# The Ankle Joint Definition of Ankle Motions Definition of Ankle

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```					                                          2006 NATA Annual Meeting
Atlanta, GA

The “Ankle” Joint
Widely viewed as a single joint

Evaluation and Management                                        Actually a series of joints that
are highly integrated
of Subtalar Joint Dysfunction                                      Inferior Tibio-Fibular Syndemosis
Gary Wilkerson, EdD, ATC                                   Talocrural Joint
Subtalar Joint
Transverse Tarsal Joint
Tarsometatarsal Joints
Metatarsophalangeal Joints

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Definition of Ankle Motions                                                  Definition of Ankle Motions
1) In relation to orthogonal cardinal planes
Axis of motion assumed ⊥ to plane of motion                            Sagittal Plane
Where do planes/axes intersect?                                       Plantar Flexion – Dorsiflexion

One segment assumed to be stationary
Are planes/axes fixed in relation to position of stationary        Frontal Plane
segment? Horizontal and vertical?                                     Abduction – Adduction?
Inversion – Eversion
Supination – Pronation

Transverse Plane
Internal Rotation – External Rotation
Foot moving on fixed leg?
Leg moving on fixed foot?

3                                               4

1
Definition of Ankle Motions                                          Definition of Ankle Motions
2)    Motion of moving (usually distal) segment in relation to
stationary adjacent (usually proximal) segment                   Simultaneous motion of both segments?
Foot motion in relation to fixed leg?                             Motion defined in relation to adjacent segment?
Open-Chain (Foot Inv-Evr OR Sup-Pro?)                          Motion defined in relation to vertical or horizontal
Leg motion in relation to fixed foot?                             reference lines?
Closed-Chain (Leg Inv-Evr OR Abd-Add?)                            Leg Angle + Foot Angle = Pronation Angle

MEDIAL                                 LATERAL

5                                                               6

Functional Axis of Subtalar Joint                               Definition of Ankle Motions
3) In relation to direction of movement around a
functional axis
Functions like “mitred hinge”                                         Definition not dependent on position of adjacent
Rotation of segments in opposite directions                        segment or vertical/horizontal reference planes
Simultaneous motion in all 3 cardinal planes

7                                                               8

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Definition of Ankle Motions                              Definition of Ankle Motions
Inversion – Eversion                                     Supination – Pronation
1) Commonly use to describe “open-chain”                1) Commonly used to define foot alignment
motion of foot in relation to leg.                      under weightbearing “closed-chain” condition.
2) Almost exclusively used to describe acute            2) Commonly used to describe foot position
ankle injury mechanism.                                 during different phases of gait cycle.

9                                                        10

Definition of Ankle Motions                              Talocrural Joint
Triplanar Displacement
“Upper Ankle Joint”
Combined Sagittal + Transverse + Frontal
motions associated with subtalar joint function
Podiatry Definition
Supination = PF + Adduction + Inversion
Pronation = DF + Abduction + Eversion

Orthopedic Definition
Inversion = PF + Adduction + Supination
Eversion = DF + Abduction + Pronation

11                                                       12

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Inferior Tibio-Fibular Syndesmosis        Talus
Key structure between leg & foot
Function similar to of ball bearing
No muscle attachments
Almost completely covered with articular cartilage

13                                                          14

Talocrural Articular Surfaces             Functional Axis of Talocrural Joint

15                                                          16

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Functional Axis of Talocrural Joint                   Ankle Ligaments - ATFL

17                            18

Subtalar Joint                                        Subtalar Joint:
“Lower Ankle Joint” – Talo-Calcaneal Joint           Calcaneus + Talus
Part of Talo-Calcaneo-Navicular (TCN) Joint

19                            20

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Functional Axis of Subtalar Joint                    Subtalar Tri-planar Motion
Frontal Plane Component
Supination or Inversion

21                                            22

Functional Axis of Subtalar Joint                    Integrated TC + ST Function
Functions like “mitred hinge”
Rotation of segments in opposite directions                            Composite
TC/ST Axis
Frontal Plane + Transverse Plane

23                                            24

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Transverse Tarsal Joint                           Transverse Tarsal Joint
Rearfoot – Forefoot                      1) Oblique axis (OTT)
S-shaped joint line                           Motion in same direction as that of ST joint
2) Longitudinal axis (LTT)
Motion in direction opposite to that of ST joint

