History Evolution of Foot and Lower Extremity Biomechanics and Foot Orthoses Kevin Kirby

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History and Evolution of Foot and 
Lower Extremity Biomechanics 
and Foot Orthoses
Kevin A. Kirby, DPM
Adjunct Associate Professor 
Department of Applied Biomechanics 
California School of Podiatric Medicine
Oakland, California 
Private Practice, Sacramento, California
2015 PAC Symposium: “Biomechanics and the Future of Footcare” 
Vancouver, BC 
April 17-18, 2015
Biomechanics and foot orthoses have 
evolved over the centuries
Many talented individuals have increased 
our knowledge in foot and lower extremity 
biomechanics and about foot orthoses 
What people and events have shaped 
history and evolution of podiatric 
biomechanics and orthoses?
What is the History of Foot 
Biomechanics and Foot Orthoses?
Aristotle
Aristotle (384-322 BC), Greek 
scientist and philosopher, was one 
of earliest biomechanics authors 
His treatise, About the Movement of 
Animals (350 BC) provided first 
scientific analysis of gait and first 
geometric analysis of muscular 
actions on bones
First accurately described GRF as : 
“…for just as the pusher pushes, so 
the pusher is pushed”
Aristotle 
(384 BC – 322 BC)
Archimedes 
Archimedes (287-212 BC) 
was Greek scientist who is 
considered one of greatest 
mathematicians of antiquity 
Discovered principles of 
hydrostatics, statics and 
physics of levers, working to 
solve the problem of moving a 
given weight by a given force
“Give me a place to stand on, 
and I will move the Earth”
Archimedes 
(287-212 BC)
Galen
Galen (129-201 AD) was Roman 
physician and surgeon
Considered first “sports physician”
Was “team doctor” to Roman 
gladiators by age 28
In his work De Motu Musculorum
(On the Motion of Muscles), he 
first explained difference between 
motor and sensory nerves and 
agonist and antagonist muscles
Sought to raise medicine to level 
of exact science
Galen 
(129-201 AD)
Leonardo DaVinci
Leonardo DaVinci (1452-1519), 
Italian painter, sculptor and 
inventor, had keen interest in form 
& function of human body 
Inspired by desire to accurately 
represent human movement in his 
paintings and sculptures
In regard to running form on 
varied surfaces, DaVinci wrote:
“He who runs down a slope has his axis on his 
heels; and he who runs uphill has it on the toes of 
his feet; and a man running on level ground has it 
first on his heels and then on the toes of his feet.”
Leonardo DaVinci
(1452-1519)
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Giovanni Borelli
Giovanni Borelli (1608-1679), 
Italian physicist, physiologist and 
mathematician, wrote first book on 
biomechanics, De Motu
Animalium, in 1685 
First to fully describe geometrical 
principles of levers of musculo-
skeletal system and that muscles 
produce much larger forces than 
resisting external forces
Borelli found forces required for 
equilibrium in various joints of 
human body before Newton
Borelli is often called: 
“Father of Biomechanics”
Giovanni Borelli 
(1608-1679)
Isaac Newton
Isaac Newton (1642-1727), 
British mathematician and 
physicist, is considered by many 
to be greatest scientist of all time
Invented calculus at age 24
Published Philosophiae Naturalis 
Principia Mathematica in 1686 
which contained his now famous 
Three Laws of Motion
Credited with creating the laws of 
inertia, acceleration, action and 
reaction forces and of gravity
Isaac Newton 
(1642-1727)
Nicolas Andry
Nicolas Andry (1658-1742), a French 
physician, first coined the term 
“orthopedics” meaning “straight 
child”
Published book, Orthopaedia: The 
Art of Correcting and Preventing 
Deformities in Children in1740
“If the feet incline too much to one 
side, you must give the child shoes 
that are higher on that side, both in 
the sole and heel, which will make 
him incline to the opposite side.“
Nicolas Andry
(1658-1742)
Petrus Camper
Petrus Camper (1722-1789) was 
a Dutch physician and pioneer in 
pediatrics 
Published one of first books on 
foot deformities, “On the Best 
Form of Shoe” in 1781, which 
was reprinted into 14 editions
Camper’s book stimulated 
interest in placing arch-
supporting orthoses into shoes 
for children’s flatfoot
Petrus Camper 
(1722-1789)
“It is surprising that while mankind in all 
ages have bestowed the greatest attention 
upon the feet of horses, mules, oxen, and 
other animals of burthen of draught, they 
have entirely neglected those of their own 
species, abandoning them to the ignorance 
of workmen, who, in general, can only 
make a shoe upon routine principles, and 
according to the absurdities of fashion, or 
