The study I will belooking at is the biomechanical principles within running. The biomechanical principles that are influenced in running are;– Friction– Forces pushing or pulling– Centre of mass FrictionThe FiveLaws of Friction:1. When thebody is moving, the friction is directly proportional to normal force andfrictional force direction is perpendicular to the normal force.2. Frictiondoesn’t depend on the area of contact so long as there is an area of contact.3.
The coefficient ofstatic friction is slightly higher the value than the coefficient of kineticfriction.4. Kineticfriction is independent of the velocity of the body.5.
Frictiondepends on the type of the surfaces in contact. Frictioncan be defined as the resistance to motion of two moving objects or surfacesthat touch. Friction plays a very important role in many sports, suchas running. Frictionalforce is encountered within each movement the runner makes on the track. Whenwe try to run our foot is pressed to the earth in backward direction and by third law of Newton (actionreaction) there will be a reaction for every action in opposite direction.
Forces can affect your running greatly and can slowyou down and speed you up. When you arerunning the most important force that you should understand is friction. There is both Static Friction and Kinetic Friction. Staticfriction is the friction before an object starts to slide, while Kineticfriction is the friction when the object is actually moving or sliding. Theformula for both is the same, except they have different coefficient offriction values.Friction is a forcethat opposes movement between two objects, (fisher 2015) but for runner’sfriction can make you faster.
Friction gives you a better and moreefficient way to use your energy into speed. Having the correct equipment suchas shoes appropriate to the type of race and track type can give you morefriction or another term for it is grip. Having more grip on the ground enablesyou to move faster with every step. The second biggest force that you deal withis air resistance or fluid friction. Air resistance is a force that slows anobject down while moving through the air. When you are running in to the wind,air resistance makes it feel like you hit a wall and can’t move forward. Factorssuch as incorrect footwear and track type and temperature can greatly affectthe frictional force on the runner and can decrease their speed.
You can seefrom the diagram below the force gravity pushes on the body as the propulsiongoes one way, friction goes the other fighting against each other making moreair resistance and acceleration. Forces pushing or pulling Centre of mass The centreof mass is an imaginary point at which the total body massis concentrated, and it is a general descriptor of whole body massmovement.The positionof your torso/head during running significantly influences kinematics,mechanical work and metabolic energy expenditure whereby heelstrike running and forefoot strike running involves differentcentre of mass positions.
Heel strike runners have a more posterior (backward)centre of mass position –the runner’s torso is kept upright (i.e. no leaning)during running; whereas forefoot runners have a more anterior (forwardleaning) centre of mass position. Leaningforward is actually better because it increases forwardmomentum and encourages a foot strike position close to or under the centre ofmass. In runners the diagonal elastic support mechanism is utilised.
This isproduced by a constant diagonal stretch and release that is enabled by thebody’s counter rotation. The force continually flows up and down these forcepathways alternately. The pattern of force distribution prevents force beingconcentrated in one area, but allows wide distribution of force throughout thebody. Elphinstone (2013)