1. The Science of Biomechanics
How Do I Move? Chapter 7
The Science of Biomechanics

2. 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”

3. 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

4. The 7 Basic Principals of Biomechanics
They all fall under the following 4 categories
Stability
Maximum Effort
Linear Motion
Angular Motion

5. Principle 1 – Stability
The lower the centre of mass, the larger the base of support, the closer the centre of mass to the base of support, and the greater the mass, the more stability increases.

6. Principle 2 – Maximum Force
The production of maximum force requires the use of all possible joint movements that contribute to the task’s objective.

7. Principle 3 – Maximum Force
The production of maximum velocity requires the use of joints in order – from largest to smallest.

8. Principle 4 – Linear Motion
The greater the applied impulse the greater the increase in velocity.

9. Principle 5 – Linear Motion
Movement usually occurs in the direction opposite that of the applied force.

10. Principle 6 – Angular Motion
angular motion is produced by the application of a force acting at some distance from an axis, that is, by torque. The application of torque produces changes in angular motion.

11. Principle 7 – Angular Motion
angular momentum is consistent when an athlete or object is free in the air. Once an athlete is airborne, he or she will travel with a constant angular motion.

12. Review of Movements from Anatomy
Planes
Sagital
Frontal, Coronal
Transverse
Axis
Horizontal
Antereoposterior
Longitudinal

13. Motion Kinematics Kinetics
describing movements with respect to time and space
Kinetics
examines the forces that produce the movement and result from the movement

14. Qualitative Analyses
Involves obtaining information, visually or auditorily,
to asses performance
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

15. Quantitative Biomechanics

16. Types of Motion
Angular motion
General motion
Linear motion

17. 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

18. 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

19. Preliminary Steps for Analyzing Human Motion
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)