Biomechanics of Foot and ankle complex along with common foot pathology like flatfeet has been discussed. Types of Flatfeet, pathophysiology & its biomechanics negative impact on gait with Orthotic treatment has been discussed. Types of CP (hemiplegia and diplegia spastic CP ), its gait patterns and appropriate orthotic management around the ankle and foot complex in child with spastic cp has been discussed including various tone reducing AFOs and Neurophysiology AFOs.

1. FOOT AND ANKLE
COMPLEX
PRESENTED BY:
FIONA VERMA, MPO 1st YEAR
6th Batch
1

2. CONTENTS
• Introduction on foot-ankle complex
• Motions of ankle-foot complex
• Ankle joint
• Ankle joint structure
• Ankle joint Axis
• Ankle joint function
• The subtalar joint
• Subtalar joint structure
• Subtalar axis
• Subtalar joint function
• Subtalar joint Kinematics
2

3. Cont.
• Transverse tarsal joint
• Structure and sub-joints
• Mid-tarsal joint Axes
• Transverse tarsal joint kinematics
• Tarso-metatarsal joint
• Joint structure
• Joint function : supination and pronation twist
• Foot Biomechanics during gait
• Flatfeet deformity
• Normal arch height and measurement
• Deviation in Osteokinematics
• Diagnosis
• Clinical diagnosis
• Radiologic diagnosis
• Pathomechanics of flatfeet
• Orthotic Management of flatfeet
3

4. • Orthotic intervention & its biomechanical considerations for A-F
complex
• Weak/absent dorsi-flexors
• Weak/absent plantar flexors
• Ankle weakness with ST instability
• Weak knee extensors
• Classification of gait patterns in spastic Hemiplegia & OM
• Classification of gait patterns in spastic Diplegia & OM
• Tone reducing AFOs
• NP-AFO
• Alternative designs of TRAFOs
• Pressure over Muscle insertion
• Optokinetic principle
• References
4

5. INTRODUCTION
o The primary role of ankle/foot complex – to bear weight.
o The complementing structures of the ankle/foot complex permit both – “stability and mobility” as
it is able to sustain large weight-bearing stresses while accommodating to a variety of surfaces and
activities.
o The ankle/foot complex meet the diverse requirements through integrated movements of:
28 bones forming 25 component joints.
 Bones of the foot:-
• Phalanges -14
• Tarsal bones -7
• Metatarsals- 5
• Sesamoids- 2
5

6. BONES OF THE FOOT 3 FUNCTIONAL SEGMENTS OF FOOT
6

7. • 25 component joints of the
ankle/foot include:
• Proximal and distal tibiofibular
joints
• Talocrural joint (ankle)
• Talocalcaneal (subtalar) joint
• Transverse tarsal (talonavicular
and calcaneocuboid) joints
• Tarsometatarsal joints-5
• Metatarsophalangeal joints -5
• Interphalangeal joints-9
7

8. MOTIONS OF ANKLE-FOOT COMPLEX
The three motions of the ankle/foot complex that approximate cardinal planes and axes are:
• Dorsiflexion/plantarflexion
• Inversion/eversion
• Adduction/abduction
Motions plane Axes Normal ROM
Dorsiflexion/plantarflexion Sagittal plane Coronal (frontal)
axis
65 ֯- 75 ֯
Inversion/eversion Frontal plane Longitudinal (A-P)
axis
Approx. 35 ֯
Adduction/abduction Transverse plane Vertical axis Approx. 30 ֯
8

9. Inversion/eversion Adduction/abduction Dorsiflexion/plantarflexion
CARDINAL AXES AND PLANES FOR
MOTION OF ANKLE/FOOT COMPLEX
9

10. • Supination /pronation motions:
Supination and pronation are the terms used to describe “composite” motions that are coupled to each
of the cardinal motions.
In non-weight bearing i.e. (open chain kinematics).
Pronation is the motion about an axis that result in coupled motions of dorsiflexion, eversion and
abduction.
Supination is the motion about an axis that results in coupled motions of plantarflexion, inversion and
adduction.
PRONATION SUPINATION 10

