不同上肢预负荷对腰部肌肉自愿收缩力量的影响

目的：本研究探索不同上肢预负荷方式和强度对腰部肌肉最大自愿收缩力量的影响。方法：本研究共招募20名被试者,每名被试者以随机的顺序先后参加4组实验。在实验过程中,被试者保持中立正直坐姿,分别在无预负荷、举臂预负荷、手拉预负荷和手握预负荷方式下进行腰部和腹部力量全力共激活,每组预负荷方式的预负荷强度设置为20%和40%最大负荷力量,同时记录双侧腰部多裂肌和竖脊肌的肌电信号。结果：在双侧多裂肌中,举臂和手拉预负荷方式的均方根值（RMS）和积分肌电值（IEMG）均大于无预负荷组（P<0.05）,手握预负荷方式和无预负荷组之间的RMS值和IEMG值无统计学差异（P>0.05）;在双侧竖脊肌中,三种预负荷方式和无预负荷组之间的RMS值和IEMG值均无统计学差异（P>0.05）。在不同预负荷方式比较中,举臂和手拉预负荷方式的RMS值和IEMG值均大于手握预负荷方式（P<0.05）,举臂预负荷的RMS值和IEMG值均大于手拉预负荷方式（P<0.05）。结论：举臂和手拉预负荷方式带来的肌肉预激活均可以有效提高腰部多裂肌的自愿收缩力量,预负荷强度越大,肌肉收缩力量可能也越大,...     

拳击运动员赛前大强度训练的脑电监控分析

目的:探讨利用脑电指标无损伤监控拳击运动训练。方法:监测拳击运动员手持2.5 kg的哑铃进行直拳空击运动直至局部肌肉力竭过程中的脑电变化。结果:赛前大强度训练后诱发脑电慢波指数增加明显(P<0.01),脑电波的δ/α曾现U型变化趋势。结论:U型曲线可能是中枢疲劳的一个特征性变化。     

肌电生物反馈对急性期脑卒中偏瘫患者上肢功能的影响

目的:评价肌电生物反馈联合常规康复训练对急性期脑卒中偏瘫患者上肢功能的影响,为脑卒中后急性期上肢运动功能障碍的康复治疗探寻更有效的方法.方法:将35例生命体征平稳、无意识障碍的急性期脑卒中偏瘫患者分为观察组18例和对照组17例.两组患者均给予神经内科药物治疗和常规康复训练,观察组患者偏瘫侧上肢加以肌电生物反馈治疗.两组均于治疗前和治疗2个月后对偏瘫侧上肢进行Bmnnstrom运动功能分级、简式Fugl-Meyer(FMA)上肢运动功能评定和腕背伸时肌肉最大收缩时肌电(EMG)幅值的测定.结果:经2个月治疗后,两组患者偏瘫侧上肢的Bnnnstrom分级、FMA及EMG幅值较治疗前均有提高(P＜0.05),且观察组各项评分均优于对照组(P＜0.05).结论:本文中观察组和对照组的患者经康复治疗后,偏瘫侧上肢的运动功能均较治疗前提高.但在脑卒中患者的急性期应用肌电生物反馈治疗联合常规康复训练,较单独使用常规运动疗法和作业疗法治疗,能更好地改善急性期脑卒中偏瘫患者上肢的功能,更显著地促进偏瘫上肢的运动功能恢复及分离运动的产生,同时对促进腕关节背伸肌力的恢复方面提供了电生理学依据.总之,在常规康复训练的基础上加用肌电生物反馈治疗,可更显著地促进急性期脑卒中偏瘫患者的上肢功能,为脑卒中急性期肢体运动障碍的康复治疗提供了更有效的方法.     

