Foot and Ankle Biomechanics 9780128154496, 0128154497

Table of contents :
Cover
Foot and Ankle Biomechanics
Copyright
List of contributors
Dedication
Contents
Preface
Anatomical Terms Used in Foot and Ankle Biomechanics
1 Anatomy of the Foot
1.1 Skeletal structures
1.1.1 Tibia and fibula
1.1.2 Segments of the foot skeleton
1.1.3 Talus
1.1.4 Calcaneus
1.1.5 Navicular
1.1.6 Cuboid
1.1.7 Medial cuneiform
1.1.8 Intermediate cuneiform
1.1.9 Lateral cuneiform
1.1.10 Metatarsals
1.1.10.1 First metatarsal
1.1.10.2 Second metatarsal
1.1.10.3 Third metatarsal
1.1.10.4 Fourth metatarsal
1.1.10.5 Fifth metatarsal
1.1.11 Phalanges
1.1.11.1 Proximal phalanges
1.1.11.2 Middle phalanges
1.1.11.3 Distal phalanges
1.2 Joints
1.2.1 Tibiofibular syndesmosis
1.2.2 Ankle joint
1.2.3 Subtalar joint
1.2.4 Talocalcaneonavicular joint
1.2.5 Calcaneocuboid joint
1.2.6 Cuboideonavicular joint
1.2.7 Cuneonavicular joints
1.2.8 Intercuneiform and cuneocuboid joints
1.2.9 Tarsometatarsal joints
1.2.10 Proximal intermetatarsal joints
1.2.11 Distal intermetatarsal joints
1.2.12 Lesser metatarsophalangeal joints
1.2.13 Hallucal metatarsophalangeal joint
1.2.14 Interphalangeal joints
1.3 Muscles and fascial specializations
1.3.1 Fascial specializations
1.3.2 Extrinsic dorsal muscles
1.3.2.1 Tibialis anterior
1.3.2.2 Extensor digitorum longus
1.3.2.3 Extensor hallucis longus
1.3.2.4 Peroneus tertius
1.3.3 Extrinsic plantar muscles
1.3.3.1 Triceps surae
1.3.3.2 Plantaris
1.3.3.3 Flexor digitorum longus
1.3.3.4 Flexor hallucis longus
1.3.3.5 Tibialis posterior
1.3.4 Extrinsic lateral muscles
1.3.4.1 Peroneus longus
1.3.4.2 Peroneus brevis
1.3.5 Intrinsic dorsal foot muscles
1.3.5.1 Extensor hallucis brevis and extensor digitorum brevis
1.3.6 Intrinsic plantar muscles
1.3.6.1 Abductor hallucis
1.3.6.2 Flexor digitorum brevis
1.3.6.3 Abductor digiti minimi
1.3.6.4 Quadratus plantae
1.3.6.5 Lumbricals
1.3.6.6 Flexor hallucis brevis
1.3.6.7 Flexor digiti minimi brevis
1.3.6.8 Adductor hallucis
1.3.6.9 Dorsal and plantar interossei
1.4 Nerves
1.4.1 The fibular nerves in the foot
1.4.2 The tibial nerves in the foot
1.5 Blood supply
1.5.1 Arteries
1.5.2 Veins
1.5.2.1 Superficial veins
1.5.2.2 Deep veins
1.5.3 Lymphatics
Further reading
2 Basic Biomechanics
2.1 Introduction
2.2 Terminology
2.3 Statics
2.4 Dynamics
2.5 Strength of materials and deformation
2.6 Viscoelasticity
2.7 Summary
References
3 Anatomical Nomenclature: Conundrums of Nonstandardized Foot and Ankle Terminology
3.1 Introduction
3.2 Anatomical descriptions
3.2.1 The persistence of eponyms
3.2.2 Regional descriptions
3.2.2.1 The distal element of the lower limb
3.2.2.2 Forefoot and hindfoot
3.2.3 Applying the anatomical position
3.2.4 Application specific human anatomical positions
3.2.5 Defining anatomical directions, planes, and axes
3.2.5.1 Posterior–anterior versus ventral–dorsal
3.2.5.2 Anatomical planes
3.2.5.3 Foot midline
3.3 Foot motions
3.3.1 Defining motions
3.3.1.1 Flexion-extension
3.3.1.2 Adduction-abduction versus external-internal rotation
3.3.2 Whole foot motions and their complexity
3.3.2.1 Plantarflexion-dorsiflexion
3.3.2.2 Inversion—eversion
3.3.2.3 Pronation—supination
3.4 Terminological implications of mathematical choices
3.5 Conclusion: standardizing foot and ankle terminology
References
4 Kinematics and Kinetics of the Foot and Ankle during Gait
4.1 Introduction
4.2 Overview of relevant anatomy
4.3 Overview of kinematic and kinetic modeling
4.4 Healthy and impaired feet
4.5 Multisegment foot models
4.6 Future areas of research
4.6.1 Biplane fluoroscopy
4.6.2 Modeling
4.7 Conclusion
References
5 Bone, Cartilage, and Joint Function
5.1 Bone components and structure
5.2 Cartilage
5.3 Joint functions
5.3.1 Talocrural joint
5.3.2 Talocalcaneal (subtalar) joint
5.3.3 Transverse tarsal joint
5.3.4 Tarsometatarsal joint
5.3.5 Metatarsophalangeal joint
5.4 Areas of future research
References
6 Muscles and Tendons
6.1 Introduction
6.2 Biomechanical function
6.2.1 Normal foot
6.2.1.1 Foot stability
6.2.1.2 Balance
6.2.1.3 Locomotion
6.2.2 Aging
6.2.3 Pathologies
6.2.3.1 Plantar fasciitis
6.2.3.2 Pes planus
6.2.3.3 Toe deformities
6.2.3.4 Diabetic neuropathy
6.2.4 Footwear and orthoses
6.2.5 Interventions
6.3 Areas of future biomechanical research
References
7 Ligaments
7.1 Introduction
7.2 Ligament anatomy