Navicular

Cuboid

25                                                           26

Transverse Tarsal Joint                           Mid-Foot Ligaments
Bifurcated Ligament
Rearfoot-Forefoot
twist

Subtalar
Joint

Transverse
Tarsal Joint

27                                                           28

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Tarsometatarsal Joints
Mid-Foot Ligaments
Collective function similar to that of
Transverse Tarsal Joint

Axis of
Axis of
1st Ray      5th Ray

Axis of
1st Ray

Axis of     Subtalar
29                            5th Ray       Axis               30

Metatarsophalangeal Joints                       Integrated Function of Foot/Ankle Joints
Integrated function of the 5 MTP joints           Weight-bearing heel elevation produces
represented by composite functional axis          hindfoot inversion
Transverse
greater extension of medial joints
Oblique
greater extension of lateral joints

31                                                             32

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Integrated Function of Foot/Ankle Joints                Heel Elevation – Hindfoot Inversion
Composite hindfoot axis
ST+TC
parallel to MTP axis
transverse
Oblique

33                                                    34

Muscle Actions: Eversion/Inversion                      Ankle/Foot Biomechanics
Forefoot, Rearfoot, & Leg mechanically linked

Lateral to ST Axis:
EVERTORS

Medial to ST Axis:
INVERTORS

35                                                    36

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Conventional View of Pronation
Pronation-Related Conditions
Focus on rearfoot
Plantar Faciitis
Medial Tibial Stress Syndrome                               Orientation of calcaneus in relation to leg
valgus position
Posterior Tibialis Tendinitis
Achilles Tendinitis                                         Status of longitudinal arch
Metatarsal Stress Fracture                                    navicular height

Patello-Femoral Syndrome
Position of talus relative to calcaneus
ACL Rupture                                                   “subtalar neutral”

37                                                    38

Frontal Plane Component of
Pronation: Integrated Joint Motions                      Subtalar Tri-planar Motion
1) Calcaneal Eversion (Valgus)

2) Internal Rotation + Lateral Deviation Of Leg

3) Plantar Flexion + Internal Rotation Of Talar Head

4) Compensatory Forefoot Supination (Varus)
Rearfoot Pronation (Subtalar Joint)
Forefoot Supination (Transverse Tarsal Joint)

39

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Pronation assessment tends to
be focused on position of foot in                             Pes Planus:
relation to horizontal support                                Plantar Flexion + Internal Rotation
surface.
of Head of Talus on Calcaneus
Pronation:

Foot Angle
vs.
Leg Angle

Leg segment does not remain
stationary in a vertical orientation                                    Associated with “Navicular Drop”
during functional activities!!!
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Gait Cycle                                                   Abnormal Pronation
Heelstrike → Mid-Stance → Toe-Off
Max pronation occurring beyond 25% of
Heelstrike to Mid-Stance
stance phase (walking)
Supination to Pronation
joint mobility
Diminished propulsive capability
shock absorption
Prolonged & excessive loads on tissues
Mid-Stance to Toe-Off                                           Improper timing of pronation may be more
Pronation to Supination                                      problematic than magnitude of pronation
joint surfaces locked
foot becomes rigid lever                                 May be due to deficiency in invertor
strength/endurance (posterior tibialis)
force transfer from Achilles tendon to toes
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Posterior Tibialis Tendon
SUPINATION
Primary insertion on navicular tuberosity
Dynamic stabilizer of medial longitudinal arch
PRONATION
Subjected to great mechanical stress
Eccentric action: Heel strike to mid-stance
MAX
Deceleration of pronation
Concentric action: Mid-stance to push-off
Supination of foot (increased rigidity)

Pathology
Tenosynovitis
Longitudinal tears
Complete rupture
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Posterior Tibialis Role in             Posterior Tibialis Test
Diminished capability to elevate heel, combined
Transfer of Force from
with lack of hindfoot supination
Rearfoot to Forefoot

1

2

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NORMAL                                      48

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Excessive Pronation                                         Forefoot-Hindfoot Twist
1) Tibia + talus internally rotated                           Forefoot relation to horizontal support surface: Neutral
Forefoot relation to hindfoot: Supinated (varus position)
2) Navicular + forefoot externally rotated
Forefoot abduction in relation to rearfoot

