scholarly journals An Improved EMG-Driven Neuromusculoskeletal Model for Elbow Joint Muscle Torque Estimation

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Bingshan Hu ◽  
Haoran Tao ◽  
Hongrun Lu ◽  
Xiangxiang Zhao ◽  
Jiantao Yang ◽  
...  
Keyword(s):  
Geometric Model ◽  
Pearson Correlation ◽  
Joint Torque ◽  
Muscle Coordination ◽  
Muscle Torque ◽  
Significant Difference ◽  
Double Muscle ◽  
Neuromusculoskeletal Model ◽  
Improved Model

The accurate measurement of human joint torque is one of the research hotspots in the field of biomechanics. However, due to the complexity of human structure and muscle coordination in the process of movement, it is difficult to measure the torque of human joints in vivo directly. Based on the traditional elbow double-muscle musculoskeletal model, an improved elbow neuromusculoskeletal model is proposed to predict elbow muscle torque in this paper. The number of muscles in the improved model is more complete, and the geometric model is more in line with the physiological structure of the elbow. The simulation results show that the prediction results of the model are more accurate than those of the traditional double-muscle model. Compared with the elbow muscle torque simulated by OpenSim software, the Pearson correlation coefficient of the two shows a very strong correlation. One-way analysis of variance (ANOVA) showed no significant difference, indicating that the improved elbow neuromusculoskeletal model established in this paper can well predict elbow muscle torque.

The Influence of Fascicle Behavior on the Lack of Velocity Dependence in Eccentric Joint Torque in Humans: In Vivo Observation

2009 ◽  
Vol 25 (2) ◽  
pp. 111-118 ◽  
Author(s):  
Kentaro Chino ◽  
Naotoshi Mitsukawa ◽  
Kai Kobayashi ◽  
Yusuke Miyoshi ◽  
Toshiaki Oda ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Triceps Surae ◽  
Joint Torque ◽  
Fascicle Length ◽  
Significant Difference ◽  
Isometric Torque ◽  
The Difference ◽  
The Relationship ◽  
Real Time Ultrasonography

To investigate the relationship between fascicle behavior and joint torque, the fascicle behavior of the triceps surae during isometric and eccentric (30 and 60 deg/s) plantar flexion by maximal voluntary and submaximal electrical activation (MVA and SEA) was measured by real-time ultrasonography. Eccentric torque at 30 and 60 deg/s was significantly higher than isometric torque under SEA, but not under MVA. However, fascicle length did not significantly differ between isometric and eccentric trials under either condition. Therefore, the difference in developed torque by MVA and SEA cannot be explained by fascicle behavior. Under both MVA and SEA conditions, eccentric torque at 30 and 60 deg/s was equivalent. Similarly, fascicle lengthening velocities at 30 and 60deg/s did not show any significant difference. Such fascicle behavior can be attributed to the influence of tendinous tissue and pennation angle, and lead to a lack of increase in eccentric torque with increasing angular velocity.

Wrist torque estimation during simultaneous and continuously changing movements: surface vs. untargeted intramuscular EMG

2013 ◽  
Vol 109 (11) ◽  
pp. 2658-2665 ◽  
Author(s):  
Ernest N. Kamavuako ◽  
Erik J. Scheme ◽  
Kevin B. Englehart
Keyword(s):  
Degrees Of Freedom ◽  
Performance Metrics ◽  
Wrist Joint ◽  
Pearson Correlation ◽  
Surface Emg ◽  
Joint Torque ◽  
Coefficient Of Determination ◽  
Significant Difference ◽  
The Difference ◽  
The Right