7.3 Mechanical properties
7.3.1 Ankle joint
7.3.1.1 Lateral collateral ligaments
7.3.1.2 Medial collateral ligaments
7.3.2 Hindfoot ligaments
7.3.2.1 Subtalar joint
7.3.2.2 Talonavicular joint
7.3.3 Midfoot ligaments
7.3.3.1 Plantar fascia
7.3.3.2 Metatarsal base ligaments
7.3.4 Forefoot
7.3.5 Variations in mechanical properties
7.3.5.1 Changes in activity level
7.3.5.2 Foot comorbidity
7.3.5.3 Age effects
7.3.5.4 Influence of anthropometric effects
7.4 Ligament sprains
7.5 Overcoming limitations
7.6 Future areas of research
References
8 Plantar Soft Tissue
8.1 Introduction
8.2 Anatomy
8.2.1 Gross anatomy
8.2.2 Histological or biochemical
8.2.3 Medical imaging of tissue thickness
8.3 Biomechanical function
8.4 Mechanical properties
8.4.1 Structural in vivo testing
8.4.2 Structural ex vivo testing
8.4.3 Material ex vivo testing
8.4.4 Ultrasound
8.4.5 Other in vivo techniques
8.5 Effect of aging
8.6 Diabetic plantar soft tissue
8.6.1 Other pathologies associated with the plantar soft tissue
8.7 Areas of future biomechanical research
References
9 Multisegment Foot Models
9.1 Basic principles of multisegment foot models
9.1.1 Overview of motion capture
9.1.2 Why use a multisegment foot model?
9.2 Selecting an appropriate multisegment foot model
9.2.1 Segments and bone groupings
9.2.2 Marker type and placement
9.2.3 Coordinate systems
9.2.4 Offsets
9.2.5 Standardized description of multisegment foot models
9.3 Review of current multisegment foot models
9.3.1 Milwaukee kinematic model
9.3.2 Leardini/Rizzoli kinematic model
9.3.3 Oxford kinematic model
9.3.4 MacWilliams/Kinfoot kinetic model
9.3.5 Bruening kinetic model
9.3.6 Direct comparison of current multisegment foot models
9.4 Applications, considerations, and limitations
9.4.1 Clinical applications
9.4.2 Sources of error
9.5 Areas of future biomechanical research
References
10 Invasive Techniques for Studying Foot and Ankle Kinematics*
10.1 Introduction
10.2 Early invasive studies of foot and ankle biomechanics
10.3 Radiostereometric analysis
10.3.1 Technique
10.3.2 Talocrural joint
10.3.3 Relationship between the joints distal to the talus
10.3.4 Transferral of rotation between the leg and the foot
10.3.5 Ankle mortise width
10.4 Applications and significance of studies using intracortical pins for foot and ankle kinematics
10.4.1 Skin movement artifact in foot and ankle kinematics
10.4.2 Ankle kinematics
10.4.3 Foot and ankle basic research in walking and running kinematics
10.4.4 Applied studies of orthoses and shoe conditions
10.5 Limitations and future directions
Appendix: Insertion of markers in bones of the foot and ankle
References
11 Biplane Fluoroscopy
11.1 Introduction
11.2 Background and history of biplane fluoroscopy
11.2.1 Overview of how X-ray imaging works
11.2.2 Overview of biplane system history and evolution
11.2.2.1 Intact C-arm systems for foot bone tracking
11.2.2.2 Disarticulated C-arm systems for foot bone tracking
11.2.2.3 Custom dedicated biplane hardware for foot bone tracking
11.3 Other techniques for tracking foot bone kinematics
11.4 Challenges specific to foot and ankle tracking with biplane fluoroscopy
11.5 Overview of biplane hardware
11.6 Overview of biplane software
11.7 Clinical biplane foot and ankle studies
11.7.1 Biplane systems consisting of two C-arms
11.7.2 Biplane systems consisting of two modified C-arms
11.7.3 Biplane systems consisting of independent X-ray sources and image intensifiers
11.8 Future applications and directions
References
12 Plantar Pressure and Ground Reaction Forces
12.1 Introduction: clinical relevance of force and pressure measurements in foot and ankle biomechanics
12.2 Background: force versus pressure
12.2.1 History
12.2.2 Development of measurement technologies
12.2.3 Visualization and analytical options
12.3 Research applications and selected clinical examples
12.3.1 Diabetes
12.3.2 Children’s flatfoot
12.3.3 Sports
12.4 Areas of future research
References
13 Electromyography and Dynamometry for Investigating the Neuromuscular Control of the Foot and Ankle
13.1 Introduction
13.2 Electromyography
13.2.1 Surface electromyography
13.2.2 Indwelling electromyography and motor unit recordings
13.3 Dynamometry
13.3.1 Isometric
13.3.2 Dynamic
13.4 Ankle and foot related considerations and insights
13.4.1 Motor unit behavior and quantity