the depraved taste of the day. Thus, from 
our earliest infancy, shoes, as at present 
worn, serve but to deform the toes and 
cover the feet with corns, which not only 
render walking painful, but, in some cases, 
absolutely impossible.” P. Camper, 1781
Petrus Camper 
Shoe Fashions 
from 1760 
Lewis Durlacher
Lewis Durlacher (1792-1864), a 
British chiropodist, was royal 
chiropodist appointed to Queen 
Victoria
In 1845, he developed leather 
foot orthosis to correct for 
“plantar pressure lesions” and 
“foot imbalances”
Durlacher first described 
intermetatarsal neuroma, over 
30 years before T.G. Morton
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Hugh Owen Thomas
Hugh Owen Thomas (1834-1891) 
was a British orthopedic surgeon 
with interest in treating feet
In 1874, Thomas suggested using 
a “few pennies worth of leather” 
for lifts, bars, and wedges on 
shoes to treat foot problems
Invented, in 1876, “crooking” of 
shoe heel, to extend the heel 
under the antero-medial aspect of 
shoe sole for treating pronated 
feet (now called “Thomas heel”)
Hugh Owen Thomas
(1834-1891)
Newton Melman Shaffer
Newton M. Shaffer (1846-
1928), a New York City 
orthopedist, first described 
high arched foot with 
multiple clawtoes
Became widely known as 
“Shaffer’s Foot” 
Also designed a high-
medial arched orthosis 
with a heel cup which 
became known as a 
“Shaffer Plate” 
Newton M. Shaffer 
(1846-1928)
Royal Whitman
Royal Whitman (1857-
1946) was a 1882 
Harvard Medical School 
graduate and New York 
City orthopedic surgeon 
that had special interest 
in foot function
Wrote numerous 
textbooks on orthopedic 
surgery and taught 
orthopedics for 40 years
Royal Whitman 
(1857-1946)
Whitman’s “Weak Foot”
Whitman’s description of 
“weak foot” very closely 
matches our current 
description of the pronated, 
flat-arched foot with an 
internally rotated tibia
Whitman’s Three Grades of “Weak Foot”
1st Degree: The normal foot improperly used, as 
shown by the method of standing and walking
2nd Degree: The foot in which the range of voluntary 
motion is restricted, showing disuse of function, and 
in which the elements of deformity are apparent 
when weight is borne
3rd Degree: That in which the passive range of 
motion is restricted, or in which there are evident 
weakness and deformity. This limitation of motion 
depends, as a rule, on accommodative changes in 
structure to the habitual postures or to the deformity
Whitman R: A study of the weak foot, with reference to its causes, its diagnosis, and its cure; with an 
analysis of a thousand cases of so-called flat-foot. JBJS, 8:42-77, 1896.
Whitman’s Foot Brace
Developed in 1885
Made from plaster cast 
taken with foot in 
supinated position 
18-20 gauge sheet 
steel was formed into a 
high medial arch brace
Goal was to raise 
medial arch so foot 
would be less pronated
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Percy Willard Roberts
Percy W. Roberts (1867-1937), American orthopedic 
surgeon, developed metal foot orthosis in 1912
Roberts foot orthosis had deep inverted heel cup that 
attempted to tilt rearfoot into inverted position 
Had medial and lateral clips and narrow heel cup
Roberts brace applied too much force over too little 
areaand tended to cause irritation to plantar foot
1895 - Beginning of Chiropody
During most of 19th century, medical doctors 
showed little interest in treating foot problems
Barbers, families and practically anyone that 
showed an interest in treating feet adopted the 
“craft” of foot care to fill the void in healthcare of 
the foot that was left by medical doctors
In 1895, group of dedicated practitioners in New 
York successfully appealed to NY State 
Legislature to first establish chiropody (now 
podiatry) as a licensed profession
First Podiatry Society 
& School Formed
In 1895, Pedic Society of New 
York became first official society 
for chiropody/podiatry
First school of chiropody 
established in New York in 1911
In 1912, first national podiatry 
association, and precursor to 
current APMA, American National 
Chiropody Association, was 
formed and is now 100 years old
First Issue of Pedic Society 
Items – First “Podiatry Journal”
Alfred Joseph, First 
President of National 
Association of 
Chiropodists”
Podiatric Approach to Foot 
Biomechanics in Early 20th Century
Approach to foot mechanics in 
early 20th century was based 
largely on shape of medial 
longitudinal arch with “normal foot” 
being viewed as having “normally 
arched architecture” with 
treatments geared toward 
restoring a “normal arch”
Many podiatrists relied on 
orthopedic shoe makers to make 
