than 10% 29/36 or 80% more than 5% Greatest decrease 49% Smallest decrease 2% Average decrease 14.7%
Summary In the first study, with the use of the orthotic during stance, hallux dorsiflexion was increased an average of 109% In the second study, with the use of the orthotic in gait, sub-hallux pressures were reduced an average of 14.7%.
Take Home When the first ray can t plantarflex, the big toe won t work but you can make it work better with the correct orthosis
Take Home Plantarflex the first ray when casting Positive cast not overfilled Prescribe to prevent rearfoot eversion Prescribe to decrease force under the first metatarsal head Stable Shoes
ProLab Orthotics / USA