Haraldur Sigurðsson, Melkorka Pétursdóttir Pétursdóttir and Kristín Briem
Background:
Anterior cruciate ligament (ACL) injuries are serious and debilitating with societal consequences but no strong biomechanical risk factors. A novel method developed at the University of Iceland is to classify the shape of the waveform into either potentially injurious („early peak“), or benign waveforms irrespective of the magnitude of force. The aim of this project is to evaluate if the early peak waveform is associated with increased risk of ACL injury.
Methods:
Female athletes (N = 52) performed ten repetitions per leg of a cutting maneuver measured with an 8 camera motion capture system using retroreflective markers and force plate. Medical records 5-8 years after the data collection showed that 7 athletes had undergone ACL reconstructive surgery on nine legs. Knee abduction moment waveforms were classified with a cluster anaylsis into the early peak waveform, or other waveforms. The risk of ACL injury was calculated using a mixed logistic regression (alpha = 0.05).
Results: One third of all recorded trials had the early peak waveform. The early peak waveform was associated with a 7-fold increase in the risk of ACL injury (95% CI 2.5 – 25, p = 0.00024).
Conclusions: The early peak waveform was a strong risk factor for future ACL injury. As the current study was small, there is a non-trivial risk of false discoveries. If these results are replicated in larger prospective studies, the early peak waveform may be modifiable through training to prevent ACL injuries.
