scholarly journals Acute effect of partial body weight suspension on the level of cocontraction and gait biomechanics in women with knee osteoarthritis

2020 ◽  
Vol 33 ◽  
Author(s):  
Deborah Hebling Spinoso ◽  
Marcus Vinicius de Sobral Carvalho ◽  
Ana Carolina de Souza Trentin ◽  
Marcelo Tavella Navega
Keyword(s):  
Body Weight ◽  
Knee Osteoarthritis ◽  
Vastus Lateralis ◽  
Functional Limitation ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Treadmill Running ◽  
Significance Level ◽  
Significant Difference ◽  
Partial Body

Abstract Introduction: Knee osteoarthritis (OAK) is one of the most prevalent rheumatic diseases in the population, characterized by functional limitation and gait difficulties with profound clinical relevance, as walking is the most frequently performed daily activity. These functional limitations may be more pronounced when the disease is associated with obesity. Objective: To investigate the effect of different body weight suspension percentages on gait biomechanical variables and co-contraction percentages in women with OAK. Method: Fourteen women aged 50-75 years, with a body mass index between 26 and 35 and radiological diagnosis of OAK participated in the study. On the first day, anamnesis and familiarization with gait on the treadmill was performed. On the second day, treadmill gait assessment was performed using partial body weight support (SPPC) in three conditions-15%, 30%, and 45% suspension. During the evaluation, electromyographic and kinematic data were collected. The variables analyzed were percentage of hip (gluteus maximus/rectus femoris), knee (femoral biceps/vastus lateralis), and ankle (anterior tibial/lateral gastrocnemius), and length and step widths. A one-way analysis of variance was conducted, with a significance level of p < 0.05. Results: There was no significant difference in the length and step width and the level of co-contraction between the running conditions analyzed. Conclusion: Body weight suspension using SPPC during treadmill running did not alter the biomechanical variables of the gait of women with OAK.

Muscle coordination in cycling: effect of surface incline and posture

1998 ◽  
Vol 85 (3) ◽  
pp. 927-934 ◽  
Author(s):  
Li Li ◽  
Graham E. Caldwell
Keyword(s):  
Lower Extremity ◽  
High Speed ◽  
Vastus Lateralis ◽  
Activity Patterns ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Knee Extensors ◽  
Emg Activity ◽  
Muscle Coordination

The purpose of the present study was to examine the neuromuscular modifications of cyclists to changes in grade and posture. Eight subjects were tested on a computerized ergometer under three conditions with the same work rate (250 W): pedaling on the level while seated, 8% uphill while seated, and 8% uphill while standing (ST). High-speed video was taken in conjunction with surface electromyography (EMG) of six lower extremity muscles. Results showed that rectus femoris, gluteus maximus (GM), and tibialis anterior had greater EMG magnitude in the ST condition. GM, rectus femoris, and the vastus lateralis demonstrated activity over a greater portion of the crank cycle in the ST condition. The muscle activities of gastrocnemius and biceps femoris did not exhibit profound differences among conditions. Overall, the change of cycling grade alone from 0 to 8% did not induce a significant change in neuromuscular coordination. However, the postural change from seated to ST pedaling at 8% uphill grade was accompanied by increased and/or prolonged muscle activity of hip and knee extensors. The observed EMG activity patterns were discussed with respect to lower extremity joint moments. Monoarticular extensor muscles (GM, vastus lateralis) demonstrated greater modifications in activity patterns with the change in posture compared with their biarticular counterparts. Furthermore, muscle coordination among antagonist pairs of mono- and biarticular muscles was altered in the ST condition; this finding provides support for the notion that muscles within these antagonist pairs have different functions.

scholarly journals Differences in Simulated EMG Activities between a Non-Rotational Shot and an Ordinary Instep Kick Identified by Principal Component Analysis

