Biomechanical Principles and Applications PSE4U Mr. 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 to asses performance

Quantitative Biomechanics

Types of Motion Linear motion Angular motion General 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)