不同负荷方式引起的腰部肌肉表面肌电信号变化特征

采用时频、复杂度和定量递归信号分析方法对Biering-sorensen和Ito-Shirado条件下腰部肌肉表面肌电信号的变化规律和特点进行了比较。10名正常受试者分别参加Biering-sorensen和Ito-Shirado运动负荷试验,分别获取两侧L2～L3和L5～S1部位表面肌电信号。研究发现,以上两种运动负荷方式下平均功率频率和复杂度时间序列曲线呈单调递减型变化,而确定性线段百分数时间序列曲线呈单调递增型变化。双因素方差分析表明负荷方式和采样部位对以上信号分析指标变化斜率的影响均有显著统计学意义,证明Biering-sorensen负荷方式较Ito-Shirado负荷方式对腰部肌肉表面肌电信号特征有较大的影响,而采样部位也是腰部肌肉功能评价不可忽视的因素。     

A型肉毒毒素联合肌电生物反馈治疗脑卒中后上肢肌痉挛的临床疗效分析

目的:分析A型肉毒毒素与肌电生物反馈联合用于治疗脑卒中后上肢肌痉挛的临床疗效。方法:选择2014年10月至2016年12月辽宁本溪市中心医院和北京博爱医院收治的84例脑卒中后上肢肌痉挛患者,并将其随机分为观察组和对照组,每组42例。两组患者均首先接受常规康复训练,随后对照组加用肌电生物反馈治疗,观察组患者在对照组的基础之上注射A型肉毒毒素。采用改良Ashworth痉挛量表(MAS)比较两组治疗前后的上肢肌痉挛改善情况,采用Fugl-Meyer评定量表评价患者上肢运动功能,采用量角器测量治疗前后患者的腕关节主动活动范围,采用改良的Barthel指数评价患者治疗前后的日常生活能力。结果:治疗后,观察组的上肢痉挛改善总有效率显著高于对照组(P0.05);治疗2周和4周时,两组的Fugl-Meyer评分、腕关节主动活动范围、改良的Barthel指数(MBI)均较治疗前显著升高(P0.05),且观察组治疗后2周和4周的Fugl-Meyer评分、腕关节主动活动范围、改良的Barthel指数(MBI)均显著高于对照组(P0.05)。结论:A型肉毒毒素与肌电生物反馈联合用于治疗脑卒中后上肢肌痉挛的临床疗效显著,可有效降低患者上肢痉挛状态,改善上肢和腕部运动能力,提高患者的日常生活能力。     

基于表面肌电的不同脊柱前后倾角坐姿腰部肌肉收缩情况研究

摘要 目的：本研究通过飞行座椅模拟飞行员坐姿状态,利用表面肌电技术对不同脊柱前后倾角坐姿的腰部肌肉收缩情况进行评价,为飞行员的坐姿提供一定的参考。方法：本研究共招募20名被试者,每名被试者先后参加三组实验。在实验过程中,被试者坐于飞行座椅中并保持躯体中立正直状态,通过调节脚踏板位置使脊柱前后倾角分别固定为90 °、100 °和110 °,要求被试者尽全力使全身肌肉收缩15 s,同时记录双侧多裂肌和竖脊肌的肌电信号,为避免发生肌肉疲劳,每组间隔1分钟。结果：四块所测肌肉在100 °脊柱前后倾角下的均方根值（RMS）和积分肌电值（IEMG）均大于90 °（P＜0.01）;右侧多裂肌在110 °脊柱倾角下的RMS值大于90 °（P＜0.05）;左侧多裂肌和左右竖脊肌在100 °脊柱前后倾角下的RMS值大于110 °（P＜0.05）,右侧竖脊肌在100 °脊柱前后倾角下的IEMG值大于110 °（P＜0.01）;在每组肌肉中,其余脊柱前后倾角之间肌电信号的比较没有统计学意义（P＞0.05）。结论：在不同的脊柱前后倾角中,左右多裂肌和竖脊肌在脊柱前后倾角为100 °的坐姿中能发挥更大的肌肉力量。     

红霉素对兔Oddi括约肌和十二指肠肌电活动的影响

红霉素对兔Ｏｄｄｉ括约肌和十二指肠肌电活动的影响王玲康喜荣张经济（兰州医学院生理学教研室兰州７３００００）红霉素（ｅｒｙｔｈｒｏｍｙｃｉｎ，ＥＭ）可与胃动素受体结合，使内源性胃动素释放，诱发小肠移行性综合肌电（ｍｉｇｒａｔｉｎｇｍｙｏｅｌｅｃｔｒｉｃ...     

