Topic 01 – Introduction to Biomechanics in Sport
Lesson Learning Outcomes
- Define biomechanics and its application in sport and exercise
- Identify the goals of sport and exercise biomechanics
- Describe the methods commonly utilized to achieve the goals of sport and exercise biomechanics
- Define mechanics and its organization
- Define units of measurement for length, time and mass
Guiding Questions
- Why is it important to understand biomechanics in sport and exercise?
- How can biomechanics be applied to sport and exercise through the use of real-life examples?
- What are the different units of measurement and how can they be used to understand movement in sport and exercise?
Definition of biomechanics
The word biomechanics can be divided into two parts: the prefix bio- and the root word mechanics. The prefix bio- indicates that biomechanics has something to do with living or biological systems. The root word mechanics indicates that biomechanics has something to do with the analysis of forces and their effects. Therefore, it appears that biomechanics is related to the study of forces and their effects on living systems, including plants and animals.
Biomechanics is defined as the study of the structure and function of biological systems by means of the methods of mechanics (Hatze, 1974).
What are the goals of sports and exercise biomechanics?
As defined earlier, biomechanics includes the study of all living things, plant and animal; animal biomechanics includes only animals as subjects of study; human biomechanics includes only humans; and sport and exercise biomechanics includes only humans involved in exercise and sport.
Therefore, sport and exercise biomechanics can be defined as the study of forces and their effects on humans in exercise and sport. What are the goals of studying these forces and their effects?
The goal of sport and exercise biomechanics is performance improvement in exercise or sport. A secondary goal is injury prevention and rehabilitation. Although they seem to be different goals, they are both equally important towards ensuring that an athlete improves his or her performance. These can be achieved through improvements to technique, training methods and equipment.
Performance Improvement:
- Technique improvement
The most common method for improving performance in sport is to improve an athlete’s technique. The application of biomechanics to improve technique
may occur in two ways: Teachers and coaches may use their knowledge of mechanics to correct actions of a student or athlete in order to improve the execution of a skill, or a biomechanics researcher may discover a new and more effective technique for performing a sport skill. In the first instance, teachers and coaches use qualitative biomechanical analysis methods in their everyday teaching and coaching to effect changes in technique. Coaches and teachers use biomechanics
to determine what actions may improve performance. In the second instance, a biomechanics researcher uses quantitative biomechanical analysis methods to discover new techniques, which then must be communicated to the teachers and coaches who will implement them.
- Equipment improvement
Biomechanics can contribute to performance improvement by improving the design for equipment used in various sports. The equipment worn may influence the performance, either directly or through injury prevention.
Example – Swimsuit
Speedo introduced its LZR Racer swimsuit in February 2008. The Speedo LZR Racer was designed by Speedo scientists and engineers to minimize muscle vibration and reduce drag with compression panels that streamlined the shape of the swimmer. The LZR swimsuits had polyurethane panels and no stitched seams. Within six weeks of its introduction, 13 world records were set by swimmers wearing the Speedo LZR Racer. At the 2008 Beijing Olympic Games, swimmers wearing the Speedo suits set 23 world records and won more than 90% of all the gold medals in swimming.
The rules makers in many sports, including popular sports like golf, tennis and cycling regulate the designs of the equipment used in their sports to keep the sports challenge. FINA (Federation Internationale de Natation), the international governing body for the sport of swimming revised its rules regarding swimsuits in 2009 and again in 2010 and the Speedo LZR racer may no longer be worn in FINA-sanctioned events.
- Training improvement
Biomechanics has the potential to lead to modifications in training and thus improvements in performance. This application of biomechanics can occur in several ways. An analysis of the technique deficiencies of an athlete can assist the coach or teacher in identifying the type of training the athlete requires to improve.
Example: Figure Skating
Training camps for junior female skaters held at the U.S. Olympic Training Center in Colorado Springs in the mid-1980s included biomechanical analyses of the skaters attempting double and some triple jumps. Many of the skaters who attempted triple twisting jumps were unsuccessful. An initial analysis revealed that some were unsuccessful in the triples because they were not bringing their arms in tight enough to cause them to spin faster while they were in the air. Further biomechanical analysis revealed that they were unable to bring their arms in tight enough or quickly enough due to inadequate strength in their arm and shoulder musculature. After their training programs were modified to include upper body strength training to increase arm and shoulder strength, several of the skaters were able to complete triple jumps successfully in the subsequent training camps.
Injury Prevention and Rehabilitation:
Injury prevention and rehabilitation is also argued to be the primary goal of sports and exercise biomechanics. Biomechanics is useful to sports medicine professionals in identifying what forces may have caused an injury, how to prevent the injury from recurring (or occurring in the first place), and what exercises may assist with rehabilitation from the injury. Biomechanics can be used to provide the basis for alterations in technique, equipment, or training to prevent or rehabilitate injuries.
- Techniques to Reduce Injury
Gymnastics provides an example of how biomechanics may aid in reducing injuries (especially from the impact forces that gymnasts experience when landing from stunts). Judges award higher points to gymnasts who “stick” their landings. But such landings may involve greater and more dangerous impact forces. These impact forces are the cause of overuse injuries in many gymnasts. A landing in which the gymnast flexes at the knees, hips, and ankles may reduce the impact forces, but it also results in a lower score. Outcome of related researches was a rule change allowing for landing strategies that reduced these impact forces without penalty to the gymnast’s score.
