基于AVR单片机的肌电信号生物反馈测试仪的设计

肌电信号(EMG)是一种伴随肌肉运动而产生的生物电信号,对表面EMG的分析研究可发现它与肌肉生理状态和肢体运动模式之间的对应关系。基于生物反馈技术研制肌电信号生物反馈仪采用AT-MEGA16 AVR单片机为核心元件,通过信号调理电路消除表面EMG工频干扰和噪声,并利用声光报警反馈肌肉紧张程度信息。本文介绍了肌电信号生物反馈仪的基本构成及其特点,并对肌电生物信号的特点和提取方法进行了分析,采用均方根值(RMS)法实时反映肌肉活动状态,试验结果表明本系统能有效缓解肌肉的紧张程度,在康复医学方面有较好的应用前景。     

基于脑电与肌电对中风偏瘫病人肌肉能力恢复研究的进展

现代医学认为,脑卒中是指脑局部血液循环障碍所致的神经功能缺损综合征。中医认为半身不遂、口舌歪斜、偏身麻木等症状是＂中风＂后的表现[1]。在中风之后,大脑的控制信号不能很好地到达手脚处的肌肉,使该部位的运动肌肉的电活动电位处于一种较低的水平,从而导致病人无法很好地控制手脚,造成基本生活的不便。利用EMG-EEG结合进行辅助治疗技术的发展将会给中风病人带来福音。本文将从肌电控制、脑电控制、肌电脑电结合三方面对此问题展开讨论。     

The Effects of a Four-Week Muscle Strengthening Program on Maximum Acceptable Lifting Load

The purpose of this study is to investigate the effects of a traditional strengthening program on subjects' maximum acceptable lifting load. Nineteen (nine males, ten females) university students volunteered for the present study. They were randomly divided into a training group (five males, seven females) and a control group (four males, three females). The training group participated in 12 sessions of alternate day traditional dead weight strengthening programs for a period of 4 weeks. The measurements of the training effects included assessment of the maximum acceptable lifting load by psychophysical approach and isokinetic peak torque of the back extensors, knee extensors, shoulder abductors, and elbow flexors. Multivariate ANOVA was used to test for the training effect. Results revealed significant improvement in the maximum acceptable lifting load (p < 0.001) and back extensors peak torque (p = 0.039) after 4 weeks of training. It is concluded that a 4-week free weight muscle training program is effective in improving an individual's maximum acceptable lifting load. This type of physical training program may be useful to people engaged in manual material handling tasks.     

肌电生物反馈疗法结合综合康复训练对脑卒中恢复期患者下肢运动功能的影响

目的观察肌电生物反馈疗法结合综合康复治疗对脑卒中偏瘫患者下肢功能的影响。方法本院康复科收治的脑卒中偏瘫患者40例随机分为两组,治疗组和对照组各20例,两组患者均给予常规神经内科治疗、综合康复治疗,治疗组加用AM-800神经功能重建仪进行下肢肌电生物反馈疗法,共治疗4周。观察两组治疗前后临床神经功能缺损评分、运动功能评定(Fugl-Meyer评定法,FMA)、功能独立性评定(FIM量表)。结果经治疗后,两组患者神经功能缺损评分均有下降,Fugl-Meyer上肢得分、下肢得分及肢体运动总分均上升,其中治疗组相比对照组神经功能缺损评分下降值更显著,FIM量表评分、Fugl-Meyer下肢得分上升更显著(P<0.05)。结论肌电生物反馈疗法结合综合康复治疗,能有效改善脑卒中患者下肢运动功能,并且可以改善患者的功能独立性,降低神经缺损程度。     

NIOSH提举指数在下背痛流行病学研究中的应用

[目的 ]探讨美国国家职业安全卫生研究所提出的手工作业提举指数 (LI)与下背痛患病率的关系。[方法 ]在 3个具有典型提举作业的工厂中采用流行病学横断面调查方法 ,利用NIOSH提出的提举指数进行接触负荷评价 ,按照Nordic肌肉骨骼症状分析调查表对 491名从事手工提举作业的工人和 3 4名无明显提举任务的行政人员进行问卷调查 ,并对静态肌力进行测试。根据提举指数分为 0 ,～ 1,～ 2 ,～ 3 ,>3共 5组。观察各组工人不同部位肌肉骨骼疾患的患病情况 ,并分析提举指数与下背痛患病的关系。 [结果 ]在肌肉骨骼症状中 ,下背痛的发生率最高。当LI增高时 ,下背痛的OR值也随之增加 ,但其峰值出现在～ 3组 (OR =1.3 5 ) ,而LI >3 ,其OR值并非最高 ,仅为 1.3 0。平均腰拉力最大的为～ 1组 ( 95 .5 9± 2 1.76)kg ,而对照组和LI >3组则分别为 ( 80 .3 6± 14 .49)kg、( 86.85± 2 0 .3 3 )kg。 [结论 ]提举指数对手工提举所引起的下背痛是一个有意义的危险度评价指标。过度手工提举活动可能降低腰拉力。     