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 154
Author(s):  
Tasuku Miyoshi ◽  
Yasuhisa Kamada ◽  
Yoshiyuki Kobayashi
Keyword(s):  
Principal Component Analysis ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Principal Component ◽  
Rectus Femoris ◽  
Component Analysis ◽  
Vastus Intermedius ◽  
Longus Muscle ◽  
Instep Kick ◽  
Tensor Fasciae Latae

The aim of this study was to clarify the major differences in the electromyographic (EMG) activities in the hip joint required to achieve a non-rotational (NR) shot as compared with an instep kick from the spatiotemporal data. For this purpose, simulated EMG activities obtained from NR shots and instep kicks were analyzed using principal component analysis (PCA). The PCA was conducted using an input matrix constructed from the time-normalized average and the standard deviation of the EMG activities (101 data x (15 muscles; iliacus, gluteus maximus, rectus femoris, biceos femoris, vastus lateralis, vastus medialis, vastus intermedius, semimembranosus, semitendinosus, sartorius, tensor fasciae latae muscle, adductor magnus muscle, adductor longus muscle, gasctrocnemius, and tibialis anterior)). The PCA revealed that the 3rd, 4th and 8th principal component vectors (PCVs) of the 10 generated PCVs were related to achieving the NR shot (p < 0.05).

Training-induced alterations of the fatty acid profile of rabbit muscles

2002 ◽  
Vol 50 (3) ◽  
pp. 357-364 ◽  
Author(s):  
Éva Szabó ◽  
R. Romvári ◽  
Hedvig Fébel ◽  
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Fatty Acid Profile ◽  
Acid Composition ◽  
Vastus Lateralis ◽  
Total Activity ◽  
Treadmill Running ◽  
Control Group ◽  
Daily Routine ◽  
Significant Difference

The present study was designed to investigate whether meat-type rabbits are able to perform treadmill running as a daily routine exercise, and if so, whether the exercise induces specific proportional changes in the fatty acid composition of their muscles. After a four-week training period 8-week-old rabbits were slaughtered and the total activity of plasma lactate dehydrogenase was measured, showing a significant difference between the exercised and control groups (429 ± 126 IU/l vs. 639 ± 203 IU/l). Furthermore the fatty acid composition of m. longissimus dorsi (MLD) and m. vastus lateralis (MVL) was determined by means of gas chromatography. Exercise increased the proportions of oleic acid (C18:1 n-9) in both MLD and MVL as compared to the control group. However, the level of stearic (C18:0) and arachidonic (C20:4 n-6) acids significantly decreased in the MVL after the exercise. Changes in the fatty acid profile resulting from the physically loaded condition were of the same tendency in both muscles, adding that the MVL might have been exposed to the exercise more intensively; alterations there occurred in a more pronounced manner. Based on the inference that the composition of membrane structure was also affected, these alterations may have important consequences on meat quality.

scholarly journals THE EFFECT OF LOCAL VIBROSTIMULATION ON ELECTROMYOGRAPHY PARAMETERS IN ROWERS

2017 ◽  
Vol 3 ◽  
pp. 325
Author(s):  
Kalvis Ciekurs ◽  
Viesturs Krauksts ◽  
Daina Krauksta ◽  
Baiba Smila ◽  
Aivars Kaupuzs
Keyword(s):  
Biceps Brachii ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Erector Spinae ◽  
Mathematical Statistics ◽  
Triceps Brachii ◽  
The Mean ◽  
Moving Speed