custom leather foot or steel 
appliances to treat “weak feet”
Early 20th Century 
Treatment of “Weak 
Feet” Used Whitman’s 
Concepts
Otto Frederick Schuster
Otto F. Schuster (1881-
1936) arrived in US in 1906 
from Hamburg, Germany 
where he had trained as a 
brace maker
Schuster started making 
Whitman braces for Royal 
Whitman and other 
orthopedists in NY in 1909
Became a podiatrist in 1911 Otto F. Schuster 
(1881-1936)
First Podiatric 
Orthopedics Text
Otto F. Schuster became 
professor of orthopedics at 
NY Podiatry School
In 1927, published first 
podiatric orthopedics text, 
Foot Orthopedics, later 
rewritten by his podiatrist-
son, Otto N. Schuster 
Foot Orthopedics remained 
in use as a valuable 
textbook until 1950s
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Roberts-Whitman Brace
In the 1920s, Otto F. Schuster 
combined ideas of Roberts 
brace with Whitman brace to 
make Roberts-Whitman brace 
Roberts-Whitman brace had 
deep inverted heel cup, high 
medial arch and wider profile 
that provided better pronation 
control and allowed for more 
comfortable medial arch 
Otto Schuster created 
Roberts-Whitman Brace 
Dudley J. Morton
Dudley Joy Morton (1884-1960) 
was physician, anatomist and 
anthropologist
Work focused on shortened 1st 
metatarsal, “hypermobility” of 1st 
metatarsal segment and 
correlation of 1st ray mechanics to 
excessive foot pronation
Published book, The Human 
Foot, It’s Evolution, Physiology 
and Functional Disorders, in 1935
Dudley J. Morton 
(1884-1960)
Morton Was First to Describe Load-
Deformation of 1st Ray in 1935
“If the plantar ligaments of 
any segment are slack 
when the head of its 
metatarsal bone lies on 
the same plane as the 
others whose ligaments 
are taut, that segment will 
fail to share in the carriage 
of body weight….” 
Morton DJ: The Human Foot: Its Evolution, Physiology 
and Functional Disorders. Columbia University Press. 
Morningside Heights, New York, 1935. 
“…the plantar ligaments of the first metatarsal 
segment in these feet were lax when the other 
ligaments had become tense under body weight; 
hence the first metatarsal still retained a margin of 
dorsal extension and therefore was ineffective as a 
weightbearing structure.”
Morton DJ: The Human Foot: Its Evolution, Physiology and Functional Disorders. Columbia 
University Press. Morningside Heights, New York, 1935. 
Morton believed “hypermobility of first 
metatarsal” affects foot in three ways:
1. Second metatarsal has “increased burden” 
since first metatarsal “fails to assume” its 
normal share of weight
2. Foot pronates because “medial buttress” is 
ineffective until “slack in its ligaments is taken 
up” as pronation increases
3. As pronation advances, “functional stresses are 
thrown increasingly on muscles on inner side of 
ankle, imposing them undue strain”
Morton DJ: Physiological 
considerations in the 
treatment of foot 
deformities. JBJS, 
19:1052-1056, 1937.
Morton’s Compensating Insole
In 1932, Morton designed a 
“compensating insole” that 
focused on elevating first 
metatarsal head and 
preventing pronation 
compensation for short, 
“hypermobile” first ray
Morton also designed in-
shoe support with high 
medial arch-flange to resist 
pronation 
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First Plaster Splint Impression 
Casting of Foot
Edward Reed, MD, an 
orthopedic surgeon from 
Santa Monica, California, 
was first to describe 
plaster splint impression 
casting for foot orthoses 
in 1933
Reed EN: A simple method for making plaster casts of 
feet. JBJS, 17:1007, 1933.
Alan Murray & Benjamin Levy
In 1930s, Alan Murray, ice 
skater, developed shoe molded 
directly onto cast of foot called 
the Murray Space Shoe
NY podiatrist, Benjamin Levy, 
developed idea of using inner 
sole from Murray Space Shoe as 
a removable cork and leather 
insole with a toe crest, became 
known as Levy mold.
Levy B: An appliance to induce toe flexion on weight bearing. J 
Natl Assoc of Chiropodists, 40(6):24-33, 1950.
John Tinkham Manter
John T. Manter (1910-1968), was 
professor of zoology at Columbia 
University and professor of anatomy 
at University of South Dakota
Wrote numerous articles on zoology, 
animal locomotion and 
biomechanics
In 1941, Manter wrote first English 
language scientific paper on subtalar 
joint and midtarsal joint axes 
Manter JT: Movements of the subtalar and transverse tarsal joints. Anat 
Rec, 80:397-410, 1941. 
John T. Manter 
(1910-1968)
Manter’s Mean STJ Axis Location 
in 16 Cadaver Feet
Manter JT: Movements of the subtalar and transverse tarsal joints. Anat Rec, 80:397-
410, 1941. 
