Assessing head impact reduction through under-mat systems: A fall simulation study of Ippon-Seoi-Nage and Osoto-Gari in Judoka

Abstract

Concussion rates are increasing in the sport of Judo. Most research on prevention focuses on how athletes respond to throws or the types of protective equipment they use to reduce impacts to the head and body. There is, however, a lack of research on the effectiveness of Judo mats in minimizing the risk of concussion during falls. In response to this research need, the proposed study explored the material properties of Judo under-mat systems by measuring their energy absorption through static testing. It also examined how different under-mat systems mitigate impact force, reduce acceleration, and lower the risk of head injuries during simulated dynamic falls in Judoka. Specifically, the study simulated scenarios when an athlete lands on the mat after being thrown with the Osoto-Gari technique and when an athlete hits the head on the mat while being thrown with the Ippon-Seoi-Nage technique. Four under-mat systems commonly seen in Judo training centers in Ontario were examined: a Judo mat with no under-mat, a pool noodle under-mat, a hockey puck under-mat, and an insulation under-mat system. Descriptive statistics, including means and standard deviations, were computed, and inferential statistical analyses were performed utilizing mixed factorial ANOVAs to address the purpose of this study. The static testing results showed that the pool noodles and hockey pucks absorbed less energy than the baseline under-mat system, but they may provide more cushioning for athletes during falls. The dynamic simulations and human participant testing revealed that the pool noodle and hockey puck under-mat systems seemed to better mitigate the risk of concussion based on measures of force, linear and angular acceleration during the simulation of Osoto-Gari and Ippon-Seoi-Nage Judo techniques. The outcome of this study provides an avenue to assess the effectiveness of Judo under-mat systems in training centers to prevent concussion risk.