13.4.2 Maximal voluntary contractions and knee angle
13.4.3 History-dependence of force
13.5 Future research
References
14 From Impossible to Unnoticed: Wearable Technologies and The Miniaturization of Grand Science
14.1 Introduction
14.1.1 Tech affords understanding
14.1.2 Wearable domains
14.1.3 Breakout box: what makes a successful wearable device?
14.2 The past
14.2.1 Force and pressure
14.2.2 Health and activity sensing
14.3 The present
14.3.1 Force and pressure sensing
14.3.2 Health and activity monitoring
14.3.3 Actuation and assistance
14.3.4 Haptics
14.3.4.1 Sensory substitution
14.3.4.2 Cueing and notification
14.3.5 Motion capture
14.4 The future
References
15 Integrated Laboratories for Pursuing Pedal Pathologies
15.1 Introduction
15.2 Our method of approach
15.3 Integrated laboratories
15.3.1 Epidemiology
15.3.2 In vivo experimentation
15.3.2.1 Gait analysis
15.3.2.2 Plantar pressure assessments
15.3.2.3 Measures of foot structure
15.3.2.4 Other measures
15.3.3 In vitro experimentation
15.3.3.1 Histology
15.3.3.2 Cadaveric simulators
15.3.4 In silico simulation
15.3.4.1 Medical image processing
15.3.4.2 Finite element modeling
15.3.4.3 Musculoskeletal modeling
15.3.4.4 Sensitivity studies
15.3.4.5 Validation
15.4 Case study of the integrated laboratories concept to the study of hallux rigidus
15.4.1 Epidemiology
15.4.2 In vivo experimentation
15.4.3 In vitro experimentation
15.4.4 In silico simulation
15.5 Future biomechanical research
References
16 Radiographs
16.1 Introduction
16.2 Radiographic technology
16.3 Standard radiographic views of the foot and ankle
16.4 Definitions of X-ray measurements of foot shape
16.5 Foot-specific applications and considerations
16.6 Clinical X-ray measures of foot shape
16.7 Issues with X-ray measures of foot shape
16.8 Areas of future biomechanical research
References
17 Computed Tomography of the Foot and Ankle
17.1 Introduction
17.1.1 History and development of computed tomography
17.1.2 Comparison to other imaging modalities
17.1.3 Computed tomography protocols for the foot and ankle
17.2 Foot-specific applications and considerations
17.2.1 Disease diagnosis
17.2.2 Surgical assessment and planning
17.2.3 Biomechanics research
17.2.3.1 Kinematic measurements
17.2.3.2 Bone density properties
17.2.3.3 Computational models
17.2.3.4 Shape modeling and assessment
17.3 Areas of future biomechanical research
References
18 Weight-bearing Computed Tomography of the Foot and Ankle
18.1 Introduction
18.2 Biases of conventional radiography
18.3 Technical aspects
18.4 Indications
18.5 3D biometrics
18.6 Advantages and limitations of weight-bearing computed tomography
18.7 Future areas of research
18.8 Conclusion
Acknowledgments
Conflict of interest statement
References
Further reading
19 Magnetic Resonance Imaging of the Foot and Ankle
19.1 Introduction
19.2 Magnetic resonance imaging sequences
19.3 Magnetic resonance imaging versus computed tomography
19.4 Magnetic resonance imaging appearance of musculoskeletal tissue—normal and pathology
19.4.1 Short T2 tissues
19.4.2 Tendons
19.4.3 Pseudo tendon pathology—the magic angle effect or phenomenon
19.4.4 Ligaments
19.4.5 Bone
19.4.6 Hyaline and fibrocartilaginous cartilage
19.4.7 Muscle
19.4.8 Bursa/synovia
19.5 Tailored magnetic resonance imaging protocol for the foot and ankle—indication driven
19.5.1 Imaging orientation
19.5.2 Tailored magnetic resonance imaging protocols
19.5.3 Optimized imaging planes
19.5.4 Metal artifact reduction sequences
19.6 Magnetic resonance imaging anatomy of the foot and ankle
19.6.1 Ankle
19.6.1.1 Ligaments
19.6.1.2 Bony defects and ligament injuries
19.6.2 Hindfoot
19.6.2.1 Tendons
19.6.2.2 Enthesitis—plantar fasciitis
19.6.3 Midfoot
19.6.3.1 Degenerative joint disease
19.6.3.2 Stress fractures
19.6.4 Forefoot
19.6.4.1 Morton’s neuroma
19.6.4.2 Osteomyelitis
19.6.4.3 Plantar plate tears
19.7 Areas of future research
19.7.1 Radiation-free bone imaging
19.7.2 Magnetic resonance imaging scan time reduction
19.7.3 Volumetric, isotropic 3D magnetic resonance imaging sequences
References
20 Biomechanical Assessment of Soft Tissues in the Foot and Ankle Using Ultrasound
20.1 Introduction
20.1.1 Ultrasound imaging, how it works
20.2 Ultrasound assessment of structural changes: the effect of weightbearing activities
