Intro To Biomechanics

— Study of the mechanical laws/forces relating to the movement of living systems

Two Divisions:

  1. Kinetics:

  • forces that cause or change motion

  1. Kinematics

  • description of motion independent of the cause

Kinetics

— Mechanical loads on the human body

  • tension and combined loads

  • effects loading

  • acute versus repetitive loads

  • study of forces

Basic Concepts:

Mass

— quantity of matter that makes up a given object

  • causes object to have weight

  • represented by m

  • units are kg

Inertia

— tendency to resist change in state of motion

  • object remains at rest/unchanging motion unless acted on by an external force

  • proportional to mass

  • has NO units

Force

— influence that can cause an object to change it’s velocity

  • a push or pull

  • characterized by magnitude, direction, and point of application

  • unit is the Newton (N)

Weight

— force exerted on an object during gravity

  • attractive force that the earth exerts on a body

  • unit is in Newtons (N)

Net Force

— the single resultant force derived from the vector composition of all the acting factors

Torque

— measure of force that causes an object to rotate about an axis

  • ability of a force to cause rotation on a lever

  • T=Fd

Amount of torque depends on:

Kinematics

— Study of the description of motion

— What we observe:

  • form and technique

  • range of motion

  • sequencing

  • timing

  • velocity and acceleration

Forms of Motion

Linear Displacement

— whole segment moves in linear plane

  • no fixed points

  • F=m*a

Angular Displacement/Rotation

— motion of rotation around an axis

  • fixed points

Three Main Types:

  1. Linear

— motion along a line; also called translation

  1. Angular (rotary)

— motion around a fixed axis

  1. Oscillatory

— back and forth swinging motion