11. ANKLE JOINT
The term ankle refers specifically to the talocrural joint, the articulation between the distal tibia and
fibula (proximally) and the body of talus (distally).
The Ankle is a synovial hinge joint with a joint capsules and associated ligaments.
It is considered to have a single oblique axis with one degree of freedom around which motion of
dorsiflexion/plantarflexion occurs.
ANKLE JOINT STRUCTURE
PROXIMAL ARTICULAR SURFACE:
• Distal tibia
• Tibial and fibular malleoli
DISTAL ARTICULAR SURFACE:
• Body of the talus
11

12. PROXIMALARTICULAR SURFACES:
The proximal segment of the ankle is composed of the- concave surface of distal tibia and of tibial &
fibular malleoli.
The structure of distal tibial and two malleoli resembles and is referred to as a mortise. Why?
The mortise of the ankle is adjustable, relying on the proximal and distal tibiofibular joints to both
permit and control the changes in the mortise.
12

13. Proximal and distal tibiofibular joint are anatomically distinct from the ankle joint, but functionally
linked exclusively to the ankle.
Proximal tibiofibular joint: plane synovial joint formed by articulation of the head of fibula with
posterolateral aspect of the tibia.
The motion at this joint is consistently small but relevance of its motion will be discussed later.
Distal tibiofibular joint: syndesmosis or fibrous union between the concave facet of the tibia and
convex facet of fibula.
13

14. • The function of talocrural joint is dependent on the stability of the tibiofibular mortise. The ankle
mortise would be unable to grasp or hold on to the talus if one side of the mortise were missing.
• Conversely, ankle mortise must have mobility functions as well- this belongs primarily to the fibula.
DISTALARTICULAR SURFACE:
Body of talus- forms distal articular surface body of talus
14

15. CAPSULE AND LIGAMENTS:
The capsule of the ankle joint is fairly thin and especially weak anteriorly and posteriorly. Therefore, the
stability of the ankle depends on an intact ligamentous structure.
The ligaments that support the P&D tibiofibular joints – crural tibiofibular interosseous ligament.
2 major ligament complexes that maintain the contact and congruence of the mortise and talus –
Medial collateral ligament (MCL)
Lateral collateral ligament (LCL)
15

16. AXIS OF THE ANKLE JOINT
In a neutral position, the joint axis passes approximately though :
fibular malleolus body of the talus through or just below the tibial malleolus.
More posterior position of fibular malleolus = normal tibial torsion.
Talar rotation (abduction/adduction) and talar tilt (inversion/eversion) : talar rotation is 7 ֯ medial
and 10 ֯ lateral rotation. Talar tilt is 5 ֯ or less in frontal plane.
a) 14 ֯ from TP b) 23 ֯ from FP
16

17. Arthrokinematics of talocrural joint:
The talus rolls within the mortise during dorsiflexion and plantarflexion.
• Dorsiflexion: motion of head of talus moves dorsally while body of talus moves posteriorly.
• Plantarflexion: motion of head of talus moves ventrally while the body moves anteriorly.
The distally inclined and posterior placement of the joint axis from lateral side will create motion across-
three planes (triplanar) while still around a single fixed axis.
DF of foot:
not only bring the foot upwards (sagittal plane)
Simultaneously bring it slightly lateral to leg (transverse plane)
Appears to turn the foot longitudinally away from the midline (frontal plane)
PF of foot:
Brings the foot downward (sagittal plane)
Foot rotates medial to leg (transverse plane)
Appears to turn the foot longitudinally towards the midline (frontal plane)
17