Manter’s Study Determined STJ Axis 
to Transverse and Sagittal Planes
Manter’s 1941 study found that mean position 
of STJ axis in 16 cadaver feet was angulated 
160 from sagittal plane and 420 from 
transverse plane
Manter’s study only determined angular 
deviation of STJ axis from cardinal planes, 
but did not determine spatial location of STJ 
axis in relation to plantar foot (i.e. whether 
STJ axis was medially or laterally positioned)
Manter JT: Movements of the subtalar and transverse tarsal joints. Anat Rec, 80:397-410, 
1941.
Manter was also one of first researchers to study 
axes of rotation of MTJ 
Calcaneus clamped in apparatus to stabilize 
rearfoot and rods and pointers driven into unknown 
bones in forefoot
Pointers aligned against glass plates to determine 
axes of rotation
Forefoot moved with unknown magnitude and 
direction of input force to determine axes of rotation
Manter JT: Movements of the subtalar and transverse tarsal joints. Anat Rec, 80:397-410, 1941.
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Longitudinal transverse tarsal joint axis
– 90 from transverse plane
– 150 from sagittal plane
Oblique transverse tarsal joint axis
– 520 from transverse plane
– 570 from sagittal plane
Manter’s Midtarsal Joint Axes
Oblique axis
Longitudinal 
axis
John H. Hicks
John H. Hicks (1915-1992), orthopedic surgeon from 
Birmingham, UK, had great interest in foot 
biomechanics and performed pioneering research 
Wrote series of classic scientific papers from 1953-
1961 on biomechanics of foot, plantar fascial function 
and biomechanics of balance relative to GRF
Also determined axes of motion of ankle joint, STJ, 
MTJ, first ray and fifth ray
John H. Hicks 
(1915-1992)
In 1953, Hicks found two distinct MTJ axes– Oblique midtarsal joint (OMTJ) axis
– Antero-posterior midtarsal joint (APMTJ) axis
However, Hicks’ MTJ axes were in different 
locations to Manter’s MTJ axes
Hicks JH: The mechanics of the foot. I. The joints. Journal of Anatomy. 87:25-31, 1953.
Hicks’ Midtarsal Joint Axes
Hicks was first to describe the “Windlass Effect” 
of hallux dorsiflexion in 1954
Hicks, JH: The mechanics of the foot. II. The plantar aponeurosis and the arch. Journal of Anatomy. 
88:24-31, 1954.
Hallux dorsiflexion in cadavers and live subjects 
produced following simultaneous responses:
Increase in medial longitudinal arch height
Inversion of rearfoot
External rotation of leg
Appearance of tight band in region of plantar 
aponeurosis
Windlass and Reverse Windlass Effect
Hicks also noted that body weight flattened arch and 
plantarflexed hallux more forcefully into ground
Effect of hallux forcefully pressing into ground was 
noted to nearly disappear with transection of plantar 
fascia in cadaver foot
Hicks JH: The mechanics of the foot. II. The plantar aponeurosis and the arch. Journal of Anatomy. 
88:24-31, 1954.
Windlass Effect Reverse Windlass Effect
Herbert Oliver Elftman
Herbert O. Elftman, PhD, 
professor of anatomy at 
Columbia University, wrote 
many papers on foot and 
lower extremity biomechanics 
from 1934 to 1970
Elftman proposed that MTJ 
has joint axes and motion 
that may be affected by 
subtalar joint pronation and 
supination 
Elftman H: The transverse tarsal joint and its control. Clin. 
Orthop., 16:41-44, 1960.
Herbert O. Elftman 
(1902-1988)
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Elftman thought that in the pronated foot major 
axis of TNJ (TN-1) was directly in line with CC-1:
“allows the forepart of the foot to move freely 
with respect to hindpart without movement of the 
talus with respect to the calcaneus”
Thought that MTJ axis changes in location as 
STJ rotates from pronated to supinated position:
“In passing from pronated to supinated position 
there is a continuous change in positions of 
significant joint elements and, consequently, of 
instantaneous transverse tarsal axis.”
Verne Thompson Inman 
Verne T. Inman, MD, PhD 
(1905-1980) began to 
research lower extremity 
biomechanics in 1957 at UC 
Berkeley due to need for 
better prostheses in post-
WW II amputees 
His two books: The Joints of 
the Ankle and Human 
Walking are classics in foot 
and lower extremity 
biomechanics
Verne T. Inman 
(1905-1980)
Howard Davis Eberhart 
Howard D. Eberhart was professor in 
civil engineering at UC Berkeley, when 
accident required BK amputation
Verne Inman, professor of orthopedic 
surgery at UC Berkeley, was surgeon 
that amputated Eberhart’s leg in 1944
In order to research lower limb 
biomechanics and develop better 
prosthesis designs, Eberhart teamed 
with Inman and became director of 
Prosthetics Devices Research Project 
at UC Berkeley Dept. of Engineering
Howard D. Eberhart 
(1906-1993)
UC Biomechanics Lab
UCBL was center of 
research in foot and lower 
extremity biomechanics 
and prosthetics research 
from 1957 to 1974 at 
UCSF and UC Berkeley
During its time, UCBL 
produced more research 
and notable researchers 
in foot and lower 
extremity biomechanics 
than any other in world
Dr. Verne Inman (center), Professor 
Howard Eberhart (right), and W.H. 
