Diurnal changes in the amplitude of the Hoffmann reflex in the human soleus but not in the flexor carpi radialis muscle
Diurnal changes in the amplitude of the Hoffmann reflex in the human soleus but not in the flexor carpi radialis muscle
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DOI：
10.1007/s00221-005-0172-1
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发表时间：
2006-03-01
影响因子：
2
通讯作者：
Collins, DF
中科院分区：
文献类型：
--
作者：
Lagerquist, O;Zehr, EP;Collins, DF
在非人类哺乳动物中观察到了反射幅度在一天中的变化。目前的实验测试了昼夜波动是否也发生在人类身上。霍夫曼反射（H-反射）振幅测量比目鱼肌和桡侧腕屈肌（FCR）肌肉从收集的数据在12小时内7：00 -9：00上午和下午7：00-9：00在4小时的时间间隔，M/H募集曲线，并计算两个措施的H-反射兴奋性。最大H反射（H-max）计算为三个最大H反射的平均值。还从M/H募集曲线的上升支（H-A，n = 10）采集H反射，相应的M波为5% M-max。所有数值均标准化为最大M波（M-max）。比目鱼肌H反射振幅和跖屈最大随意等长收缩力（MVIC）显著小于（p < 0.05）早晨（H-max=57.2% M-max，H-A= 42.3%，M-max，MVIC = 162.1 Nm）（H-max = 69. 1% M-max，增加20.1%，H-A = 54. 1% M-max，增加27.4%，MVIC = 195.8 Nm，增加20.8%）。相比之下，FCR H反射振幅和FCR MVIC在所有测试期间均保持不变。数据显示，昼夜波动存在于人比目鱼肌的振幅中，但不存在于FCR H反射中。在解释H-反射数据时，必须考虑人比目鱼肌H-反射振幅的昼夜波动，特别是当使用跨越数天的重复测量设计时。
Changes in the reflex amplitude throughout the day have been observed in non-human mammals. The present experiment tested whether diurnal fluctuations also occur in humans. Hoffmann reflex (H-reflex) amplitude was measured in soleus and flexor carpi radialis (FCR) muscles from the data collected over a 12-h period between 7:00-9:00 a.m. arid 7:00-9:00 p.m. At 4-h intervals, M/H recruitment curves were obtained, and two measures of H-reflex excitability were calculated. The maximal H-reflex(H-max) was calculated as the average of the three largest H-reflexes. H-reflexes were also sampled from the ascending limb of the M/H recruitment curve (H-A, n = 10), with a corresponding M-wave of 5% M-max. All values were normalized to the maximal M-wave (M-max). Soleus H-reflex amplitude and plantar flexion maximal voluntary isometric contraction force (MVIC) were significantly smaller (p < 0.05) in the morning (H-max=57.2% M-max, H-A=42.3%, M-max, MVIC = 162.1 Nm) than in the evening (H-max = 69.1 % M-max, a 20.1 % increase, H-A = 54.1 % M-max, a 27.4% increase and MVIC = 195.8 Nm, a 20.8% increase). In contrast, FCR H-reflex amplitude and FCR MVIC were unchanged across all testing sessions. The data show that diurnal fluctuations are present in the amplitude of the human soleus but not in the FCR H-reflex.. Diurnal fluctuation in the human soleus H-reflex amplitude must be considered when interpreting H-reflex data, especially when a repeated measures design spanning several days is utilized.