Introduction to Sports Biomechanics: Analysing Human Movement ...

INTRODUCTION TO SPORTS BIOMECHANICS
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SUMMARY
function of the environmental, task and organismic constraints on that movement.
This approach recognises that each sports performer brings to a specific movement task,
such as throwing a javelin, a set of organismic constraints unique to that person. These
determine which movement patterns, from the many possible solutions to the task and
environmental constraints, are best suited to that individual. Environmental constraints
are largely related to rules, equipment and, unsurprisingly, the environment in which
the activity occurs. Organismic constraints include anatomical and anthropometric
factors and fitness. Task (or biomechanical) constraints include the forces and torques
needed to perform the movement plus inertia, strength, speed and accuracy. This
approach has not yet been developed sufficiently by sports biomechanists to be an
alternative way of identifying critical features of a movement. However, awareness of
the constraints on a particular movement can help the movement analyst to identify
critical features with more confidence, in combination with deterministic modelling or,
perhaps, the movement principles approach.
The long jump example on pages 62–71 will have shown you that deterministic
modelling is not a ‘quick fix’ for identifying critical features of a sports movement for
qualitative analysis, even when the objective performance criterion is easily identified.
However, although it takes some time to complete, it is not too difficult once you have
practised it well and if you are very familiar with the sports movement involved. The
same is true for quantitative analysts using hierarchical modelling to identify the
important performance variables to be measured. When the performance variable is
subjective, as in all sports in which subjective judging determines the outcome score
(e.g. gymnastics, diving and figure skating), an obvious alternative is to base the critical
features on the judging guidelines for the particular sport. These should largely have
been developed from movement principles applicable to movements within that sport,
so this approach has much to recommend it, particularly for inexperienced movement
analysts.
In this chapter, we considered how qualitative biomechanical analysis of movement
is part of a multidisciplinary approach to movement analysis. We looked at several
structured approaches to qualitative analysis of movement, all of which have, at their
core, the identification of critical features of the movement studied. We identified four
stages in a structured approach to movement analysis, considered the main aspects of
each stage and noted that the value of each stage depends on how well the previous
stages have been implemented. We saw that the most crucial step in the whole approach
is how to identify the critical features of a movement, and we looked at several ways of
doing this, but found that none is foolproof. We worked through a detailed example
of the best approach, using deterministic models, and considered the ‘movement
principles’ approach and the role of phase analysis of movement.