Lecture 1, Introduction to Biomechanics - Defining Terms and Concepts Flashcards
Defining Kinesiology
kinesis = movement, activity
logia = a branch of learning
kinesiology examines movements from the cellular (anatomy, physiology) to the societal level
ex. physiological, mechanical and psychological mechanisms
- biomechanics is connected to all the different fields
Defining Biomechanics
biology = the study of living organisms
mechanics = analysis of forces and their effects (study of forces)
biomechanics is the study of forces and their effects on living systems
The History of Biomechanics
- Giovanni Alfonso Borelli (1608-1679) was a Renaissance Italian physiologist, physicist, and mathematician
- he contributed to the modern principle of scientific investigation by testing hypotheses against observation
- trained in mathematics he studied the mechanics of animal locomotion and used microscopy to investigate the stomatal movement of plants
- everything is based on observation
The History of Biomechanics (Marey)
- etienne jules marey was a french scientist, who was a pioneer of photography and an influential pioneer of the history of cinema
- marey was interested in the “animal mechanism” and developed cameras that could record several phases of movement on one photographic surface (flying pelican captured in 1882) - capture different movements and different stages (need clear observation so we can minimize error)
- movement occurs too quickly and we simply cannot see
The History of Biomechanics (Bernstein)
- the word biomechanics was coined by Nikolai Bernstein (1896-1966), a Soviet neurophysiologist (largely self-taught)
- Bernstein was one of the pioneers in the field of motor control and motor learning; the field that examines how the central nervous system controls posture and movement
- his first scientific work was in 1922, when he examined movement during manual labour to optimize productivity
- his research showed that most movements are composed of smaller movements and if any one of these smaller movements are altered the movement as a whole is affected
- since he did his research behind the iron curtain of the USSR, his ideas only became known to Western scientists in the 1960s, when his work was translated into English from Russian
- observed human movement where they noticed certain patterns developing that were creating injuries and they started making recommendations where people can do things in shifts or change what it is they are interacting with (by changing what we do and how we do it we can create safer movements)
- teach movement patterns to others (coaching someone else how to move by observing, watching and taking note) - watching and be able to freeze movement is what created biomechanics and then being able to improve movement
The History of Sport Biomechanics (latest)
- by the early 20th century researchers had a variety of devices, including cameras and pressure-sensitive equipment, to measure and record forces and motions in a variety of activity
- the Baseball Magazine commissioned a study in 1912 to determine the speed of a baseball (and identify key pitching mechanics)
- the mechanics of other sports quickly followed: sprinting (1920), swimming (1930), and track and field skills (1939)
- in 1955, the book Scientific Principles of Coaching was published, one of the first texts to emphasize mechanics (technique)
- by the 1960’s the field of biomechanics had formally arrived
Biomechanics is…
- biomechanics is the study of structure and function of the biological systems by means of the methods of mechanics
- biomechanics is the study of all living things, a fairly broad topic
- we might want to narrow our focus of study to sport and exercise
- we can then define sport and exercise biomechanics (purposeful, goal-directed tasks that humans perform) as the study of forces and their effects on humans in exercise and sport
- biomechanics is the study of forces and its effects on human system
But…What is Biomechanics Really About?
- biomechanics deals with quantitative reasoning, the ability to reason quantitatively and to model and solve problems with quantitative methods
- generally there are three basic steps in solving a problem:
◦ understand the problem
(identify known and unknown
information)
◦ carry out a strategy for solving
the problem (identify the
process)
◦ check your answer (identify
what it means) - many problems are posed in real-life settings (applications), to understand how and why the human body moves in the way that it does
- biomechanics deals with constrains (formal answer that we are looking for after looking at the constrains and task factors)
Defining Mechanics
- the science concerned with the effects of forces acting on objects
- system is the thing you are studying
Rigid-Body Mechanism
deformation is zero or so small that it can be neglected (force that is applied to system but system does not change its shape or deform (most of the body are going to be rigid-body)
Deformable-Body Mechanics
any body changes its shape (or volume) while being acted upon by any kind of external force (it can be temporary or permanent / it can be bent or deformed)
Why Study Biomechanics? (5)
- to improve performance..by improving technique (the body is always capable of doing more - with a new way of performing the technique could be changed to arch over the bar and land on something safe rather than having to land on your feet with high jump)
- to improve performance..by changing equipment used (the full body suit reduces resistance by 5% or klap skate increases contact time with ice)
- to improve performance..by making modifications in training (make the body better and stronger by changing training)
- to prevent or recover from injury..finding techniques to reduce injury (can withstand the force or train safely)
- to prevent or recover from injury..designing equipment to reduce injury
Kinematic
examining or describing movement (simply a description of what is happening and no talk about force)
describing motion over space and time
- running shoes are stiffer and padded (foot is locked in certain position)
- offer protection yet also alter technique and foot movement
- high-heeled shoes provide limited support (foot acts as a spring as it flexes and extends)
- the foot flexes more in high heels
- greater range of motion of the foot when wearing heels
- tissues that stretch act like a spring
Kinetics
study of forces (how much force was produced and how many effect does the forces have)
study of forces causing or resulting from motion
- runners wearing sneakers land heel first (when you land heel force there is a spike in force - more likely to hurt yourself)
- runners wearing heels land on the front-foot (the little spike in force is gone being exposed to less force at the knee, hip and feet - exposed to less force)
the knees and ankle absorb less force when landing on the front foot (more comfortable, safer ride)
Statics (can be understood in three different ways)
- in a constant state of motion (static state (constant velocity) - are you moving or not and what does it look like
- constant = doing the same thing, not changing and refers to how fast you are moving)
- motionless
- moving at a constant speed
