Introduction to Sports Biomechanics: Analysing Human Movement ...

leading into the acquisition of other relevant knowledge, being translated into a systematic
observation strategy, driving the evaluation and diagnosis, and providing the
structure for the intervention.
The requisite knowledge for development of a systematic observation strategy
(see the next section) includes how to observe, based on the overall movement or its
phases (see Appendix 2.2), the best observation (or vantage) points, and how many
observations are needed. Aids to the development of this strategy include the use of
videography and rating scales. It is advisable for all movement analysts to practise
observation even when using video, particularly if movements are fast and complex, as
in notating games. Furthermore, the analyst should develop pre-pilot and pilot protocols
to ensure all problems are overcome before the ‘big day’. The maxim ‘pilot, pilot,
then pilot some more’ is well founded.
Knowledge of effective instruction, feedback and intervention provide the appropriate
information to translate critical features into intervention cues, couched in
behavioural terms, which are appropriate to one’s ‘clients’. These should not be verbose
– no more than six words – and figurative not literal. Remember that analogies must
be meaningful; advising that the backhand clear in badminton is like ‘swiping a fly off
the ceiling with a towel’ has no meaning to someone who has never performed such an
action or seen another person do it. The cues to be devised can be verbal, visual, aural or
kinaesthetic, and may differ for various phases of a movement; for example a javelin
coach may see value in attending to the aural cues of footfall during the run-up, but
would switch to other cues for the delivery phase. The movement analyst needs, therefore,
to derive relevant cues for each movement phase, and should attend to: the cue
structure (what the action is); its content (what does the action – the doers); and
cue qualification (how to gauge success). Special conditions may be added if more
information is needed. Examples include: rotate (action) the hip and trunk (the doers);
swing (action) the arm (doer) forwards (qualification).
OBSERVATION STAGE – OBSERVING RELIABLY
QUALITATIVE ANALYSIS OF SPORTS MOVEMENTS
As should be evident from Box 2.2, this stage primarily involves implementing the
observation strategy devised in the preparation stage, and videographing the performers
involved in the study. I use the term ‘videographing’ (or video recording) the
performers advisedly; first, considerable skill is needed to observe reliably fast
movements in sport by eye alone (see Table 2.1) and, secondly, good digital video
cameras are now readily available and not expensive.
We need to record sports movements as they are fast and the human eye cannot
resolve movements that occur in less than 0.25 s. Two important benefits of videography
are that the performers can observe their own movements in slow motion and
frame by frame, and that it makes qualitative analysis much easier. However, there are
some potential drawbacks. Performers might be aware of the cameras and, consciously
or subconsciously, change movement patterns (the Hawthorne effect). Also, there
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