Henderson (in wheelchair) in 
Biomechanics Laboratory at U.C. 
Berkeley.
D. Gilbert Wright
Researcher at UC Biomechanics 
Lab who, in 1964, performed 
classic studies of range of motion 
of STJ during walking and on 
elastic properties of plantar fascia
Wright DG, Rennels DC: 
A study of the elastic 
properties of plantar 
fascia. JBJS, 46 
(A):482-492, 1964.
Wright DG, Desai SM, Henderson WH: Action of the subtalar and 
ankle-joint complex during the stance phase of walking. 
JBJS, 46 (A): 361, 1964.
John B. Saunders
Chairman of Dept of Anatomy at UC 
Berkeley from 1938-1956
Coauthored classic article on 
determinants of gait, described how 
locomotion mechanisms minimize 
excursion of CoM during gait
Saunders JB, Inman 
VT, Eberhart HD: The 
major determinants in 
normal and 
pathological gait. JBJS, 
35A:543-558, 1953.
John B. Saunders 
(1903-1991)
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In 1969, dental student, R.E. Isman, did study 
with Verne Inman at UC Biomechanics Lab that 
measured STJ axis in 46 cadaver feet 
STJ was 420 inclinated from transverse plane 
and 230 adducted from sagittal plane
Isman RE, Inman VT: Anthropometric studies of the human foot and ankle. Bull Pros Research, 
10:97-129, 1969.
Henderson & Campbell: UCBL
Henderson and Campbell 
developed high heel-cupped 
polypropylene orthosis with 
high medial and lateral flanges 
at UC Biomechanics Lab in 
1967
Henderson WH, Campbell JW: U.C.B.L. shoe insert casting and 
fabrication. Technical Report 53. Biomechanics Laboratory, 
University of California at San Francisco and Berkeley, 1967.
UCBL orthosis primarily used 
by orthopedic community for 
treatment of pediatric flexible 
flatfoot deformity
Merton Louis Root
Merton L. Root (1922-2002) 
became interested in research as a 
WW II army paratrooper 
After war decided to pursue career 
in podiatry in 1948 after seeing 
need for better research in podiatry
Graduated from California College 
of Chiropody in 1952
Started world’s first Department of 
Podiatric Biomechanics in 1966 at 
CCPM in San Francisco
Merton L. Root 
1922-2002
San Francisco Bay Area became hub for foot 
and lower extremity biomechanics research and 
development in late 1950s and 1960s
Root’s Eight Biophysical 
Criteria for “Normalcy”
Eight biophysical criteria for 
“normalcy” proposed by Root, et 
al in 1971
Root ML, Orien WP, Weed JH, Hughes RJ: Biomechanical 
Examination of the Foot, Volume 1. Clinical Biomechanics 
Corporation, Los Angeles, 1971.
Root, et al proposed that all feet 
and lower extremities which did 
not meet criteria for “normal” 
had structural defects and were, 
therefore, “abnormal”
Root’s “Deformities” 
Based on STJ Neutral
Root developed biomechanical 
classification system based on 
concept that STJ neutral was 
ideal foot position during gait
Root classified “foot types” with 
frontal plane positions of 
rearfoot to tibia, forefoot to 
rearfoot, and first ray position 
relative to 1st -5th metatarsal
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Root Developed “Neutral 
Suspension Casting Method”
In 1971, Root, Weed and Orien 
described “neutral suspension casting 
technique” with plaster splints to 
accomplish the following objectives:
Capture STJ in neutral position
Dorsiflex the 4th and 5th metatarsals
Pronate midtarsal joint to maximum to 
“lock” forefoot against rearfoot
Preserve NWB plantar contour of foot
Root ML, Weed JH, Orien WP: Neutral Position Casting Techniques, 
Clinical Biomechanics Corp., Los Angeles, 1971.