- Equipment Designs to Reduce Injury
An example of biomechanics affecting the design of sport equipment to reduce injury involves the running shoe industry. Running shoes available in the early 1970s were too stiff for many inexperienced runners and impact injuries like shin splints were common. Softer shoes that followed did not provide much stability and in turn led to injured in ankle, hip and knees. Biomechanics research funded by various shoe companies led to many of the features offered in modern running shoes, providing both stability and cushioning. These improvements have resulted in fewer running injuries.
Sport and exercise biomechanics can lead to performance improvement and may aid in injury prevention and rehabilitation through improvements in technique, equipment design and training. As more coaches, teaches and athletes become more exposed to biomechanics, we can expect improvements in techniques to occur more rapidly. A brief review of the history of sports can give us some insights into why biomechanics has not had the impact on sport that it seems capable of.
The organisation of mechanics
Mechanics is the science concerned with the effects of forces acting on objects. The objects refer to humans and the implements that may be manipulated during sport and exercise.
Mechanics may be divided into: rigid-body mechanics, deformable-body mechanics, fluid mechanics, relativistic mechanics, and quantum mechanics. Each branch of mechanics is best suited for describing and explaining specific features of our physical world.
Rigid-body mechanics is best suited for describing and explaining the gross movements of humans and implements in sports and exercise. In rigid-body mechanics, the objects being investigated are assumed to be perfectly rigid; that is, they do not deform by bending, stretching, or compressing. In describing and explaining the gross movements of the human body and any implements in sport and exercise, we will consider the segments of the human body as rigid bodies that are linked together at joints. In reality, the segments of the body do deform under the actions of forces. These deformations are usually small and don’t appreciably affect the gross movements of the limbs or the body itself, so we can get away with considering the body as a system of linked rigid bodies.
Rigid-body mechanics is subdivided into statics, or the mechanics of objects at rest or moving at constant velocity, and dynamics, or the mechanics of objects in accelerated motion. Dynamics is further subdivided into kinematics and kinetics. Kinematics deals with the description of motion, whereas kinetics deals with the forces that cause or tend to cause changes in motion. Our first exploration into biomechanics is concerned with statics.
Basic Dimensions and Units of Measurement Used in Mechanics
Mechanics is a quantitative science and therefore so is biomechanics. Some of the common mechanical terms we used for measurements may include speed, inertia, power, momentum, force, mass, weight, distance, velocity and acceleration.
- Length
Length is used to describe the space in which movement occurs. Length is also the most important dimension in sport such as shot putting or high jumping where how far or how high is the actual measure of performance. In some sports, length may not be the actual measure of performance, but it may be a critical component. How far a golfer can drive the ball off the tee is one way of determining success in golf. Length is also an important dimension when we consider the anthropometry of athletes, the length of the implements and length may be a dimension of the sport specified by the rules of the activity, such as the length and width of a football field or playing court or the height of a basket. The Système International d’Unités (International System of Units) or SI unit of measurement for length is the meter, abbreviated as m, which is about 3.28 ft or 39in. One foot is about 0.3048 m. Other units for length includes centimetre (cm), inch (in), kilometres (km) or miles.
- Time
Time is an important dimension of performance in almost all sports. Time can be the performance measure, or it can be the important determinant of success – e.g. reaction time in goalkeeping. Time may also be a dimension specified by rules of the activity like game time, time-outs etc. The SI unit for time is second (s). Speed and velocity, for instance, are derived from length and time and are expressed as some unit of length per unit of time. Acceleration is also derived from length and time measures.
- Mass and Inertia
In mechanics, we refer to the property of an object to resist changes in its motion as inertia. Mass is the measure of inertia, whereas weight is the measure of the force of gravity acting on an object. The mass of implement or athlete or body part has a great effect on the execution of the performance, because the mass of the object to be moved or stopped determines how much effort is required to get the object to move or stop the object from moving. The SI unit of measurement for mass is kilogram (kg). The kilogram is the SI unit of measure for mass and is abbreviated as kg. One kilogram weighs 2.2 pounds. One kilogram is 1000 grams.
Summary
- Biomechanics is the study of forces and their effects on living systems, whereas sport and exercise biomechanics is the study of forces and their effects on humans in exercise and sport.
- Application of biomechanics may lead to performance improvement or the reduction and rehabilitation of injury through improved techniques, equipment, or training.
- The advent and widespread use of electronic digital computers made biomechanical research more feasible throughout the 1970s and 1980s.
- Sport and exercise biomechanics is concerned primarily with that branch of mechanics called rigid-body mechanics. Statics and dynamics are the subdivisions of
rigid-body mechanics. Kinematics and kinetics are the further subdivisions of dynamics.
- The fundamental dimensions used in mechanics are length, time, and mass. The SI units of measurement for these dimensions are the meter (m) for length, the second (s) for time, and the kilogram (kg) for mass.