20.2.1 Assessment of plantar soft tissue thickness in relation to weightbearing activities
20.2.2 Assessment of plantar fascia thickness in relation to weightbearing activities
20.2.3 Assessment of Achilles tendon thickness in relation to weightbearing activities
20.2.4 Summary and limitations of weightbearing ultrasound
20.3 Ultrasound assessment combined with measurement of load
20.3.1 Ultrasound combined with load cells to assess the mechanical properties of the plantar soft tissue
20.3.2 Ultrasound combined with dynamometry to assess the mechanical properties of Achilles tendon
20.3.3 Summary and limitations of ultrasound assessment combined with measurement of load
20.4 Ultrasound elastography (sonoelastography)
20.4.1 Ultrasound elastography to assess the mechanical properties of plantar soft tissue
20.4.2 Ultrasound elastography to assess the mechanical properties of plantar fascia
20.4.3 Ultrasound elastography to assess the mechanical properties of Achilles tendon
20.4.4 Summary and limitations of ultrasound elastography
20.5 Conclusion and future areas of research
References
21 3D Surface Scanning of the Foot and Ankle
21.1 Introduction
21.1.1 The history and development of 3D scanning
21.1.2 Technologies
21.1.2.1 Contact scanners (coordinate measuring machines)
21.1.2.2 Noncontact scanners
21.2 Foot-specific applications and considerations
21.2.1 Reliability and comparisons to other techniques
21.2.2 Population studies
21.2.3 Orthoses and footwear
21.2.4 Musculoskeletal models
21.2.5 Bones and other internal anatomy
21.3 Areas of future biomechanical research
References
22 Cadaveric Gait Simulation
22.1 Introduction
22.2 Techniques for dynamic gait simulation
22.3 Limitations of dynamic gait simulation
22.4 Clinical applications of dynamic gait simulation
22.5 Areas of future biomechanical research
22.6 Conclusion
References
23 Finite Element Modeling
23.1 Introduction
23.2 Basic concepts of finite element modeling
23.3 Applications of finite element analysis in foot biomechanics
23.3.1 Simulation of the interaction between foot and footwear
23.3.2 Simulation of healthy foot biomechanics
23.3.3 Finite element modeling for the in vivo material characterization of soft tissues
23.3.4 Simulation of pathological conditions
23.3.4.1 Biomechanics of the pathologic foot
23.3.4.2 Study of surgical interventions
23.4 Modeling strategies
23.4.1 Geometry design
23.4.1.1 3D modeling versus 2D modeling
23.4.1.2 Modeling of the entire foot compared to anatomically focused modeling
23.4.1.3 Anatomically detailed compared to idealized modeling
23.4.2 Meshing
23.4.2.1 Element type selection
23.4.2.2 Mesh convergence
23.4.3 Material properties
23.4.3.1 Bone and cartilage
23.4.3.2 Ligaments and tendons
23.4.3.3 Soft tissues
23.4.4 Solver selection
23.4.5 Reliability assessment
23.5 Limitations and future research toward clinically applicable finite element modeling
23.6 Summary
References
24 Musculoskeletal Modeling of the Foot and Ankle
24.1 Introduction
24.1.1 Musculoskeletal models and their development
24.1.2 Validation techniques
24.1.3 Challenges in modeling the foot and ankle
24.2 Foot specific models and applications
24.3 Areas of future biomechanical research
References
25 Predicting and Preventing Posttraumatic Osteoarthritis of the Ankle
25.1 Introduction: pathomechanical origins of posttraumatic osteoarthritis
25.2 Pathomechanics I: acute joint injury severity
25.3 Pathomechanics II: chronic stress aberration
25.4 Pathomechanics III: altered kinematics
25.5 Areas of future biomechanical research
25.5.1 Posttraumatic ankle osteoarthritis: opportunities for intervention informed by pathomechanical knowledge
25.6 Summary/conclusion
References
26 Mechanics of Biological Tissues
26.1 Introduction
26.2 Materials and methods
26.2.1 Finite element modeling of the foot
26.2.2 Formulation of constitutive models
26.2.2.1 Linear elastic constitutive models
26.2.2.2 Hyperelastic constitutive models
26.2.2.3 Visco-hyperelastic model
26.2.3 Identification of constitutive parameters
26.2.3.1 Constitutive parameter identification for bone
26.2.3.2 Constitutive parameter identification for cartilage
26.2.3.3 Constitutive parameter identification for plantar soft tissue
26.2.3.4 Constitutive parameter identification for ankle ligaments
26.2.4 Numerical analyses of foot functionality