In this paper, the predictive capability of surface and untargeted intramuscular electromyography (EMG) was compared with respect to wrist-joint torque to quantify which type of measurement better represents joint torque during multiple degrees-of-freedom (DoF) movements for possible application in prosthetic control. Ten able-bodied subjects participated in the study. Surface and intramuscular EMG was recorded concurrently from the right forearm. The subjects were instructed to track continuous contraction profiles using single and combined DoF in two trials. The association between torque and EMG was assessed using an artificial neural network. Results showed a significant difference between the two types of EMG ( P < 0.007) for all performance metrics: coefficient of determination (R2), Pearson correlation coefficient (PCC), and root mean square error (RMSE). The performance of surface EMG (R2 = 0.93 ± 0.03; PCC = 0.98 ± 0.01; RMSE = 8.7 ± 2.1%) was found to be superior compared with intramuscular EMG (R2 = 0.80 ± 0.07; PCC = 0.93 ± 0.03; RMSE = 14.5 ± 2.9%). The higher values of PCC compared with R2 indicate that both methods are able to track the torque profile well but have some trouble (particularly intramuscular EMG) in estimating the exact amplitude. The possible cause for the difference, thus the low performance of intramuscular EMG, may be attributed to the very high selectivity of the recordings used in this study.

scholarly journals The effect of stretch–shortening magnitude and muscle–tendon unit length on performance enhancement in a stretch–shortening cycle

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Martin Groeber ◽  
Savvas Stafilidis ◽  
Arnold Baca
Keyword(s):  
Performance Enhancement ◽  
Vastus Lateralis ◽  
Unit Length ◽  
Knee Kinematics ◽  
Joint Torque ◽  
Physiological Relevance ◽  
Significant Difference ◽  
Human Muscles ◽  
Stretch Shortening Cycle

AbstractStretch-induced residual force enhancement (rFE) is associated with increased performance in a stretch–shortening cycle (SSC). Although the influence of different range of motions and muscle–tendon unit lengths has been investigated in pure stretch-hold experiments in vivo, the contribution to a SSC movement in human muscles remains unclear. In two sessions, 25 healthy participants performed isometric reference (ISO), shortening hold (SHO) and SSC contractions on an isokinetic dynamometer. We measured the net knee-joint torque, rotational mechanical work, knee kinematics and fascicle behavior (m. vastus lateralis) of the upper right leg. In session 1 the SHO- and SSC-magnitude was changed respectively (SHO: 50°–20°, 80°–20° and 110°–20°; SSC: 20°–50°–20°, 20°–80°–20° and 20°–110°–20°) and in session 2 the muscle–tendon unit length (SHO: 50°–20°, 80°–50° and 110°–80°; SSC: 20°–50°–20°, 50°–80°–50° and 80°–110°–80°; straight leg = 0°). In both sessions, rotational work was significantly (p < 0.05) increased in the SSC compared to the SHO contractions (in the range of 8.1–17.9%). No significant difference of joint torque was found in the steady-state for all SSC-magnitudes compared to the corresponding SHO contractions in session 1. In session 2, we found only significantly (p < 0.05) less depressed joint torque in the SSC at the longest muscle–tendon unit length compared to the corresponding SHO condition, without any differences in knee kinematics and fascicle behavior. Therefore, the physiological relevance of rFE might be particularly important for movements at greater muscle–tendon unit lengths.

In-vivo evaluation of the effect of cyanoacrylate on prosthetic vascular graft infection – does cyanoacrylate increase the severity of infection?

VASA ◽  
2020 ◽  
Vol 49 (4) ◽  
pp. 281-284
Author(s):  
Atıf Yolgosteren ◽  
Gencehan Kumtepe ◽  
Melda Payaslioglu ◽  
Cuneyt Ozakin
Keyword(s):  
Vascular Graft ◽  
Graft Infection ◽  
Vascular Graft Infection ◽  
Group 4 ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2 ◽  
Prosthetic Vascular Graft Infection ◽  
Group 1