Forefoot -
Hindfoot                    Hindfoot
Neutral                    Pronation

Compensatory
Forefoot
Supination
Tendency for
Lateral Lift-Off

49                                                                     50

Fabrication of Thermoplastic Orthotics

52

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Fabrication of Thermoplastic Orthotics        Fabrication of Thermoplastic Orthotics

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Fabrication of Thermoplastic Orthotics        Chronic Ankle Dysfunction
10% to 50% of all lateral ankle sprains
Pain
Swelling
Giving-way
Repetitive reinjury

Isakov et al, Int J Sport Biomech, 1986
Karlsson & Lansinger, Clin Orthop, 1992
Konradsen et al, Foot Ankle, 1991
Peters et al, Foot Ankle, 1991
Smith & Reischl, AJSM, 1986
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MRI Studies:
Chronic Ankle Dysfunction                            Ankle Pathology
Clinicians often underestimate
1) Undiagnosed subtalar pathology?               severity of ankle ligament damage
Frey: FAI, 1996
Initial diagnosis vs. MRI results

2) Inadequate compensation for rotary
instability?                                  Subtalar ligaments are often
damaged by inversion injury
Togichi et al: FAI, 1998
> 50% of lateral ankle sprain cases

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Subtalar Pathology                                  Subtalar Joint:
Lateral Talocalcaneal Ligament
Lateral Pain/Instability
Interosseus Talocalcaneal Ligament
Sinus Tarsi Syndrome
Abnormality of one or more structures within
Cervical Ligament                                              sinus tarsi or tarsal canal
Feeling of hindfoot instability
Responsive to injection of local anesthetic
Etiology:
Sinus                    Trauma: 70% of cases
Tarsi                    Insidious inflammation: 30% of cases
Ankylosing spondylitis
Rheumatoid arthritis
Gout
LTCL
Ganglion cyst
Foot deformity

59                                                                       60

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Sinus Tarsi                                                                                      Subtalar Pathology
Separates anterior & posterior articulations
of subtalar joint                                                                            Lateral Talocalcaneal Ligament
Inferior Peroneal Retinaculum
Contents:                          Sinus
Tarsi                                                     Inferior Extensor Retinaculum - Lateral Root
Fat, nerves, arteries
Joint capsules (anterior & posterior)
ITFL & CL
Inferior Extensor Retinaculum “Roots”
Medial
Intermediate
Lateral

Inf. Per. Ret.
61    LTCL                              Inf. Ext. Ret.   62

Subtalar Joint Ligaments                                                              Lateral Ankle Sprain
ITCL
Pathomechanics
Cervical
Ant.Band                 Ligament
Post Band

Inf Ext Ret

Plantar                 ITCL
Ant.Band                                  Calcaneo-             Ant. Band
Post Band                                             Navicular
Ant.Band                   Ligament        Capsule of
Post Band                           Post ST Articulation

Post Band = Capsule of
Post ST Articulation

63                                                       64

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Talocrural PF:
VGRF Medial to ST Axis
ST Axis Orientation

65                              66

Typical Mechanism of LAS

2

1

67                              68

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Forefoot – Rearfoot Torque Transfer        Subtalar Inversion +
External Leg Rotation

69                                                                  70

Frontal Plane Lateral Talar Tilt
Locked Joints = Rigid Lever                Excessive talar tilt associated with ATFL damage

Widely viewed as a component of the ATFL injury mechanism

Support systems designed to restrict frontal plane motion

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Simplistic View of Ankle Sprain
Talar Tilt vs. Rotary Subluxation                                           Mechanism of Injury
ATFL critical role: restraint of
transverse plane rotation

Cass & Settles: FA, 1994
Colville et al: AJSM,1990
Hintermann: MSSE, 1999
Johnson & Markolf: JBJS(A), 1983
McCullough & Burge: JBJS(B), 1980
Parlasca et al: Clin Orthop, 1979
Rasmussen & Tovborg: Acta Orthop Scand, 1981
Renstrom et al: FA, 1988
Stormont et al: AJSM, 1985
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Ankle Taping
Lateral Subtalar Sling
Stirrup strips & heel locks
High-strength semi-elastic tape
Encasing hindfoot probably resists lateral distraction of          1 or 2 strips oriented at 45º in sagittal
joint surfaces within the frontal plane                            plane & wrapped around leg

spans all joints between forefoot & leg

4th & 5th Tarsometatarsal Joints
Transverse Tarsal Joint
Subtalar Joint
Talocrural Joint

