Learning how injuries happen can help us prevent and treat them. Unfortunately, you can’t just do a study asking people to hurt themselves on purpose… those pesky ethical committees would never approve of your brilliant study.
Then how are we supposed to collect such data? Accidentally of course!
Researchers in Germany were doing a study with soccer players performing a run and cut maneuver while being recorded with 3D motion capture and EMG (electromyography – which measures muscle activity).1
During one of the run and cut trials, one of the soccer players actually rolled their ankle by accident! It happened while all the recording equipment was running! Serendipity defined.
What did we learn?
FYI: it wasn’t a bad sprain – probably just a grade I – the player didn’t need medical attention and recovered in about 10 days. Learn more about ankle sprains here.
How It Happened
Once the heel hit the ground, the players ankle quickly and excessively inverted (side bent inward), internally rotated (rotated inward) and plantar-flexed (foot pointed straight). That’s not really surprising, based on previous research. 2
Furthermore, the muscles on the front and outside of the shin (tibialis anterior and peroneous longus) were delayed - being silent on impact, but then became excessively active.
What’s really interesting is what happened before the heel hit the ground…
Right before the heel hit the ground, the biomechanics of the pelvis, hip, and knee were different than the previous 16 trials, but not the ankle!
The pelvis was less rotated, and hip flexion was delayed – leading to more flexion on impact. Knee flexion was delayed, and quadriceps timing was altered, leading to a fully extended knee on impact.
Summary: the players foot hit the ground with the whole leg in an awkwardly rotated and excessively straight position, and then proceeded to roll the ankle.
This is just one example, and there are probably tons of different ways you can land that cause your ankle to roll. But the important point here is that the leg was in an awkward position before it even landed!
This is important information – research like this explains why certain things work and others do not when it comes to injury prevention. The authors of this study highlight the importance of considering the entire body, and not just the ankle joint, in preparatory adjustments and landing response.
I’ve long advocated the importance of coordination (rather than strength, flexibility, etc.) in injury prevention, and the research generally supports it. Yes, it’s all important, but we should be mindful of what needs to be emphasized, and what doesn’t.
Finally, let’s not forget that not all injuries can be prevented! The player in this study did 16 normal trials before rolling their ankle – so it’s not like he was incapable of doing it right.
In the end, it may have just been a mistake (like many injuries) – plain ol’ bad luck!
Either way, this is some cool injury science. What do you think?
1. Gehring D, Wissler S, Mornieux G, & Gollhofer A (2013). How to sprain your ankle – a biomechanical case report of an inversion trauma. Journal of biomechanics, 46 (1), 175-8 PMID: 23078945
2. Fong DT, Ha SC, Mok KM, Chan CW, & Chan KM (2012). Kinematics analysis of ankle inversion ligamentous sprain injuries in sports: five cases from televised tennis competitions. The American journal of sports medicine, 40 (11), 2627-32 PMID: 22967824