26.2.4.1 Ankle movements
26.2.4.2 Gait cycle
26.2.4.3 Foot and footwear interaction
26.2.4.4 Diabetic condition
26.2.5 Limitations of computational modeling
26.2.6 Future biomechanics research
26.3 Conclusion
References
27 Clinical Examination of the Foot and Ankle
27.1 Introduction
27.2 Demographics
27.3 Vital signs
27.4 Patient history
27.5 Assessment of pain
27.6 Visual observation/inspection
27.6.1 Skin
27.6.2 Edema
27.6.3 Atrophy
27.6.4 Temperature
27.6.5 Scarring
27.6.6 Callus patterns
27.6.7 Exostoses
27.6.8 Ankle and foot deformities
27.7 Lower extremity alignment
27.8 Foot posture or foot shape
27.8.1 Planus foot type
27.8.2 Cavus foot type
27.9 Limb length
27.10 Radiographic examination
27.11 Range of motion/flexibility/joint mobility
27.12 Joint mobility
27.13 Ligamentous/stability testing
27.14 Tendon
27.15 Muscle strength
27.16 Sensory testing
27.17 Circulation
27.18 Foot and ankle specific testing
27.19 Footwear examination
27.20 Functional assessment
27.21 Outcomes assessment
27.22 Areas of future biomechanical research
References
28 Foot Type Biomechanics
28.1 Introduction
28.2 Structural foot type
28.3 Functional foot type
28.4 Foot type biomechanics
28.5 Association with pain and injury
28.5.1 Pain and injury
28.6 Treatments
28.7 Areas of future biomechanical research
References
29 Traumatic Foot and Ankle Injuries
29.1 Introduction
29.2 Pilon fractures
29.2.1 Etiology and pathophysiology
29.2.2 Symptoms
29.2.3 Diagnostics/classification
29.2.4 Treatment
29.3 Calcaneal fractures
29.3.1 Etiology and pathophysiology
29.3.2 Symptoms
29.3.3 Diagnostics/classification
29.3.4 Treatment
29.4 Talus fractures
29.4.1 Etiology and pathophysiology
29.4.2 Symptoms
29.4.3 Diagnostics/classification
29.4.4 Treatment
29.5 Tarsometatarsal (Lisfranc) injuries
29.5.1 Etiology and pathophysiology
29.5.2 Symptoms
29.5.3 Diagnostics/classification
29.5.4 Treatment
29.6 Metatarsal fractures
29.6.1 Etiology and pathophysiology
29.6.2 Symptoms
29.6.3 Diagnostics/classification
29.6.4 Treatment
29.7 Midfoot crush injuries
29.7.1 Etiology and pathophysiology
29.7.2 Symptoms
29.7.3 Treatment
29.8 Acute ankle sprains
29.8.1 Etiology and pathophysiology
29.8.2 Symptoms
29.8.3 Treatment
29.9 Syndesmosis tears
29.9.1 Etiology and pathophysiology
29.9.2 Symptoms
29.9.3 Treatment
29.10 Achilles tendon rupture
29.10.1 Etiology and pathophysiology
29.10.2 Symptoms
29.10.3 Treatment
29.11 Areas of future research
References
30 The Pediatric Foot
30.1 Introduction
30.2 Common pathologies affecting pediatric feet
30.2.1 Congenital foot deformities
30.2.2 Developmental foot deformities
30.2.3 Foot pathologies associated with other conditions
30.3 Functional assessment of the pediatric foot
30.4 Areas for future research
References
31 Neurological Foot Pathology
31.1 Introduction
31.2 Stroke
31.2.1 Pathology related to the musculoskeletal system
31.2.2 Impact on kinematics
31.2.3 Impact on foot function
31.2.4 Clinical treatment
31.3 Cerebral palsy
31.3.1 Definition
31.3.2 Structural deformities and gait deviations
31.3.3 Treatment
31.4 Toe walking
31.4.1 Diagnosis and etiology
31.4.2 Biomechanical and musculoskeletal function
31.4.3 Treatment
31.5 Peripheral neuropathy
31.5.1 Background
31.5.2 Musculoskeletal and movement implications
31.6 Foot drop
31.6.1 Pathology
31.6.2 Impact on biomechanics
31.6.3 Treatment
31.7 Tarsal tunnel syndrome
31.7.1 Pathology
31.7.2 Impact on biomechanics
31.7.3 Treatment
31.8 Morton’s neuroma
31.8.1 Pathology
31.8.2 Impact on biomechanics
31.8.3 Treatment
31.9 Charcot foot
31.9.1 Pathology
31.9.2 Impact on biomechanics
31.9.3 Treatment
31.10 Charcot-Marie-Tooth disease
31.10.1 Pathology
31.10.2 Impact on biomechanics—pediatric and young adult
31.10.3 Impact on biomechanics
31.10.4 Treatment
31.11 Friedreich’s ataxia
31.11.1 Background and pathology
31.11.2 Gait analysis
31.11.3 Musculoskeletal effects
31.11.4 Clinical treatment
31.12 Poliomyelitis
31.12.1 Pathology
31.12.2 Current status
31.12.3 Impact on biomechanics
31.12.4 Treatment
31.13 Areas of Future Research
References
32 Chronic Foot and Ankle Injuries
32.1 Introduction
32.1.1 Chronic injury through microtrauma
32.1.2 Chronic injury through macrotrauma
32.1.3 Impairment-based rehabilitation model for treating chronic injuries
32.1.4 Role of patient-oriented outcomes