75                                                 76

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Lateral Subtalar Sling                                                                   Lateral Subtalar Sling
ER of leg generates tension within
Tension generated within longitudinal fibers of tape                                         longitudinal fibers of tape
Vertical component resists frontal plane motion of foot                                       restrains INV of lateral border of foot
A-P component resists anterior translation of talus (anterior drawer)                         restrains IR of talus in relation to leg ER

77                                                                78

Subtalar Joint Ligaments
Intermediate       Cervical                                  Lateral Subtalar Sling
Root -         Ligament
Inf. Ext. Ret.                Ext.Dig.
Ant. Articular Surface                            Brevis                          Wilkerson: AJSM, 1991
Medial Root -
Inf. Ext. Ret
Standard: Gibney/Heel-Locks
Lateral Root -              Modified: Gibney/Heel-Locks + Lateral Subtalar Sling
Inf. Ext. Ret.
2 - 3 hours of football practice
Peroneal
Tendons

Interosseus                          Posterior
Talo-Calcaneal                        Articular
Ligament                             Surface

Capsule of
Posterior
Subtalar
Articulation
Superior
View
ST Axis
80

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Wilkerson: AJSM, 1991
Ankle Capsule: Normal vs. Distended
Post-ex INV restraint increased 94%
Untaped INV: 40º
Tape residual restriction: 8.5º vs 16.5º

8.5º        16.5º

Sagittal: 9.56 Nm (7 ft lbs)
Frontal: 6.67 Nm (5 ft lbs)

81                                          82

ATFL-Capsule Compaction                                                           Antero-Lateral Impingement
Edema proteins absorbed by synovium
Chronic inflammatory response
Synovial hypertrophy
Development of extensive adhesions
Fibrous scarring of synovium
Hyalinization of lesion
Chondromalacia of talus

83                                          84

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Ankle Impingement Syndrome                                             Medial Subtalar Sling
Support of medial longitudinal arch
Restraint of subtalar eversion
Decreased Antero-Lateral Impingement
Decreased load on Posterior Tibialis
Protection of Deltoid Ligament
Protection of Tibio-Fibular Syndesmosis

85                                                                     86

Subtalar Sling: Mechanical Effect                                   Antero-Posterior Displacement (mm)
Wilkerson G, Kovaleski J, Meyer M, Stawitz C
6 degree of freedom arthrometer                    125 N (28 lb) anterior-posterior force
23 physically active subjects                   Significant Trial X Method interaction (p <.001)
12 males & 11 females
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No history of ankle dysfunction
Standard taping vs. modified taping
Modified: medial + lateral ST sling                                       16

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Estimated Marginal Means
12

METHOD
10
1

8                              2
1          2           3
Untaped   Taped      Untaped
Pre-Ex
TRIAL   Post-Ex    Post-Ex
87                                                                     88

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Measurement of
Advantages of Taping                                                Inversion Velocity &
Improved Joint Position Sense                                      Leg External Rotation

Peroneal Facilitation

Inversion Deceleration
3X greater restraint
of Max ER
Restriction of Max Subtalar Motion
2X greater reduction
Control of Anterior Drawer                                                                 of Avg Inv Velocity

2X greater reduction
Restraint of Anterolateral Rotary Instability?                                             of Peak Inv Velocity

89                                                  90

Mechanical
Advantages of Bracing                                                   Effect?

Ease of Application

Improved Joint Position Sense

Inversion Deceleration

Restriction of Max Inversion

Restriction of Leg Rotation???          45°

91

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Ankle Brace Designs                                    Measurement of Leg External Rotation

Articulated Stirrup

Lace-Up Ankle Gauntlet
(with or without straps)

Combination

No Brace: 11.7 ±3.9
93                                          94

Measurement of Leg Rotation                            Summary

Gary-Wilkerson@utc.edu

10.7 ±4.2         11.5 ±4.6
www.utc.edu/gatp → “Program News”

9.9 ±3.1         11.4 ±3.8            8.5 ±3.1

No Brace: 11.7 ±3.9
95                                          96

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