Relationship Between Knee Extensors Power Output and Vastus Lateralis EMG Activation in Elderly Women: Influence of Mother Wavelet Selection

Purpose:The main objective of this study was to compare frequency parameters produced by six mother wavelets pinpointing the most feasible to investigate electromyographic (EMG) parameters while producing knee extension power in elderly women. The influence of different load conditions in mother wavelet selection and power output were also analyzed.Methods:Thirteen sedentary elderly women (69.3 ± 4.1 years) took part in the study. Participants executed 6 repetitions of 3 load condition (30%, 50% and 70% of the maximal) with the concentric phase of the knee extension movement as quickly as possible. Kinematic data obtained by video analysis, an anthropometric model and Newtonian mechanics were used to calculate knee extensors’ power. A continuous wavelet analysis was used as a time-frequency transformation strategy of vastus lateralis and biceps femoris EMG data and six different mother wavelets were selected: Morlet; 4th, 8th and 44th order Daubechie, 4th order Coiflet and 5th order Symlet.Results:44th order Daubechie showed the highest maximal cross correlation value and no differences were seen between different mother wavelets and cross correlation at zero lag and in the lag variable. Although increased knee extensors peak power at higher loads were seen, no differences in vastus lateralis or biceps femoris root mean square values were obtained.Conclusion:44th order Daubechie mother wavelet was pinpointed as the most suitable to obtain EMG time-frequency parameters. We have also seen that different load conditions do not seem to have an influence on mother wavelet selection.

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Appropriate Mother Wavelets for Continuous Gait Event Detection Based on Time-Frequency Analysis for Hemiplegic and Healthy Individuals

Sensors ◽

10.3390/s19163462 ◽

2019 ◽

Vol 19 (16) ◽

pp. 3462 ◽

Cited By ~ 2

Author(s):

Ning Ji ◽

Hui Zhou ◽

Kaifeng Guo ◽

Oluwarotimi Samuel ◽

Zhen Huang ◽

...

Keyword(s):

Event Detection ◽

Selection Criteria ◽

Tibialis Anterior Muscle ◽

Heel Strike ◽

Mother Wavelet ◽

Time Frequency ◽

Wavelet Selection ◽

Effective Assessment ◽

Mother Wavelets ◽

Selection Of

Gait event detection is a crucial step towards the effective assessment and rehabilitation of motor dysfunctions. Recently, the continuous wavelet transform (CWT) based methods have been increasingly proposed for gait event detection due to their robustness. However, few investigations on determining the appropriate mother wavelet with proper selection criteria have been performed, especially for hemiplegic patients. In this study, the performances of commonly used mother wavelets in detecting gait events were systematically investigated. The acceleration signals from the tibialis anterior muscle of both healthy and hemiplegic subjects were recorded during ground walking and the two core gait events of heel strike (HS) and toe off (TO) were detected from the signal recordings by a CWT algorithm with different mother wavelets. Our results showed that the overall performance of the CWT algorithm in detecting the two gait events was significantly different when using various mother wavelets. By using different wavelet selection criteria, we also found that the accuracy criteria based on time-error minimization and F1-score maximization could provide the appropriate mother wavelet for gait event detection. The findings from this study will provide an insight on the selection of an appropriate mother wavelet for gait event detection and facilitate the development of adequate rehabilitation aids.

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Electromyographic Comparison of Five Lower-Limb Muscles between Single- and Multi-Joint Exercises among Trained Men

Journal of Sports Science and Medicine ◽

10.52082/jssm.2021.56 ◽

2021 ◽

pp. 56-61

Author(s):

Nicolay Stien ◽

Atle Hole Saeterbakken ◽

Vidar Andersen

Keyword(s):