18. ANKLE JOINT FUNCTION
In gait, ankle joint functions in two modes: open chain kinematics and close chain kinematics.
Open chain kinematics: (distal segment is free)
Calcaneus and foot move in relative to fixed tibia and talus.
• foot dorsiflexion/ plantarflexion motion: is carried out by the free distal segment of foot in & around
the fixed talus and tibia. (sagittal plane)
• Abduction/adduction motion: occurs distal to STJ axis. (transverse plane)
• Inversion/eversion motion: calcaneus (frontal plane)
Closed chain kinematics: (distal segment is not free)
Proximal and distal to STJ axis motion occurs in relative to fixed distal foot.
• Ankle DF: Tibia progress forward ( sagittal plane) and tibia rotates internally ( transverse plane)
• Ankle PF: tibia progress backward (SP) and tibia rotates externally (TP)
• Inversion/eversion is performed by calcaneus in similar manner.
18

19. During ankle joint plantarflexion/dorsiflexion, the shape of the body of talus facilities joint stability.
How?
Trochlear surface of talus – wider (anteriorly) than posteriorly.
Dorsiflexion of ankle in
weight-bearing
Tibia rotates over the
talus
The concave T-F segment
slides forward
The wider anterior talus
wedge into the mortise
Closed-pack position
plantarflexion of ankle in
weight-bearing
Tibia rotates over the
talus
The concave T-F segment
slides backward
The narrower body of
talus is within mortise
Loose-packed position
19

20. Asymmetry in size and orientation of M-L facets of ankle joint:
Significance: greater displacement of fibular malleolus than tibial malleolus as the tibia and fibula move
together during dorsiflexion. But this requires mobility of fibula at both proximal and distal tibiofibular
joints.
Medial facet
Lateral facet
20

21. THE SUBTALAR JOINT
The subtalar joint is also known as “talocalcaneal joint”, is a composite joint formed by three separate
plane articulations between the talus(superiorly) and the calcaneus (inferiorly).
SUBTALAR JOINT STRUCTURE
21

22. SUBTALAR JOINT LIGAMENTS
Additional ligaments supporting the subtalar joint:-
• Calcaneofibular ligament
• Interosseous talocalcaneal ligament
• Cervical ligament
22

23. SUBTALAR JOINT AXIS AND FUNCTION
The subtalar joint axis is:
1. Incline 42 ֯ upward and anteriorly from the transverse plane (with broad interindividual range of 29 ֯
to 47 ֯ )
2. Incline medially 16 ֯ from the sagittal plane (the broad range of 8 ֯ to 24 ֯ )
Clearly, motion about this oblique axis will cross all three planes. So the subtalar joint motion will be a
coupled motion of “supination and pronation” and cannot occur independently.
Transverse plane Sagittal plane 23

24. NON-WEIGHT BEARING STJ MOTION
In non-weight bearing supination and pronation, subtalar motion is described by the motion of it’s
distal components (the calcaneus and distal foot) on a stationary talus and tibia.
Open chain supination:
 Calcaneal Adduction
 Calcaneal inversion (or Varus)
 Calcaneal plantarflexion.
Open chain pronation:
 Calcaneal Abduction
 Calcaneal eversion (or valgus)
 Calcaneal dorsiflexion.
The most readily observable movement of calcaneus during supination and pronation will be
“inversion and eversion” .
Eversion is referred to as “valgus” movement and Inversion is referred to as “Varus” movement.
24

25. WEIGHT-BEARING STJ MOTION
In weight-bearing supination and pronation, subtalar motion is described by both proximal components
(tibia & talus) and distal component (calcaneus) on a fixed distal foot.
In closed chain, calcaneus is free to move in coronal plane (inversion/eversion) but limited to move in
transverse (adduction/abduction) and sagittal plane (PF/DF).
So these two coupled component movement is accomplished by – head of the talus.
Closed chain supination:
 Calcaneal inversion (or Varus)
 Talus abduction
 Talus dorsiflexion
 Tibiofibular lateral rotation
Closed chain pronation:
 calcaneal eversion (or Valgus)
 Talus adduction
 Talus plantarflexion
 Tibiofibular medial rotation.
https://www.youtube.com/watch?v=0R4zRSE_-40
25