Local vibrostimulation (further in text - LV) is innovation as a part of training method that helps athletes to regain the power and get ready for next training faster. There are many discussions about how to increase moving speed in rowers. Many scientists research the possibilities of increasing moving speed in this sport. The following methods were used in the study: tests – Concept-2, LV manipulations, electromyography and mathematical statistics. The electromyography was made with Biometric LTD. LV manipulations were done to the muscles erector spinae, latisimus dorsi, teres major, teres minor, trapezius, infraspinatus, deltoideus, slenius capitis, triceps brachii, gluteus maximus, semitendinosus, biceps femoris, semimembranosus, castrocnemius, tendo calcaneus, rectus femoris, vastus lateralis, tensor fascia latae, vastus medialis, sarterius, ligamentum patellae, tibialis anterior, rectus abdominis, pectoralis major and biceps brachii. We using 100 Hz frequency, 2 – 4 mm amplitude and different pressure on the muscles. The total LV application time was 5 to 20  min. The obtained data were processed using mathematical statistics. The results: having stated the result difference before LV and after it. The results testify significant improvement of Concept-2 tests results and electromyography results, what is showed by the difference of the mean results. Comparing the results of the rowers of EG and CG they have differences in the left side muscle latissimus dorsi after the t-test where p>0.05, but stating the percentage of the mean result difference of this muscle it was found out that p>0.05 what also shows significant changes in the muscle biopotential (mV).

scholarly journals Intervenção para o controle do peso corporal de adolescentes, utilizando videogames ativos: um estudo piloto

2018 ◽  
Vol 16 (2) ◽  
pp. 51-55
Author(s):  
Catiana Leila Possamai Romanzini ◽  
Beatriz Lara Leile Pavanello ◽  
Kessi Cassiane Iarosz ◽  
Vinícius Zandonadi Pires
Keyword(s):  
Body Weight ◽  
Pilot Study ◽  
Waist Circumference ◽  
Video Games ◽  
Anthropometric Measures ◽  
Significance Level ◽  
Active Video Games ◽  
Significant Difference ◽  
Active Video ◽  
Before And After

Estratégias de intervenção que utilizam exergames que visam o estímulo à prática de atividade física, bem como à redução do tempo em comportamento sedentário, parecem ser caminhos promissores para lidar com o aumento das taxas de obesidade. Este foi o intuito do Projeto de Extensão “Exergaming para a saúde: intervenção para o controle do peso corporal em adolescentes utilizando videogames ativos”, contemplado com fomento do MEC/PROEXT no ano de 2013. O objetivo do estudo foi verificar o efeito de uma intervenção de oito semanas com videogames ativos sobre variáveis relacionadas ao peso corporal de adolescentes. Foi realizado um estudo piloto de intervenção de oito semanas com duração de 60 minutos por sessão, com uso dos exergames. Participaram do estudo oito escolares, com média de idade de 11,5±0,5 anos. Medidas antropométricas antes e após a intervenção foram realizadas. Utilizou-se a estatística descritiva e o teste t pareado, no SPSS 20.0 com nível de significância de p0,05. Observou-se que houve diferença estatisticamente significativa somente na circunferência de cintura (cm) com redução de 2,8 cm (p = 0,028). As demais variáveis analisadas não foram diferentes. O estudo piloto de uma intervenção de oito semanas com videogames ativos demonstrou possibilidade de redução de medidas antropométricas, tais como a circunferência de cintura dos adolescentes. Sugere-se que novos estudos com exergames tenham enfoque neste desfecho em um período mais longo de intervenção e/ou com maior número de sessões durante a semana.ABSTRACT. Intervention for the control of body weight in adolescents using active video games: a pilot study. Intervention strategies that use exergames that aim to stimulate the practice of physical activity, as well as the reduction of the time in sedentary behavior, through promising ways to deal with the increase of obesity rates. This is the way of Extension Project “Exergaming for health: intervention for the control of body weight in adolescents using active video games”, with fomentation of MEC/PROEXT in 2013. The aim of this study was to verify the effect of an eight-week intervention with active video games on variables related to adolescent body weight. An eight-week intervention study with a duration of 60 minutes per session, with use of exergames was performed. Eight schoolchildren participated, with mean age of 11.5±0.5 years. Anthropometric measures before and after the intervention were performed. Descriptive statistics and the non-parametric equivalent of paired t-test were used in SPSS 20.0 with significance level of p0.05. It was observed that there was a significant difference only in waist circumference (cm) with a reduction of 2.8 cm (p = 0.028). The other variables analyzed were not different. The pilot study of an eight-week intervention with active videogames demonstrated the possibility of reducing anthropometric measures, such as the waist circumference of adolescents. We suggested that new studies with exergames focus on this outcome over a longer period of intervention and/or with a larger number of sessions during the week. 