Combined Effect of Dynapenia (Muscle Weakness) and Low Vitamin D Status on Incident Disability

Background and objective

There is little epidemiologic evidence considering the combined effect of dynapenia and low 25-hydroxyvitamin D [25 (OH) D] on incident disability. Our aim was to investigate whether the combination of dynapenia and low 25 (OH) D serum levels increases the risk of activities of daily living (ADL) incident disability.

Detraining Effects on Muscle Quality in Older Men with Osteosarcopenia. Follow-Up of the Randomized Controlled Franconian Osteopenia and Sarcopenia Trial (FrOST)

The present study aimed to determine the effect of detraining on muscle quality (MQ) in older men with osteosarcopenia. Forty-three community-dwelling older men (78 ± 4 years) were randomly allocated to a consistently supervised high-intensity resistance exercise training (HIRT) group (n = 21) or a control group (CG, n = 22). The HIRT scheduled a periodized single set protocol twice weekly. After the intervention, the men were subjected to six months of detraining. Muscle quality (MQ), defined as maximum isokinetic hip/leg extensor strength per unit of mid-thigh intra-fascia volume, was determined by magnetic resonance imaging (MRI) or per unit of thigh muscle mass assessed by dual-energy X-ray absorptiometry (DXA). Intention-to-treat analysis with multiple imputations was applied. We observed significant exercise effects for MQ (p = 0.001). During detraining, the HIRT group lost about one-third of the intervention-induced gain and displayed significantly (p = 0.001) higher MQ reductions compared to the CG. Nevertheless, after training and detraining, the overall intervention effect on MQ remained significant (p ≤ 0.004). In summary, six months of absence from HIRT induce a significant deleterious effect on MQ in older osteosarcopenic men. We conclude that intermitted training programs with training breaks of six months and longer should be replaced by largely continuous exercise programs, at least when addressing MQ parameters.     

生物反馈联合电刺激及阴道哑铃康复训练对促进产妇盆底肌力恢复的效果观察

目的观察生物反馈联合电刺激及阴道哑铃康复训练对促进产妇盆底肌力恢复的效果。方法选取2017年7月至2018年3月我院收治的盆底功能障碍产妇60例,随机分为两组各30例。对照组采用生物反馈联合电刺激,观察组在此基础上采用阴道哑铃康复训练。观察对比两组的阴道静息压、盆腔器官脱垂程度及性生活质量。结果治疗后,观察组的FSFI评分和阴道静息压高于对照组(P <0.05)。治疗后,观察组的盆腔器官脱垂程度低于对照组(P <0.05)。结论对盆底功能障碍产妇采用生物反馈联合电刺激及阴道哑铃康复训练,可有效增强盆底肌力,改善盆腔器官脱垂症状,提高性生活质量。     

Effects of Cannabidiol Supplementation on Skeletal Muscle Regeneration after Intensive Resistance Training

Cannabidiol supplements (CBD) are increasingly consumed by athletes to improve regeneration. However, the evidence for the pro-regenerative effects of CBD in sports is quite limited. Therefore, our aim was to investigate the effects of a single CBD supplementation in a six-arm placebo-controlled crossover study after resistance training on performance and muscle damage. Before and after the resistance training, one-repetition maximum in the back squat (1RM BS), countermovement jump (CMJ), and blood serum concentrations of creatine kinase (CK) and myoglobin (Myo) were measured in healthy, well-trained participants. 16 out of 21 participants completed the study and were included in the analysis. In 1RM BS, a significant decrease was observed after 24 h (p < 0.01) but not after 48 and 72 h. A significant group difference was detected after 72 h (p < 0.05; ES = 0.371). In CMJ, no significant changes were observed. The CK and Myo concentrations increased significantly after 24 h (CK: p < 0.001; Myo: p < 0.01), 48 h (CK: p < 0.001; Myo: p < 0.01) and 72 h (CK: p < 0.001; Myo: p < 0.001). After 72 h, significant group differences were observed for both muscle damage biomarkers (CK: p < 0.05 ES = 0.24; Myo: p < 0.05; ES = 0.21). The results show small but significant effects on muscle damage and recovery of squat performance after 72 h. However, more data are required for clearer statements concerning potential pro-regenerative effects of CBD supplementation after resistance training.     