26. Weight-bearing subtalar joint and it’s effect on the leg:
weight-bearing subtalar supination/pronation require talus head motion in DF/PF and AB/AD body
of talus lodged within mortise also moves.
The tibia (leg) remains unaffected by talar sagittal motions whereas ankle joint cannot absorb
component motions of talus in transverse plane without affecting the leg.
In WB ST supination = the head of talus abduct hence, the body of talus must rotate laterally.
In WB ST pronation = the head of talus adduct hence, the body of talus must rotate medially.
These rotation of body of talus within the mortise can only occur if “the superimposed mortise moves
with it”
26
The subtalar joint visualized as mitered hinge between the leg and the foot

27. SUBTALAR JOINT ROM AND SUBTALAR
NEUTRAL
The range of subtalar supination & pronation is difficult to determine because of the triplanar nature of
movement and component contributions vary with the inclination of subtalar axis.
The calcaneus inversion/eversion (Varus/Valgus) component of STJ motion can be measured in both
weight-bearing and non-weight bearing by:
• Using posterior calcaneus and posterior midline of the leg as reference points.
• Neutral position (0 ֯ ) – when the two posterior lines align to form a straight line
27

28. This subtalar neutral position of the STJ used as a reference for the “normal” or “ideal” foot position.
The weight-bearing position of the posterior calcaneus in relation to the posterior midline of the leg-
Increase in the medial angle b/w the 2 reference lines – Valgus of calcaneus (or Calcaneovalgus)
Decrease in the medial angle b/w the 2 reference lines- Varus of calcaneus (or Calcaneovarus)
For individuals without impairment:
Total range of subtalar motion is 25 ֯ to 40 ֯ with calcaneal inversion of 20 ֯ to 30 ֯ & calcaneal eversion
of 5 ֯ to 10 ֯.
28

29. TRANSVERSE TARSAL JOINT
The transverse tarsal joint, also called the Midtarsal or Chopart joint, is a compound joint formed by:
• Talonavicular joint
• Calcaneocuboid joint
The two joint together present an S-shaped joint line that transects the foot horizontally, dividing the
hind-foot from mid-foot and forefoot.
29

30. TRANVERSE TARSAL JOINT STRUCTURE
Talonavicular joint:
Proximal portion is formed by – anterior portion of
head of talus (convex)
Distal portion is formed by- posterior aspect of
navicular bone (concave)
In weight-bearing, talonavicular joint and subtalar
joint are both anatomically and functionally
related.
Calcaneocuboid joint:
Proximally- anterior portion of calcaneus
Distally- posterior cuboid bone.
The calcaneocuboid joint, like the talonavicular
joint is linked in weight-bearing to subtalar joint.
30

31. TRANSVERSE TARSAL JOINT AXIS
Elftman, Manter and Hicks have proposed longitudinal and oblique
axes of mid-tarsal joint around which the talus and calcaneus move
on the relatively fixed naviculocuboid unit.
• Longitudinal axis:
31
Transverse plane Sagittal plane

32. • Oblique Axis of transverse tarsal joint:
The oblique Axis is positioned approximately 57 degree medial to sagittal plane
52 degree superior to the transverse plane.
32
Transverse plane Sagittal plane

33. MIDTARSAL JOINT LOCKING/UNLOCKING
Subtalar joint position influences the mid-tarsal joint alignment and foot’s flexibility and rigidity. The
important foot functioning & biomechanics during the gait becomes possible due to the MTJ
locking/unlocking mechanism. How?
In pronation  MTJ unlocks TN and CC joint axes becomes parallel foot becomes mobile.
In supination MTJ locks TN and CC joint axes becomes non-parallel foot becomes rigid.
33

34. WEIGHT-BEARING HINDFOOT PRONATION &
TTJ MOTION
The major functioning of TTJ is to compensate the forefoot for hind-foot. Therefore, during
weight-bearing hindfoot pronation following adjustments are being made:
pronation of the hindfoot medial rotation of leg lateral border of foot is lifted from ground
TTJ absorb the hindfoot pronation  TTJ makes the distal segments “forefoot” to supinate 
maintains a normal weight-bearing forces.
This specific movement of transverse tarsal joint into either supination or pronation is dependent on
the demands of the terrain.
34
b. Normal Bilateral standing c. On uneven terrain
a. Normal unilateral WB