32.2 Chronic ankle instability
32.2.1 Anatomy overview
32.2.2 Etiology
32.2.2.1 Mechanism of injury and pathomechanics
32.2.3 Clinical impairments
32.2.3.1 Range of motion
32.2.3.2 Strength
32.2.3.3 Balance
32.2.3.4 Functional activity
32.2.4 Treatment
32.2.4.1 Acute management
32.2.4.2 On-going management
32.3 Plantar fasciitis
32.3.1 Anatomical overview
32.3.2 Etiology
32.3.2.1 Mechanism of injury and pathomechanics
32.3.3 Clinical impairments
32.3.3.1 Range of motion
32.3.3.2 Strength
32.3.3.3 Functional activity
32.3.4 Treatment
32.3.4.1 Acute management
32.3.4.2 On-going management of clinical impairments
32.4 Tendinopathy (Achilles, peroneal, and posterior tibialis)
32.4.1 Anatomical overview
32.4.2 Etiology
32.4.2.1 Mechanism of injury and pathomechanics
32.4.2.1.1 Achilles tendon
32.4.2.1.2 Tibialis posterior tendon
32.4.2.1.3 Peroneal tendon
32.4.3 Clinical impairments
32.4.4 Treatment
32.5 Stress fractures (navicular, metatarsals)
32.5.1 Anatomical overview
32.5.2 Etiology
32.5.2.1 Mechanism of injury and pathomechanics
32.5.3 Clinical impairments
32.5.4 Treatment
32.6 Sesamoiditis
32.6.1 Anatomical overview
32.6.2 Etiology
32.6.2.1 Mechanism of injury and pathomechanics
32.6.3 Clinical impairments
32.6.4 Treatment
32.7 Retrocalcaneal bursitis
32.7.1 Anatomical overview
32.7.2 Etiology
32.7.2.1 Mechanism of injury and pathomechanics
32.7.3 Clinical impairments
32.7.4 Treatment
32.8 Areas of future research for chronic foot and ankle injuries
References
33 Hallux Valgus
33.1 Introduction
33.2 Prevalence
33.3 Etiology
33.3.1 Genetics and race
33.3.2 Structural and biomechanical factors
33.3.3 Footwear
33.4 Diagnosis and imaging
33.4.1 Clinical diagnosis
33.4.2 Radiographic assessment
33.4.3 Ultrasound
33.4.4 Computed tomography
33.4.5 Magnetic resonance imaging
33.5 Clinical presentation
33.5.1 Foot pain
33.5.2 Footwear
33.5.3 Self-reported function and quality of life
33.6 Functional outcomes
33.6.1 Balance and falls
33.6.2 Hallux flexion and abduction
33.6.3 Gait analysis
33.6.3.1 Kinematics
33.6.3.2 Plantar pressures
33.6.3.3 Muscle activity
33.6.3.4 Temporospatial parameters
33.7 Treatment pathways
33.7.1 Nonsurgical treatment
33.7.1.1 Expert opinion and current practice
33.7.1.2 Foot orthoses
33.7.1.3 Splints and toe separators
33.7.1.4 Manual therapy
33.7.1.5 Taping
33.7.1.6 Exercise
33.7.1.7 Botulinum toxin A injection
33.7.2 Surgical treatment
33.8 Future directions for research
33.9 Summary
References
34 Osteoarthritis of the Foot and Ankle
34.1 Introduction
34.1.1 Osteoarthritis symptoms and diagnosis
34.1.2 Structural changes
34.1.3 Risk factors and classification of osteoarthritis
34.1.4 Foot and ankle osteoarthritis subtypes
34.2 First metatarsophalangeal joint osteoarthritis
34.2.1 Etiology and impact
34.2.2 Clinical findings
34.2.3 Structural and biomechanical features
34.2.4 Clinical and biomechanical effects of conservative treatment
34.3 Midfoot osteoarthritis
34.3.1 Etiology and impact
34.3.2 Clinical findings
34.3.3 Structural and biomechanical features
34.3.4 Clinical and biomechanical effects of conservative treatment
34.4 Ankle osteoarthritis
34.4.1 Etiology and impact
34.4.2 Clinical findings
34.4.3 Structural and biomechanical features
34.4.4 Clinical and biomechanical effects of conservative treatment
34.5 Areas of future biomechanical research
34.6 Summary
References
35 Diabetic Foot Disease
35.1 Background on diabetes
35.2 Overview of key negative outcomes of diabetic foot disease
35.2.1 Diabetic peripheral neuropathy
35.2.2 Peripheral vascular disease
35.2.3 Diabetic plantar ulceration
35.2.4 Foot deformities
35.2.5 Lower-extremity fractures
35.2.6 Charcot neuroarthropathy
35.2.7 Lower extremity amputation
35.3 Risk factors for the development and progression of diabetic foot disease
35.4 Changes in kinematics and kinetics in diabetic foot disease
35.5 Changes in tissue characteristics
35.5.1 Muscle: fatty infiltration and reduction of intrinsic foot muscle volumes
35.5.2 Bone
35.5.3 Cartilage
35.5.4 Tendon
35.5.5 Plantar fascia
35.6 The relationship between foot deformities and plantar ulceration
35.7 The relationship between lower extremity fractures and Charcot neuropathic osteoarthropathy
35.8 Areas of future biomechanical research
References
36 Rheumatic Foot Disease
36.1 Introduction
36.2 Rheumatoid arthritis
