Biomechanics and Gait Analysis

Cover
Biomechanics and
Gait Analysis
Copyright
Dedication
Contents
List of Figures
List of Contributors
Preface
1 Introduction to biomechanics
	1.1 Introduction
	1.2 The history of biomechanics
		1.2.1 A trip down the memory lane
		1.2.2 Archimedes: an early biomechanist
	1.3 Areas of biomechanical inquiry: examples of diverse and unique questions in biomechanics
		1.3.1 Developmental biomechanics
		1.3.2 Exercise biomechanics
		1.3.3 Rehabilitative biomechanics
		1.3.4 Occupational biomechanics
		1.3.5 Forensic biomechanics
	1.4 A quick look into the future of biomechanics
	References
	Suggested readings
2 Basic biomechanics
	2.1 Introduction
	2.2 Analysis of movement
	2.3 Basic terminology for analyzing movement
		2.3.1 Basic bio terms/concepts
		2.3.2 Basic mechanics terms/concepts
	2.4 Basic bio considerations
		2.4.1 Basic biomechanics of bones
		2.4.2 Basic biomechanics of joints
		2.4.3 Basic biomechanics of muscles
	2.5 Basic mechanics considerations
		2.5.1 Linear kinematics
			2.5.1.1 Special case of linear kinematics: projectiles
		2.5.2 Angular kinematics
		2.5.3 Linear kinetics
		2.5.4 Angular kinetics
	2.6 Summary and concluding remarks
	References
	Further readings
3 Advanced biomechanics
	3.1 Injuries and biomechanics
		3.1.1 Running injuries
	3.2 Biomechanical statistics
		3.2.1 The single-subject approach for biomechanics and gait analysis
		3.2.2 Bringing together running injuries and the single-subject approach
	3.3 Final considerations
		3.3.1 Take home messages
	References
4 Why and how we move: the Stickman story
	4.1 Briefly introducing Stickman
	4.2 The Stickman’s evolution of movement
	4.3 The Stickman’s performance of movement
	4.4 The Stickman learns how to move
	4.5 The Stickman’s mechanics
	4.6 The Stickman’s goodbye
	References
5 Power spectrum and filtering
	5.1 Introduction
	5.2 A simple composite wave
	5.3 Spectral analysis
	5.4 Fourier series
	5.5 Discrete Fourier analysis
		5.5.1 Data sampling
		5.5.2 The discrete Fourier transform
		5.5.3 Spectral leakage
	5.6 Stationarity and the discrete Fourier transform
	5.7 Short-time discrete Fourier transform
	5.8 Noise
	5.9 Data filtering
	5.10 Practical implementation
	5.11 Conclusion
	References
6 Revisiting a classic: Muscles, Reflexes, and Locomotion by McMahon
	6.1 Introduction
	6.2 Fundamental muscle mechanics
		6.2.1 Early ideas about muscle mechanics
		6.2.2 Isolated muscles
		6.2.3 Force–velocity curves
		6.2.4 Active and passive components
		6.2.5 Stress–strain relationship
		6.2.6 Summary
	6.3 Muscle heat and fuel
		6.3.1 Heat production
		6.3.2 Activation heat
		6.3.3 Shortening and lengthening heat
		6.3.4 Thermoelastic effects
		6.3.5 Lactic acid
		6.3.6 Phosphates
		6.3.7 Effects of exercise
		6.3.8 Summary
	6.4 Contractile proteins
		6.4.1 Organization of muscles
		6.4.2 Actin, myosin, and troponin
		6.4.3 Sliding filament model
		6.4.4 Tension–length curves
		6.4.5 Sarcoplasmic reticulum
		6.4.6 Tropomyosin and troponin
		6.4.7 Titin
		6.4.8 Summary
	6.5 Sliding movement: Huxley’s model revisited
		6.5.1 Other theoretical models
		6.5.2 Evidence supporting independent force generators
		6.5.3 Formulation of the model
		6.5.4 Attachment and detachment
		6.5.5 Crossbridge distribution for isotonic shortening
		6.5.6 Setting the constants
		6.5.7 Isotonic stretching
		6.5.8 Hill’s revisions in heat production
		6.5.9 Reversible detachment
		6.5.10 Problems and further updates of the model
		6.5.11 Summary
	6.6 Force development in the crossbridge
		6.6.1 Early transients
		6.6.2 Rapid elasticity and the series elastic component
		6.6.3 Summary
	6.7 Reflexes and motor control
		6.7.1 Organization of the motor control system
			6.7.1.1 Spinal cord
			6.7.1.2 Brain stem
			6.7.1.3 Sensorimotor cortex and basal ganglia
			6.7.1.4 Cerebellum
		6.7.2 Muscle fiber types
		6.7.3 Motor units
		6.7.4 Muscle proprioceptors
		6.7.5 Axons
		6.7.6 Reflexes
		6.7.7 Tremor
		6.7.8 Negative feedback and time delays
		6.7.9 Renshaw Cells
		6.7.10 Summary
	6.8 Neural control of locomotion
		6.8.1 Gait comparisons
		6.8.2 Control of a single limb
		6.8.3 Reflex reversal
		6.8.4 Mechanical oscillator
		6.8.5 Entrainment of frequency
		6.8.6 Stimulated locomotion
		6.8.7 Legged vehicles
		6.8.8 Summary
	6.9 Mechanisms of locomotion
		6.9.1 Motion-capture laboratories
		6.9.2 Determinants of gait
		6.9.3 Inverted pendulum walking
		6.9.4 Locomotion in reduced gravity
		6.9.5 Elastic storage of energy
		6.9.6 Cost of running
		6.9.7 Up- and downhills
		6.9.8 Running with weights
		6.9.9 Summary
	6.10 Effects of scale
		6.10.1 Dimensionless analysis