35. WEIGHT-BEARING HINDFOOT SUPINATION
& TTJ MOTION
supination of the subtalar joint in weight-bearing lateral rotation of leg  medial border of foot is
lifted from the ground  TTJ makes the distal segment “forefoot” to pronate in a limited range upto
some extend maintain normal weight-bearing forces.
35
a) STJ supination upto certain point, TTJ has limited
pronation.
b) & c) STJ supination exceeds, TTJ fails to compensate

36. TARSOMETATARSAL JOINT
The tarsometatarsal (TMT) joints also known as Lisfranc joint are plane synovial joints formed by:
• Posteriorly: distal row of tarsal bones
• Anteriorly: bases of five metatarsals
36

37. TMT JOINT AXES
Each TMT joint is considered to have a unique, although
not fully independent, axis of motion. Hicks examined the
axes for five rays.
Each axis is oblique  triplanar motion.
• Axis of 1st ray: inclined in such a way that DF of 1st ray
includes IN & AD
PF includes EV & ABD
• Axis of 5th ray: provides opposite arrangement of
components.
37

38. TARSOMETATARSAL JOINT FUCNTION
When hindfoot position is at an end point in its available ROM or transverse tarsal joint is inadequate to
provide full compensation, the TMT joint will come into its function to adjust the forefoot position.
Supination Twist
38
Extreme pronation at subtalar
joint in weight-bearing
Midtarsal joint supination is
insufficient to counteract
1st and 2nd ray is pushed
into DF by GRF
4th and 5th ray plantarflex at TMT joint
This component motion causes inversion of entire
forefoot around hypothetical axis at 2nd ray

39. 39
Extreme supination at subtalar
joint in weight-bearing
Transverse tarsal joint gets
locked in supination
1st and 2nd ray will plantarflex by
muscles controlling them
4th and 5th rays are pushed
into dorsiflexion by GRF
This component motion
causes forefoot
eversion
Pronation Twist

40. BIOMECHANICS OF FOOT DURING GAIT
1. At heel-strike:
Hind-foot supinate
2. From H.S to F.F:
Hind-foot pronate
Forefoot- supinate
3. During mid-stance:
Hind-foot prepare to
supinate
4. At heel-off:
Hind-foot supinated
Fore-foot pronate
5. After heel-off
Hind-foot pronate
Forefoot-pronate
6. At toe-off:
Hind-foot supinate
STJ pronation
• Tibial internal rotation
• STJ pronates- Midtarsal
joint unlocks
• Foot pliability increases.,
Forefoot supinate
• Foot Accommodate to
achieve WB
STJ supination
• Tibial external rotation
• STJ supinates- Midtarsal
joint locks
• Foot act as rigid lever
• Effective to achieve push-
off.
• Forefoot pronate to
maintain balance

41. FLATFEET
41
Physiological flatfeet
(Flexible flatfeet)
Pathological flatfeet
(Rigid flatfeet)
Causes:-
• Long standing
• Obesity
• Minor trauma
• Hypotonia
The longitudinal arch
present in NON-WB
and lost in WB
The longitudinal arch is
lost in both WB & NON-
WB conditions
FLATFEET
Causes:-
• Posterior tibialis
tendon dysfunction
• Tarsals coalition
• Achilles tendon
spasticity
• Accessary navicular
• CP

42. NORMAL ARCH HEIGHT & MEASUREMENT
42
Medial longitudinal arch: measurement parameters
Reference:
file:///C:/Users/Lenovo/Downloads/arch%20support.pdf

43. FLATFEET
Optimal alignment & deviation of optimal alignment in flatfeet:
Normal: the plump line should lie equidistant from the medial malleoli (anterior or posterior view)
Deviation observed in flatfeet: One malleolus appears more prominent or lower than the other with
calcaneal eversion, signifies pes planus or flatfeet.
43