狗小肠消化间期复合肌电的微机分析

本文报道利用微机处理狗小肠消化间期复合肌电（ＩＭＣ）周期，定量地分析了１４只狗十二指肠和空肠各个时相中所含锋电位簇数、锋电位数、平均每簇所含锋电位数和各时相所占时程。并比较了十二指肠和空肠的差异。以上定量化的分析为生理、药理等领域有关肠道运动功能的研究提供了精确的定量化的客观依据。     

振动训练对制动大鼠单一肌梭电生理活动的影响

采用石膏固定建立后肢制动模型,用空气隔绝法记录大鼠单一肌梭的电生理活动,用振动仪给制动+振动组比目鱼肌施加高频振动,7 d后观察大鼠制动侧比目鱼肌肌梭的电生理活动变化。比目鱼肌的湿重与非制动侧相比降低了15.33%±4.76%(P<0.05);有自发放电的肌梭数量减少(P<0.05);静息放电频率降低(P<0.05)。制动期间施加高频振动组,比目鱼肌湿重减少的程度明显降低(P<0.05);自发放电的肌梭数量、肌梭的放电频率明显高于制动组(P<0.05)。制动期间的肌肉振动对制动所致肌梭电生理活动特性的改变有明显的对抗作用。     

Spatial distribution of surface EMG on trapezius and lumbar muscles of violin and cello players in single note playing

Musicians activate their muscles in different patterns, depending on their posture, the instrument being played, and their experience level. Bipolar surface electrodes have been used in the past to monitor such activity, but this method is highly sensitive to the location of the electrode pair. In this work, the spatial distribution of surface EMG (sEMG) of the right trapezius and right and left erector spinae muscles were studied in 16 violin players and 11 cello players. Musicians played their instrument one string at a time in sitting position with/without backrest support. A 64 sEMG electrode (16 × 4) grid, 10 mm inter-electrode distance (IED), was placed over the middle and lower trapezius (MT and LT) of the bowing arm. Two 16 × 2 electrode grids (IED = 10 mm) were placed on the left and right erector spinae muscles. Subjects played each of the four strings of the instrument either in large (1 bow/s) or detaché tip/tail (8 bows/s) bowing in two sessions (two days). In each of two days, measurements were repeated after half an hour of exercise to see the effect of exercise on the muscle activity and signal stability. A “muscle activity index” (MAI) was defined as the spatial average of the segmented active region of the RMS map. Spatial maps were automatically segmented using the watershed algorithm and thresholding. Results showed that, for violin players, sliding the bow upward from the tip toward the tail results in a higher MAI for the trapezius muscle than a downward bow. On the contrary, in cello players, higher MAI is produced in the tail to tip movement. For both instruments, an increasing MAI in the trapezius was observed as the string position became increasingly lateral, from string 1 (most medial) toward string 4 (most lateral). Half an hour of performance did not cause significant differences between the signal quality and the MAI values measured before and after the exercise. The MAI of the left and right erector spinae was smaller in the case of backrest support, especially for violin players. Back muscles of violin and cello players were activated asymmetrically, specifically in fast movements (detaché tip/tail). These findings demonstrate the sensitivity and stability of the technique and justify more extensive investigation following this proof of concept.     

EMG power spectra of trunk muscles during graded maximal voluntary isometric contraction in flexion-rotation and extension-rotation

