scholarly journals The Effect of Repetitive Rugby Scrummaging on Force Output and Muscle Activity

2017 ◽  
Vol 01 (03) ◽  
pp. E89-E93 ◽  
Author(s):  
Darryl Cochrane ◽  
Keegan Harnett ◽  
Nicolas Lopez-Villalobos ◽  
Jeremy Hapeta
Keyword(s):  
Force Production ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Mean Amplitude ◽  
Erector Spinae ◽  
Medial Gastrocnemius ◽  
Median Frequency ◽  
Force Output ◽  
Subsequent Performance

AbstractDuring rugby scrummaging, front row forwards encounter high levels of force that has been suggested to cause transient fatigue and is likely to reduce subsequent performance. However, little is known about the effect of repetitive scrummaging on force output and onset of fatigue. Twelve male front row forwards (21.5±2.3 yr; height 185.7±4.4 cm; body mass 108.5±7.1 kg) each performed three sets of five maximal-effort isometric scrums for 10 s, with 40 s rest separating each repetition; 2 min recovery was provided between each set. Force output and electromyography (EMG) of the right medial gastrocnemius (MG), biceps femoris (BF), gluteus maximus (GM), erector spinae (ES), rectus abdominis (RA), external oblique (EO), internal oblique (IO), and rectus femoris (RF) were assessed. There was no significant force decrement from performing 15 scrums and no fatigue was detected from EMG median frequency and mean amplitude. For training and practice purposes, coaches and trainers can be confident that 15 individual repetitive static scrums against a machine are unlikely to cause a reduction in force production and promote fatigue. However, the effect of rugby-related activities in conjunction with scrummaging requires further research to determine if transient fatigue is causal to scrummaging for subsequent performance.

The Effect of Strength Shoes on Muscle Activity during Quiet Standing

2000 ◽  
Vol 16 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Karl Frank ◽  
Richard V. Baratta ◽  
Moshe Solomonow ◽  
Mackie Shilstone ◽  
Kevin Riché
Keyword(s):  
Center Of Pressure ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Surface Emg ◽  
Erector Spinae ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Quiet Standing ◽  
Emg Activity

The goal of this work was to study the effect of Strength Shoes on the activity of leg and postural muscles to gain insight into the mechanisms by which the shoes may improve athletic performance. Surface EMG signals were obtained from the tibialis anterior, medial gastrocnemius, rectus femoris, biceps femoris, gluteus maximus, and erector spinae of 18 healthy athletic subjects. The subjects stood quietly while wearing either normal athletic shoes or Strength Shoes. EMG root mean square value was compared in each muscle using trimmed paired t tests. Significant (p < .002) increases in EMG activity were found in the MG, TA, GM, and ES muscles when the subjects were wearing Strength Shoes as compared to normal shoes. These changes served to stiffen the ankle, counteracting the dorsiflexion moment created by the shoes, and to support an anterior leaning posture, which compensates for the anterior shift in center of pressure. No significant changes were detected in the activities of RF or BF muscles. Using Strength Shoes increased activity in the triceps surae complex and in other muscles mat support the changes in postural requirements caused by the anterior shift in center of pressure.

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 The importance of functional diagnostics in preventing and rehabilitating gymnast injuries with the assistance of the tensiomyography (TMG) method: a case study

2015 ◽  
Vol 7 (4) ◽  
pp. 29-36
Author(s):  
ALMIR ATIKOVIĆ ◽  
MITIJA SAMARDŽIJA PAVLETIĆ ◽  
MUHAMED TABAKOVIĆ
Keyword(s):  
Exercise Program ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Muscle Stiffness ◽  
Erector Spinae ◽  
Radial Deformation ◽  
Lumbar Region ◽  
The Time Domain ◽  
Two Stages