44. DEVIATION IN OSTEOKINEMATICS
In either the rigid or flexible type of pes planus, bony displacement will be in such a manner:
Talar head: displaced anteriorly, medially and inferiorly.
Navicular bone: depressed causing tension in the spring ligament & lengthening of tibialis posterior
muscle.
44

45. DIAGNOSIS
CLINICAL DIAGNOSIS
• Appearance on/off weight
• ROM
• Clinical Maneuvers
• Gait observation
• Areas of tenderness
• Manual muscle testing
• Extra pedal findings
• Clinical test : Navicular drop test, Feiss
line test.
RADIOLOGIC DIAGNOSIS
• Kite’s angle
• CYMA line
• Calcaneal pitch
• Meary’s angle
45

46. CLINICAL TEST
46
FEISS LINE TEST:
Navicular bone position in relation to
the head of 1st MT and MM
NAVICULAR DROP TEST:
The height of NT is measured in neural
(A) and then relaxed standing (B)

47. DIAGNOSTIC REPRESENTATION
47
NORMAL KITE’S
ANGLE:
15-30 degrees
INCREASED KITE’S
ANGLE:
>30 degree
CYMA line (midtarsal joint line)

48. DIAGNOSTIC REPRESENTATIONS
48
MEARY’S TEST (TALAR-1ST MT TEST)
NORMAL
ALIGNMENT
ABNORMAL ALIGNMENT IN PES PLANUS

49. DIAGNOSTIC REPRESENTATIONS
49
CALCANEAL PITCH ANGLE
NORMAL
ALIGNMENT
ABNORMAL ALIGNMENT IN PES PLANUS

50. PATHOMECHANICS
50
Over-pronated foot
Unlocked mid-tarsal joint
Terminal stance causes rear-foot to plantar-flex on
forefoot
This places extreme overload on
supporting structures
Progressively over time, unlocked MT
joint succumbs constant deforming
force
Supporting structure begin to attenuate
and finally rupture

51. BIOMECHANICAL NEGATIVE IMPACT OF
FLATFEET
Alternations or disadvantages that occur due to flatfeet or pes planus:-.
• Unlocked midtarsal leads hyper flexible foot throughout gait.
• Loss of arch stability.
• Failure to provide adequate windlass mechanism.
• Failure of propulsion stage at terminal stance of gait cycle.
• Instability in propulsion phase.
51

52. ORHTOTIC MANAGEMENT OF FLATFEET
Flexible flatfeet (FFF):-
Orthotic treatment goal:
• To aid in arch realignment
• Control excessive motion of lower extremity and tibia
• Symptoms associated like pain & discomfort
o MEDIALARCH SUPPORTS:
52

53. o SOLE WEDGES:
o HEEL WEDGES:
53

54. o CUSTOMISED INSOLES:
o CONVENTIONAL FOOT ORTHOSIS WITH ARCH SUPPORTS:
54

55. ORTHOTIC INTERVENTION AND ITS BIOMECHANICAL
CONSIDERATIONS FOR ANKLE-FOOT COMPLEX
The orthotic management, biomechanical requirements and the specification of the appropriate orthosis will be
divided into three sections based on the nature of the principal impairment. Which are being addressed, these are:-
I. Conditions which result in weakness of the muscles which control the ankle-foot complex (and in selected
cases the knee).
II. Upper motor neuron lesions which result in hypertonicity or spasticity of the muscles.
III. Conditions which result in pain or instability due to loss of integrity of the structure of the lower leg and
ankle-foot complex.

