Introduction to Sports Biomechanics: Analysing Human Movement ...

Figure 2.7 Level 4 of long jump model – factors affecting take-off speed – avoiding the blind alley.
our model, in Figure 2.7. Although mean force and acceleration path of the jumper’s
centre of mass won’t yet appear to be observable, we do have the right relationship, as
the jumper correctly needs to try to maximise both of these factors.
Figure 2.8 Take-off velocity components.
QUALITATIVE ANALYSIS OF SPORTS MOVEMENTS
Now all we have to do is develop observable features that capture these biomechanical
entities. We will take a step aside for the moment, as the observable features
we need flow more naturally from considering the vertical and horizontal components
(in black) of the take-off velocity (see Figure 2.8), rather than the take-off speed, which
is simply the magnitude of the overall take-off velocity in Figure 2.8; the take-off angle
specifies the direction of the take-off velocity. Hence, the take-off velocity can be
specified by either the take-off speed and angle, as in Figure 2.5, or the horizontal and
vertical take-off velocities, as in Figure 2.9. The latter approach is much better here,
indeed it is crucial, because what happens on the take-off board differs significantly for
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