Root Functional 
Orthosis
Root was one of first to experiment with new 
materials called thermoplastics and began to 
develop his Root Functional Orthosis in 1958
RFO had lower MLA than previous orthoses since 
Root didn’t believe that high MLA or arch pain was 
necessary to control abnormal pronation
Root designed his RFO to allow the STJ to function 
in neutral position by preventing “compensation” for 
rearfoot and forefoot “deformities”
Root’s Lectures Notes 
Published by Sgarlato
Thomas E. Sgarlato, DPM, 
took over as chairman of 
world’s first Department of 
Podiatric Biomechanics from 
Root (due to illness) in 1969
Sgarlato worked with podiatry 
students and biomechanics 
faculty to publish Root’s 
lecture notes as “A 
Compendium of Podiatric 
Biomechanics” in March 1971
Thomas E. Sgarlato
Normal and Abnormal Function of 
the Foot, by Root, Orien and Weed 
in 1977, was foot and lower 
extremity biomechanicstextbook
Text described normal and 
abnormal mechanics of foot and 
lower extremity, biomechanics of 
foot pathologies and how foot 
structure may predict foot function
John Herbert Weed 
(1938-1992)
William Phillip Orien
E.J. Van Langelaan
E.J. Van Langelaan, orthopedic 
surgeon in Netherlands, did first 
modern study on motions of STJ 
and MTJ in 1983 in his landmark 
PhD thesis using 3D xray 
photogrammetry
Performed under guidance of 
Antony Huson, PhD at University 
of Leiden, Netherlands
Van Langelaan EJ: A kinematical analysis of the tarsal joints. Acta 
Orthop Scand, 54:Suppl. 204, 135-229, 1983. 
E.J. Van Langelaan
Apparatus Used in Van 
Langelaan Study
(Videos courtesy of A. Huson, MD, PhD)
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Thoughts from Van Langelaan
“ ...intertarsal joints are not ‘complicatedly structured but 
functionally simple hinge joints’. Movements are found to 
take place around an axis which moves continuously, 
and the position of which could be approximated with the 
aid of a bundle of discrete helical axes.”
“The relative axes within a bundle proved to approach 
each other more closely at characteristic sites in the 
tarsus.” TNJ: central portion of talar head, CCJ: dorsal-
medial-superior corner of CCJ
Benno M. Nigg
Benno Nigg, trained as nuclear 
physicist, became interested in 
biomechanics in 1971
Founded and developed 
world’s largest biomechanics 
research facility at University of 
Calgary in 1981
Has authored/edited 10 books 
and has authored over 290 
scientific papers on sports 
shoes and foot and lower 
extremity biomechanics
Benno M. Nigg
Howard J. Dananberg
Howard Dananberg 
popularized concept that 
functional hallux limitus was 
key to abnormal foot function
FnHL thought to produce 
“sagittal plane blockade“ 
during walking that caused 
pronation of foot as result
Patented “kinetic wedge” to 
address his theory of “sagittal 
plane blockade” 
Dananberg, HJ: Gait style as an etiology to chronic postural pain. 
Part I. Functional hallux limitus. JAPMA, 83:433-441, 1993.
Howard J. Dananberg
Richard L. Blake
Richard Blake, a 1981 CCPM 
Biomechanics Fellowship 
graduate, developed the 
Blake Inverted Orthosis from 
1981-1982
Blake RL, Denton J: Functional foot orthoses for athletic injuries. 
JAPMA, 75:359-362,1985.
Blake RL, Ferguson H: Foot orthosis for the severe flatfoot in sports. 
JAPMA, 81:549, 1991.
Blake RL: Inverted functional orthoses. JAPMA, 76:275-276, 1986.
Blake RL, Ferguson H: "The inverted orthotic technique:”, in Valmassy, 
R.L.(editor), Clinical Biomechanics of the Lower Extremities, Mosby-
Year Book, St. Louis, 1996.
Richard Blake
Blake Inverted Orthosis
As Dr. Blake developed his BIO, he discovered 
that increasing levels of cast inversion increased 
pronation control from his inverted orthosis due 
to increased MLA height and inverted heel cup
However, as cast inversion approached 100, Dr. 
Blake noted new orthosis problems:
– Plantar fascial irritation
– Foot slid laterally off of orthosis plate
– Excessive orthosis arch height caused late 
midstance pronation, instead of late midstance 
supination, during walking
Blake Inverted 
Orthosis
Positive cast of BIO inverted 
15, 25 or 350 which causes 
varus heel cup and higher 
medial arch to orthosis
Modified medial arch fill and 
plantar fascial accommodation 
are added to prevent plantar 
fascial irritation
Heel cups of 20 mm and flat 
rearfoot posts are standard 
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New Research on STJ Axis 
Location Emphasized STJ Kinetics
In 1987, concept that STJ axis location may be 
determined clinically and that GRF medial to STJ axis 
causes supination moments and GRF lateral to axis 
causes STJ pronation moments was first introduced
Kirby KA: Methods for determination of positional variations in the subtalar joint axis. JAPMA, 77: 228-
234, 1987.