Background: The tensiomyography assessment offers information, in the time domain, regarding the following parameters: maximal radial deformation or displacement of the muscle belly, contraction time, reaction time, sustain time and relaxation time. The aim of this study is to provide information about muscle stiffness, the mechanic and contractile properties using the TMG muscles after 4 months rehabilitation process gymnast. Material/Methods: Four muscles were chosen on both lateral sides involved in artistic gymnastics performance: biceps femoris, erector spinae, gluteus maximus, rectus femoris. The testing sample in this study was taken from the Croatian Republic’s senior representative who won third place 2012 and eighth place 2015 in the floor routine at the ECh. Results: The testing and measuring took place after the subject injured the lumbar region of the spinal cord and after a four-month prevention exercise program. After the first two stages of measuring, the differences can be found in: BF: -7%; ES: +17%; GM: -8%; RF: +11%. Generally speaking, a dependent t-test did not reveal significant differences in between the first and second measurement point (t = 1.941, df = 39, P < 0.059). Conclusions: This approach can be used to investigate top athletes who are in the process of training for muscle recovery as a result of skeletal muscle injury.

scholarly journals Acute Responses of Core Muscle Activity during Bridge Exercises on the Floor vs. the Suspension System

2021 ◽  
Vol 18 (11) ◽  
pp. 5908
Author(s):  
Jim T. C. Luk ◽  
Freeman K. C. Kwok ◽  
Indy M. K. Ho ◽  
Del P. Wong
Keyword(s):  
Muscle Activity ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Suspension System ◽  
Erector Spinae ◽  
Healthy Male ◽  
Neuromuscular Activation ◽  
Lumbar Multifidus ◽  
Acute Responses

This study aimed to compare the neuromuscular activation of selected core musculature in supine and prone bridge exercises under stable versus suspended conditions. Forty-three healthy male participants were recruited to measure the electromyographic activities of the rectus abdominis (RA), lumbar multifidus (LM), thoracic erector spinae (TES), rectus femoris (RF), gluteus maximus (GM), and biceps femoris (BF) during supine and prone bridge exercises under six conditions: control, both arms and feet on the floor (Pronecon and Supinecon); arms on the floor and feet on the suspension system (Prone-Feetsuspension and Supine-Feetsuspension); and arms on the suspension system and feet on the floor (Prone-Armsuspension and Supine-Armsuspension). Prone-Armsuspension yielded significantly higher activities in the RA, RF, TES, and LM than Prone-Feetsuspension (p < 0.01) and Pronecon (p < 0.001). Moreover, Supine-Feetsuspension elicited significantly higher activities in the RA, RF, TES, LM, and BF than Supine-Armsuspension (p < 0.01) and Supinecon (p < 0.001). Furthermore, Supine-Feetsuspension elicited significantly higher activities in the RF, TES, and BF than Supinecon (p < 0.01). Therefore, if the RA and/or RF were the target training muscles, then Prone-Armsuspension was recommended. However, if the TES, LM, and/or BF were the target training muscles, then Supine-Feetsuspension was recommended.

Assessment of Muscles Fatigue during 400-Meters Running Strategies Based on the Surface EMG Signals

2019 ◽  
Vol 42 ◽  
pp. 1-13
Author(s):  
Hayder A. Yousif ◽  
Abdul Rahim Norasmadi ◽  
Ahmad Faizal Bin Salleh ◽  
Zakaria Ammar ◽  
Khudhur A. Alfarhan
Keyword(s):  
Frequency Domain ◽  
Research Work ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Surface Emg ◽  
Median Frequency ◽  
Bipolar Electrodes ◽  
Time Frequency ◽  
Full Speed

The aim of this research work is to assess the muscles fatigue of the male runner during 400 meters (m) running with three types of running strategies. The Electromyography (EMG) signals from the Rectus Femoris (RF), Biceps Femoris (BF), Gluteus Maximus (GM), Gastrocnemius Lateralis (GL), and Gastrocnemius Medialis (GMS) were collected by using bipolar electrodes from the right lower extremity’s muscles. EMG signals were collected during the run on the tartan athletic track. Five subjects (non-athletes) had run 400m with three various types of running strategies. The first type: the first 200m running 85-93% of full speed and the last 200m sprinting (full speed), second type: the first 300m running 85-93% of sprinting and the last 100m sprinting, and third type: running 85-93% of sprinting for 400m. The EMG signals were transformed to the time-frequency domain using Short Time Fourier Transform to calculate the instantaneous mean frequency (IMNF) and instantaneous median frequency (IMDF). The less index fatigues were during 1st strategy, while the RF, BF, GM, and GL muscles got recovered with IMNF and IMDF with the three strategies, and the GMS muscle has less negative regression slope value with IMNF with 1st strategy during the 4th 100m of the 400m running event. From the results, it can be concluded the running with the 1st strategy get less fatigues compared with the 2nd and 3rd strategy based on the results of time-frequency domain features (IMNF and IMDF).

