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1

Use of the surface electromyography for a quantitative trend validation of estimated muscle forces

Żuk M., Syczewska M., Pezowicz C.

Biocybernetics and Biomedical Engineering

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2018

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Vol. 38, no. 2

243--250

EN

Surface EMG is a non-invasive measurement of an individual muscle activity and it can be used as the indirect form of a simulated muscle forces validation. The quantitative curves comparison has some potential, which has not been fully exploited yet [13]. The purpose of current study was to quantitatively compare muscle forces predicted using musculoskeletal models to measured surface electromyography signals. A metrics based on correlation and an electromechanical delay correction for a quantitative trend validation has been proposed. Kinematics of a normal gait was collected for three healthy subjects together with ground reaction forces and EMG signals of eight different muscles of both legs. Dynamic simulations have been performed for two models of differing complexity from OpenSim library (Gait2392 and Gait2354) [2,5,6], static optimization method and computed muscle control algorithm [20] have been used. It has been shown, that the level of force-EMG trend compliance, obtained for applied models and simulation techniques, is related rather to the selected muscle than to applied optimization criteria or technique. The contribution of analyzed muscles during gait has been predicted better by complex model than by simplified model. Moreover relationship between the body proportion of subject and the degree of correlation has been observed. Proposed metrics and obtained results can be the basis for further identification of cost functions, which could most closely describe motor control strategy.

2

Assessment of Muscle Forces and Joint Reaction in Lower Limbs During the Take-Off from the Springboard

Dziewiecki K., Mazur Z., Blajer W.

Acta Mechanica et Automatica

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2012

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Vol. 6, no. 4

11-14

EN

Computer simulation methods, based on the biomechanical models of human body and its motion apparatus, are commonly used for the assessment of muscle forces, joint reactions, and some external loads on the human body during its various activities. In this paper a planar musculoskeletal model of human body is presented, followed by its application to the inverse simulation study of a gymnast movement during the take)off from the springboard when performing the handspring somersault vault on the table. Using the kinematic da) ta of the movement, captured from optoelectronic photogrammetry, both the internal loads (muscle forces and joint reactions) in the gym) nast’s lower limbs and the external reactions from the springboard were evaluated. The calculated vertical reactions from the springboard were then compared to the values assessed using the captured board displacements and its measured elastic behaviors.

3

Możliwości wykorzystania sygnału EMG do sterowania

Nawrocka A., Moszkowski T., Szefer P.

Aktualne Problemy Biomechaniki

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2011

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z. 5

109--114

PL

Celem przeprowadzonych badań było wykazanie użyteczności sygnału EMG (elektromiograficznego) w teorii sterowania. Przeprowadzono badanie stwierdzające powiązanie pomiędzy aktywnością elektryczną mięśni (biceps i triceps brachii) a siłą mięśniową w warunkach statycznych. Opracowano algorytm obróbki danych elektromiograficznych. Wykazano liniową zależność pomiędzy omawianymi wielkościami fizycznymi jednocześnie potwierdzając użyteczność sygnału EMG jako sygnału sterującego. Jednakże zaleca się poszerzenie przeprowadzonych badań o badania dynamiczne skurczu mięśnia.

EN

The aim of the study was to perform sEMG (surfacial electromyography) signal analysis focusing on its applicability for control purposes. Research that aimed at determining the relation between electromuscular activity and static muscular force was conducted. Algorithm for processing of the obtained data was prepared. Linear dependence of the aforementioned quantities was established, therefore the convenience of usage of sEMG as a control signal was confirmed. However, further research on the dynamics of muscular contraction is necessary.

4

Badania modelowe jako narzędzie identyfikacji sił mięśni żwaczowych

Wojnarowski J., Margielewicz J., Chladek W.

Acta Mechanica et Automatica

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2010

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Vol. 4, no. 3

138-142

PL

W pracy przedstawiono metodykę identyfikacji sił mięśni żwaczowych narządu żucia. W zaproponowanym podejściu przeprowadzono ocenę sił mięśniowych narządu żucia, z uwzględnieniem oddziaływania układu nerwowego. Taki sposób prowadzenia badań modelowych jest alternatywnym ujęciem problemu równowagi biostatycznej narządu żucia, w stosunku do dotychczas stosowanych metod obliczeniowych. Dodatkowo podczas przeprowadzonych obliczeń numerycznych uwzględniono ograniczenia, związane z maksymalną wydolnością poszczególnych mięśni żwaczowych. Wyniki obliczeń numerycznych przedstawiono w postaci przebiegów czasowych sił mięśni narządu żucia oraz charakterystyki odwzorowującej wpływ przyłożenia zewnętrznego obciążenia do łuku zębowego żuchwy.

EN

The paper presents a methodology to identify the forces of masticatory muscles. The proposed approach was evaluated masticatory muscle forces, including the impact of the nervous system. This method of research is an alternative model of the problem of balance of masticatory biostatic, with respect to existing methods of calculations. In addition, in carrying out numerical calculations take into account constraints related to the maximum capacity of the individual muscles. The results of numerical calculations are presented in the form of time histories of forces of masticatory muscles and the characteristics of mapping decisions and brokering the impact of application of external load to the arch of the mandible.