		6.10.2 Scaling by geometric similarity
		6.10.3 The role of gravity and geometry
		6.10.4 Body proportions
		6.10.5 Metabolic power
		6.10.6 Summary
	6.11 Conclusion
	References
	Further reading
7 The basics of gait analysis
	7.1 Introduction
	7.2 The concept of skill
	7.3 The skill of gait
		7.3.1 Definition of gait analysis
	7.4 Periods and phases of gait
	7.5 Spatiotemporal parameters of gait
		7.5.1 Step width and lateral stepping gait: a special case
		7.5.2 Stride time and variability: a special case
	7.6 Determinants of gait
	7.7 Conclusions
	References
	Further reading
8 Gait variability: a theoretical framework for gait analysis and biomechanics
	8.1 Introduction
	8.2 Conceptual approaches to gait variability
		8.2.1 Amount of variability
		8.2.2 Complexity of variability
		8.2.3 Optimal movement variability
		8.2.4 Summary: sources of gait variability
	8.3 Gait analysis and biomechanical measurements for gait variability
		8.3.1 Equipment options for data collection
			8.3.1.1 Visual observation
			8.3.1.2 Instrumented gait walkways
			8.3.1.3 Foot-switch systems
			8.3.1.4 Inertial sensors
			8.3.1.5 Three-dimensional motion capture systems
			8.3.1.6 Force plate systems
		8.3.2 Selection of task demands and environmental conditions
		8.3.3 Analyzing the amount of gait variability
		8.3.4 Analyzing the complexity of gait variability
			8.3.4.1 Largest Lyapunov exponent
			8.3.4.2 Approximate entropy
			8.3.4.3 Detrended fluctuation analysis
	8.4 Examples from clinical research
		8.4.1 Gait variability as a biomarker of aging or pathology
		8.4.2 Gait variability as an outcome measure following intervention
	8.5 Future directions
	References
9 Coordination and control: a dynamical systems approach to the analysis of human gait
	9.1 Introduction
	9.2 Hallmark properties of a dynamical system
		9.2.1 State space
		9.2.2 Modality, inaccessibility, and sudden jumps
		9.2.3 Divergence
		9.2.4 Critical fluctuations, critical slowing down, and hysteresis
		9.2.5 Interim summary
	9.3 A dynamical systems approach to gait analysis
		9.3.1 Phase portraits and phase angles
		9.3.2 Continuous and point estimate relative phase
		9.3.3 Phase portrait normalization
		9.3.4 The Hilbert transform for estimating relative phase
		9.3.5 Statistical summaries of relative phase dynamics
	9.4 Applications of relative phase dynamics to human gait
		9.4.1 Relative phase dynamics after anterior cruciate ligament reconstruction surgery
		9.4.2 Relative phase dynamics and aging
	9.5 Summary and concluding remarks
	References
10 A tutorial on fractal analysis of human movements
	10.1 Introduction
	10.2 Fractal theory and its connection to human movement
		10.2.1 A geometrical interpretation
		10.2.2 A statistical interpretation: demystifying fractal analysis
		10.2.3 Fractals in physiology and psychology
	10.3 Fractal analysis of time series data
		10.3.1 Detrended fluctuation analysis
			10.3.1.1 Best practices suggestions for applying detrended fluctuation analysis to human movement data
				Plot your data
				Time series length
				Choosing a polynomial order
				Which timescales should you use?
		10.3.2 Multifractal detrended fluctuation analysis: It’s still that simple (almost)
			10.3.2.1 An intuitive introduction to multifractals
			10.3.2.2 A brief tutorial on multifractal detrended fluctuation analysis
			10.3.2.3 Practical considerations
	10.4 Applications to laboratory data
		10.4.1 Example 1: Application to human gait
			10.4.1.1 Monofractal results and discussion
			10.4.1.2 Multifractal results and discussion
			10.4.1.3 General discussion
		10.4.2 Example 2: Detrended fluctuation analysis applied to visual-motor tracking
			10.4.2.1 Results and discussion
	10.5 Conclusion
	References
11 Future directions in biomechanics: 3D printing
	11.1 Introduction
	11.2 Lower extremity applications
		11.2.1 Foot orthoses
		11.2.2 Ankle foot orthoses
	11.3 Upper extremity applications
	11.4 Methods for three-dimensional printing assistive devices
	11.5 Anatomical modeling for surgical planning
	11.6 Fracture casting
	11.7 Upper extremity three-dimensional printed exoskeleton for stroke patients
	11.8 Implementation of a three-dimensional printing research laboratory
	11.9 Current Food and Drug Administration recommendations of three-dimensional printed medical devices
		11.9.1 Design
		11.9.2 Materials
		11.9.3 Printing characteristics/parameters
		11.9.4 Physical/mechanical assessment
		11.9.5 Biological considerations
	11.10 Limitations
	11.11 Future perspectives
	References
Index
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