Summary. Background: Prosthetic vascular graft infection (PVGI) is a complication with high mortality. Cyanoacrylate (CA) is an adhesive which has been used in a number of surgical procedures. In this in-vivo study, we aimed to evaluate the relationship between PVGI and CA. Materials and methods: Thirty-two rats were equally divided into four groups. Pouch was formed on back of rats until deep fascia. In group 1, vascular graft with polyethyleneterephthalate (PET) was placed into pouch. In group 2, MRSA strain with a density of 1 ml 0.5 MacFarland was injected into pouch. In group 3, 1 cm 2 vascular graft with PET piece was placed into pouch and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. In group 4, 1 cm 2 vascular graft with PET piece impregnated with N-butyl cyanoacrylate-based adhesive was placed and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. All rats were scarified in 96th hour, culture samples were taken where intervention was performed and were evaluated microbiologically. Bacteria reproducing in each group were numerically evaluated based on colony-forming unit (CFU/ml) and compared by taking their average. Results: MRSA reproduction of 0 CFU/ml in group 1, of 1410 CFU/ml in group 2, of 180 200 CFU/ml in group 3 and of 625 300 CFU/ml in group 4 was present. A statistically significant difference was present between group 1 and group 4 (p < 0.01), between group 2 and group 4 (p < 0.01), between group 3 and group 4 (p < 0.05). In terms of reproduction, no statistically significant difference was found in group 1, group 2, group 3 in themselves. Conclusions: We observed that the rate of infection increased in the cyanoacyrylate group where cyanoacrylate was used. We think that surgeon should be more careful in using CA in vascular surgery.

In-vivo anti-oxidant screening of Tectona grandis extract

2020 ◽  
Vol 9 (1) ◽  
pp. 1-4
Author(s):  
Tamilarasi G P ◽  
Sabarees G
Keyword(s):  
Biochemical Parameters ◽  
Tectona Grandis ◽  
The Body ◽  
Altered Expression ◽  
Physiological Conditions ◽  
Synthetic Drugs ◽  
Significant Difference ◽  
Anti Oxidant ◽  
Radical Generation

Oxidation is an essential reaction in the human body, which determines the expression of proteins in the body. This results in the altered expression like rapid growth resulting in cancers and other disorders. Many synthetic drugs are available in the market that is effective in limiting the free radical generation and the reaction of radicals with cells. Unfortunately, all those synthetic drugs were found to cause side effects and adverse effects in the body. But given the accuracy of the predictability of the results and administration, this research focuses on testing the anti-oxidant efficiency in rat models testing the biochemical parameters. Investigations have also been done on the anti-oxidant activity of Tectona, but every research was concentrated to prove the anti-oxidant activity only. extract had been tested for anti-oxidant activity by estimating various tissue parameters and it showed better activity. As predicted, there is a significant difference in the and results which can be explained are due to the physiological conditions that exist inside the body.

Effect of a-Week Summer Camp on the Hopelessness and Self-Esteem of the University Students Attending Sport Sciences Faculty

2018 ◽  
Vol 7 (4) ◽  
pp. 42-49 ◽  
Author(s):  
Korkmaz YİĞİTER ◽  
Hakan TOSUN
Keyword(s):  
University Students ◽  
Summer Camp ◽  
Pearson Correlation ◽  
Self Esteem ◽  
Female Students ◽  
T Test ◽  
Significance Level ◽  
Significant Difference ◽  
Post Test ◽  
The University

The aim of this study is to investigate the effects of participation in a 1-week summer camp on thehopelessness and self-esteem of the university students attending Sport Sciences Faculty. Participants were 36university students assigned to experiment group using a random procedure. Coopersmith Self-esteem and Beck Hopelessness Scales were completed at the beginning and end of the summer camp by designed the university. The obtained data were analysed in the SPSS 18.0 program and the significance level was taken as 0.05. The descriptive statistics, independent simple t test, paired simple t test and Pearson correlation were used for analyse the data in the study. According to the results of the research, no significant difference was observed in the comparison of the hopelessness and self-esteem levels between pre and post-test. In addition, there was a significant difference in the hopelessness level of male and female students but any significant difference was not observed in terms of self-esteem. There was a significant relationship between hopelessness and self-esteem pre and post-test. These result shows that a 1-week summer camp cannot change the hopelessness or self-esteem level. However, as the self-esteem rises, the rate of despair decreases whereas as the despair rises, the selfesteem decreases.

