Biomechanics and electromyography of a common idiopathic low back disorder.
Biomechanics and electromyography of a common idiopathic low back disorder.
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常见特发性腰背疾病的生物力学和肌电图。
DOI：
10.1097/01.brs.0000065568.47818.b9
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发表时间：
2003
期刊：
影响因子：
3
通讯作者：
Aghazadeh,Fereydoun
中科院分区：
文献类型：
--
作者：
Solomonow,Moshe;Hatipkarasulu,Selen;Zhou,BingHe;Baratta,RichardV;Aghazadeh,Fereydoun
研究设计：在体猫准备组加载到不同幅度的腰椎屈曲和卸载对照组。目的：为了证明一个静态，恒定的负荷屈曲腰椎的结果在一个复杂的神经肌肉疾病。背景资料摘要：流行病学表明，静态腰椎屈曲是一个原因，下背部疾病。几乎没有直接的实验证据描述引起这种疾病的生理和生物力学过程。最近的证据表明，脊柱在恒定位移下的静态屈曲导致肌肉痉挛和延长的恢复期。脊柱在各种大小的恒定载荷（与恒定位移相反）下对屈曲的反应尚不清楚。假设在恒定载荷下的静态腰椎屈曲可能引起脊柱韧带、椎间盘等的蠕变，方法.猫的腰椎在生理负荷强度从轻到重的恒定负荷静态屈曲20分钟，同时记录腰椎粘弹性组织的蠕变和来自L3-L4到L5-L 6的多裂肌的EMG。记录持续超过7小时的休息期后，静态屈曲终止。结果。痉挛和反射性肌电图下降是明显的，在加载期间，和一个短暂的浪涌的EMG活动发生在休息期开始。3-4小时后出现第二次EMG活动激增。无论负荷大小如何，神经肌肉疾病的四个组成部分都存在。结论：即使在很轻的负荷下，20分钟的恒定负荷静态屈曲也能引起四组分神经肌肉障碍。该疾病是由粘弹性组织的蠕变引起的，这导致痉挛和肌肉过度兴奋持续> 24小时。虽然这种疾病是短暂的，但与其发展相关的生理和生物力学原理也可以解释累积性创伤疾病。
Study Design.In vivo feline preparation groups loaded into lumbar flexion at different magnitudes and an unloaded control group.Objective.To demonstrate that a static, constant load flexion of the lumbar spine results in a complex neuromuscular disorder.Summary of Background Data.Epidemiology suggests that static lumbar flexion is a cause of low back disorders. There is little direct experimental evidence describing the physiologic and biomechanical processes that elicit the disorder. Recent evidence shows that static flexion of the spine under constant displacement results in muscular spasms and a prolonged recovery period. The response of the spine to flexion under constant load of various magnitudes (as opposed to constant displacement) is not known. It was hypothesized that static lumbar flexion under constant load may elicit creep in spinal ligaments, discs, etc., causing microdamage and development of a neuromuscular disorder.Methods.The lumbar spine of the feline was subjected to 20 minutes of constant load static flexion at physiologic load intensities from light to heavy while creep of lumbar viscoelastic tissues and EMG from the multifidus muscles of L3–L4 to L5–L6 were recorded. Recordings were continued over a 7-hour rest period after the static flexion was terminated.Results.Spasms and decreasing reflexive EMG were evident during the loading period, and a transient surge of EMG activity occurred at the beginning of the rest period. A second surge of EMG activity was seen 3–4 hours later. The four components of the neuromuscular disorder were present regardless of the load magnitude. A model was developed to quantify the disorder.Conclusion.A four-component neuromuscular disorder was elicited by a 20-minute constant load static flexion even when very light loads were applied. The disorder was elicited by creep of the viscoelastic tissues, which resulted in spasms and muscular hyperexcitability lasting for> 24 hours. Although the disorder was transient, the physiologic and biomechanical principles associated with its development could also explain cumulative trauma disorders.