The Foot In Closed Chain

Functional Foot Type Closed Chain Characteristics
By Dennis Shavelson, DPM
Biomechanics Editor, PRESENT Podiatry

As discussed foundationally, each Functional Foot Type(FFT) has a set of characteristics associated with that foot type1-2-3.

Although some of the characteristics may be shared by more than one foot type, there are some (or a group of some), for each of the FFT’s, that characterize that foot type.   The more characteristics of a foot type present in a given patient, the closer that patient is to being a “pure” example of that foot type3. (See figure 1)

This means that beyond the SERM-PERM testing4 for a patient’s FFT, overlaps can be determined which impact the clinical care decisions of patients by analyzing the presenting characteristics of each patient as a starting point to developing a plan for foot type-specific care. 

In addition, as previously discussed, there are concomitant factors, such as weight, activity level, health state, etc. that impact the extent and progression of hallmark characteristics.

Although many patients share the same foot type, variations in closed chain characteristics and concomitant factors make each patient a case of one and well trained and practiced Functional Foot Typers dispensing Foot Centrings are once again finding themselves atop the biomechanical pyramid that Dr. Root placed us on thirty + years ago.

Hallmark Foot Typing Characteristics

X-Ray Presentation

FFT X-ray Characteristics
Rigid/Rigid Img 2
High CIA++++, Bullet Hole Sinus Tarsi ++++, Intact CYMA Line ++++, Low Talo Calc Angle ++++, Lateral STJ Axis ++++, Plantarflexed 1st Ray ++++, Low HAV++++, Low IM++++, Low PASA++++
Rigid/Stable High CIA+++, Bullet Hole Sinus Tarsi +++, Intact CYMA Line ++++, Low Talo Calc Angle +++, Lateral STJ Axis +++, Plantarflexed 1st Ray +++, Low HAV+++, Low IM+++, Low  PASA+++
Rigid/Flexible Img 2
High CIA+++, Bullet Hole Sinus Tarsi +++, Intact CYMA Line ++++, Low Talo Calc Angle +++, Lateral STJ Axis +++, Plantarflexed 1st Ray +++, Low HAV+++, Low IM+++, Low  PASA+++

 

Rigid/Flat High CIA++, Bullet Hole Sinus Tarsi ++, Intact CYMA Line ++, Low Talo Calc Angle ++, Lateral STJ Axis ++, Plantarflexed+ or Dorsiflexed+-++++ 1st Ray, HAV +-++++, IM +-++++, PASA, +-++++,
Stable/Stable Img 2
Normal CIA, Sinus Tarsi, CYMA Line, Talo Calc Angle, Neutral STJ Axis, Neutral 1st Ray, Normal HAV, IM and PASA

 

Stable/Flexible Low CIA+, Closed Sinus Tarsi+, Broken CYMA Line+, High Talo Calc Angle+, Lateral STJ Axis+, Dorsiflexed 1st Ray+, High HAV+, High IM+ and High PASA+
Stable/Flat Low CIA++, Closed Sinus Tarsi++, Broken CYMA Line++, High Talo Calc Angle++, Lateral STJ Axis++, Dorsiflexed 1st Ray++, High HAV++, High IM++, High PASA++
Flexible/Flexible Img 2
Low CIA+++, Closed Sinus Tarsi+++, Broken CYMA Line+++, High Talo Calc Angle+++, Lateral STJ Axis+++, Dorsiflexed 1st Ray+++, High HAV+++, High IM+++, High PASA+++

 

Flexible/Flat Low CIA++++, Closed Sinus Tarsi++++, Broken CYMA Line++++, High Talo Calc Angle++++, Lateral STJ Axis++++, Dorsiflexed 1st Ray++++, High HAV++++, High IM++++, High PASA++++
Flat/Flexible Vertical CIA, Obliterated Sinus Tarsi, Broken CYMA Line++++, High Talo Calc Angle++++, Lateral STJ Axis++++, Dorsiflexed 1st Ray++++, High HAV++++, High IM++++, High PASA++++, Arthritic Changes Rearfoot and Forefoot++
Flat/Flat Img 2
Vertical-Negative CIA, Obliterated Sinus Tarsi, Fixed and Broken CYMA Line++++, High Talo Calc Angle++++, Lateral STJ Axis++++, Dorsiflexed 1st Ray++++, High HAV++++, High IM++++, High PASA++++, Advanced Arthritic Changes Rearfoot and Forefoot++

