Biomechanics of supination ankle sprain: a case report of an accidental injury event in the laboratory

Ankle sprain is the most common injury in sports, but the mechanism of injury is not clear. Injury mechanisms can be studied through many different approaches. Over the years, ankle kinematics has been studied during simulated subinjury or close-to-injury situations, that is, sudden simulated ankle spraining motion on inversion platforms. Because these tests did not induce real injury, they could only somewhat suggest the ankle kinematics during an ankle sprain injury. The most direct way is to investigate real injuries using biomechanical measuring techniques. However, it is obviously unethical to do experiments where test subjects are purposefully injured. Nevertheless, in rare cases, accidents may occur during biomechanical testing. It has been shown that video sequences from sports competitions can provide limited but valuable information for qualitative ankle injury analysis. However, quantitative biomechanics analysis of sport injury is not easy as it requires calibrated multiview video sequences. This study presented an accidental supination ankle sprain injury that occurred in a laboratory under a high-speed video and plantar pressure capturing setting.