Resistance Training ◽

Vastus Lateralis ◽

Gluteus Maximus ◽

Rectus Femoris ◽

Biceps Femoris ◽

Knee Extension ◽

Knee Extensors ◽

Vastus Medialis ◽

Leg Press ◽

Emg Amplitude

Resistance-training exercises can be classified as either single- or multi-joint exercises and differences in surface electromyography (EMG) amplitude between the two training methods may identify which muscles can benefit from either training modality. This study aimed to compare the surface EMG amplitude of five hip- and knee extensors during one multi-joint (leg press) and two single-joint exercises (knee extension and kickback). Fifteen resistance-trained men completed one familiarization session to determine their unilateral six repetitions maximum (6RM) in the three exercises. During the following experimental session, EMG amplitudes of the vastus lateralis, vastus medialis, rectus femoris, gluteus maximus and biceps femoris of the left leg were measured while performing three repetitions on their respective 6RM loads. The multi-joint exercise leg press produced higher EMG amplitude of the vastus lateralis (ES = 0.92, p = 0.003) than the single-joint exercise knee extension, whereas the rectus femoris demonstrated higher EMG amplitude during the knee extension (ES = 0.93, p = 0.005). The biceps femoris EMG amplitude was higher during the single-joint exercise kickback compared to the leg press (ES = 2.27, p < 0.001), while no significant differences in gluteus maximus (ES = 0.08, p = 0.898) or vastus medialis (ES = 0.056, p = 0.025 were observed between exercises. The difference in EMG amplitude between single- and multi-joint exercises appears to vary depending on the specific exercises and the muscle groups tested. Leg press is a viable and time-efficient option for targeting several hip- and knee extensors during resistance training of the lower limbs, but the single-joint exercises may be preferable for targeting the rectus femoris and biceps femoris.

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Regional and muscle-specific adaptations in knee extensor hypertrophy using flywheel versus conventional weight-stack resistance exercise

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2018-0774 ◽

2019 ◽

Vol 44 (8) ◽

pp. 827-833 ◽

Cited By ~ 4

Author(s):

Tommy R. Lundberg ◽

Maria T. García-Gutiérrez ◽

Mirko Mandić ◽

Mats Lilja ◽

Rodrigo Fernandez-Gonzalo

Keyword(s):

Resistance Exercise ◽

Muscle Hypertrophy ◽

Vastus Lateralis ◽

Knee Extensor ◽

Rectus Femoris ◽

Knee Extension ◽

Knee Extensors ◽

Cross Sectional ◽

Proximal Site ◽

Before And After

This study compared the effects of the most frequently employed protocols of flywheel (FW) versus weight-stack (WS) resistance exercise (RE) on regional and muscle-specific adaptations of the knee extensors. Sixteen men (n = 8) and women (n = 8) performed 8 weeks (2–3 days/week) of knee extension RE employing FW technology on 1 leg (4 × 7 repetitions), while the contralateral leg performed regular WS training (4 × 8–12 repetitions). Maximal strength (1-repetition maximum (1RM) in WS) and peak FW power were determined before and after training for both legs. Partial muscle volume of vastus lateralis (VL), vastus medialis (VM), vastus intermedius (VI), and rectus femoris (RF) were measured using magnetic resonance imaging. Additionally, quadriceps cross-sectional area was assessed at a proximal and a distal site. There were no differences (P > 0.05) between FW versus WS in muscle hypertrophy of the quadriceps femoris (8% vs. 9%), VL (10% vs. 11%), VM (6% vs. 8%), VI (5% vs. 5%), or RF (17% vs. 17%). Muscle hypertrophy tended (P = 0.09) to be greater at the distal compared with the proximal site, but there was no interaction with exercise method. Increases in 1RM and FW peak power were similar across legs, yet the increase in 1RM was greater in men (31%) than in women (20%). These findings suggest that FW and WS training induces comparable muscle-specific hypertrophy of the knee extensors. Given that these robust muscular adaptations were brought about with markedly fewer repetitions in the FW compared with WS, it seems FW training can be recommended as a particularly time-efficient exercise paradigm.