In 1989, concept of rotational equilibrium used to 
explain how balance of STJ moments may 
explain abnormal internal forces within foot and 
different types of foot pathology
Kirby KA: Rotational equilibrium across the subtalar joint axis. JAPMA, 79: 1-14, 1989.
In 1992, medial heel skive technique, was first 
described as method to increase varus shape of 
heel cup in functional foot orthosis 
Designed to increase STJ supination moment from 
orthosis and more effectively treat symptoms 
caused by excessive pronation moments such as 
PTTD and children’s flatfoot deformity
Kirby KA: The medial heel skive technique: improving pronation control in foot orthoses. JAPMA, 82: 
177-188, 1992.
In 2001, new theory of foot 
function, Subtalar Joint Axis 
Location and Rotational 
Equilibrium (SALRE) Theory was 
first introduced
Described how concepts of STJ 
axis spatial location and rotational 
equilibrium may be combined to 
explain many observations 
relating to biomechanical function
Also offered explanation for 
biomechanical effect of certain 
foot surgeries 
Kirby KA: Subtalar joint axis location and rotational equilibrium 
theory of foot function. JAPMA, 91:465-488, 2001.
SALRE Theory Explains How 
Orthoses Alter STJ Moments
If orthosis is designed to 
“control pronation”, ORF 
will be shifted medially so 
STJ supination moment 
is increased
If orthosis is designed to 
“control STJ supination”, 
then ORF will be shifted 
laterally so STJ pronation 
moment is increased
Kirby KA: Subtalar joint axis location and rotational 
equilibrium theory of foot function. JAPMA, 
91:465-488, 2001.
ORFORF
ORFORF
As STJ axis becomes 
medially deviated, orthosis 
has decreased area medial 
to STJ axis to cause STJ 
supination moments
Medial deviation of STJ 
decreases orthosis ability 
to supinate STJ
Child with Flatfoot Deformity
Supination Area 
of Foot Orthosis
Normal STJ Axis Location
Supination Area 
of Foot Orthosis
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Tissue Stress Model
Tissue stress model first proposed as 
a model for mechanical foot therapy 
in 1995 by McPoil and Hunt
McPoil TG, Hunt GC: Evaluation and management of foot and ankle disorders: 
Present problems and future directions. JOSPT, 21:381-388, 1995.
Tissue stress model is not a novel 
idea since it is based on same ideas 
are already in current use in 
treatment of parts of body other than 
foot and lower extremity 
Tissue stress model doesn’t rely on 
“unreliable measurement techniques”
Thomas G. McPoil
Gary C. Hunt
Tissue Stress Model
Tissue stress model and its clinical 
applications have been discussed by 
other authors as a clinical method by 
which to more effectively prescribe 
custom foot orthoses 
Fuller EA: Center of pressure and its theoretical relationship to foot pathology. JAPMA, 89 
(6):278-291, 1999.
Fuller EA: Reinventing biomechanics. Podiatry Today, 13:(3), December 2000.
Kirby KA: Tissue stress approach to mechanical foot therapy. Precision Intricast Newsletter, 
February 2002.
Kirby KA: The biomechanics of tissue stress. Precision Intricast Newsletter, Payson, Arizona, 
March 2002.
Kirby KA: Using the tissue stress approach in clinical practice. Precision Intricast Newsletter, 
April 2002.
Tissue Stress Allows Efficient 
Determination of Orthosis Goals
Orthosis goals are best achieved by 
specifically designing CFO to :
– reduce stress on injured structural components 
within foot and lower extremity
– optimize function of foot and lower extremity for 
specific weightbearing activities
– prevent other injuries or pathologies from 
occurring due to foot orthosis therapy
Steps to Using Tissue Stress
1. Specifically identify anatomical 
structures which are source of 
patient’s complaints
2. Determine structural and/or 
functional variables which may be 
source of pathological forces on 
injured structures
3. Designorthosis/shoe treatment plan 
which will most effectively reduce 
pathological forces on injured 
structural components, will optimize 
gait function and will not cause other 
pathology or symptoms
Paul Robert Scherer
Paul Scherer, DPM, is former professor 
of biomechanics at CCPM and current 
professor of biomechanics at CSPM 
Scientific chair for first ten PFOLA 
Conferences which were world-class 
international events that presented 
latest knowledge in biomechanics and 
foot orthosis therapy
His book “Recent Advances in Orthotic 
Therapy” is premier educational 
resource detailing scientific research 
evidence for orthosis therapy
Benno Nigg’s 
Preferred Movement 
Pathway Model
In 2001, Benno Nigg proposed “preferred 
movement pathway model” of orthosis function
Nigg proposes that orthoses do not function by 
realigning skeleton but rather alter input signals into 
plantar foot that change “muscle tuning
Nigg proposed that if foot orthosis counteracts 
preferred movement path, then muscle activity will 
increase and that optimal shoe or foot orthosis 
design will reduce or minimize muscle activity
Nigg BM: The role of impact forces and foot pronation: a new paradigm. Clin J Sport Med, 11:2-9,
2001.