Are leg electromyogram profiles in squat is symetrical? (Case study)

2017 ◽  
Vol 27 (78) ◽  
pp. 65-74
Author(s):  
Krzysztof Kmiecik ◽  
Henryk Król ◽  
Grzegorz Sobota
Keyword(s):  
Body Mass ◽  
Body Height ◽  
Force Plate ◽  
Gluteus Maximus ◽  
Movement Patterns ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Erector Spinae ◽  
Measuring System ◽  
Load Increase

The action of the central nervous system that controls neuromuscular functions reflect electromyograms (EMGs) profiles of muscle activity of the basic muscles. However, there seems to be a relationship between the EMGs profiles and the movement patterns (e.g., values of extremity joins angles). We want to find out how changes EMG profiles and movement patterns of the squat movement with increasing loads and especially we want to determine degree of symmetry of selected homologous muscles. Due to the lack of critical information addressing symmetry, we studied the EMG profiles of six homologous leg muscles (i.e. tibialis anterior, gastrocnemius, rectus femoris, biceps femoris, gluteus maximus and erector spinae) during squat movement depending on load size. For this purpose we checked the usefulness of the multimodular measuring system (SMART-E, BTS) and force plate Kistler. Smart Analyser software was used to create a database allowing the chosen EMG profiles and movement patterns to be compared. In this study participated eleven healthy man, however two were selected for analysis. The first of subject was 36 years (body mass 82 kg; body height 180 cm; 1RM in full squat 140 kg). The second one was 28 years (body mass 90 kg; body height 183 cm; 1RM in full squat 110 kg). The subjects performed consecutive sets of a single repetition of full squat with the increasing load (70, 80, 90 and 100% 1RM the anticipated maximum weight), until the appointment of one repetition maximum. For analysis, however, only samples with moderate and maximal loads (70% and 100% 1RM, respectively) were selected. The sum of the differences in normalized amplitude values of individual pairs of homologous muscles was taken as a measure of symmetry/asymmetry of the EMG profile. The load increase of the squat contributed to the increase asymmetry of the profiles of pairs homologous muscles of the lower extremities. Greater asymmetry of subject A.M. in a squat with a load of 100% 1RM resulted that the fluidity of the movement was worsened.

scholarly journals Muscle Activation Patterns Correlate With Race Walking Economy in Elite Race Walkers: A Waveform Analysis

2019 ◽  
Vol 14 (9) ◽  
pp. 1250-1255
Author(s):  
Josu Gomez-Ezeiza ◽  
Jordan Santos-Concejero ◽  
Jon Torres-Unda ◽  
Brian Hanley ◽  
Nicholas Tam
Keyword(s):  
Muscle Activation ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Medial Gastrocnemius ◽  
Initial Contact ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Race Walking ◽  
Walking Economy

Purpose: To analyze the association between muscle activation patterns on oxygen cost of transport in elite race walkers over the entire gait waveform. Methods: A total of 21 Olympic race walkers performed overground walking trials at 14 km·h−1 where muscle activity of the gluteus maximus, adductor magnus, rectus femoris, biceps femoris, medial gastrocnemius, and tibialis anterior were recorded. Race walking economy was determined by performing an incremental treadmill test ending at 14 km·h−1. Results: This study found that more-economical race walkers exhibit greater gluteus maximus (P = .022, r = .716), biceps femoris (P = .011, r = .801), and medial gastrocnemius (P = .041, r = .662) activation prior to initial contact and weight acceptance. In addition, during the propulsive and the early swing phase, race walkers with higher activation of the rectus femoris (P = .021, r = .798) exhibited better race walking economy. Conclusions: This study suggests that the neuromuscular system is optimally coordinated through varying muscle activation to reduce the metabolic demand of race walking. These findings highlight the importance of proximal posterior muscle activation during initial contact and hip-flexor activation during early swing phase, which are associated with efficient energy transfer. Practically, race walking coaches may find this information useful in the development of specific training strategies on technique.