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Force fluctuations are modulated by alternate muscle activity of knee extensor synergists during low-level sustained contraction

Journal of Applied Physiology ◽

10.1152/japplphysiol.00418.2004 ◽

2004 ◽

Vol 97 (6) ◽

pp. 2121-2131 ◽

Cited By ~ 47

Author(s):

Motoki Kouzaki ◽

Minoru Shinohara ◽

Kei Masani ◽

Tetsuo Fukunaga

Keyword(s):

Correlation Coefficient ◽

Muscle Activity ◽

High Frequency ◽

Vastus Lateralis ◽

Frequency Component ◽

Knee Extension ◽

Voluntary Contraction ◽

High Frequency Component ◽

Knee Extensors ◽

Force Fluctuations

The study examined the hypothesis that altered synergistic activation of the knee extensors leads to cyclic modulation of the force fluctuations. To test this hypothesis, the force fluctuations were investigated during sustained knee extension at 2.5% of maximal voluntary contraction force for 60 min in 11 men. Surface electromyograms (EMG) were recorded from the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) muscles. The SD of force and average EMG (AEMG) of each muscle were calculated for 30-s periods during alternate muscle activity. Power spectrum of force was calculated for the low- (≤3 Hz), middle- (4–6 Hz), and high-frequency (8–12 Hz) components. Alternate muscle activity was observed between RF and the set of VL and VM muscles. The SD of force was not constant but variable due to the alternate muscle activity. The SD was significantly greater during high RF activity compared with high VL and VM activity ( P < 0.05), and the correlation coefficient between the SD and AEMG was significantly greater in RF [0.736 (SD 0.095), P < 0.05] compared with VL and VM. Large changes were found in the high-frequency component. During high RF activity, the correlation coefficient between the SD and high-frequency component [0.832 (SD 0.087)] was significantly ( P < 0.05) greater compared with other frequency components. It is suggested that modulations in knee extension force fluctuations are caused by the unique muscle activity in RF during the alternate muscle activity, which augments the high-frequency component of the fluctuations.

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Can Hip Joint Position affect Quadriceps Muscle Responses during Knee Extension Exercise?

International Journal of Sports Medicine ◽

10.1055/a-1179-8374 ◽

2020 ◽

Vol 41 (13) ◽

pp. 929-935

Author(s):

Denis César Leite Vieira ◽

Marco Aurélio Araujo Dourado ◽

Lucas Ugliara ◽

Joao Luiz Quagliotti Durigan ◽

Brad J. Schoenfeld ◽

...

Keyword(s):

Vastus Lateralis ◽

Muscle Thickness ◽

Rectus Femoris ◽

Peak Torque ◽

Quadriceps Muscle ◽

Knee Extension ◽

Knee Extensors ◽

Work Output ◽

Before And After ◽

Knee Extension Exercise

AbstractThis study investigated the acute effects of seated and supine knee extension exercise on muscle swelling, torque, and work output. Twelve resistance-trained men performed two isokinetic concentric-only knee-extension training protocols at different hip positions in a counter-balanced order. They completed the knee extension exercise in the seated (hip angle at 85°) and supine (hip angle at 180°) positions. The torque and work output were assessed during each set. Moreover, muscle thickness of the middle and proximal vastus lateralis and rectus femoris were evaluated before and after each protocol and used as an indicator of muscle swelling. Middle rectus femoris and proximal vastus lateralis thickness increased significantly (p=0.01) with no difference between exercise variations. However, the middle vastus lateralis thickness increased (p=0.01) only after the seated knee extension exercise (~7%). Knee extensors’ peak torque and work output were approximately 8% higher (p=0.04) in the seated when compared to the supine hip position. There was a similar decrease in torque and work output throughout both protocols (p=0.98). In conclusion, seated knee extension exercises produced greater torque, work output, and muscle swelling in the vastus lateralis when compared to the supine knee extension exercise.

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Muscle coordination in cycling: effect of surface incline and posture

Journal of Applied Physiology ◽

10.1152/jappl.1998.85.3.927 ◽

1998 ◽

Vol 85 (3) ◽

pp. 927-934 ◽

Cited By ~ 78

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.