Levels of selected metals in coriander (Coriandrum sativum L.) leaves cultivated in four different areas of Ethiopia

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Pearson Correlation ◽  
Absorption Spectrometry ◽  
Coriandrum Sativum ◽  
Good Source ◽  
Digestion Method ◽  
Flame Atomic Absorption ◽  
Significant Difference ◽  
Metal Levels ◽  
Good Percentage ◽  
Coriander Leaves

Coriander (Coriandrum sativum L.) is one of the herbs which is used for medicinal and food purposes. In the present study the levels of selected metals in coriander leaves were determined in the samples collected from four different farmlands (Sebeta, Mekanisa, Holeta and Gefersa) in Ethiopia where its cultivation is common. The levels of metals were determined after digestion of samples with the mixture of 4 mL of HNO3 and 4 mL of HClO4 at 300 oC for 3:00 hours by flame atomic absorption spectrometry. The optimized wet digestion method for coriander leaves analysis was validated through the recovery experiment and a good percentage recovery was obtained (93.2-101%). The levels of metals were found in the range Ca, 2319–3503 mg/kg; Zn, 33.4–54.8 mg/kg and Cr, 5.55-9.86 mg/kg while the trace metals Cu, Ni, Cd and Pb were too low to be detected. The results indicated that Ethiopian coriander is a good source of essential metals and free from the toxic metals Pb and Cd. A statistical analysis of variance (ANOVA) at 95% confidence level indicated that there is significant difference (p &lt; 0.05) in the levels of all detected metals between the four sample means. The Pearson correlation was used to predict the dependence of metal levels on one another. The levels of the metals determined in this study compared well with those reported for coriander leaves from some other parts of the world.

Alternativas farmacéuticas: ¿pueden ser intercambiables?

2020 ◽  
Vol 2 (2) ◽  
pp. 38-42
Author(s):  
Miriam del Carmen Carrasco-Portugal ◽  
Francisco Javier Flores-Murrieta
Keyword(s):  
Generic Substitution ◽  
In Vivo Studies ◽  
Regulatory Agencies ◽  
European Medicines Agency ◽  
Reference Formulation ◽  
Active Moiety ◽  
Significant Difference ◽  
Pharmaceutical Form ◽  
Extent Of Absorption

Pharmaceutical alternatives are products with the same active moiety, but different salt, ester or pharmaceutical form. Regulatory agencies have different criteria for this kind of drug. The European Medicines Agency (EMA) accepts the generic substitution using these alternatives, whereas the Food and Drug Administration (FDA) only authorizes generic substitution of pharmaceutical equivalents. The objective of this paper is to describe some relevant aspects that should be considered before deciding on making a generic substitution with pharmaceutical alternatives. It is important to note that a pharmaceutical alternative must show no significant difference in the rate and extent of absorption (bioequivalence) in a well-conducted in vivo study when compared with the reference formulation. Current Mexican regulations state that generic substitution is possible using pharmaceutical alternatives when bioequivalence is demonstrated in in vivo studies conducted under the NOM-177-SSA1-2013 criteria. In conclusion, generic substitution with pharmaceutical alternatives is possible if these products demonstrate in vivo bioequivalence when compared with the reference product.

Aberrant β-catenin activity in hepatoid adenocarcinoma of the stomach

2020 ◽  
Vol 20 ◽  
Author(s):  
Nan Wang ◽  
Rui Kong ◽  
Wei Han ◽  
Jie Lu
Keyword(s):  
Hepatocellular Carcinoma ◽  
Pearson Correlation ◽  
Clinicopathological Characteristics ◽  
Cancer Tissue ◽  
Hepatoid Adenocarcinoma ◽  
Tumor Initiating Cells ◽  
Significant Difference ◽  
Diagnostic Confusion ◽  
Hematoxylin And Eosin ◽  
Cancer Tissues