EMG Activity of Six Muscles and VMO:VL Ratio Determination during a Maximal Squat Exercise

1995 ◽  
Vol 4 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Peter A. Schaub ◽  
Teddy W. Worrell
Keyword(s):  
Lower Extremity ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Emg Activity ◽  
Kinetic Chain ◽  
Maximal Voluntary Isometric Contraction ◽  
Knee Rehabilitation ◽  
Intraclass Correlations ◽  
Ratio Determination

During knee rehabilitation, squats are a commonly used closed kinetic chain exercise. We have been unable to locate data reporting electromyographic (EMG) activity of lower extremity musculature during maximal effort squats and the contribution of gastrocnemius and gluteus maximus muscles. Therefore, the purposes of this study were (a) to quantify EMG activity of selected lower extremity muscles during a maximal isometric squat and during a maximal voluntary isometric contraction (MVIC), and (b) to determine ratios between the vastus medialis oblique (VMO) and vastus lateralis (VL) during maximal isometric squat and MVIC testing. Twenty-three subjects participated in a single testing session. Results are as follows: intraclass correlations for MVIC testing and squat testing ranged from .60 to .80 and .70 to .90, respectively. Percentage MVIC during the squat was as follows: rectus femoris 40 ± 30%, VMO 90 ± 70%, VL 70 ±40%, hamstrings 10 ± 10%, gluteus maximus 20 ± 10%, and gastrocnemius 30 ± 20%. No statistical difference existed in VMO:VL ratios during MVIC or squat testing. We conclude that large variations in muscle recruitment patterns occur between individuals during isometric squats.

Mono- and Biarticular Muscle Activity during Jumping in Different Directions

2003 ◽  
Vol 19 (3) ◽  
pp. 205-222 ◽  
Author(s):  
Stephanie L. Jones ◽  
Graham E. Caldwell
Keyword(s):  
Muscle Activity ◽  
Vastus Lateralis ◽  
Activity Patterns ◽  
Center Of Mass ◽  
Reaction Force ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Jump Condition ◽  
Activity Level ◽  
Biarticular Muscle

This study examined the role of mono- and biarticular muscles in control of countermovement jumps (CMJ) in different directions. It was hypothesized that monoarticular muscles would demonstrate the same activity regardless of jump direction, based on previous studies which suggest their role is to generate energy to maximize center-of-mass (CM) velocity. In contrast, biarticular activity patterns were expected to change to control the direction of the ground reaction force (GRF) and CM velocity vectors. Twelve participants performed maximal CMJs in four directions: vertical, forward, intermediate forward, and backward. Electromyographical data from 4 monoarticular and 3 biarticular lower extremity muscles were analyzed with respect to segmental kinematics and kinetics during the jumps. The biarticular rectus femoris (RF), hamstrings (HA), and gastrocnemius all exhibited changes in activity magnitude and pattern as a function of jump angle. In particular, HA and RF demonstrated reciprocal trends, with HA activity increasing as jump angle changed from backward to forward, while RF activity was reduced in the forward jump condition. The vastus lateralis and gluteus maximus both demonstrated changes in activity patterns, although the former was the only monoarticular muscle to change activity level with jump direction. Mono- and biarticular muscle activities therefore did not fit with their hypothesized roles. CM and segmental kinematics suggest that jump direction was initiated early in the countermovement, and that in each jump direction the propulsion phase began from a different position with unique angular and linear momentum. Issues that dictated the muscle activity patterns in each jump direction were the early initiation of appropriate forward momentum, the transition from countermovement to propulsion, the control of individual segment rotations, the control of GRF location and direction, and the influence of the subsequent landing.

