Validity of a portable hanging scale to assess the isometric muscle strength during knee movement

Inexpensive and practical equipment to assess muscle strength can disseminate objective measures, which can provide valid information to implement effective treatment and exercise training. The purpose of the study was to examine the instrumental validity of the hanging scale (HS) to assess the muscle strength during knee flexion and extension by comparing the peak force values to a standard equipment (laboratory-grade load cell [LLC]). Knee isometric strength was assessed on thirty-two subjects (16 women and 16 men, 22 [5] years, 171 [9] cm, 69 [15] kg, 23 [4] kg/m²). The knee flexion was tested by placing the volunteer's body in prone with the knee flexed at 90°. Knee extension was assessed with the volunteer seated on a chair with the feet resting on the floor, knees, and hips flexed at 90°. No differences were observed comparing the isometric peak forces between a laboratory-grade load cell and a HS (p > 0.05). The intraclass correlation coefficient (ICC)_1,1 returned values above 0.90. The Cronbach's α test also returned values above 0.90 for all comparisons. Bland-Altman results showed high levels of agreement with low risk of bias. The HS appears to be a valid method to assess the knee isometric strength. The portability, the cost-effectiveness and the simple user-friendly system provides an effective way to assess the knee isometric strength.     

不同干预方式对斜方肌在运动中激活模式的影响

目的 分析正常人斜方肌的激活特征,观察不同干预方式对斜方肌异常者激活模式恢复的作用。方法 2017年9月至10月,互联网招募肩关节正常人(正常组,n = 20)和肩关节不适者(观察组,n = 20),在无干预、上斜方肌(UT)静力牵拉、下斜方肌(LT)等长收缩和组合干预后,均完成直臂侧上举、坐姿划船和反向飞鸟动作。测试记录肌电信号的均方根值(RMS),计算最大自主收缩肌电百分比(MVE%),观察激活比例和激活时间。结果 无干预时,与对照组比较,观察组UT MVE%增加(P < 0.05),激活时间提前(P < 0.05);中斜方肌(MT)和LT MVE%降低(P < 0.05),激活时间延迟(P < 0.05);UT/LT和UT/MT增加(P < 0.05)。UT静力牵拉、LT等长收缩和组合训练后,两组不同肌肉MVE%、激活时间、激活比例在不同动作下均有不同程度改变(P < 0.05)。结论 斜方肌三束在不同动作中,激活程度与激活时间不同;在运动开始前进行UT静力牵拉和LT等长收缩可以改善肩关节不适者的斜方肌在运动中的激活模式,有利于肩关节发挥正常功能。     

Collagen gel contraction as a measure of fibroblast function in an animal model of subsynovial connective tissue fibrosis

Carpal tunnel syndrome (CTS) is a peripheral neuropathy characterized by non‐inflammatory fibrosis of the subsynovial connective tissues (SSCT). A rabbit model of CTS was developed to test the hypothesis that SSCT fibrosis causes the neuropathy. We used a cell‐seeded collagen‐gel contraction model to characterize the fibrosis in this model in terms of cellular mechanics, specifically to compare the ability of SSCT cells from the rabbit model and normal rabbits to contract the gel, and to assess the effect of transforming growth factor‐β1,which is upregulated in CTS, on these cells. SSCT fibrosis was induced in six retired breeder female rabbits which were sacrificed at 6 weeks (N = 3) and 12 weeks (n = 3). An additional two rabbits served as controls. SSCT was harvested according to a standard protocol. Gels seeded with SSCT cells from rabbits sacrificed at 6 weeks had significantly higher tensile strength (p < 0.001) and Young's modulus (p < 0.001) than gels seeded with cells from rabbits sacrificed at 12 weeks or control animals. TGF‐β1 significantly increased the decay time constant (p < 0.001), tensile strength (p < 0.001), and Young's modulus (p < 0.001) regardless of the cell source. This model may be useful in screening therapeutic agents that may block SSCT fibrosis, identifying possible candidates for CTS treatment. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:668–674, 2015.     