Effects of Resistance Training on Functional Strength and Muscle Mass in 70-Year-Old Individuals With Pre-sarcopenia: A Randomized Controlled Trial

Objective

Sarcopenia has been defined as age-related loss of muscle mass and function. The aim of this randomized controlled trial was to examine the effects of a 10-week instructor-led resistance training program on functional strength and body composition in men and women aged 70 years with pre-sarcopenia.

Impact of Malnutrition Status on Muscle Parameter Changes over a 5-Year Follow-Up of Community-Dwelling Older Adults from the SarcoPhAge Cohort

This study aimed to assess the impact of malnutrition on the 5-year evolution of physical performance, muscle mass and muscle strength in participants from the SarcoPhAge cohort, consisting of community-dwelling older adults. The malnutrition status was assessed at baseline (T0) according to the “Global Leadership Initiatives on Malnutrition” (GLIM) criteria, and the muscle parameters were evaluated both at T0 and after five years of follow-up (T5). Lean mass, muscle strength and physical performance were assessed using dual X-ray absorptiometry, handgrip dynamometry, the short physical performance battery test and the timed up and go test, respectively. Differences in muscle outcomes according to nutritional status were tested using Student’s t-test. The association between malnutrition and the relative 5-year change in the muscle parameters was tested using multiple linear regressions adjusted for several covariates. A total of 411 participants (mean age of 72.3 ± 6.1 years, 56% women) were included. Of them, 96 individuals (23%) were diagnosed with malnutrition at baseline. Their muscle parameters were significantly lower than those of the well-nourished patients both at baseline and after five years of follow-up (all p-values < 0.05), except for muscle strength in women at T5, which was not significantly lower in the presence of malnutrition. However, the 5-year changes in muscle parameters of malnourished individuals were not significantly different than those of well-nourished individuals (all p-values > 0.05).     

Assessing Additional Characteristics of Muscle Function With Digital Handgrip Dynamometry and Accelerometry: Framework for a Novel Handgrip Strength Protocol

Maximal handgrip strength (HGS) is a convenient and reliable, but incomplete, assessment of muscle function. Although low HGS is a powerful predictor of poor health, several limitations to maximal HGS exist. The predictive value of HGS is restricted because low HGS is associated with a wide range of unspecified health conditions, and other characteristics of muscle function aside from strength capacity are not evaluated. Current HGS protocol guidelines emphasize the ascertainment of maximal force, which is only a single muscle function characteristic. Muscle function is intrinsically multivariable, and assessing other attributes in addition to strength capacity will improve screenings for age-related disabilities and diseases. Digital handgrip dynamometers and accelerometers provide unique opportunities to examine several aspects of muscle function beyond strength capacity, while also maintaining procedural ease. Specifically, digital handgrip dynamometry and accelerometry can assess the rate of force development, submaximal force steadiness, fatigability, and task-specific tremoring. Moreover, HGS protocols can be easily refined to include an examination of strength asymmetry and bilateral strength. Therefore, evaluating muscle function with new HGS technologies and protocols may provide a more comprehensive assessment of muscle function beyond maximal strength, without sacrificing feasibility. This Special Article introduces a novel framework for assessing multiple attributes of muscle function with digital handgrip dynamometry, accelerometry, and refinements to current HGS protocols. Such framework may aid in the discovery of measures that better predict and explain age-related disability, biological aging, and the effects of comorbid diseases that are amenable to interventions. These additional HGS measures may also contribute to our understanding of concepts such as resilience. Using sophisticated HGS technologies that are currently available and modernizing protocols for developing a new muscle function assessment may help transform clinical practice by enhancing screenings that will better identify the onset and progression of the disabling process.     

Effects of Egg White Protein Supplementation on Muscle Strength and Serum Free Amino Acid Concentrations

The aim of this study was to evaluate the effects of egg white protein compared to carbohydrate intake prior to exercise on fat free mass (FFM), one repetition maximum (1RM) muscle strength and blood biochemistry in female athletes. Thirty healthy female collegiate athletes were recruited for this study and matched by sport type, body fat percentage and 1RM leg curl muscle strength. Participants were randomly divided into two groups: protein group (15.0 g egg white protein; 75 kcal) and carbohydrate group (17.5 g maltodextrin, 78 kcal). Supplements were administered daily at the same time in a double-blind manner prior to training during an 8-week period. Measurements were performed before and after the 8-week regimen. The mean dietary energy intake did not change throughout the study period. FFM and 1RM assessments (i.e., leg curl, leg extension, squat, and bench press) increased in both groups. Furthermore, serum urea and serum citrulline levels after the 8-week regimen increased significantly only in the protein group. Our findings indicated that compared to the carbohydrate supplement, the protein supplement was associated with some changes in protein metabolites but not with changes in body composition or muscle strength.     