scholarly journals EFFECTS OF TRADITIONAL STRENGTH TRAINING AND OLYMPIC WEIGHTLIFTING IN HANDBALL PLAYERS

2019 ◽  
Vol 25 (3) ◽  
pp. 230-234
Author(s):  
Bárbara Slovak ◽  
Leandro Carvalho ◽  
Fernando Rodrigues ◽  
Paulo Costa Amaral ◽  
Deborah Duarte Palma ◽  
...  
Keyword(s):  
Strength Training ◽  
Vastus Lateralis ◽  
Vertical Jump ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Level Of Evidence ◽  
Jump Performance ◽  
Plyometric Exercise ◽  
Regular Training

ABSTRACT Introduction Olympic weightlifting has been adopted as an alternative to plyometric exercise. However, the effects of these exercises in young handball athletes is not known. Objective To compare the effect of Olympic weightlifting training with traditional strength training on jumping, squatting and acceleration performance in young handball athletes. Ten female handball athletes were evaluated. After six weeks of regular training, the athletes underwent eight weeks of training specifically designed for the survey, with equivalence of the total volume of training and differences in the means used. The evaluations were performed after six weeks of regular training (Baseline), after four weeks of traditional strength training and after four weeks of Olympic weightlifting. Vertical Jumps with and without movement of the arms, acceleration of 10 m, 20 m and 30 m, and 1RM in squatting were quantified. Results Increases (p<0.05) were observed in accelerations and squatting in the Olympic weightlifting and in squatting in the traditional strength training. Differences in coordination, time to activation of the gastrocnemius, vastus lateralis, rectus femoris, biceps femoris and gluteus maximus, peak force and power and rate of force development between the jumps and exercises used in the training are hypotheses to be considered for the different responses adaptations found in the jumps. Conclusion The Olympic weightlifting training resulted in an increase in accelerations and strength, but not in vertical jump performance in young handball athletes. Level of Evidence I; Prognostic Studies - Investigation of the Effect of a Patient Characteristic on Disease Outcome.

Analysis of Lower Limb Muscle Function in Ergometer Rowing

1988 ◽  
Vol 4 (4) ◽  
pp. 315-325 ◽  
Author(s):  
J.-M. John Wilson ◽  
D. Gordon E. Robertson ◽  
J. Peter Stothart
Keyword(s):  
Lower Limb ◽  
Muscle Function ◽  
Tibialis Anterior ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Peak Force ◽  
Lower Limb Muscle ◽  
Limb Muscle

In an effort to seek further understanding of lower limb muscle function in the rowing movement, an electromyographic analysis was undertaken of rowers rowing on a Gjessing ergometer. A strain gauged transducer was inserted in the ergometer linkage between handle and flywheel to detect pulling force. Electrodes were placed on the following lower limb muscles: gluteus maximus, biceps femoris, rectus femoris, vastus lateralis, gastrocnemius, and tibialis anterior. Linear envelope electromyograms from each muscle and the force signals were sampled synchronously at 50 Hz. The results indicated that all six muscles were active from catch to finish of the drive phase. Biceps femoris, gluteus maximus, gastrocnemius, and vastus lateralis all began their activity at or just prior to catch and reached maximal excitation near peak force of the stroke. Rectus femoris and tibialis anterior activity began prior to the catch and reached maximal excitation subsequent to peak force. The coactivation of the five leg muscles, of which four were biarticular, included potentially antagonistic actions that would cancel each other’s effects. Clearly, however, other explanations must be considered. Both gastrocnemius and biceps femoris have been shown to act as knee extensors and may do so in the case of the rowing action. Furthermore, rectus femoris may act with unchanging length as a knee extensor by functioning as a rigid link between the pelvis and tibia. In this manner, energy created by the hip extensors is transferred across the knee joint via the isometrically contracting rectus femoris muscle.

Sign in / Sign up

Export Citation Format

Share Document