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Muscle Coactivation Before and After the Impact Phase of Running Following Isokinetic Fatigue

Journal of Athletic Training ◽

10.4085/1062-6050-46.1.11 ◽

2011 ◽

Vol 46 (1) ◽

pp. 11-19 ◽

Cited By ~ 19

Author(s):

Eleftherios Kellis ◽

Andreas Zafeiridis ◽

Ioannis G. Amiridis

Keyword(s):

Muscle Activation ◽

Biceps Femoris ◽

Knee Extension ◽

Knee Extensors ◽

Training Experience ◽

Cross Sectional ◽

Muscle Activation Patterns ◽

Strength Capacity ◽

Before And After ◽

The Impact

Abstract Context: The effects of fatigue on impact loading during running are unclear, with some authors reporting increased impact forces and others reporting decreased forces. Objective: To examine the effects of isokinetic fatigue on muscle cocontraction ratios about the knee and ankle during running. Design: Cross-sectional study. Setting: Neuromechanics laboratory. Patients or Other Participants: Female middle-distance runners (age = 21.3 ± 1.93 years) with at least 5 years of training experience. Intervention(s): Participants ran on the treadmill at 3.61 m/s before and immediately after the fatigue protocol, which consisted of consecutive, concentric knee extension-flexion at 120°/s until they could no longer produce 30% of the maximum knee-extension moment achieved in the familiarization session for 3 consecutive repetitions. Main Outcome Measure(s): Electromyographic (EMG) amplitude of the vastus medialis (VM), biceps femoris (BF), gastrocnemius (GAS), and tibialis anterior (TA) was recorded using surface electrodes. Agonist∶antagonist EMG ratios for the knee (VM∶BF) and ankle (GAS∶TA) were calculated for the preactivation (PR), initial loading response (LR1), and late loading response (LR2) phases of running. Hip-, knee-, and ankle-joint angular displacements at initial foot contact were obtained from 3-dimensional kinematic tracings. Results: Fatigue did not alter the VM∶BF EMG ratio during the PR phase (P > .05), but it increased the ratio during the LR1 phase (P < .05). The GAS∶TA EMG ratio increased during the LR1 phase after fatigue (P < .05) but remained unchanged during the PR and LR2 phrases (P > .05). Conclusions: The increased agonist EMG activation, coupled with reduced antagonist EMG activation after impact, indicates that the acute decrease in muscle strength capacity of the knee extensors and flexors results in altered muscle-activation patterns about the knee and ankle before and after foot impact.

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Characterization of kinesiological patterns of the frontal kick, mae-geri, in karate experts and non-karate practitioners

Revista de Artes Marciales Asiáticas ◽

10.18002/rama.v9i1.1163 ◽

2014 ◽

Vol 9 (1) ◽

pp. 20 ◽

Cited By ~ 3

Author(s):

António M. VencesBrito ◽

Marco A. Colaço Branco ◽

Renato M. Cordeiro Fernandes ◽

Mário A. Rodrigues Ferreira ◽

Orlando J. S. M. Fernandes ◽

...

Keyword(s):

Muscle Activity ◽

Vastus Lateralis ◽

Plantar Flexion ◽

Neuromuscular Control ◽

Rectus Femoris ◽

Biceps Femoris ◽

Knee Extension ◽

Maximum Speed ◽

Ballistic Performance ◽

The Impact

Presently, coaches and researchers need to have a better comprehension of the kinesiological parameters that should be an important tool to support teaching methodologies and to improve skills performance in sports. The aim of this study was to (i) identify the kinematic and neuromuscular control patterns of the front kick (mae-geri) to a fixed target performed by 14 experienced karate practitioners, and (ii) compare it with the execution of 16 participants without any karate experience, allowing the use of those references in the analysis of the training and learning process. Results showed that the kinematic and neuromuscular activity during the kick performance occurs within 600 ms. Muscle activity and kinematic analysis demonstrated a sequence of activation bracing a proximal-to-distal direction, with the muscles presenting two distinct periods of activity (1, 2), where the karateka group has a greater intensity of activation – root mean square (RMS) and electromyography (EMG) peak – in the first period on Rectus Femoris (RF1) and Vastus Lateralis (VL1) and a lower duration of co-contraction in both periods on Rectus Femoris-Biceps Femoris and Vastus Lateralis-Biceps Femoris (RF-BF; VL-BF). In the skill performance, the hip flexion, the knee extension and the ankle plantar flexion movements were executed with smaller difference in the range of action (ROA) in the karateka group, reflecting different positions of the segments. In conclusion, it was observed a general kinesiological pattern, which was similar in karateka and non-karateka practitioners. However, in the karateka group, the training induces a specialization in the muscle activity reflected in EMG and kinematic data, which leads to a better ballistic performance in the execution of the mae-geri kick, associated with a maximum speed of the distal segments, reached closer to the impact moment, possibly representing more power in the contact.

