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Where you find links to relevant online Bio-Mechanics video's

After the link description is a brief description of run time and type

Centre of Mass Visualisation 30 seconds intuitive

CoM & Body as rigid linked model 29 mins simple animated mathematical models

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Three Cs Part Two - Centre of Pressure and Centre of Force

Two very important concepts to understand in biomechanics are Centre of Pressure and Centre of Force. These are often used interchangeably but are actually different, mostly though, by convention, it is CoP that is used when considering how normal forces act over an area. Normal force means that force perpendicular to the surface of interest. When 2 objects act on each other with force then there will always be an interface that has some area and the forces acting over that area are called pressure. Pressure if Force divided by area and the unit of pressure is the Pascal, however 1 pascal is very small at 1N/m^2 or 100grams spread over 1million sq millimeters = 0.00001 grams / mm^2. So it is common to use kilopascals (1000 pascals) or KPa as the standard unit of pressure. Go here for a PPT presentation on CoF Vs CoP

Torque Moments Levers

Torque, Moments, Axis and Levers - now this is the meat of podiatric biomechanics. Torque and moment are used to describe rotational force, i.e. force applied to a lever about some axis of rotation. Moment is the more usual term in biomechanics and moments of force are in the units of Newton.meters Nm. Why? because Newton is the basic unit of force and metre is the measure of the length of the lever. So the unit of mass is kilogram and gravity (on earth) acting on 1kg is equal to 9.87Newtons, why? Because as we've seen before the acceleration of gravity is 9.87m/s^2 and if you remember Force = Mass x Acceleration (f=ma) Example: a lever 500mm long with a force applied of 250N results in a moment of 125Nm Simple enough of course. There are classically 3 types of lever, 1) force-fulcrum-load, 2) Force-load-fulcrum 3) Load-force fulcrum and they can all be seen in the body (https://www.slideshare.net/spanglerscience/muscle-leversppt-presentation Although a lever is a

Moment of inertia and Centre of Mass

Sorry to scare you but as we've just taken a look at inertia I thought I'd do this little snippet on 'moment of inertia' its important and useful in biomechanics, why? Well I'll tell you: As you'll remember, inertia is a body's resistance to change in velocity and inertial force is the ficticious force that manifests in the presence of acceleration, proportional to the acceleration ( times the mass) but in the opposite direction. Considering the inertia in this 1st case it is often quite convenient to just ignore inertial force. So say you want to push something in a straight line, like a sledge across the ice with your fat mate sitting on it. The sledge and your mate weigh 200kg and you apply a force of 500N to the centre of mass then the acceleration will be what? Get out the handy equation f=ma - rearrange to find the acceleration a=f/m plug in the numbers we know 500/200 and viola a=2.5m/s/s. After a couple of seconds you stop pushing and he's goi

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