Pedal Conditions

FFT Foot Conditions
Rigid/Rigid Hallux Rigidus +++, Hallux Malleus, 1=5 Hammertoes, Haglund’s Deformity++++
Rigid/Stable Bunions+, FHL ++, FHE +, 2-5 Hammertoes +
Rigid/Flexible Bunions+-++++, FHL +-++++, FHE, +-++++, 2-5 Hammertoes +-++++, Plantar Fascitis +++, Morton’s Neuroma +++, Met Cuneiform Exostosis +++, Bunionette +++
Rigid/Flat Bunions++++, FHL ++++, 2-5 Hammertoes ++++
Stable/Stable Problems only if patient is overweight, overactive, bunions + late, Plantar Fasciitis +, Bunionette ++
Stable/Flexible Bunions ++, FHL ++, FHE ++, 2-5 Hammertoes, Morton’s Neuroma ++, Met Cuneiform Exostosis ++
Stable/Flat Extremely Rare Foot Type, Surgical Failure, i.e. met primus elevatus postop
Flexible/Flexible PTTD +++, Bunions Late+-++++, Extensor Substitution +-++++
Flexible/Flat PTTD ++++
Flat/Flexible Extremely Rare Foot Type, Surgical failure i.e. valgus producing dwyer postop, PTTD +
Flat/Flat Non Functional, Non Correctable Foot Type, Surgical Salvage Considerations, Low Level Lifestyle
Flat/Flat Non Functional, Non Correctable Foot Type, Surgical Salvage Considerations, Low Level Lifestyle

General Guidlines Rearfoot Alone Forefoot Alone
Rigid
Poor Shock Absorption,  Poor Morpher, Excellent Rigid Lever
Hallux Rigidus, 1-5 Hammertoes,
Stable
Good Shock Absorber, Good Morpher, Good Rigid Lever
Bunion, 2-5 Hammertoe, Plantar Fascial and Neuroma Problems Late and Low Level
Flexible
Excellent Shock Absorber, Excellent Morpher, Poor Rigid Lever
Bunions, 2-5 Hammertoes, Neuromata, Bunionette, Plantar Fascitis, 2nd Met Capsulitis, Freibergs, 2nd Met Stress Fracture
Flat
Poor Shock Absorber, Poor Morpher, Poor Rigid lever
NON Functional, Osteoarthritis +++

Postural Sequellae

FFT Postural Information
Rigid/Rigid Equinus +++, Shock problems, degenerative knee, hip, lower back problems, tight musculature
Rigid/Stable Equinus ++, Shock problems
Rigid/Flexible Equinus ++, Knee, Lower back Problems Early, Runners Knee, Shin Splints
Rigid/Flat Equinus +, Severe Postural Sequelae, Low Back, Knees, Hips
Stable/Stable No Postural Sequelae Unless Stressed or Overused
Stable/Flexible Collapsed Posture, Knee Hip, Low Back Sequelae
Stable/Flat Severe Postrual Sequelae, Late
Flexible/Flexible Genu Valgum, Coxa Vara, Lumbar Lordosis, Shin Splints, Runner’s Knee, Collapsed Posture Early, Poor Function
Flexible/Flat Genu Valgum, Coxa Vara, Lumbar Lordosis, Shin Splints, Runner’s Knee
Flat/Flexible Poor Performance
Flat/Flat Very Poor Performance, Major Postural Sequelae included, Gait

FFT Rearfoot Alone Forefoot Alone
Rigid
Postural Shock Problems, Equinus, Degenerative Joint Disease
Shock Problems, Degenerative Joint Disease
Stable
Stable Posture Unless Stressed
Depends on Rearfoot
Flexible
Flexible Posture, Collapse +++
Depends on Rearfoot
Flat
Tight, Non Functional Posture

Characteristic Lesion Patterns

FFT Lesion Patterns
Rigid/Rigid First Met Callus
Rigid/Stable Mild First Met or Second Met Callus
Rigid/Flexible Medial Heel Callus ++, IP Hallux Callus +++, 2nd Met callus
Rigid/Flat 5th Met Callus ++
Stable/Stable Callus Hallux IP Joint, 2nd Met If Stressed or Late
Stable/Flexible Medial Heel Callus +
Stable/Flat Medial Heel Callus +
Flexible/Flexible Medial Heel Callus+++, Medial First Met Callus ++, IP Hallux Callus ++, 2nd met callus+++, 5th Met callus++
Flexible/Flat Medial Heel Callus, Medial First Met Callus +++, IP Hallux Callus ++, 2nd met callus++++, 5th Met callus+++
Flat/Flexible Fifth Met Callus +++=
Flat/Flat Fifth met Callus ++++