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The Association of Multiple Gene Variants with Ageing Skeletal Muscle Phenotypes in Elderly Women

Genes ◽

10.3390/genes11121459 ◽

2020 ◽

Vol 11 (12) ◽

pp. 1459

Author(s):

Praval Khanal ◽

Lingxiao He ◽

Adam J. Herbert ◽

Georgina K. Stebbings ◽

Gladys L. Onambele-Pearson ◽

...

Keyword(s):

Skeletal Muscle ◽

Elderly Women ◽

Biceps Brachii ◽

Vastus Lateralis ◽

Elbow Flexion ◽

Knee Extension ◽

Nucleotide Polymorphisms ◽

Cross Sectional ◽

Caucasian Women ◽

Fto Rs9939609

There is a scarcity of studies that have investigated the role of multiple single nucleotide polymorphisms (SNPs) on a range of muscle phenotypes in an elderly population. The present study investigated the possible association of 24 SNPs with skeletal muscle phenotypes in 307 elderly Caucasian women (aged 60–91 years, 66.3 ± 11.3 kg). Skeletal muscle phenotypes included biceps brachii thickness, vastus lateralis cross-sectional areas, maximal hand grip strength, isometric knee extension and elbow flexion torque. Genotyping for 24 SNPs, chosen on their skeletal muscle structural or functional links, was conducted on DNA extracted from blood or saliva. Of the 24 SNPs, 10 were associated with at least one skeletal muscle phenotype. HIF1A rs11549465 was associated with three skeletal muscle phenotypes and PTK2 rs7460 and ACVR1B rs10783485 were each associated with two phenotypes. PTK2 rs7843014, COL1A1 rs1800012, CNTF rs1800169, NOS3 rs1799983, MSTN rs1805086, TRHR rs7832552 and FTO rs9939609 were each associated with one. Elderly women possessing favourable genotypes were 3.6–13.2% stronger and had 4.6–14.7% larger muscle than those with less favourable genotypes. These associations, together with future work involving a broader range of SNPs, may help identify individuals at particular risk of an age-associated loss of independence.

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Behavior of coactive muscles during fatigue

Journal of Applied Physiology ◽

10.1152/jappl.1993.74.1.170 ◽

1993 ◽

Vol 74 (1) ◽

pp. 170-175 ◽

Cited By ~ 110

Author(s):

J. A. Psek ◽

E. Cafarelli

Keyword(s):

Time Course ◽

Vastus Lateralis ◽

Biceps Femoris ◽

Close Correlation ◽

Voluntary Contraction ◽

Knee Extensors ◽

Emg Activity ◽

Short Period ◽

Force Time ◽

Knee Flexors

Coactivation is antagonist muscle activity that occurs during voluntary contraction. Recently, we showed that the extent of coactivity in the knee flexors decreases after a short period of resistance training of the knee extensors (8). The purpose of the present experiment was to study the time course of coactivation in the knee flexors during fatigue of the knee extensors. Ten male subjects performed repeated submaximal static leg extensions in a low-intensity long-duration and a high-intensity short-duration fatigue protocol until they could no longer produce the required force [time limit of endurance (Tlim)]. Maximal voluntary contraction (MVC), submaximal force, and surface electromyographic (EMG) activity were measured periodically. Vastus lateralis EMG increased progressively during fatigue of the extensor muscles (P < 0.05), resulting in a 38% change from control at Tlim. Biceps femoris EMG, which was our measure of coactivation, also increased by approximately 60% at Tlim in each protocol (P < 0.05). These observations lead us to conclude that a small but significant force loss during repeated static contractions to Tlim is due to an increase in antagonist activity. Moreover, the close correlation between the antagonist and agonist EMG supports the notion of a "common drive" to both motoneuron pools (10).

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