Table of Contents
Introduction 1 About This Book 1
Foolish Assumptions 2
Icons Used in This Book 3
Beyond the Book 3
Where to Go from Here 4
Part I: Getting Started with Biomechanics 5
Chapter 1: Jumping Into Biomechanics 7
Analyzing Movement with Biomechanics 7
Mechanics 8
Bio 9
Expanding on Mechanics 10
Describing motion with kinematics 11
Causing motion with kinetics 13
Putting Biomechanics to Work 14
Chapter 2: Reviewing the Math You Need for Biomechanics 15
Getting Orientated 16
Brushing Up on Algebra 17
Following the order of operations 17
Defining some math operations 19
Isolating a variable 20
Interpreting proportionality 22
Looking for the Hypotenuse 23
Using the Pythagorean theorem 24
De-tricking trigonometric functions: SOH CAH TOA 26
Unvexing Vector Quantities 31
Resolving a vector into components 33
Composing a vector from components 35
Chapter 3: Speaking the Language of Biomechanics 37
Measuring Scalars and Vectors 38
Standardizing a Reference Frame 39
Directing your attention to locations of the body 40
Referencing planes and axes 40
Describing Movement: Kinematics 42
Typecasting motion: Linear, angular, and general 42
Describing how far: Distance and displacement 43
Describing how fast: Speed and velocity 44
Changing velocity: Acceleration 45
Pushing and Pulling into Kinetics 45
Forcing yourself to understand Newton’s laws of motion 47
Using the impulse–momentum relationship 49
Working with Energy and Power 49
Mechanical work 49
Mechanical energy 50
Mechanical power 51
Turning Force into Torque 51
Dealing with Measurement Units 51
Using the Neuromusculoskeletal System to Move 52
The skeletal system 53
The muscular system 53
The nervous system 55
Part II: Looking At Linear Mechanics 57
Chapter 4: Making Motion Change: Force 59
Pushing and Pulling: What Is Force? 59
Working with Force Vectors 65
Using the force components to find the resultant 66
Resolving a force into components 68
Classifying Forces 69
Contact and noncontact forces 69
Internal and external forces 70
Feeling the Pull of Gravity 74
Slipping, Sliding, and Staying Put: Friction Is FμN 76
Materials do matter: The coefficient of friction (μ) 80
Squeezing to stick: Normal reaction force (N) 81
Chapter 5: Describing Linear Motion: Linear Kinematics 83
Identifying Position 84
Describing How Far a Body Travels 85
Distance.85
Displacement 86
Describing How Fast a Body Travels 88
Speed 89
Velocity 90
Momentum 92
Speeding Up or Slowing Down: Acceleration 92
Constant acceleration 95
Projectile motion 95
Chapter 6: Causing Linear Motion: Linear Kinetics 103
Clarifying Net Force and Unbalanced Force 103
Newton’s First Law: The Law of Inertia 106
Newton’s Third Law: The Law of Equal and Opposite Action–Reaction 107
Newton’s Second Law: The Law of Acceleration 109
Deriving the impulse–momentum relationship from the law of acceleration 112
Applying the impulse–momentum relationship for movement analysis 114
Chapter 7: Looking At Force and Motion Another Way: Work, Energy, and Power 119
Working with Force 120
Energizing Movement 122
Kinetic energy 123
Potential energy 124
Conserving Mechanical Energy 128
Powering Better Performance 130
The Work–Energy Relationship 131
Part III: Investigating Angular Mechanics 137
Chapter 8: Twisting and Turning: Torques and Moments of Force 139
Defining Torque 140
Lining up for rotation: The moment arm of a force 141
Calculating the turning effect of a force 142
Measuring Torque 144
Muscling into torque: How muscles serve as torque generators 145
Resisting torque: External torques on the body 148
Expanding on Equilibrium: Balanced Forces and Torques 149
Locating the Center of Gravity of a Body 152
Chapter 9: Angling into Rotation: Angular Kinematics 157
Measuring Angular Position 157
Describing How Far a Body Rotates 160
Angular distance 161
Angular displacement 162
Describing How Fast a Body Rotates 163
Angular speed.163
Angular velocity 164
Speeding Up or Slowing Down: Angular Acceleration 165
Relating Angular Motion to Linear Motion 167
Angular displacement and linear displacement 168
Angular velocity and linear velocity 169
Angular acceleration and linear acceleration 171
Chapter 10: Causing Angular Motion: Angular Kinetics 173
Resisting Angular Motion: The Moment of Inertia 174
The moment of inertia of a segment174
The moment of inertia of the whole body 178
Considering Angular Momentum 180
Angular momentum of a rigid body 180
Angular momentum of the human body when individual segments rotate 181
A New Angle on Newton: Angular Versions of Newton’s Laws 181
Maintaining angular momentum: Newton’s first law.182
Changing angular momentum: Newton’s second law 186
Equal but opposite: Newton’s third law189
Changing Angular Momentum with Angular Impulse 191
Chapter 11: Fluid Mechanics 193
Buoyancy: Floating Along 193
