No 'magic bullet' to accurately predict injuries in football players, insists expert, as Premier League returns

And as the Premier League restart looms, it’s crucial coaching staff rely on communication and dialogue - not just complex data analysis - to ensure players stay away from the treatment table.

That’s according to Dr James Malone, Senior Lecturer in Coaching Science at Liverpool Hope University.

He says many clubs have invested heavily in tech and analysis to help them predict which players might be more susceptible to picking up injuries, while also helping them adapt training regimes to mitigate the risk.

But for Dr Malone - a specialist in training, recovery and testing among athletes - there’s no ‘magic bullet’; injury prediction based on data collection is still in its infancy.

And if clubs are to ward-off the ‘soft-tissue injuries’ concerning managers ahead of football’s restart, they need to be wary that no current system is anywhere near fool-proof.

Dr Malone, who has worked with clubs across Europe, including Liverpool, Ajax and Borussia Dortmund, explains: “There have been many studies looking at injury prediction in elite athletes, particularly football.

“If there was such a mechanism it would be absolutely priceless to clubs.

“But we’re still some way from being able to accurately predict injuries based on things like training loads.

“In my opinion, the idea of ‘prediction’ is difficult. I don't think we'll ever be able to do that to its full extent.

“What metrics, numbers and data analysis can identify are ‘associations’ with injury risk. But we can’t be 100% certain if and when an injury will actually occur.

“As we approach football’s restart in England and with injuries at the forefront of minds, clubs need to remember that there’s no magic bullet here.”

Dr Malone says a major facet of current injury prediction methods involves taking a player’s injury as a starting point and working back through historical training data to see if trends can be spotted.

A recent joint investigation by Liverpool Hope University and Liverpool John Moores University analysed injuries suffered in training among 192 pro players from across Europe.

The research looked at something called ‘acute:chronic workload ratios’, or ‘ACWR’, which is commonly used across a number of sports to calculate the ‘sweet spot’ for training - where athletes are pushed hard but not to the point of breakdown.

Dr Malone hoped to find a link between non-contact injuries - to muscles, tendons and ligaments - and ‘workload variables’, such as how far and fast they were sprinting and running.

But having analysed data from a month’s worth of training sessions prior to injury, there was no clear link’ in injury type or severity when you compared what players were actually doing using the ACWR calculation.

That study, published in the International Journal of Sports Medicine, concluded: “This highlights that injuries in the current population occur regardless of the fluctuation in the workload experienced in the weeks preceding injury."

And if injury prediction is to become truly accurate, it needs to take into account other factors - including the genetic make-up of a player and also crucial psychological elements, such as whether a player is likely or not to play through the pain of a niggle, potentially exacerbating an injury.

Dr Malone adds: “In the past four or five years, data science has become a huge thing in football.

“If you look at the Premier League you have lots of job titles like ‘Head of Analytics’.

“But data scientists also need to look at the complexities and coaching aspects of the game, not just the data.

“Coaches and managers are relying on sport scientists to give them contextual information from the data sets they’ve gathered. That’s what underpins physical training plans for individual players.

“A practitioner might think, ‘I’ve got the data, I can perform a magic algorithm and here’s the positive output’. But if it’s data from a system that’s not reliable, it’s not valid. In fact, it’s been proved by research not to be particularly good.

“The ‘acute:chronic workload ratios’, or ‘ACWR’, is a classic case where the measure was popularised from a limited number of publications and then picked up by football practitioners.

“Everyone jumped on the bandwagon, assuming it was a great metric.

“But when people began digging into the calculation they quickly realised there are lots of flaws in it.

“Yet there are still football practitioners who keep it in their back pocket, as it were, thinking, ‘At least we’re trying something that might help’.”

The answer for managers is potentially a very simple one - talk to their players.

Dr Malone says: “Until we get to a point where injury prediction based on things like GPS data and workload variables is more accurate, it’s my view that open dialogue is going to be crucial.

“Talk to players about how they’re feeling. Use common sense at all times. And then use the available technology to enhance your own decision making process.

“It’s also important that every facet of the managerial structure is working together and maintaining that open dialogue, from the medical staff, to the fitness coaches, to the head coach.

“The more people you’ve got communicating, the harder it might become.”

A huge piece of the puzzle - still waiting to be solved - is looking at the genetic make-up of a player and analysing if they’re more or less susceptible to a soft tissue injury.

But Dr Malone warns: “The risk is that this becomes an arms race - where only the richest clubs could afford to do it.”

For the time being, there are certain factors that might mean a player is more likely to break down when the Premier League returns on June 17, and when the Championship season resumes on June 20th.

Dr Malone reveals: “If a player has had a prior injury, it’s often never going to be 100 per cent back to normal, particularly where there is scar tissue.

“You have to manage the player while understanding the injury is likely to recur again.

“Age is a big factor, too, as the older we get the more likely we are to get injured.

“From a positional perspective, wide midfielders and full backs who do more high speed distance running are also more susceptible to soft tissue injury.

“And strikers do a lot more work now than they did 10 years ago.”

Crucially, what players really need is a break - and then a long pre-season - once the 2019/20 season comes to an end.

Dr Malone is urging football authorities not to rush-in to next season, adding: “The short term focus is getting the current season finished.

“But you don’t want players to jump into next season too quickly just because this one has been extended.

“How will some of those places susceptible to injury cope in the next season if they don't have the correct pre-season?

“We can’t say to the players, ‘Right, you’ve got a week or so off and then we go again into a condensed preseason’ - because a solid preseason is one of the fundamentals of injury prevention.

“You need enough time to ramp-up the training and then taper down in order to bring about adaptation in the body.

“Considering that players will still need to play the rearranged Euro 2020 tournament next year also, the season is also going to be longer than normal which compounds the issue of rushing pre-season further.”

https://www.hope.ac.uk/