Siegmund Gunter P, Blouin Jean-Sébastien, Carpenter Mark G, Brault John R, Inglis J Timothy
MEA Forensic Engineers & Scientists, Richmond, BC, Canada.
BMC Musculoskelet Disord. 2008 Jun 5;9:80. doi: 10.1186/1471-2474-9-80.
The cervical multifidus muscles insert onto the lower cervical facet capsular ligaments and the cervical facet joints are the source of pain in some chronic whiplash patients. Reflex activation of the multifidus muscle during a whiplash exposure could potentially contribute to injuring the facet capsular ligament. Our goal was to determine the onset latency and activation amplitude of the cervical multifidus muscles to a simulated rear-end collision and a loud acoustic stimuli.
Wire electromyographic (EMG) electrodes were inserted unilaterally into the cervical multifidus muscles of 9 subjects (6M, 3F) at the C4 and C6 levels. Seated subjects were then exposed to a forward acceleration (peak acceleration 1.55 g, speed change 1.8 km/h) and a loud acoustic tone (124 dB, 40 ms, 1 kHz).
Aside from one female, all subjects exhibited multifidus activity after both stimuli (8 subjects at C4, 6 subjects at C6). Neither onset latencies nor EMG amplitude varied with stimulus type or spine level (p > 0.13). Onset latencies and amplitudes varied widely, with EMG activity appearing within 160 ms of stimulus onset (for at least one of the two stimuli) in 7 subjects.
These data indicate that the multifidus muscles of some individuals are active early enough to potentially increase the collision-induced loading of the facet capsular ligaments.
颈多裂肌附着于下颈椎小关节囊韧带，而颈椎小关节是一些慢性挥鞭伤患者的疼痛来源。在挥鞭伤暴露过程中，多裂肌的反射性激活可能会导致小关节囊韧带损伤。我们的目标是确定颈椎多裂肌对模拟追尾碰撞和声刺激的起始潜伏期和激活幅度。
将线状肌电图（EMG）电极单侧插入9名受试者（6名男性，3名女性）C4和C6水平的颈多裂肌。然后让坐着的受试者接受向前加速（峰值加速度1.55g，速度变化1.8km/h）和声刺激（124dB，40ms，1kHz）。
除一名女性外，所有受试者在两种刺激后均表现出多裂肌活动（8名受试者在C4水平，6名受试者在C6水平）。起始潜伏期和EMG幅度均不随刺激类型或脊柱水平而变化（p>0.13）。起始潜伏期和幅度变化很大，7名受试者在刺激开始后160ms内（两种刺激中至少一种）出现EMG活动。
这些数据表明，一些人的多裂肌激活得足够早，可能会增加碰撞引起的小关节囊韧带负荷。