Effects of Preloaded Isokinetic versus Pure Isokinetic Training on Dynamic and Static Lumbar Muscle Strength and Endurance

A training study was conducted to investigate effects of two modes of exercise on the strength and endurance characteristics of the lumbar musculature. Twenty symptom free male subjects were divided into either a preloaded isokinetic (49 Nm preload) or a pure isokinetic training group. Both groups trained for five sets of 10 repetitions at 30°/s for 3 sessions per week for 1 month. Maximum preloaded isokinetic endurance and strength increased 26% (P < .001) and 20% (P = .001) for the preloaded isokinetic group and –1% (NS) and 3% (NS) for the pure isokinetic group. Maximum isometric strength and isometric endurance increased 11% (P < .001) and 3% (NS) for the preloaded isokinetic group and 9% (NS) and 18% (P = .024) for the pure isokinetic group. Both training regimes did not significantly change EMG spectral parameters. The preloaded isokinetic group exhibited retention of strength and endurance gains for as long as a year. The results indicated that the preloaded isokinetic group yielded superior gains in strength and endurance as compared with the pure isokinetic group except for isometric endurance. The observed retention of gains in the preloaded group during follow-ups may help direct rehabilitation to include eccentrics with isokinetic training.     

镉对大鼠离体心脏乳头肌力学特性的影响

[目的 ]研究镉对离体心室乳头肌力学特性的影响。 [方法 ]取Wistar大鼠左心室乳头肌 ,分别测定镉对离体心室乳头肌主动张力 (PT)、最大收缩和舒张速率 (±dT dtmax)、dT dtmax位点时收缩成分缩短速度 (VCE)及刺激至张力峰值时程 (TPT)的影响。 [结果 ]当镉离子浓度为 ( 2 75× 10 - 5)mol L时 ,对乳头肌收缩张力无明显作用 ,但已引起 +dT dtmax和 -dT dtmax显著降低 ,镉离子浓度达 ( 5 45× 10 - 5)mol L时 ,才对乳头肌的PT产生明显影响 ,用肾上腺素、氯化钙和肾上腺素加氯化钙进行干预 ,可见到乳头肌收缩能力迅速恢复。 [结论 ]镉离子使乳头肌的±dT dtmax、PT和VCE明显降低 ,使TPT延长 ,钙或 (和 )肾上腺素可以对抗镉对乳头肌的上述作用     

A 12-Week Randomized Double-Blind Placebo-Controlled Clinical Trial,Evaluating the Effect of Supplementation with a Spinach Extract on Skeletal Muscle Fitness in Adults Older Than 50 Years of Age

The aim of a 12-week randomized double-blind placebo-controlled study was to assess the effect of daily supplementation with a natural extract of Spinacia oleracea L. (4 × 500 mg capsules/day; total 2 g per day) combined with a moderate-intensity training program (1 h session/3 times a week) on skeletal muscle fitness in adults over 50 years of age. Muscle strength assessed by isokinetic and isometric dynamometry improved significantly in the experimental (n = 23) and the placebo (n = 22) groups, but the magnitude of improvement was higher in the experimental group, with between-group differences in almost all variables, including isokinetic at 60° s⁻¹ in knee extension, peak torque (p < 0.007); total work per repetition maximum (p < 0.009); isokinetic at 180°s⁻¹ in knee extension, peak torque (p < 0.002); total work (p < 0.007); total work per repetition maximum (p < 0.005); average power (p < 0.027); isometric in knee extension, peak torque (p < 0.005); and average peak torque (p < 0.002). Similar findings were observed for muscle quality. Changes in quality of life (SF-36) were not found, except for improvements in the role physical (p < 0.023) and role emotional (p < 0.001) domains, likely as a result of the physical training sessions. A nutritional survey did not revealed changes in dietary habits. No adverse events were recorded. In subjects over 50 years of age, moderate-intensity strength training combined with daily supplementation for 12 weeks with a natural extract of Spinacia oleracea L. improved muscle-related variables and muscle quality. Maintaining muscle health is a key component of healthy aging.     