起源点邻近二尖瓣环的频发室性早搏体表心电图特征及射频消融治疗

目的评估起源点邻近二尖瓣环的频发室性早搏(简称室早)体表心电图特点及射频消融治疗效果。方法10例频发室早患者接受常规电生理检查及射频消融治疗,对所有病例12导联体表心电图进行分析。结果10例室早均消融成功,并证实起源点邻近二尖瓣环的不同部位,根据成功消融靶点将本组病例分为3组,二尖瓣环前侧壁组(4例)、二尖瓣环后侧壁组(3例)、二尖瓣环后间隔组(3例)。所有病例胸前导联R波移行区位于V1～V2导联,绝大部分病例V6导联可见s波。对各组二尖瓣环室早心电图做进一步比较,可概括出系列心电图判断指标用以估计消融靶点的部位。结论射频消融治疗起源点邻近二尖瓣环的频发室早可取得良好效果,掌握其体表心电图特点有助于判定室早的起源部位。     

Cyclic adenosine monophosphate modulation of contractility via slow Ca2+ channels in chick heart

The catecholamines exert a positive inotropic effect associated with elevated tissue cyclic AMP levels and possibly with increase in the number of membrane slow cationic channels available for voltage activation. In the present study, catecholamines (isoproterenol, dopamine and dobutamine) were tested for their ability to affect the maximum upstroke velocity (+ V_max) of the slow action potentials, the first derivative ($\text{d}\text{T}\text{d}\text{t}$) of developed tension accompanying the slow responses, and the tissue cyclic AMP levels in the ventricular myocardium of isolated perfused chick hearts. To study the slow channels exclusively, the fast Na⁺ channels were voltage inactivated by elevated (25 mm) K⁺. In this condition of functional removal of the fast channels, the heart could not be excited by intense electrical stimulation. It was found that these catecholamines induced slow action potentials accompanied by contractions. Elevation of the concentration of these agents produced increases in + V_max, $\text{d}\text{T}\text{d}\text{t}$, and cyclic AMP in a dose-dependent fashion; a close correlation was obtained between the cyclic AMP level, + V_max and $\text{d}\text{T}\text{d}\text{t}$. These results support the hypothesis that the increases in + V_max of the slow action potentials and in contraction are explained by increase in the number of available slow channels mediated by intracellular cyclic AMP levels, and the resulting increase in the Ca²⁺ influx.     

Role of cholecystokinin in the regulation of liquid gastric emptying and gastric motility in humans: studies with the CCK antagonist loxiglumide

Background—Exogenous cholecystokinin (CCK)inhibits antral motility and slows gastric emptying (GE) but the effectof endogenous CCK on the gastric motor mechanisms responsible for GEremains unclear.
Methods—The effect of the CCK-A antagonistloxiglumide (LOX) on GE and motility was studied using magneticresonance imaging in six healthy volunteers after ingestion of 500 mlIntralipid 10% (550 kcal). Subjects were studied in the supineposition on two occasions during intravenous infusion of LOX(66 µmol/kg/h for 10 min followed by 22 µmol/kg/h) or placebo. GEwas determined every 15 minutes using transaxial abdominal scans andmotility was studied by means of 120 coronal scans, 1.2 seconds apart. For each coronal image the proximal and distal (antral) diameters weremeasured at a fixed point in the stomach to determine contraction frequency (ACF) and amplitude (AMP).
Results—GE was faster during LOX infusion thanplacebo (t_1/2 31 (22) versus 115 (67) minutes, p<0.03).There was little variation in the diameter of the proximal stomach witheither LOX or placebo. In the distal stomach marked contractileactivity was observed during LOX (ACF 2.9 (0.2) versus 1.5 (2.9) duringplacebo, p<0.01). AMP also increased during LOX compared with placebo(56 (22)% versus 27 (16)%, p<0.001).
Conclusion—The increases in antral motility arelikely to contribute to the acceleration of GE and suggest that CCK mayregulate GE by acting on the distal stomach although an effect on theproximal stomach cannot be excluded.

Keywords:loxiglumide; magnetic resonance imaging; gastricemptying; gastric motility; antral contraction

     

Prediction of Abnormal Myocardial Relaxation From Signal Processed Surface ECG

Background

Myocardial relaxation is impaired in almost all cases with left ventricular diastolic dysfunction (LVDD) and is a strong predictor of cardiovascular and all-cause mortality.

非重度反流性食管炎患者消化间期和消化期食管运动功能的探讨

为探讨非重度反流性食管炎(NSRE)的发病机制,本研究对10例NSRE患者和10名健康人(HS)进行同步胃窦、下食管括约肌(LES)和食管体部连续测压5小时,观察消化间期和消化期的食管功能。结果显示,NSRE和HS组的LES压力变化类似,在移行性复合运动(MMC)Ⅰ期时,LES压力较低,分别为23.3±3.0和16.1±2.7(NS),MMCⅡ期时升高29.2±3.7和30.5±4.1(NS),而MMCⅢ期明显升高为53.4±6.1和43.4±6.0(与Ⅰ期比,P相似文献