[Music] foreign I use performance as a general way to describe how well we do something so for example Performance might be how fast we want to run a 5k or how far we can run performance may be you know regaining regular movement after an injury so for example on a cardiac rehab program someone's performance goal may be that they want to be able to walk across the room because they're so deconditioned to begin with so performance is a wide range of descriptions of how well someone does something anything from an elite athlete to a mere mortal from a very basic perspective performance is nothing more than a bunch of movements put together these movements are flexions and extensions internal external rotations ABA deductions what have you you learn about these movements in your class on functional Anatomy your anatomical Kinesiology class kn245 well movement in a very basic sense is a change in position and time period or from a mechanics displacement in time and when we study the displacements in some time period we're actually in a branch mechanics called kinematics this is the study of of movement without regarding the forces causing movement and when we're in our body mechanics class we're actually spend a lot of time understanding the relationship between position or really change in position velocity how fast we're changing position and acceleration how fast we're changing velocity so we in my in a biomechanics class you actually spend quite a bit of time understanding these three parameters both in the linear world and in angular world well what causes a displacement in time period Well force does a force is defined as a push or pull that tends to cause movement when we're studying the forces that cause the displacement in some time period which yields a movement flexion extension what have you and you put those movements together you have a particular performance when we're studying forces we're in the branch of mechanics called kinetics in our biomechanics classes here at UNLV we take a Newtonian approach to understanding kinetics and we use Newton's three laws law of inertia law of acceleration law of action reaction to understand human movement law of inertia is simply an observation and it states that an object will stay at rest or it will continue with its state of motion unless if force causes a change in that motion law of acceleration describes what a force does and it says when a force is applied to an object it will accelerate it based upon the equation f equals m a and then third law is a law of actual reaction this is one that probably is easiest to remember but it's actually the hardest to really truly understand this law states that for every force acting on an object there's an equinox of force created by the object or vice versa for every Force created by an object there's an equal and opposite force acting on the object what's important about that law is that when we use this law law of acceleration f equals m a what we're doing is we're actually identifying all the forces acting on the object not by the object and we're adding up those forces and we can understand the acceleration of the object so we'll spend some time in biomechanics in that class understanding these three laws how to use them to understand human movement well word of forces come from well they come external to the body for example gravity or mentioned the ground reaction force these are forces that are coming from outside the human and those are important to understand but forces also come from inside the person for example for muscles we also have ligaments and attendants what have you but in this case I just put muscle here because muscle is a force generating structure in the body generates a force that force causes a displacement time period of some segment that's that displacement time period is a movement we put a name on that movement extension flexion what have you and we put those movements together and we have a performance in biomechanics we'll actually study the forced velocity relationship the link tension relationship of muscle contraction what these represent are characteristics of how well muscle generates Force based upon how fast it's being asked to contract or how long the muscle is when we're asking it to contract so the force velocity and length tension relationship we may also get into a little bit of the energy Pathways for example I'm talking about VO2 or rate of oxygen consumption maybe anaerobic production of of energy but we may actually talk about how muscles generate Force via physiology and then ultimately how those forces are linked to a performance well how do muscles know what to do well we have the central nervous system or nervous system in general the nervous system tells the muscle what to do it also receives information back from different sensors within the body as well as external to the body the and then directs motor signals to the muscles telling which muscles to fire which muscles to contract which muscles to relax when to confire how much to to fire at any particular time which ultimately generates a force which causes a displacement time period which is a movement flexion extension what have you and ultimately that's a performance I put environment over here environment is anything external to the person and obviously things like wind humidity temperature surface characteristics these are all environment issues but environment could also be psychological that is if you're going to go up and shoot a free throw in your backyard your you may have a different performance than if you shoot a free throw in front of 22 000 people watching you trying to shoot that free throw so environment could also be a psychological impact on what the central nervous system does generating a signal to a muscle which generates a force which causes a displacement in time period which is a movement and you put those movements together you have a performance if based upon some external environment I generate the wrong signal or I generate the wrong amount of force at the wrong amount of time ultimately we're going to have an incorrect Force it's going to cause an incorrect displacement in time period which is going to be an incorrect movement and ultimately during performance so by understanding all aspects of this model we can actually understand human performance now as an undergraduate you're asked to take all these different types of classes listed over here and you need to work on integrating the information from all the different courses to understand human performance if you're just a biomechanist and you just focus on kinetics and kinematics of human movement you're actually going to end up being Limited in understanding performance you need to understand not only the kinetics and kinematics but you need to understand Energy Systems you need to understand motor control you need to understand functional Anatomy you need to understand more to learning where you do this and then you do it again and again and again you need to understand injury because if you do these movements too long or too much force is generated you could ultimately have an injury that could either cause an energy or you could understand how to rehabilitate someone so sports medicine or athletic training are more General so Kinesiology in essence is covers all these different areas and your job as a student going into a program is to learn all these different areas and then as you complete the degree learn how to integrate all these different areas to understand human performance so what does the biomarkers do well the plot he or she applies the mechanical principles of physics and Engineering to the motion structure and function of living systems so for example in physical activity you'll find bomb mechanists working in exercise equipment design for example running shoe I mentioned we have some students who've worked at Shoe companies doing that we've had students go on to work in prosthetic and orthotic design prosthetic would be as pictured here designing a limb to replace a limb orthotic would be a device to augment a limb so like a knee brace or maybe a foot orthotic that you put inside your shoe a biomechanist may be focused on performance enhancement specialist coaching or maybe it's more broad than coaching working with a team in terms of how to improve their performance it could be ergonomics more in the workplace or it could be working in clinical setting work in a gate laboratory where you take measurements of someone's movements you give those data to a surgeon or a doctor and they use those data to help set a course of action for somebody or it could be something as simple as trying to fit someone for a bike people actually pay experts in bike fitting to be able to help them set up the bike so they can bike as fast as possible or as long as possible so where are our students well they're all over the place which is great our students end up in academics work in other institutions both in Research Laboratories as well as faculty members we've had students as I mentioned go on to work in research and development Labs we've had students go back to school and continue their education become a physical therapist and we've had students that end up in the fitness industry at all different levels of working in the fitness industry from personal training to management to teaching within the fitness industry so what is biomechanics just pulling it together science which investigates motion and the action of forces internal external including Statics Dynamics kinematics and kinetics that occur during the actions performed by living organism for example a human being and again as a biomechanics class you will be learning about all these terms and more cancer the physical activity is the study of movements and structure and function of human beings using mechanical principles of physics and Engineering or you'll learn how to use the physics of sport or how to apply physics to understand support so good luck and I hope you enjoy the rest of the course