Biomechanical Principles and Applications

PSE4UMr. MacMillan

▪ Biomechanics– The study of the structure and functions of biological systems by

means of the methods of mechanics

Hatze, 1974

▪ We might think of biomechanics as the “physics of human movement”

Biomechanics

Examines the internal and external forces acting on the human body and the effects produced by these forces

Aids in technique analysis and the development of innovative equipment designs

Draws on knowledge from sports medicine, physical therapy, kinesiology, and biomechanical engineering

Review of Movements from Anatomy

▪ Planes– Sagital– Frontal, Coronal– Transverse

▪ Axis– Horizontal– Antereoposterior– Longitudinal

Motion

▪ Kinematics– describing movements with respect to time and space

▪ Kinetics– examines the forces that produce the movement and result from the movement

Newton’s First Law: The Law of Inertia

An object will remain at rest or in a state of constant velocity unless acted upon by an external force

Newton’s Second Law: Law of Accelerations

A force applied to a body causes an acceleration of that body of a magnitude proportional to the force, in the direction of the force and inversely proportional to the body’s mass.

F = ma

Newton’s Third Law: Law of Reaction

For every action there is an equal and opposite reaction.

Qualitative Analyses

It requires:

A framework within which skilled performance can be observed

A set of principles with which movement can be analyzed

A checklist to use when identifying errors

Techniques to use for error detection and correction

Involves obtaining information, visually or auditorily, to asses performance

Quantitative Biomechanics

Types of Motion

Linear motion Angular motionGeneral motion

Types of Motion

Translation refers to movement of the body as a unit without individual segment parts of the body moving relative to one another

Linear Motion When all parts of the body move the same distance, in the same direction, at the same time

Rectilinear motion occurs when movement follows a straight line

Curvilinear motion occurs when the movement path is curved but also linear

Objectives: Identify the external forces acting on the human body

Describe the resulting motion

Describe the expected path and motion of any projectile

Differentiate between similar skills

Determine the degree of stability possessed by an athlete

Understand the causes and effects of actions

Qualitatively analyze simple sport skills that involve throwing, striking, or hitting an object

Preliminary Steps for Analyzing Human Motion

Step 1

Identify the system to be studied, which is to separate the object of interest from its surroundings

Step 2

Identify the frame of reference in which the movement takes place

Step 3

Identify the type of motion that is occurring, the body planes in which movement takes place (sagittal, frontal, or transverse), and

Identify the axes of rotation about which rotational motion occurs (sagittal, frontal, or vertical)