Considering Force Due to Motion in Fluid 197
Causing drag in a fluid 198
Causing lift in a fluid 201
Part IV: Analyzing the “Bio” of Biomechanics 205
Chapter 12: Stressing and Straining: The Mechanics of Materials 207
Visualizing Internal Loading of a Body 208
Applying Internal Force: Stress 210
Normal stress 212
Shear stress 217
Responding to Internal Force: Strain 219
Determining tensile strain 221
Determining compressive strain 221
Determining shear strain 222
Straining from Stress: The Stress–Strain Relationship 223
Give and go: Behaving elastically 224
Give and stay: Behaving plastically 224
Chapter 13: Boning Up on Skeletal Biomechanics 227
What the Skeletal System Does 228
How Bones Are Classified 228
The Materials and Structure of Bones 230
Materials: What bones are made of 231
Structure: How bones are organized 232
Connecting Bones: Joints 234
Immovable joints 234
Slightly movable joints 234
Freely movable joints 235
Growing and Changing Bone 237
Changing bone dimensions 238
Stressing bone: The effects of physical activity and inactivity 239
Chapter 14: Touching a Nerve: Neural Considerations in Biomechanics 247
Monitoring and Controlling the Body: The Roles of the Nervous System 248
Outlining the Nervous System 248
The central nervous system 250
The peripheral nervous system 250
Zeroing In on Neurons 251
Parts of neurons 251
Types of neurons 251
Controlling Motor Units 259
Motor unit recruitment 261
Rate coding 261
Chapter 15: Muscling Segments Around: Muscle Biomechanics 263
Characterizing Muscle 263
Seeing How Skeletal Muscles Are Structured 265
The macrostructure of muscles 266
The microstructure of muscle fibers.268
Comparing Types of Muscle Activity 270
Isometric activity 271
Concentric activity 272
Eccentric activity 272
Producing Muscle Force 274
Relating muscle length and tension 274
Relating muscle velocity and tension277
Stretching before Shortening: The Key to Optimal Muscle Force 279
Part V: Applying Biomechanics 283
Chapter 16: Eyeballing Performance: Qualitative Analysis 285
Serving as a Movement Analyst 286
Evaluating the Performance 287
Identifying the goal of the movement 287
Specifying the mechanical objective 289
Determining whether the goal has been reached 290
Troubleshooting the Performance 293
Constraints on performance 293
Technique errors 294
Pitching by the phases 298
Intervening to Improve the Performance 302
Adapting the constraints on throwing performance 302
Refining technique 303
Chapter 17: Putting a Number on Performance: Quantitative Analysis 305
Converting Continuous Data to Numbers 305
Measuring Kinematics: Motion-Capture Systems 306
Collecting kinematic data 307
Processing kinematic data 308
Measuring Kinetics: Force Platform Systems 310
Collecting kinetic data 310
Processing kinetic data 312
Recording Muscle Activity: Electromyography 313
Collecting the electromyogram 314
Processing the electromyogram 315
Chapter 18: Furthering Biomechanics: Research Applications 319
Exercising in Space 319
Repairing the Anterior Cruciate Ligament 320
Running Like Our Ancestors 322
Protecting Our Beans: Helmet Design 324
Balancing on Two Legs: Harder Than You Think 326
Chapter 19: Investigating Forensic Biomechanics: How Did It Happen? 329
Collecting Information for a Forensic Biomechanics Analysis 330
Witness accounts 330
Police incident investigation reports 331
Medical records 331
Determining the Mechanism of Injury 332
Evaluating Different Scenarios 335
Ending up on the far side of the road 335
Landing in water with a broken jaw 336
Part VI: The Parts of Tens 339
Chapter 20: Ten Online Resources for Biomechanics 341
The Exploratorium 341
The Physics Classroom 341
Coaches Info 342
Textbook-Related Websites 343
Topend Sports 343
Dr. Mike Marshall’s Pitching Coach Services 343
Waterloo’s Dr. Spine, Stuart McGill 344
Skeletal Bio Lab 345
Biomch-L 345
American Society of Biomechanics 346
Chapter 21: Ten Things You May Not Know about Biomechanics 347
Looking at How Biomechanics Got Its Start 347
Adding Realism to Entertainment 348
Developing Safer Motor Vehicles 348
Improving the On-Shelf Quality of Fruits and Vegetables 349
Fitting Footwear to the Activity 350
Banning Biomechanically Improved Sport Techniques 351
Re-Creating Dinosaurs 352
Designing Universally and Ergonomically 352
Giving a Hand to Prosthetics Design 353
Losing Weight to Help Your Joints 354
Chapter 22: Ten Ways to Succeed in Your Biomechanics Course 355
Go to Class and Ask Questions 355
Read the Textbook 356
Do the Problems and Review Questions at the End of the Chapter 357
Create Flashcards 357
Go to Office Hours 358
Form a Study Group with Classmates 358
Accept and Apply Newton as the Foundation of Movement Analysis 359
Talk Fluent Biomechanics with Your Classmates 359
Volunteer for Research Projects 360
Attend a Biomechanics Conference 361
Index 363
