Basic Biomechanics 9th Edition PDF

Because learning changes everything. ® Chapter 1 What Is Biomechanics? Basic Biomechanics, 9th edition By Susan J. Hall, Ph.D. Copyright © 2022 McGraw Hill. All rights reserved. No part of this publication may be reproduce...

Because learning changes everything. ® Chapter 1 What Is Biomechanics? Basic Biomechanics, 9th edition By Susan J. Hall, Ph.D. Copyright © 2022 McGraw Hill. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of McGraw Hill, including, but not limited to, network storage or transmission, or broadcast for distance learning.  Learning Objectives Define the terms biomechanics, statics, dynamics, kinematics, and kinetics, and explain the ways in which they are related. Describe the scope of scientific inquiry addressed by biomechanists. Distinguish between qualitative and quantitative approaches for analyzing human movement. Explain how to formulate questions for qualitative analysis of human movement. Use the 11 steps identified in the chapter to solve formal problems. © McGraw Hill 2  What Is Biomechanics? The term biomechanics combines the prefix bio, meaning “life,” with the field of mechanics, which is the study of the actions of forces, both the internal muscle forces produced by muscles and the external forces that act on the body. In biomechanics, we analyze the mechanical aspects of living organisms. Access the text alternative for slide images. © McGraw Hill 3  Subbranches of Biomechanics Statics: Study of systems that are in a state of constant motion, that is, either at rest (with no motion) or moving with a constant velocity. Dynamics: Study of systems subject to acceleration. Kinematics: Study of the description of motion. Kinetics: Study of the action of forces. Force can be thought of as a push or pull acting on a body. © McGraw Hill 4  What Is Kinematics? What we are able to observe visually when watching a body in motion is termed the kinematics of the movement. Kinematics is the study of the size, sequencing, and timing of movement, without regard for the forces that cause or result from the motion. The kinematics of an exercise or a sport skill is known, more commonly, as form or technique. © McGraw Hill 5  What Is Kinetics? Kinetics is the study of the forces associated with motion. Fuse/Corbis/Getty Images © McGraw Hill 6  What Is Kinesiology? Kinesiology is the study of human movement. Comstock/Getty Images © McGraw Hill 7  What Is Sports Medicine? Sports medicine is an umbrella term that encompasses both clinical and scientific aspects of exercise and sport. © McGraw Hill 8  What Problems Are Studied by Biomechanists? © McGraw Hill 9  What Problems Are Studied by Biomechanists? 1 Some biomechanists investigate what causes different species of animals to transition from walking to running. And, how do you get animals to walk or run on a treadmill in order to study this? © McGraw Hill 10  What Problems Are Studied by Biomechanists? 2 Sergey Nivens/Shutterstock Biomechanists study the energy cost of walking and running in animals and humans. Running economy is based on a complex interaction of biomechanical, metabolic, neuromuscular, and cardiorespiratory factors. © McGraw Hill 11  What Problems Are Studied by Biomechanists? 3 When not subject to gravitational force, astronauts lose significant amounts of bone mass. Exercise, however, is known to help prevent reduction of bone mass. What kinds of exercise should astronauts do while in space in order to preserve as much bone as possible? Source: NASA © McGraw Hill 12  What Problems Are Studied by Biomechanists? 4 Insufficient bone-mineral density is also a problem on Earth. Osteoporosis is a condition in which bone mineral mass and strength are so severely compromised that normal daily activities can cause bone fracturing and pain. This condition is common among the elderly. What can people do to prevent the development of osteoporosis? © McGraw Hill 13  What Problems Are Studied by Biomechanists? 5 Diminished bone density leads to increased incidence of fractures among elderly individuals, especially when sustaining a fall. To help prevent falling among elderly individuals, biomechanists study strategies for preventing falls and the characteristics of safe landings from falls. What can older individuals do to maintain a steady gait? © McGraw Hill 14  What Problems Are Studied by Biomechanists? 6 The gait of individuals with cerebral palsy is characterized by knee flexion during stance. This problem is treated by surgical lengthening of the hamstring tendons to improve knee extension during stance. Research by clinical biomechanists has resulted in improved gait among children with cerebral palsy. © McGraw Hill 15  What Problems Are Studied by Biomechanists? 