The purpose of this study was to determine the electromyographic (EMG) power spectral characteristics of seven trunk muscles bilaterally during two complex isometric activities extension-rotation and flexion-rotation, in both genders to describe the frequency-domain parameters. Eighteen normal young subjects volunteered for the study. The subjects performed steadily increasing isometric extension-rotation and flexion-rotation contractions in a standard trunk posture (40 degrees flexed and 40 degrees rotated to the right). A surface EMG was recorded from the external and internal oblique, rectus abdominis, pectoralis, latissimus dorsi, and erector spinae muscles at the 10th thoracic and the 3rd lumbar vertebral levels, at 1 kHz and 25%, 50%, 75% and 100% of maximal voluntary contraction (MVC). The median frequency (MF), mean power frequency (MPF), frequency spread and peak power were obtained from fast Fourier transform analysis. The MF and MPF for both extension-rotation and flexion-rotation increased with the grade of contraction for both males and females. The EMG spectra in flexion-rotation were different from those of extension-rotation (P < 0.001). The left external and right internal oblique muscles played the role of antagonists in trunk extension-rotation. There was an increase in the MF of the trunk muscles with increasing magnitude of contraction. Frequency-domain parameters for both the male and female subjects were significantly different (P < 0.001).     

Normalizing upper trapezius EMG amplitude: Comparison of ramp and constant force procedures

The present study compared three procedures for normalization of upper trapezius surface electromyographic (EMG) amplitudes: (a) a ramp procedure (providing data in per cent of maximal voluntary contraction, MVC); (b) a constant force procedure based on two reference contractions (two-force procedure) (%MVC) and (c) a procedure expressing muscle activation in per cent of a reference voluntary electrical activity (%RVE). The study also evaluated the repeatability of the ramp and the RVE procedures and estimated the force exertion (%MVC) corresponding to the RVE. To illustrate the ergonomic effect of different normalization procedures, trapezius EMG during two work tasks was compared after normalization by the two-force and the RVE procedures. Fifteen subjects participated in the whole study. We found that force estimates obtained by the ramp procedure equation could be translated to force estimates obtained by the two-force procedure by the equation: %MVC_2force = − 0.6 + 0.9*%MVC_ramp, although with a considerable imprecision due to large inter-individual differences. In the ramp procedure, the intra-individual test-retest coefficient of variation (CV) depended on the force level; it was 45% at 5% MVC and 10% at 30% MVC. The CV of the RVE was 15%. The reference contraction used in the RVE procedure corresponded from 13–79% MVC (median 33%MVC). The load reducing effect of an ergonomic intervention was less obvious with the RVE procedure than with the two-force procedure due to a larger inter-individual variation. The advantages and disadvantages of the different procedures are discussed.     

Histotopography and ultrastructure of the thin limbs of the loop of Henle in the hamster

Summary In the kidney of the Syrian hamster the descending thin limbs of both the short and long loops of Henle are not spatially separated from each other and descend between the vascular bundles.Ultrastructurally, five different epithelial types are distinguished in the thin limbs of the short and long loops of Henle. Short loops possess only a descending thin limb with a simply organized epithelium (type 1). Long loops comprise an upper and a lower part of the descending thin limb and the ascending thin limb. The upper part of the long descending thin limb is equipped with a complex and highly interdigitating epithelium with shallow junctions (type 2), which gradually transforms into the simple noninterdigitating type-3 epithelium of the lower part. In a minor portion of long descending thin limbs, however, the upper part begins with an even more complexly organized epithelium (type 2a) than type 2. Type-2a epithelium is conspicuously thicker and possesses a more elaborate mode of cellular interdigitation. Along the descent of this tubular part through the inner stripe of the outer medulla, type-2a epithelium transforms into type-2 epithelium. It is suggested that the long descending thin limbs, which start with type-2a epithelium, belong to the longest loops. The type-4 epithelium of the ascending thin limbs is characterized by flat and extensively interdigitating cells with shallow junctions.The unique pattern of the type-2 a epithelium favors the assumption that solute secretion essentially contributes to the increase in concentration of tubular fluid in long descending thin limbs.This investigation was supported by the Deutsche Forschungsgemeinschaft; project Kr 546 Henlesche Schleife     

Electromyography of the gluteal muscles in Hylobates,Pongo, and pan: Implications for the evolution of hominid bipedality

