Can you predict injury in footballers based on their movements?
Your first thoughts might be “Well obviously not! There are far too many things to consider and there’s no way you can predict injury.”
Before you move on, hear me out!
For football fans, every January and August is filled with jubilation, heartbreak and head shaking, as TV screens, radios and social media platforms are all inundated by transfer gossip and last minute club signings before the transfer window closes. Behind all the mania, sports and exercise medicine practitioners, such as physios, doctors and sports scientists are working away in the background, carrying out health assessments or “medicals” to try and determine if potential signings are fit and will continue to remain so, as much as possible, throughout the season.
You could say they are being asked to try and predict if the person they are assessing will or won’t get injured!
This doesn’t only happen during the transfer season. Sports practitioners make decisions on a daily or sessional basis about the “fitness” of a players for participation in training and matches. These are all done to try and minimise injury. Last season in the Premier League, it is estimated that wage bills to injured players was upwards of £100 million. Star players and teams with higher injury rates are also known to perform worse within a competitive league, possibly resulting in relegation. Therefore it’s important that where possible sports and exercise practitioners get it right.
There are a plethora of things available to help sports practitioners make decisions about suitability to play, although not all of them are necessarily useful. In football the most commonly used is the Functional Movement Screen (FMS). The FMS asks people to perform a series of movements such as squats, lunges and press ups. The sports practitioners then score the movement. Some research has found that scoring below a value of 14 increases your risk of a serious injury by up to 11 times more! The FMS is really popular and has also become an integral part of other sports such as the NFL, NHL and NBA. It has even been used for screening firefighters and Marine officers.
There has been some debate among the sports boffins about whether it can actually be used for injury prediction and measuring movement. So, we decided to do some research on it to see if the FMS can:
1. Measure movement
2. Predict injury
We did this by asking a team of footballers to complete the FMS in the preseason period. They were given a score by a certified FMS assessor and at the same time we used a 3D motion capture system to measure the movements. To do this we had to put loads of tiny spheres on them. (You may have seen this used in video games and movies such as FIFA and the Avengers.
This allowed us to check if the FMS was valid i.e. measures what it claims to measure. We were also able to then generate automatic scores from the 3D movement system and compare if either the assessor or computer generated scores could be used for predicting injury.
What did we find?
Well, whether we used the assessor or computer scores, the FMS was not able to predict injury in any of the 24 University footballers we followed. We also found that the FMS is an incredibly complex scoring tool and is not able to measure movements or performance reliably. Sports practitioners may want to reconsider using the FMS as it is not a reliable measure and doesn’t help inform their decision making processes.
So can you predict injury in footballers based on their movements?
The answer to this million dollar, (more like £100 million dollar) question is something we are still striving to answer.
The bottom line, whether you believe injury prediction is possible or not, is this. Sports practitioners are required on a regular basis, often in high pressure situations, to make judgments about future events relating to a players likelihood of getting injured. They will always be trying to predict injury. These decisions are often based on a mix of clinical experience and measures they have taken. Using the wrong tools or measures may add unnecessary noise into an already complicated processes.
One of the most important but overlooked findings from our study was that even if there were movements that predict injury you need to have the right tools to do it. Using tests which are not valid would be equivalent to using a ruler to measure how heavy someone is, it just doesn’t work. In future research we are looking to see how we can help improve performance measures and help sports practitioners with decision making in order to keep footballers on the field.