36.2.1 Early rheumatoid arthritis
36.2.2 Established rheumatoid arthritis
36.3 Spondlyarthropathies
36.4 Juvenile idiopathic arthritis
36.5 Connective tissue disorders
36.6 Gout
36.7 Future research
References
37 The Aging Foot
37.1 Changing properties and functions of foot tissues
37.1.1 Bone
37.1.2 Cartilage
37.1.3 Muscle
37.1.4 Tendon
37.1.5 Ligament
37.1.6 Skin
37.1.7 Neural
37.1.8 Fat pad
37.2 Foot posture and morphology
37.2.1 Anthropometrics
37.2.2 Foot posture
37.2.3 Arch height
37.2.4 Joint range-of-motion
37.3 Foot function (kinematics/kinetics/plantar pressures)
37.3.1 Kinetics
37.3.1.1 Ground reaction forces
37.3.1.2 Joint moments and powers
37.3.1.3 Plantar pressures
37.3.2 Kinematics
37.3.2.1 Ankle and foot
37.4 Foot posture, foot disorders, and mobility limitations
37.4.1 Foot posture and foot deformity
37.4.2 Foot posture and foot symptoms
37.4.3 Foot posture, mobility limitations, and falls
37.5 Areas for future research
References
38 Biomechanics of Athletic Footwear
38.1 Introduction
38.2 Anatomy of a running shoe
38.3 Biomechanics of athletic footwear design
38.3.1 Cushioning
38.3.2 Hindfoot stability
38.4 Types of shoes and their features
38.4.1 Casual shoes
38.4.2 Running shoes
38.4.3 Racing flats & spikes
38.4.4 Marathon shoes
38.4.5 Other sports shoes
38.4.6 New shoe innovations
38.4.6.1 Footwear embedded energy harvester
38.4.6.2 Lacing systems
38.4.6.3 3D printed midsoles and outsoles
38.4.7 Graphene outsoles
38.5 Shod versus barefoot
38.6 Footwear related injuries
38.7 Future footwear research
References
39 Minimal Shoes: Restoring Natural Running Mechanics
39.1 Introduction
39.2 Brief history of running footwear
39.3 Biomechanics of barefoot and conventional shod running
39.3.1 Barefoot running pattern
39.3.2 Conventional shod running pattern
39.3.3 Comparison of mechanics between conventional shod and barefoot running
39.4 Minimal footwear running
39.4.1 Definition of full minimalist footwear
39.4.2 Comparison of full minimal to barefoot running
39.4.3 Comparison of full minimal to partial minimal shoes
39.4.4 Comparison of full minimal to conventional footwear
39.5 Effect of minimal shoes on the foot musculoskeletal system
39.6 Summary
39.7 Future research
References
40 Foot Orthoses
40.1 Introduction
40.1.1 Design and manufacture of foot orthoses
40.2 Biomechanical effects of foot orthoses
40.2.1 Kinematic effects of foot orthosis
40.2.2 Kinetic effects of foot orthosis
40.2.3 Effects of foot orthosis on plantar pressure
40.2.4 Effects of foot orthosis on muscle activity patterns
40.3 Effects of foot orthosis on clinical conditions
40.3.1 Rheumatoid arthritis
40.3.2 Symptomatic flat foot
40.3.3 Heel pain (plantar fasciitis)
40.3.4 Osteoarthritis
40.3.5 Sports injuries and other conditions
40.4 Areas of future research
References
41 Ankle-Foot Orthoses and Rocker Bottom Shoes
41.1 Introduction
41.2 Ankle-foot orthoses
41.2.1 Controlling rotational motion
41.2.2 Controlling translational motion
41.2.3 Controlling axial forces
41.2.4 Altering the line of action of the ground reaction force
41.3 Rocker bottom shoes
41.4 Roll-over shape
41.5 Patient populations
41.5.1 Stroke
41.5.2 Cerebral palsy
41.5.3 Ankle arthritis
41.5.4 Limb salvage
41.6 Design and prescription of ankle-foot orthosis
41.6.1 Conventional versus advanced
41.6.2 Articulated versus nonarticulated
41.7 Design and prescription of rocker bottom shoes
41.8 Variations on materials
41.9 New designs
41.10 Sport applications
41.11 Areas of future research
References
42 Diabetic Footwear
42.1 Introduction
42.2 Foot biomechanics and offloading
42.3 The biomechanical effect of diabetic footwear and offloading devices
42.4 Footwear and offloading for ulcer healing
42.5 Diabetic footwear for ulcer prevention
42.6 Footwear and offloading adherence
42.7 Other considerations
42.8 Future research
42.9 Conclusions
References
43 Reconstructions for Adult-acquired Flatfoot Deformity
43.1 Introduction
43.2 Hindfoot valgus
43.2.1 Bony anatomy
43.2.2 Ligament failure
43.2.3 Surgical reconstruction
43.3 Forefoot external rotation
43.3.1 Bony anatomy
43.3.2 Ligament and tendon failure
43.3.3 Surgical reconstruction
43.4 Sag at the talonavicular joint
43.4.1 Bony anatomy
43.4.2 Ligamentous failure
43.4.3 Surgical reconstruction
43.5 Failure of the posterior tibial tendon