Background: Hepatoid adenocarcinoma of the stomach (HAS) has been recognized as a rare primary gastric tumor characterized by hepatocellular carcinoma-like histology. HAS often causes diagnostic confusion with conventional gastric adenocarcinoma (CGA) due to the difficulty to detect hepatoid differentiation solely based on findings from hematoxylin and eosin (H&E) staining. Hence, HAS should be distinguished from solid-type CGA based on their different biological behaviors. β-catenin is highly expressed in hepatocellular carcinoma (HCC), which is involved in the maintenance of tumor initiating cells, drug resistance, tumor progression, and metastasis. Methods and Results: Given the dearth of HAS cases, systematic examination of the expression of β-catenin in HAS remains under-explored. In this study, 14 cases were subjected to immunostaining with with AFP, β-catenin, glypican3, hepar-1 and CerbB-2. In parallel, the clinicopathological characteristics of these patients were collected. We detected statistically significant difference in the expression of β-catenin (P = 0.000), glypican3 (P = 0.019), and hepar-1 (P = 0.007) between HAS cancer tissues and the adjacent non-cancerous tissues. Furthermore, a significant correlation was observed between the expression of β-catenin in HAS cancer tissue and adjacent tissue (Pearson correlation coefficient: 0.686, P = 0.007). Moreover, in cancer tissues, a significant correlation was observed between the expression of β-catenin and survival time (Spearman correlationcoefficient= - 0.482, P = 0.003). However, we found the expression of β-catenin did not correlate with the degree of tumor differentiation and tumor size, age, gender, serum AFP levels, microinvasion, and metastasis (P > 0.05). Conclusion: Our findings establish β-catenin as a useful marker that can distinguish HAS from CGA and may improve the early diagnosis to guide the appropriate and timely treatment of HAS patients.

Development of Mucoadhesive Buccal Drug Delivery System of Propranolol Hydrochloride Using Aster ericoides Mucilage

2020 ◽  
Vol 10 (2) ◽  
pp. 133-148
Author(s):  
Ankaj Kaundal ◽  
Pravin Kumar ◽  
Rajendra Awasthi ◽  
Giriraj T. Kulkarni
Keyword(s):  
Buccal Cavity ◽  
Three Dimensional ◽  
Hot Water ◽  
Fickian Diffusion ◽  
Aster Ericoides ◽  
Dimensional Network ◽  
Buccal Tablet ◽  
Significant Difference ◽  
Volunteer Group

Aim: The study was aimed to develop mucoadhesive buccal tablets using Aster ericoides leaves mucilage. Background : Mucilages are naturally occurring high-molecular-weight polyuronides, which have been extensively studied for their application in different pharmaceutical dosage forms. Objective: The objective of the present research was to establish the mucilage isolated from the leaves of Aster ericoides as an excipient for the formulation of the mucoadhesive buccal tablet. Method: The mucilage was isolated from the leaves of Aster ericoides by maceration, precipitated with acetone and characterized. Tablets were prepared using wet granulation technique and evaluated for various official tests. Results: The mucilage was found to be non-toxic on A-431 and Vero cell lines. It was insoluble but swellable in cold and hot water. The results indicate that mucilage can form a three-dimensional network. The pH of the mucilage (6.82 ± 0.13) indicated that it might be non-irritant to the buccal cavity. The mucilage was found to be free from microbes. The release of drug was by Fickian diffusion. The in vivo buccal tablet acceptance was 80%. No significant difference between the diastolic blood pressure of standard and Aster tablets treated volunteer group was recorded. Conclusion: The mucilage was found to be non-toxic on A-431 and Vero cell lines. It was insoluble but swellable in cold and hot water. The results indicate that mucilage can form a three-dimensional network. The pH of the mucilage (6.82 ± 0.13) indicated that it might be non-irritant to the buccal cavity. The mucilage was found to be free from microbes. The release of drug was by Fickian diffusion. The in vivo buccal tablet acceptance was 80%. No significant difference between the diastolic blood pressure of standard and Aster tablets treated volunteer group was recorded. Other: However, to prove the potency of the polymer, in vivo bioavailability studies in human volunteers are needed along with chronic toxicity studies in suitable animal models.

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