Kinematic and Electromyographic Analysis of the Trunk and Lower Limbs During Walking in Negative-Heeled Shoes

2007 ◽  
Vol 97 (6) ◽  
pp. 447-456 ◽  
Author(s):  
Jing Xian Li ◽  
Youlian Hong
Keyword(s):  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Mean Amplitude ◽  
Erector Spinae ◽  
Lower Limbs ◽  
Electromyographic Activity ◽  
Lateral Gastrocnemius ◽  
Electromyographic Analysis ◽  
Sports Shoes

Background: We investigate kinematic adaptation and muscle activities in the trunk and lower extremities of healthy subjects during treadmill walking in negative-heeled sports shoes versus normal sports shoes. Methods: Thirteen healthy female university students participated in the study. We analyzed sagittal-movement kinematics and electromyographic findings from the erector spinae, rectus abdominus, rectus femoris, biceps femoris, tibialis anterior, and lateral gastrocnemius muscles of the dominant side in two shod conditions. Results: Negative-heeled gait is characterized by faster cadence, shorter stride length, increased maximal extension angles in the trunk and hip, increased flexion angle in the knee, larger dorsiflexion in the stance phase, and a larger range of motion of the ankle joint. Negative-heeled gait resulted in a significantly larger integrated electromyographic value, a longer duration of electromyographic activity, and a higher mean amplitude of electromyographic activity in the tibialis anterior, lateral gastrocnemius, and biceps femoris muscles. Conclusions: Negative-heeled gait compared with normal gait places a higher physiologic demand on the tibialis anterior, lateral gastrocnemius, and biceps femoris muscles when walking on a level surface. Thus, negative-heeled shoes could be of value if used in an exercise rehabilitation or training program where inclined walking is not available owing to a flat terrain. (J Am Podiatr Med Assoc 97(6): 447–456, 2007)

scholarly journals Kinematic and EMG Comparison Between Variations of Unilateral Squats Under Different Stabilities

2020 ◽  
Vol 4 (02) ◽  
pp. E59-E66
Author(s):  
Roland van den Tillaar ◽  
Stian Larsen
Keyword(s):  
Muscle Activity ◽  
Rectus Femoris ◽  
Gluteus Medius ◽  
Biceps Femoris ◽  
Peak Force ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Training Experience ◽  
Free Weight ◽  
Weight Condition

AbstractThe purpose of the study was to compare kinematics and muscle activity between two variations of unilateral squats under different stability conditions. Twelve male volunteers (age: 23±5 years, mass: 80±17 kg, height: 1.81±0.11 m, strength-training experience: 4.3±1.9 years) performed four repetitions with the same external load (≈4RM). Two variations (with the non-stance leg forwards vs. backwards) were performed in a Smith-machine and free-weight condition. The variables were barbell velocity, lifting time and surface electromyography activity of the lower extremity and trunk muscles during the descending and ascending phase. The main findings were 1) peak force was higher when performing the unilateral squats in the Smith machine; 2) peak ascending barbell velocity increased from repetition 3–4 with free weight; and 3) muscle activity from the rectus femoris, vastus lateral, biceps femoris, gluteus medius, and erector spinae increased with repetitions, whereas gluteus, and medial vastus and shank muscles were affected by the conditions. It was concluded that more peak force could be produced because of increased stability. However, peak barbell velocity increased from repetition to repetition in free-weight unilateral squats, which was probably because the participants grew more comfortable. Furthermore, increased instability causes more gluteus and vastus medial activation and foot variations mainly affected the calf muscles.

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.

Sign in / Sign up

Export Citation Format

Share Document