7 sportpoint/Shutterstock Design of prosthetic limbs, including lower limbs and feet that store and return mechanical energy during gait, is another problem addressed by biomechanists. © McGraw Hill 16  What Problems Are Studied by Biomechanists? 8 Occupational biomechanics focuses on the prevention of work-related injuries and the improvement of working conditions and worker performance. This involves studying the causes of work-related low back pain. Ian Hooton/Science Photo Library/Alamy Stock Photo © McGraw Hill 17  What Problems Are Studied by Biomechanists? 9 Jose Angel Astor Rocha/Shutterstock Biomechanists design aerodynamic helmets, clothing, and equipment, such as cycles, that can reduce the effects of air resistance during certain sports events. © McGraw Hill 18  What Problems Are Studied by Biomechanists? 10 Robert Daly/age fotostock What technique modifications can contribute to performance improvements in throwing events in track and field? Biomechanists have analyzed the factors contributing to optimum performance in events using computer simulations techniques and high-speed cameras. © McGraw Hill 19  What Problems Are Studied by Biomechanists? 11 Technique modifications can contribute to performance improvements in various sports. Biomechanists have studied these. © McGraw Hill 20  What Problems Are Studied by Biomechanists? 12 Computerized video analyses of golf swings designed by biomechanists are commonly available at golf courses and equipment shops. The science of biomechanics can play a role in optimizing the distance and accuracy of all golf shots, including putting. © McGraw Hill 21  What Problems Are Studied by Biomechanists? 13 An area of biomechanics research with implications for both safety and performance is sport shoe design. Today, sport shoes are designed both to prevent excessive loading and related injuries and to enhance performance. What factors affect the design of a shoe for a particular sport? Ingram Publishing/Alamy Stock Photo An Alpine ski boot. © McGraw Hill 22  Why Study Biomechanics? Biomechanical principles are applied by scientists and professionals in a number of fields to problems related to human health and performance. Knowledge of basic biomechanical concepts is also essential for competent physical education teachers, physical therapists, physicians, coaches, personal trainers, and exercise instructors. © McGraw Hill 23  Qualitative versus Quantitative 1 Qualitative: Description of quality without the use of numbers. Examples: Good, poor, long, heavy, flexed, and rotated. Quantitative: Involves the use of numbers. Examples: Running speed equals 5 meters per second, height equals 1.75 meters, and mass equals 68.2 kilograms. © McGraw Hill 24  Qualitative versus Quantitative 2 Quantitatively, the robot missed the coffee cup by 15 centimeters. Qualitatively, it malfunctioned. © McGraw Hill 25  Qualitative versus Quantitative 3 Brand X Pictures/Getty Images Coaches rely heavily on qualitative observations of athletes’ performances in formulating advice about technique. © McGraw Hill 26  Formal and Informal Problems 1 Formal problems are relatively easy to solve. Characterized by: A set of given information. A particular goal, answer, or desired finding. A set of operations or processes that can be used to arrive at the answer from the given information. For example: A stated math problem. © McGraw Hill 27  Formal and Informal Problems 2 In informal problems, the given information, the goal, and the processes to be used to find an answer may be unclear or not readily identifiable. These problems are relatively difficult to solve. For example: What to wear to a social gathering. © McGraw Hill 28  Steps in Solving Formal Quantitative Problems 1 Read the problem carefully. List the given information. List the desired (unknown) information for which you are to solve. Draw a diagram of the problem situation. Identify and write down the formulas that may be useful in solving the problem. Select a formula that contains both the given variables and the desired unknown variables. If a workable formula cannot be identified, check if any additional needed information can be determined by inference. Substitute the given information into the formula. © McGraw Hill 29  Steps in Solving Formal Quantitative Problems 2 Solve the equation to identify the unknown variable. Do a commonsense check of the answer derived. Clearly box in the answer and include the correct units of measurement. © McGraw Hill 30  Units of Measurement English system: System of weights and measures originally developed in England and used in the United States today. Metric system: System of weights and measures used internationally in scientific applications and adopted for daily use by every major country except the United States. © McGraw Hill 31