56. The specific treatment objectives, the biomechanical requirements and appropriate orthotic design options will be described
for each of the commonly encountered forms of muscle weakness:
a) Weak or absent dorsiflexors:
Biomechanical negative Impact: Mild weakness may result in a foot slap & total absence causes foot drop.
Biomechanical specifications: the three-point force system need to be applied in the orthotic design which will be
identified as being appropriate to control foot drop during swing and also satisfy the requirement for preventing foot slap at
heel contact is shown in fig. 1

57. • Orthotic design solutions:
1. Conventional AFO with dorsiflexion assist mechanism.
2. Posterior leaf spring orthosis (PLS)
3. Articulated plastic AFO

58. b) Weakness or absent plantar flexors:
Biomechanical negative impact: Drop-off gait pattern prior to heel –off.
Biomechanical approach: using the same biomechanical approach as in previous section, the orthotic management of this
problem requires the application of three force system as shown in fig 2.
Fig 2. Three-force system required
to control excessive dorsiflexion
during midstance.

59. Orthotic design solution:
1. Conventional AFO with plantarflexion assist mechanism- control of joint motion will additionally require an
orthotic ankle joint which will resist excessive dorsiflexion and ideally assist active plantarflexion during
appropriate periods of stance phase.
2. Articulated plastic AFO with free plantarflexion.

60. c) Ankle weakness with subtalar instability:
Biomechanical negative impact:
weakness of the pronators will result in Varus position of the foot
during swing phase.
Alternatively, weakness of the supinators will result in a valgus
position of the foot during weight bearing.
Biomechanical approach:
The thee point force system required for the treatment is shown
in Fig 3.
Fig 3. Three-force system required to
control Varus/Valgus attitude

61. • Orthotic design solutions:
1. Conventional ankle foot orthosis with T-strap
2. Solid ankle polypropylene AFO
3. Plastic AFO with T-strap
4. Spiral AFO

62. d) Weak knee extensors:
Biomechanical negative impact: knee extensor and plantar-flexor weakness resulting in ‘crouched’ standing posture & gait
pattern.
Biomechanical approach:
The treatment requires sufficient PF power to prevent the ankle dorsifexing as the patient leans forward.
Fig 4. knee stabilizing effect of the
floor reaction AFO. (a) with the
ankle in plantigrade; (b) with the
ankle plantarflexed.

63. Orthotic design solution:
in severe cases KAFO must be prescribed but in some few cases of moderate weakness where the patient is light
stature, an AFO may be sufficient to provide the necessary resistance to dorsiflexion.
Example: in case of spina bifida with sacral lesions or in CP child typically present with combination of knee
extensor and plantar-flexor weakness.
1. Floor reaction ankle-foot orthosis (FRO)

64. CLASSIFICATION OF GAIT PATTERNS IN
SPASTIC HEMIPLEGIA
There are at least four types of gait patterns seen in spastic hemiplegic based sagittal plane
kinematics:-
1. Type 1 hemiplegia: ‘drop foot’ which is noted most clearly in the swing phase.
2. Type 2 hemiplegia:
1. Equinus + neutral knee and extended hip
2. Equinus + recurvatum knee and extended hip
3. Type 3 hemiplegia: characterized by contracture by gastro-soleus spasticity or contracture (stiff
knee gait).
4. Type 4 hemiplegia: marked with pelvic asymmetry, Equinus, stiff knee gait, flexed hip and
anterior pelvic tilt.
64

65. Gait patterns and management algorithm for Spastic
Hemiplegia
65

66. GAIT PATTERNS FOR SPASTIC DIPLEGIA
1. True Equinus: calf spasticity is frequently dominant resulting in ‘true Equinus’ gait with
hidden recurvatum at knee.
2. Jump gait (with or without stiff knee): spasticity of hamstrings and hip flexors along with
calf spasticity.
3. Apparent Equinus (with or without stiff knee): spasticity of iliopsoas and hamstrings with
decreased Equinus.
4. Crouch gait (with or without stiff knee): excessive dorsiflexion at ankle with excessive hip
& knee flexion.
66

