Ankle sprain is very common in sports, and a commonly suggested etiology is the delayed peroneal muscle reaction time. Recent studies showed the successful attempts to deliver electrical stimulation to the peroneal muscles externally to initiate contraction before it could react, however, the success relies on a workable method to detect ankle sprain injury in time. This study presented a fast Fourier transform and polynomial fitting method with dorsal foot kinematics data for quick ankle sprain detection. Five males performed 100 simulated ankle sprain and 250 common sporting motion trials. Eight gyrometers recorded the three-dimensional angular velocities at 500Hz. Data were trimmed with a 0.11s window size, the suggested duration of preinjury phase in ankle sprain, and were transformed from time to frequency domain by fast Fourier transform and fitted with a fifth-order polynomial. First-order coefficients from polynomial fitting on frequency space were obtained. The method achieved 97.0% sensitivity and 91.4% specificity in identifying simulated sprains, vertical jump–landing, cutting, stepping-down, running, and walking motions, with vertical jump–landing excluded due to its relatively low specificity (67.3%). The method can be used to detect ankle sprain in sports with mainly floor movements and minimal vertical jump–landing motion.

中文翻译：

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在足背运动学数据上使用快速傅立叶变换和多项式拟合从常见的运动运动中识别模拟的踝关节扭伤运动

踝关节扭伤在运动中很常见，通常建议的病因是腓骨肌反应时间延迟。最近的研究表明，成功地尝试在外部向腓骨肌肉提供电刺激以在其反应之前开始收缩，但是，成功依赖于及时检测踝关节扭伤的可行方法。本研究提出了一种快速傅里叶变换和多项式拟合方法，该方法利用足背运动学数据快速检测踝关节扭伤。五名男性进行了 100 次模拟踝关节扭伤和 250 次常见的运动运动试验。八个陀螺仪记录了 500 度的三维角速度赫兹。数据修剪为 0.11s 窗口大小，踝关节扭伤损伤前阶段的建议持续时间，并通过快速傅里叶变换从时域转换到频域并拟合五阶多项式。得到了频率空间上多项式拟合的一阶系数。该方法在识别模拟扭伤、垂直跳跃-着陆、切割、下台阶、跑步和步行动作方面的灵敏度和特异性分别为 97.0% 和 91.4%，但由于特异性相对较低（67.3%），垂直跳跃-着陆被排除在外。该方法可用于检测主要是地板运动和最小垂直跳跃-着陆运动的运动中的踝关节扭伤。