5

Moments of muscular strength of knee joint extensors and flexors during physiotherapeutic procedures following anterior cruciate ligament reconstruction in males

Czamara A.

Acta of Bioengineering and Biomechanics

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2008

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Vol. 10, nr 3

37-44

EN

The objective of this paper was to evaluate maximal muscular strength moments of knee joint extensors and flexors in males subjected to physiotherapeutic procedures. 120 males were selected for the study. The first group consisted of 54 patients who underwent a 6 month physiotherapy programme following anterior cruciate ligament (ACL) reconstruction. The control group comprised 54 males without knee joint injuries. The measurement of muscular strength moments was performed in healthy and affected knee joint flexor and extensor muscles postoperatively, during the 13th and 21st week of physiotherapy. The patients' results were next compared with the results obtained in the control group. During the 13th week of physiotherapy, the values of postoperative maximal strength moments in knee joints were significantly lower compared to the results obtained in non-operated limbs and in the control group. The introduction of individual loads adjusted to the course of ACL graft reconstruction and fixation in the bone tunnel resulted in the improvement of maximal muscle strength values in the patients' knee joints from 13 to 21 weeks postoperatively. During the 21st week of physiotherapy, the values of the muscular strengths in the operated limbs were similar to those obtained in non-operated limbs of the patients and in the control group.

6

Adjustable mechanical stability of the balanced tibiofemoral joint in flexion/extension: a novel measuring method in vitro

Knosel M., Kubein-Meeesenburg C., Stuhmer H., Nagerl H., Mansour M., Fanghänel J.

Acta of Bioengineering and Biomechanics

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2004

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Vol. 6, nr 2

3-15

EN

A number of muscles which pull over the tibiofemoral joint (possessing maximally four kinematic degrees of freedom) is larger than necessary in order to produce static equilibria in the physiologic positions of the tibiofemoral joint. Consequently, it should be possible to balance the knee in any arbitrary position by a set of combinations of isotonic muscular forces. The corresponding equilibria of the same flexional status should be differentiated by their degree of stability. Here, we describe a novel method which allows measuring the isotonic stability in flexion/extension in vitro for examining the above theses derived theoretically. By in vitro experiments we could show for the first time that not only a) the same position in flexion can be held in differing static equilibria by correspondingly differing combinations of muscular forces, but also b) the varying degree of stability ranges from stable and indifferent to unstable. These features were related a) to rotations of the resultant muscular force in the main functional plane and b) translations of its force line in parallel to this plane in the direction of abduction/adduction. By that we are able to present a hypothesis of how nature deals with an apparent antagonism of mechanically stable posture and mechanical instability of the joint demanded in the case of fast motion.

7

Changes in power output under the influence of high-intensity training

Norkowski H., Sozański H., Buśko K.

Acta of Bioengineering and Biomechanics

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2003

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Vol. 5, nr 2

89-99

EN

The purpose of this research was to study the effect of high-intensity training programme carried out with a cycle ergometer and in the form of run intervals on physical fitness as measured in a running test and on power output measured in Wingate test. The study was carried out on 24 subjects divided into two groups: group GC (12 persons) did the high-intensity training on a cycle ergometer; group GR (12 persons) did the training in the form of running. The training lasted 8 weeks, 5 times a week in both groups. Running test consisted of a series of four 50 m sprints (25 m + 25 m back) at 15-second intervals. The training improved alactic anaerobic output (the phase of power increase and maintenance phase (IMP) in the Wingate test) by 20.3%- VV[IMP] and 9.1%P[AlMP] in the GC group and by 15.2% W[IMP] and 11.5% P[aIMP] in the GR group, and lactic anaerobic output (the phase of power decrease (DP)) by 9.1% W[DP] and 12.4% P[aDP] for group GC and by 12.8% W[DP] and 10.8% P[[aDP] for group GR. In both groups, a significant improvement in time required to cover the distance in the series of four runs was noted (significantly larger in the group GR than in the group GC). The changes in running times, in terms of percentages, differed significantly between the groups. However, the groups did not differ in terms of their Wingate test results.

8

EMG of arm and forearm muscle activities with regard to handgrip force in relation to upper limb location

Roman-Liu D., Tokarski T.

Acta of Bioengineering and Biomechanics

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2002

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Vol. 4, nr 2

33-47

EN

The aim of the study was to assess the maximum force of the handgrip depending on four different upper limb locations and to analyse the influence of limb location on muscle activities connected with the handgrip force. Five upper limb and shoulder muscles were examined: extensor carpi radialis longus, flexor carpi ulnaris, biceps brachii caput breve, deltoideus pars anterior and trapezius pars descendent. The results showed that the four upper limb locations chosen are differentiated by the value of maximum handgrip force. The study also confirmed the hypothesis that upper limb location influences the component of muscle activity which is responsible for handgrip force exertion. Such a phenomenon was especially obvious in extensor carpi radialis and deltoid pars anterior muscles. The activity of the flexor carpi ulnaris and biceps brachii caput breve muscles although strongly connected with handgrip force exertion was not sensitive to upper limb location.