The Effects of Pro-, Pre-, and Synbiotics on Muscle Wasting,a Systematic Review—Gut Permeability as Potential Treatment Target

Muscle wasting is a frequently observed, inflammation-driven condition in aging and disease, known as sarcopenia and cachexia. Current treatment strategies target the muscle directly and are often not able to reverse the process. Because a reduced gut function is related to systemic inflammation, this might be an indirect target to ameliorate muscle wasting, by administering pro-, pre-, and synbiotics. Therefore, this review aimed to study the potential of pro-, pre-, and synbiotics to treat muscle wasting and to elucidate which metabolites and mechanisms affect the organ crosstalk in cachexia. Overall, the literature shows that Lactobacillus species pluralis (spp.) and possibly other genera, such as Bifidobacterium, can ameliorate muscle wasting in mouse models. The beneficial effects of Lactobacillus spp. supplementation may be attributed to its potential to improve microbiome balance and to its reported capacity to reduce gut permeability. A subsequent literature search revealed that the reduction of a high gut permeability coincided with improved muscle mass or strength, which shows an association between gut permeability and muscle mass. A possible working mechanism is proposed, involving lactate, butyrate, and reduced inflammation in gut–brain–muscle crosstalk. Thus, reducing gut permeability via Lactobacillus spp. supplementation could be a potential treatment strategy for muscle wasting.     

Creatine Enhances the Effects of Cluster-Set Resistance Training on Lower-Limb Body Composition and Strength in Resistance-Trained Men: A Pilot Study

Creatine monohydrate (CrM) supplementation has been shown to improve body composition and muscle strength when combined with resistance training (RT); however, no study has evaluated the combination of this nutritional strategy with cluster-set resistance training (CS-RT). The purpose of this pilot study was to evaluate the effects of CrM supplementation during a high-protein diet and a CS-RT program on lower-limb fat-free mass (LL-FFM) and muscular strength. Twenty-three resistance-trained men (>2 years of training experience, 26.6 ± 8.1 years, 176.3 ± 6.8 cm, 75.6 ± 8.9 kg) participated in this study. Subjects were randomly allocated to a CS-RT+CrM (n = 8), a CS-RT (n = 8), or a control group (n = 7). The CS-RT+CrM group followed a CrM supplementation protocol with 0.1 g·kg⁻¹·day⁻¹ over eight weeks. Two sessions per week of lower-limb CS-RT were performed. LL-FFM corrected for fat-free adipose tissue (dual-energy X-ray absorptiometry) and muscle strength (back squat 1 repetition maximum (SQ-1RM) and countermovement jump (CMJ)) were measured pre- and post-intervention. Significant improvements were found in whole-body fat mass, fat percentage, LL-fat mass, LL-FFM, and SQ-1RM in the CS-RT+CrM and CS-RT groups; however, larger effect sizes were obtained in the CS-RT+CrM group regarding whole body FFM (0.64 versus 0.16), lower-limb FFM (0.62 versus 0.18), and SQ-1RM (1.23 versus 0.75) when compared to the CS-RT group. CMJ showed a significant improvement in the CS-RT+CrM group with no significant changes in CS-RT or control groups. No significant differences were found between groups. Eight weeks of CrM supplementation plus a high-protein diet during a CS-RT program has a higher clinical meaningfulness on lower-limb body composition and strength-related variables in trained males than CS-RT alone. Further research might study the potential health and therapeutic effects of this nutrition and exercise strategy.     

川芎嗪对子痫前期脐血清诱导脐动脉平滑肌细胞胶原表达的体外研究

目的探讨子痫前期患者血清诱导脐动脉平滑肌细胞(HUSMC)前胶原I、III的表达及川芎嗪对其的影响。方法采用组织块培养法培养正常妊娠HUSMC,传代后待细胞长满至70%～80%后,加或不加川芎嗪作用30min后分别加入正常妊娠及子痫前期脐静脉血清,培养48h后,MTT测定细胞活力,流式细胞学测定细胞周期,RT-PCR测定SMC前胶原I、III的表达。结果:子痫前期患者脐静脉血清培养HUSMC的细胞活力、前胶原ImRNA的表达、S及G2/M期细胞百分比明显高于正常妊娠组,G0+G1期细胞百分比明显低于妊娠组。加川芎嗪预处理后:子痫前期组HUSMC活力、前胶原I的表达、G2/M期细胞百分比明显下降,G0+G1期细胞百分比明显增加(P均<0.01)。结论子痫前期患者脐静脉血清可促进HUSMC增生及I型胶原的表达,川芎嗪可抑制HUSMC的增生及胶原形成,发挥其对子痫前期的防治作用。