The gluteal musculature of primates has been a focus of great research interest among those who study human evolution. Most current theorists agree that gluteus superficialis (= maximus) need not have changed its action in the step from pongid to hominid, but dispute has arisen over a purported change in action and role of the gluteus medius. To clarify the functions of gluteus medius, gluteus superficialis, and tensor fasciae femoris during ape locomotion, we conducted a telemetered electromyographic study of these muscles in two gibbons, one orangutan, and four chimpanzees as they walked bipedally on the ground and on a horizontal tree trunk, walked quadrupedally on the same substrates, and climbed a vertical tree trunk. The results indicate that the gluteus medius of apes is not, as has been previously suggested, primarily an extensor of the thigh; its action is chiefly that of medial rotation. The role of the gluteus medius during bipedality is the same in apes and humans–to provide side-to-side balance of the trunk at the hip. The change in the hominid lateral balance mechanism can be viewed as primarily osteological, allowing preservation of the same muscle function with an extended thigh. As a result, the stride length is increased and there occurs a diminution of the demands placed on other muscles to maintain anteroposterior balance at the hip and knee. Our data also support the view that vertical climbing may be specifically preadaptive to bipedalism. One may picture the earliest hominid as part biped, when on the ground traveling between scattered food trees, and part climber, when moving from the ground to food.     

Single bout of vibration-induced hamstrings fatigue reduces quadriceps inhibition and coactivation of knee muscles after anterior cruciate ligament (ACL) reconstruction

Persistent quadriceps strength deficits in individuals with anterior cruciate ligament reconstruction (ACLr) have been attributed to arthrogenic muscle inhibition (AMI). The purpose of the present study was to investigate the effect of vibration-induced hamstrings fatigue on AMI in patients with ACLr. Eight participants with unilateral ACLr (post-surgery time: M = 46.5, SD = 23.5 months; age: M = 21.4, SD = 1.4 years) and eight individuals with no previous history of knee injury (age: M = 22.5, SD = 2.5 years) were recruited. A fatigue protocol, consisting of 10 min of prolonged local hamstrings vibration, was applied to both the ACLr and control groups. The central activation ratio (CAR) of the quadriceps was measured with a superimposed burst of electrical stimulation, and hamstrings/quadriceps coactivation was assessed using electromyography (EMG) during isometric knee extension exercises, both before and after prolonged local vibration. For the ACLr group, the hamstrings strength, measured by a load cell on a purpose-built chair, was significantly (P = 0.016) reduced about 14.5%, indicating fatigue was actually induced in the hamstrings. At baseline, the ACLr group showed a trend (P = 0.051) toward a lower quadriceps CAR (M = 93.2%, SD = 6.2% versus M = 98.1%, SD = 1.1%) and significantly (P = 0.001) higher hamstrings/quadriceps coactivation (M = 15.1%, SD = 6.2% versus M = 7.5%, SD = 4.0%) during knee extension compared to the control group. The fatigue protocol significantly (P = 0.001) increased quadriceps CAR (from M = 93.2%, SD = 6.2% to M = 97.9%, SD = 2.8%) and significantly (P = 0.006) decreased hamstrings/quadriceps coactivation during knee extension (from M = 15.1%, SD = 6.2% to M = 9.5%, SD = 4.5%) in the ACLr group. In conclusion, vibration-induced hamstrings fatigue can alleviate AMI of the quadriceps in patients with ACLr. This finding has clinical implications in the management of recovery for ACLr patients with quadriceps strength deficits and dysfunction.     

Activation of shoulder muscles in healthy men and women under isometric conditions

Purpose: Due to the low osseous lead of the shoulder joint a large portion of the shoulder muscles, in addition to executing movements, deals with stabilising tasks. This requires a permanent readjustment of the intermuscular co-ordination of all involved muscles. The aim of the study was to verify the existence of gender dependent differences in intramuscular co-ordination patterns of shoulder muscles.

Method: Fifteen healthy men and nine healthy women, who executed 24 isometric exercises in sagittal, frontal and horizontal planes with a loading of 50% of their individual isometric maximum force, were investigated. In every plane, four angular positions were chosen and both opposite force directions were measured, respectively. SEMG was taken from 13 muscles of the shoulder and the upper arm. Due to inter-individual differences SEMG amplitudes were normalised. Results: Gender specific differences of functional intermuscular co-ordination patterns could be proven systematically. Women showed less activation of muscles acting in the main force direction. In addition, those muscles less necessary for the actual force production were more activated in women than in men.

