Office of Research & Sponsored Projects, Rocky Mountain University of Health Professions, Provo, UT 84601, USA.
Division of Research, Force Science® Institute Ltd, Mankato, MN 56001, USA.
Forensic Sci Int. 2022 Aug;337:111371. doi: 10.1016/j.forsciint.2022.111371. Epub 2022 Jun 23.
With over 72,000 offenses between 2010 and 2020 in the USA, knives were the third most commonly used weapon in all violent crimes between behind personal weapons and handguns.
Examine the performance of different stab (Thrust and overhead) and slash (Figure 8 and Reverse) knife motions to determine how long it takes to execute each motion. In addition, examine the variability in executing each motion to inform future self-defense strategies.
Twenty subjects (Females, n = 4; Males, n = 16; Height: 179.96 ± 8.66 cm; Weight: 94.99 ± 22.37 kg; Age: 36.95 ± 10.63 years) who were all active-duty law enforcement officers (LEOs) with 13.52 ± 11.23 years of LEO experience were recruited to participate in the study. Each subject completed two trials of the knife motions while wearing wearable motion sensors (ADPM) and recorded with a high-speed camera (GoPro) while using a training knife (Cold Steel).
The time to complete the motions were: Thrust, 0.61 ± 0.15 s; Overhead, 0.68 ± 0.14 s; Figure 8, 1.07 ± 0.21 s; and Reverse, 0.62 ± 0.11 s. The Figure 8 motion was significantly slower than the other three motions: F (3, 57) = 101.19, p < 0.001, ηp2 = 0.84. The reliability analysis reported trivial variability and a high level of agreement: Thrust, ICCα = 0.701, SEM = 0.09 s, CV% = 15.02; Overhead, ICCα = 0.878, SEM = 0.05 s, CV% = 6.93; Figure 8, ICCα = 0.906, SEM = 0.07 s, CV% = 6.25, Reverse, ICCα = 0.420, SEM = 0.10 s, CV% = 17.31.
Most LEOs or civilians within striking distance of someone with a knife may not be able to avoid contact from the knife attacks based on the speed knife attacks could occur.
The reference data provides pertinent information to update evidence-based training approaches to knife attack preparation and defense.
研究不同的刺（推和过顶）和砍（8 字形和反向）刀动作的性能，以确定执行每个动作所需的时间。此外，还研究了执行每个动作的可变性，以便为未来的自卫策略提供信息。
招募了 20 名受试者（女性，n=4；男性，n=16；身高：179.96±8.66cm；体重：94.99±22.37kg；年龄：36.95±10.63 岁），他们都是现役执法人员（LEO），拥有 13.52±11.23 年的 LEO 经验。每位受试者在佩戴可穿戴运动传感器（ADPM）的情况下完成两次刀动，并使用训练刀（Cold Steel）用高速摄像机（GoPro）进行记录。
完成动作的时间分别为：推，0.61±0.15s；过顶，0.68±0.14s；8 字形，1.07±0.21s；反向，0.62±0.11s。8 字形运动明显慢于其他三个运动：F（3，57）=101.19，p<0.001，ηp2=0.84。可靠性分析报告了微不足道的可变性和高度的一致性：推，ICCα=0.701，SEM=0.09s，CV%=15.02%；过顶，ICCα=0.878，SEM=0.05s，CV%=6.93%；8 字形，ICCα=0.906，SEM=0.07s，CV%=6.25%；反向，ICCα=0.420，SEM=0.10s，CV%=17.31%。
大多数 LEO 或处于持刀人可触及距离内的平民，可能无法避免基于持刀攻击速度的接触，因为持刀攻击可能会发生。
参考数据为更新基于证据的培训方法以准备和防御刀攻击提供了相关信息。