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14
Chris Nester
Chris Nester, first a podiatrist 
then a PhD in biomechanics, 
became foot biomechanics 
researcher at University of 
Salford, UK
Along with coworkers, Nester 
has performed important 
pioneering bone pin research 
in kinematics of foot joints in 
both cadaver and live feet
Chris Nester Nester and coworkers were first to suggest that 
previous model of simultaneously occurring oblique 
and longitudinal MTJ axes can not occur and should 
be replaced by a single moving MTJ axis
Simple concept described by Nester et al is very 
important for understanding MTJ biomechanics: 
“axes of rotation do not determine the motion at a 
joint; rather, the motion determines the axis”
Nester CJ, Findlow A, Bowker P: Scientific approach to the axis of rotation of the midtarsal joint. 
JAPMA, 91(2):68-73, 2001.
Also proposed three “reference axes” for MTJ:
– Medial-lateral MTJ axis (z-axis)
– Anterior-posterior MTJ axis (x-axis)
– Vertical MTJ axis (y-axis)
Nester CJ, Findlow AH: Clinical and experimental models of the midtarsal joint. Proposed terms of 
reference and associated terminology. JAPMA, 96:24-31, 2006.
Important Coworkers Have 
Further Developed STJ Theory
Eric Fuller, introduced concept that 
CoP position relative to STJ axis 
can be used to predict how 
different tissues will be stressed
Fuller EA: Center of pressure and its theoretical relationship to foot 
pathology. JAPMA, 89 (6):278-291, 1999.
Co-developed concept of STJ 
axis/tissue stress approach to 
biomechanical therapy
Fuller EA, Kirby KA: Subtalar joint equilibrium and tissue stress 
approach to biomechanical therapy of the foot and lower 
extremity. In Albert SF, Curran SA (eds): Biomechanics of the 
Lower Extremity: Theory and Practice, Volume 1. Bipedmed, 
LLC, Denver, 2013, pp. 205-264.
Eric Fuller
Simon Spooner, PhD, developed STJ 
axis locator and promoted analyzing 
orthosis function with FEA
Spooner SK, Kirby KA: The subtalar joint axis locator: A preliminary 
report. JAPMA, 96:212-219, 2006.
Craig Payne and coworkers showed 
correlation of STJ axis location to 
supination resistance
Payne C, Munteaunu S, Miller K: Position of the subtalar joint axis and 
resistance of the rearfoot to supination. JAPMA, 93(2):131-135, 2003.
Javier Pascual Huerta, PhD and 
coworkers demonstrated how max 
pronated STJ position affects foot 
resistance to supination with orthoses
Pascual Huerta J, Ropa Moreno JM, Kirby KA: Static response of 
maximally pronated and nonmaximally pronated feet to frontal plane 
wedging of foot orthoses. JAPMA, 99:13-19, 2009.
Simon Spooner
Craig Payne 
Javier Pascual Huerta 
Future for Foot and Lower Extremity 
Biomechanics and Orthoses?
Key to developing better understanding of gait 
function and pathologies will be dependent on 
research that determines forces and moments 
acting on foot and lower extremity
Research into new orthosis designs to reduce 
abnormal forces and moments causing certain 
pathologies will be important for further progress
Better understanding of biological and mechanical 
nature of human tissues will also be critical to 
developing better treatment methods
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15
Biomechanics and Historical 
Sources
W. Eric Lee: Podiatric Historian from UK
Lee W E: Merton L. Root: An appreciation. The Podiatric Biomechanics Group 
Focus. 2(2): 32-68, 2003.
Richard O. Schuster: Podiatrist from US 
(nephew of Otto N. Schuster)
Schuster RO: A history of orthopedics in podiatry. JAPA, 64(5):332-345, 1974.
Benno Nigg: Biomechanics Researcher
Nigg BM: “Selected historical highlights”, in Biomechanics of the Musculo-skeletal 
System, 2nd Edition, (B.M. Nigg and W. Herzog, eds), John Wiley and Sons, 
New York, 1999, pp. 3-35.
William Eric Lee
Richard Schuster
Benno Nigg
Conclusion
History demonstrates that foot and lower extremity 
biomechanics theory and foot orthosis treatments 
have all evolved over time
Many individuals have made contributions towards 
better understanding of lower extremity function and 
treating foot and lower extremity mechanical 
pathologies with orthoses
Examples of those that changed history in foot-health 
professions show that advances in knowledge require 
sacrifice, determination and hard work