67. 67
Apparent Equinus
gait pattern
Crouched gait pattern
Jump gait pattern

68. Gait patterns and management algorithm for Spastic Diplegia
68

69. TRAFOs
Significance of TRAFO:
• In case of hypertonia or hypertonicity – which presents with increased stretch reflex responses
leading to spasticity or rigidity. This spasticity is a result of disordered sensori-motor control that
present as sustained involuntary muscle activation, the changes in lower extremity can cause an
energy inefficient gait that is physically challenging & requires high level of concentration.
• Such gait can often be improved by special designed ankle foot orthosis (AFO), this special group
of AFOs termed as tone- reducing AFOs (TRAFOs)
• These AFOs aim to address such problems by reducing spasticity through the incorporation of
tone-reducing mechanisms that inhibit motor neurons that innervate spastic muscles.
Commonly used tone-reducing intervention include:-
 Inhibition of hypertonic reflexes
 Pressure over muscle insertions
 Prolonged Stretch strategies
 orthokinetics principle
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70. NP-AFO DESIGN CONCEPT
Neurophysiological AFOs:
• The design concept include Neurophysiological principles of Inhibition and facilitation
incorporated in a customized plastic AFOs with total contact design.
• Working principle:
inhibition: neurophysiological forces are used to inhibit certain abnormal tonic reflex activity.
Facilitation: activation of normal postural reactions through stimulation of key points of control.
• Neurophysiological forces incorporated in NP-AFO designs are of various patterns:
1) A three-point pressure system to biomechanically control calcaneal Varus. (fig-1)
2) A neurophysiological force on lateral aspect of plantar surface of foot to facilitate the eversion
reflex (peroneal) and recruit more proximal controls (vastus lateralis and gluteus medius). (fig-2)
3) A neurological force to inhibit the toe-grasp reflex (toe flexors) by unweighting the metatarsal
heads through use of a metatarsal arch. (fig-3)
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71. 71
Fig-1 Fig-2 Fig- 3

72. Use of foam toe-separators:
It is considered to be an effective treatment in patients with a separate toe-grasping reflex (plantar
grasp) to inhibit excess toe flexing (& ankle plantarflexion) tone and reduce pain.
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Toe-separators fabricated from
plastazote and toe extension
Toe- separators is
place under the toes.
Superior view

73. ALTERNATIVE DESIGN STRATEGIES IN
TRAFOs
• Toe-grasp reflex:
Spastic inhibitors bars and metatarsal arch supports can also be
used in AFO to unweigh metatarsal heads. (A & B)
• Positive supporting reaction reflex:
Also Triggered by pressure over ball of foot resulting in total
extensor pattern with noted increase tone in PF and inversion.
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Metatarsal pad under
heads of MT
A- toe-extension plate

74. Continue..
• The Inversion reflex and eversion reflex.
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Medial extension of MT pad
to elicit inversion reflex : In
case of tonic evertor reflex

75. • Pressure over Muscle Insertion:
Farber reported in 1974, that continuous firm pressure at the point of insertion has a tone-reducing
effect.
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Patella-tendon bearing
design AFO

76. • Orthokinetic Principle:
Originally developed in 1927 by Julius Fuchs, an orthopedic surgeon, which focuses on the physical
effects of materials placed over muscle bellies. There are dual Orthokinetic concepts used in it which
are Interrelated and must be applied simultaneously.
1) Passive field materials (cool, rigid and smooth) – produce inhibitory effect
2) Active field materials (warm, expansive and textured) – produce fascilitatory effect
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Bivalved Chattanooga articulating orthosis

77. REFERRENCES
• Joint structure and function a comprehensive analysis, Cynthia Norkin
• https://pubmed.ncbi.nlm.nih.gov/20184503/#:~:text=Tone%2Dreducing%20ankle%2Dfoot%20ort
hoses,their%20biomechanic%20and%20neurophysiologic%20effects.
• https://doctorlib.info/medical/anatomy/28.html
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4994968/#:~:text=Motion%20of%20the%20ankle
%20occurs,40%E2%80%9355%C2%B0%20of%20plantarflexion.
• http://www.oandplibrary.org/cpo/pdf/1986_01_015.pdf
• https://www.amputation.research.va.gov/limb_loss_prevention/Midtarsal_Joint_Locking.asp
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THANK
YOU