43.5.1 Clinical assessment
43.5.2 MRI assessment
43.5.3 Surgical reconstruction
43.6 Gastrocnemius and Achilles tightness
43.6.1 Clinical assessment
43.6.2 Surgical treatment
43.7 Medial arch eversion
43.7.1 Clinical assessment
43.7.2 Bony anatomy
43.7.3 Ligamentous failure
43.7.4 Surgical reconstruction
43.8 Special considerations
43.9 Future biomechanical studies and conclusion
References
44 Cavus Foot Reconstructions
44.1 Introduction
44.2 Etiology
44.2.1 Traumatic
44.2.2 Neurologic
44.2.3 Residual clubfoot
44.2.4 Idiopathic
44.3 Clinical presentation and associated pathology
44.4 Physical exam
44.5 Imaging
44.5.1 X-rays
44.5.2 Weight-bearing CT scan
44.6 Biomechanical changes of pes cavus
44.6.1 Hindfoot
44.6.2 Forefoot
44.6.3 Soft tissues
44.7 Conservative management
44.8 Surgical management
44.8.1 Overview
44.8.2 Gastrocnemius recession/Achilles tendon lengthening
44.8.3 Plantar fascia release
44.8.4 Peroneus longus to brevis transfer
44.8.5 Posterior tibial tendon lengthening and transfer
44.8.6 Dorsiflexion osteotomy or fusion of first ray
44.8.7 Calcaneal osteotomy
44.8.8 Modified jones procedure
44.8.9 Lesser toe deformities
44.8.10 Triple arthrodesis and midfoot fusion
44.8.11 Treatment of associated ankle pathology
44.8.12 Postoperative care
44.8.13 Complications
44.9 Areas of future research
References
45 Biomechanics of Hindfoot Fusions
45.1 Introduction
45.2 Complex hindfoot biomechanics
45.3 Conditions that may require hindfoot fusion
45.3.1 Flatfoot
45.3.2 Cavus foot syndromes
45.3.3 Rheumatoid arthritis
45.3.4 Osteoarthritis
45.3.5 Calcaneal fractures
45.3.6 Talar fractures and dislocations
45.3.7 Tarsal coalitions
45.3.8 Accessory navicular
45.4 Presurgical assessment
45.4.1 Clinical exam
45.5 Imaging
45.6 Goals in treatment
45.6.1 Treatment goals in flatfoot/cavus syndromes
45.6.2 Treatment goals in rheumatoid arthritis
45.6.3 Treatment goals in osteoarthritis
45.6.4 Treatment goals in calcaneal fractures
45.6.5 Treatment goals in talar fractures and dislocations
45.7 Corrective options
45.7.1 Distraction subtalar fusion
45.7.2 Lateral column lengthening
45.7.3 Double hindfoot fusion
45.7.4 Subtalar and talonavicular fusion
45.7.5 Triple arthrodesis
45.7.6 Pantalar arthrodesis
45.7.7 General complications
45.7.8 Postoperative management requirements in hindfoot fusions
45.8 Areas of future interest
References
46 Biomechanics of Foot and Ankle Fixation
46.1 Introduction
46.2 Screws
46.3 Plates
46.4 Post and screw constructs
46.5 Nails
46.6 Beams
46.7 Areas of future research
References
47 Ankle Arthroplasty and Ankle Arthrodesis
47.1 Introduction
47.2 Brief description and history of surgical techniques
47.2.1 Ankle arthrodesis
47.2.2 Ankle arthroplasty
47.3 Biomechanical factors in presurgical assessment and consideration of arthroplasty or arthrodesis
47.3.1 Limb alignment with arthroplasty
47.3.2 Bony and ligamentous ankle anatomy with arthroplasty
47.3.3 Ankle motion in the three cardinal planes with arthroplasty
47.3.4 Bony morphology and alignment with arthrodesis
47.4 Biomechanical considerations/complications of arthroplasty or arthrodesis
47.4.1 Ankle alignment/malalignment
47.4.2 Gait mechanics
47.4.3 Arthritis at distal joints
47.4.4 Component wear or failure
47.4.5 Cadaveric gait simulation of arthroplasty and arthrodesis
47.4.6 Computational models of arthroplasty and arthrodesis
47.5 Biomechanical outcomes
47.6 Clinical outcomes
47.6.1 Safety
47.6.2 Effectiveness
47.6.3 Costs
47.6.4 Patient subgroups
47.7 Areas of future biomechanical research
References
48 Prosthetic Feet
48.1 Introduction
48.2 Prescription and expected use of prosthetic feet
48.2.1 Activity levels
48.2.2 Activity bouts and durations
48.2.3 Activity in different environments
48.3 Form of prosthetic feet
48.3.1 Solid ankle cushioned heel
48.3.2 Fixed-angle stiffness
48.3.3 Variable-angle stiffness
48.3.4 Variable stiffness
48.3.5 Powered prosthetic feet
48.4 Function of prosthetic feet
48.4.1 Clinical trials
48.4.1.1 Clinical trials examining effects of stiffness
48.4.1.2 Clinical trials examining effects of damping
48.4.1.3 Powered prosthetic feet
48.4.2 Mechanical property tests
48.4.2.1 Stiffness, hysteresis, and energy
48.4.2.2 Roll-over shape
48.4.3 Musculoskeletal modeling and simulation
48.5 Future prosthetic foot research
References
Index