Earlier this month, Gareth Bale moved from
Tottenham to Real Madrid for a record-breaking
£85 million, after settling for a measly
£300,000 a week wage. This means, if he were
to get injured resulting in time out, which
is on average 18 days in football, he'd get
paid £770,00 without even kicking a ball.
So, injury prevention is clearly important.
Can we predict these expensive and sometimes
career-ending injuries? Of course in some
cases, injuries are the result of random dirty
tackles, but in others, it's a combination
of fatigue, physical weakness and overuse.
These injuries have the potential to be predicted,
and the goal of my PhD is to create a model
to achieve this. We can firstly monitor a
player's activity using the GPS devices they
wear in both training sessions and matches.
From this, we can establish relationships
between this data and the injury.
As you can see here for example, this is one
player's activity during one training session.
The same player, this is his activity analysed
over a month. One way of identifying injury
risk is to track the relationship between
muscle stress and high-intensity movement.
Generally, the more high-intensity movements
there are, the greater the muscle stress.
So if you went for a run, there'd be more
stress on your muscles than if you went for
a leisurely stroll. That same principal applies
here. The yellow line is muscle stress and
the purple line is high-intensity movement.
As you can see, they are interdependent, and
injury risk is highlighted when there is a
discrepancy between the two. So when muscle
stress continues to rise despite a fall in
high-intensity movements, in this case, the
player should have taken a couple of days
to recover, but instead, he continued to play
and train for the next six days until he was
sidelined with a muscle strain. So the information
is all there. The pattern recognition process
is the challenge, analysing relationships
and reoccurrences in a mass of data, both
in one player's history and in the squad as
a whole. In this case, I identified muscle
fatigue from over-training as the major factor
in the resulting injury.
But, does it always work? Well in the club
I'm currently at, there have been five muscle
injuries so far this season. Of these, and
based on the model, I have managed to identify
injury risk between three days and two weeks
prior to injury in all cases. The model itself
is not perfect, but prevention is cheaper
than the cure, because I could work on research
into this for the next 77 years, and still
not have earned as much as Gareth Bale will
during one injury. Thank you.
