Theory
Basic principles of physics can be used to understand and improve the efficiency of each lift. Understanding ideas such as torque, force, power, and moment of inertia can help us determine the stresses placed on the human body and modify technique to maximize the amount of weight moved.
All of these concepts rely on Newton's Second Law which states:
This fundamental idea can then be further applied to rotational motion, allowing us to determine the torque placed on joints.
All of these concepts rely on Newton's Second Law which states:
- The net force of a body is equal to its' mass multiplied by its' acceleration or
- F = ma
This fundamental idea can then be further applied to rotational motion, allowing us to determine the torque placed on joints.
The Law of Conservation of Energy can also allow us to determine the power produced by a lifter:
- Total Mechanical Energy = Kinetic Energy + Potential Energy = 0
- Potential Energy = mgh (where m = mass, g = gravity, and h = height)
- Kinetic Energy = (1/2)mv^2 (where m = mass and v = velocity)
- Work = Force * Distance
- Power = Work / Time
Torque measures how much a force acting on a body causes it to rotate and can be expressed with these two equations:
- τ = rFsinφ (where r = radius, F = force, φ = angle at which the force is applied)
- τ = Fd (where d = the perpendicular distance from the pivot point to the line of action F)