Conclusions: Functionally comparable shoulder function showed a gender dependency in terms of functional intermuscular co-ordination.     

Linear relationship between electromyography and shear wave elastography measurements persists in deep muscles of the upper extremity

Recent works have demonstrated a linear relationship between muscle activation and shear modulus in various superficial muscles. As such, it may be possible to overcome limitations of traditional electromyography (EMG) methods by assessing activation using shear wave elastography. However, the relationship has not been wholly validated in deep muscles. This study measured the association between squared shear wave velocity, which is related to shear modulus, and activation within superficial and deep muscles. This relationship was also compared between surface and intramuscular EMG electrodes. We simultaneously recorded EMG and shear wave velocity in one deep (brachialis) and one superficial (brachioradialis) muscle in ten healthy individuals during isometric elbow flexion across a wide range of contraction intensities. Muscle activation and squared shear wave velocity demonstrated good reliability (ICC > 0.75) and showed a linear relationship (P < 0.05) for all muscle/EMG electrode type combinations (study conditions) after down-sampling. Study condition was not a significant within-subject factor to the slope or intercept of the relationship (P > 0.05). This work demonstrates that activation of both superficial and deep muscles can be assessed noninvasively using ultrasound shear wave elastography and is a critical step toward demonstrating elastography’s utility as an alternative to EMG.     

上肢精准电磁功率计（臂力计）用于心肺代谢等整体功能评估的临床观察研究*

目的: 受试者分别用上肢（臂力计）和下肢精准电磁功率计（自行车）进行症状限制性极限心肺运动试验（CPET）,分析探讨上肢CPET的临床价值。方法: 15例受试者（正常人6例和慢病患者9例）签署知情同意书后在不同的2 d里分别完成上肢和下肢精准电磁功率计CPET,分析CPET数据、计算相关核心指标,探究上肢和下肢CPET的异同及其相关性。结果: ①全体15例受试者男8女7,其中6例正常人和9例慢病患者亚组相比仅年龄（（33.2±12.7）比（53.6±8.5）岁）和无诊断疾病有显著差异（P<0.05）。②全体受试者上肢CPET峰值心率（（131.0±19.0）比（153.0±22.0） bpm,P<0.05）和血压均低于下肢CPET,但血压差异无统计学意义（P>0.05）;上肢CPET的峰值潮气量（（1.3±0.4）比（1.8±0.4） L）和分钟通气量（（51.4±21.1）比（67.9±22.1） L/min）均显著低于下肢（P均<0.05）,而峰值呼吸频率无显著差异;采用上肢CPET时,运动时间（（6.4±0.6）比（8.5±1.2） min）要短于下肢CPET;峰值负荷功率（（73.2±19.6）比（158.5±40.3）W/min）、峰值摄氧量（（1.1±0.4）比（1.7±0.4）L/min）、无氧阈（（0.6±0.2）比（0.9±0.2） L/min）、峰值氧脉搏（（8.6±2.3）比（10.9±2.6） ml/beat）、摄氧通气效率峰值平台（34.7±4.3比39.8±5.3）均较低,而二氧化碳排出通气效率最小值（32.6±3.8比28.7±4.9）及斜率（33.9±4.3比28.3±6.2）高于下肢CPET（P均<0.05）。正常人和慢病两亚组各自的比较结果与整体比较结果无显著差异。③上肢CPET的运动时间,峰值心率,峰值呼吸频率、潮气量、分钟通气量,峰值负荷功率实测值及百分预计值,峰值摄氧量实测值、公斤体重值和百分预计值,无氧阈实测值、公斤体重值,峰值氧脉搏的实测值,摄氧通气效率峰值平台、二氧化碳排出通气效率最小值和斜率的实测值及百分预计值与下肢CPET的结果相关性较好,其余指标无显著相关性。结论: 作为下肢CPET的补充,上肢CPET用于整体功能状态评估具有极高的可行性和更高的安全性,对于指导安全有效个体化精准运动整体方案的实施提供了重要补充,值得进一步深入探究。