FFT Rearfoot Alone Forefoot Alone
Rigid
Callus Depends on Forefoot
First met Callus
Stable

Callus Depends on Forefoot

Mild or Late 2nd met callus, Mild 5th met Callus, Mild IP Hallux Callus
Flexible
Navicular Callus
2nd met Callus, IP Hallus Callus, 5th met Callus
Flat
Lateral heel callus, Fifth Met Callus
5th Met Callus

Shoe Wear Characteristic

FFT Lesion Patterns
Rigid/Rigid Medial Heel Wear ++++, 1st met Wear+++, 5th met Wear+
Rigid/Stable Medial Heel Wear ++++ 1-2 Met Wear, 5th Met Wear++
Rigid/Flexible Medial Heel Wear ++++, Lateral Forefoot Wear, 2nd met Wear ++, IP Hallux Wear +++
Rigid/Flat Medial Heel Wear ++++, 5th Met ++++
Stable/Stable Medial Heel Wear ++, Normal Forefoot Wear  Unless Stressed
Stable/Flexible Medial Heel Wear ++
Stable/Flat Medial Heel Wear ++, 5th met Wear ++
Flexible/Flexible Medial Heel Wear +, Expanded Medial Counter +++
Flexible/Flat Medial Heel Wear +, Expanded Medial Counter ++++
Flat/Flexible Lateral Heel Wear ++, Lateral Forefoot Wear ++++
Flat/Flat Lateral Heel Wear +++, Lateral Forefoot Wear ++

FFT Rearfoot Alone Forefoot Alone
Rigid
Narrow Forefooted Shoe, Medial Heel Wear ++++, Needs High Throat
First Met Wear, Fifth Met Wear
Stable

Medial Heel Wear ++

2-3 Met Wear
Flexible
Wide Forefooted ShoeMedial Heel Wear +, Medial Midsole Wear, Medial Counter Expanded
2nd Met,Wear, Fifth Met Wear, IP Hallux Wear
Flat
Wide Forefooted Shoe, Lateral Heel Wear, Needs Low Counter
Lateral Forefoot Wear

FFT Precursors

FFT Precursors
Rigid/Rigid Sinus Tarsi, MP Flexion ++++, Medial Calcaneal ++, Cuboid
Rigid/Stable Sinus Tarsi ++, MP Flexion ++, Medial calcaneal ++
Rigid/Flexible Sinus Tarsi ++MP Flexion +++, 2nd Met +++, Medial Calcaneal +++
Rigid/Flat Sinus Tarsi ++++MP Flexion ++, Medial Calcaneal +++
Stable/Stable Precursors When Stressed or Late
Stable/Flexible MP Flexion +++, 2nd Met ++
Stable/Flat Sinus Tarsi +, 2nd met +
Flexible/Flexible PTTD, 2nd met ++, Medial Calcaneal
Flexible/Flat PTTD,
Flat/Flexible PTTD,
Flat/Flat Sinus Tarsi, Navicular, Cuboid

FFT Rearfoot Alone Forefoot Alone
Rigid
Sinus Tarsi
MP Flexion, 1st Met, 1st Met Cuneiform
Stable
Precursors When Stressed or Late
None Unless Stressed or Overused
Flexible
PTTD, Cuboid, 5th Met Base
MP Flexion, 2nd met, 5th Met head
Flat
PTTD, Cuboid, 5th Met Base
2nd met, 5th Met, Navicular, Cuboid

Legend Depending on Confirmatories and Purity of FFT
+ Mild and/or Late Development
++ Moderate and/or Earlier Development
+++ Major and Early Development
++++ Major and Late Development

###

References:

  1. Shavelson, Dennis: The Pedal Snowflakes, The Foot in Closed Chain, Present Podiatry Ezine 09/14/09: https://www.podiatry.com/ezines/?pub_year=2009§ion_id=51#ezine509
  2. Shavelon, Dennis: A Closer Look at Neoteric Biomechanics; Podiatry Today, September 2007, pp 147-153
  3. Shavelson, D. Steinberg,J, Bakotic, B: Chapter 25, The Diabetic Foot;Principles of Diabetes Mellitus, 2nd Edition, Elisiver Publishing, Switzerland; February, 2010 pp 528-551
  4. Shavelson, Dennis: The Functional Foot Typing Forefoot Examination; The Foot In Closed Chain, Present Podiatry; Ezine 03/29/10:
    https://www.podiatry.com/ezines/?pub_year=2010§ion_id=51#ezine584



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