Introduction to Sports Biomechanics: Analysing Human Movement ...

INTRODUCTION TO SPORTS BIOMECHANICS
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BOX 2.3 SUMMARY OF UNIVERSAL AND PARTIALLY GENERAL MOVEMENT
PRINCIPLES (see Appendix 2.2 for details of those in the first two
categories)
Universal principles
These should apply to all sports tasks:
Use of the stretch–shortening cycle of muscle contraction.
Minimisation of energy used to perform the task.
Control of redundant degrees of freedom in the segmental chain.
Partially general principles
These apply to groups of sports tasks, such as those dominated by speed generation:
Sequential action of muscles.
Minimisation of inertia (increasing acceleration of movement).
Impulse generation or absorption.
Maximising the acceleration path.
Stability.
Specific principles
These apply to the specific sports task under consideration and are derived and used for the long
jump on pages 62–71 (see also Study task 5).
BOX 2.4 LEAST USEFUL MOVEMENT PRINCIPLES (IN MY EXPERIENCE)
Summation of joint torques – cannot be observed and rarely measured, or estimated,
accurately.
Continuity of joint torques – as above.
Equilibrium or stability – grossly oversimplified principle for fast movements.
Nature of segments – I have never been sure what this means.
Compactness – another grossly oversimplified principle for fast movements.
Spin – say no more!
sports movement, or selecting the principles that conform to the constraints on the
movement, by applying Box 2.3 for example. The principles used should be specific to
the sport, the performer and the constraints on the movement. With a very sharp
warning that any set of movement principles is neither a list to be run through in all
circumstances nor a ‘cookbook’, the principles in Box 2.3 are those that I have found
most useful in devising deterministic models for sporting activities in which I have been