scholarly journals Tensiomyographic Responses to Warm-Up Protocols in Collegiate Male Soccer Athletes

2021 ◽  
Vol 6 (4) ◽  
pp. 80
Author(s):  
Michael J. Redd ◽  
Tristan M. Starling-Smith ◽  
Chad H. Herring ◽  
Matt S. Stock ◽  
Adam J. Wells ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Warm Up ◽  
Performance Variables ◽  
Leg Muscles ◽  
Main Effect ◽  
Before And After ◽  
Main Effects ◽  
Knee Flexors

The mechanical properties of knee flexors and extensors in 15 collegiate male soccer players following different warm-up protocols [small-sided games (SSG), dynamic (DYN), and plyometric (PLY)] were evaluated. Tensiomyography (TMG) was used to assess contraction time (Tc), delay time (Td) and maximal displacement (Dm) of the rectus femoris (RF) and biceps femoris (BF) of both legs before and after each warm-up, while countermovement jump height variables, 20 m sprint, t-test and sit-and-reach were measured following the warm-ups. TMG was analyzed using a three-way [condition × time × leg] ANOVA, while performance variables were analyzed with a repeated measures ANOVA. Main effects of time were observed for BF-Tc (p = 0.035), RF-Td (p < 0.001), and BF-Td, (p = 0.008), and a main effect of condition was seen for RF-Tc (p = 0.038). Moreover, participants’ 20 m sprint improved following SSG (p = 0.021) compared to DYN and PLY. Sit-and-reach was greater following PLY (p = 0.021). No significant interactions were noted for the measured TMG variables. Warm-up-specific improvements were demonstrated in sprint speed and flexibility following SSG and PLY, respectively. The present study revealed changes in certain TMG measures following the warm-ups that suggest enhanced response of lower leg muscles regardless of specific activities used.

scholarly journals Leg Muscle Activity and Perception of Effort before and after Four Short Sessions of Submaximal Eccentric Cycling

2020 ◽  
Vol 17 (21) ◽  
pp. 7702
Author(s):  
Pierre Clos ◽  
Romuald Lepers
Keyword(s):  
Muscle Activity ◽  
Peak Power ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Peak Power Output ◽  
Leg Muscles ◽  
Perception Of Effort ◽  
Before And After ◽  
Power Outputs

Background: This study tested muscle activity (EMG) and perception of effort in eccentric (ECC) and concentric (CON) cycling before and after four sessions of both. Methods: Twelve volunteers naïve to ECC cycling attended the laboratory six times. On day 1, they performed a CON cycling peak power output (PPO) test. They then carried-out four sessions comprising two sets of 1 to 1.5-min cycling bouts at 5 intensities (30, 45, 60, 75, and 90% PPO) in ECC and CON cycling. On day 2 and day 6 (two weeks apart), EMG root mean square of the vastus lateralis (VL), rectus femoris (RF), biceps femoris (BF), and soleus (SOL) muscles, was averaged from 15 to 30 s within each 1-min bout and perception of effort was asked after 45 s. Results: Before the four cycling sessions, while VL EMG was lower in ECC than CON cycling, most variables were not different. Afterwards, ECC cycling exhibited lower RF EMG at 75 and 90% PPO (all p < 0.02), lower VL and BF EMG at all exercise intensities (all p < 0.02), and inferior SOL EMG (all p < 0.04) except at 45% PPO (p = 0.07). Perception of effort was lower in ECC cycling at all exercise intensities (all p < 0.03) but 60% PPO (p = 0.11). Conclusions: After four short sessions of ECC cycling, the activity of four leg muscles and perception of effort became lower in ECC than in CON cycling at most of five power outputs, while they were similar before.

Transdermal delivery of carnosine into equine skeletal muscle

2021 ◽  
pp. 1-6
Author(s):  
B.P. Dieter ◽  
C.J. Macias ◽  
T.J. Sharpe ◽  
B. Roberts ◽  
M. Wille ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Transdermal Delivery ◽  
Repeated Measures ◽  
Muscle Metabolism ◽  
Enzyme Linked Immunosorbent Assay ◽  
Time To Exhaustion ◽  
Thoroughbred Racehorses ◽  
Repeated Measures Analysis ◽  
Main Effect ◽  
Main Effects

The dipeptide carnosine consists of β-alanine and L-histidine. It plays a major role in skeletal muscle metabolism, especially as an intracellular buffer and antioxidant. Increasing intramuscular carnosine has been shown to improve recovery from exercise and increase anaerobic threshold and time-to-exhaustion. Dietary supplementation with carnosine does not effectively increase intramuscular carnosine due to the presence of carnosinase in the blood. However, an effective transdermal delivery process could expediently increase intramuscular concentrations of carnosine. This study’s objective was to examine the efficacy of a transdermal system for delivering carnosine into the skeletal muscle of horses, using a randomised, placebo controlled, crossover study. Carnosine plus a proprietary transdermal delivery agent or the agent alone (placebo) were applied to the middle gluteal muscles of 10 Thoroughbred racehorses, and muscle biopsies were taken before and 30, 60, and 120 min after application. Muscle carnosine concentration was measured using an enzyme-linked immunosorbent assay. A two-way repeated measures analysis of variance was used to test for the main effects of time and treatment (placebo or carnosine) as well as an interaction between time and treatment. Independent F-tests examined the change in intramuscular carnosine levels from baseline to each time point (30, 60, and 120 min). There was a significant main effect of treatment (P=0.004), no significant main effect for time (P=0.18), and a non-significant interaction of treatment with time (P=0.08). Mean intramuscular carnosine concentrations increased from baseline to 120 min. Compared to concentrations following placebo application, carnosine was greater by ~35% at 30 min (P=0.002) and ~46% after 60 min (P=0.044), but not at 120 min (P=0.20). The results indicated that intramuscular carnosine can be increased using a transdermal delivery system within 60 min of application which could have important implications for the health of horses, and their capacity to perform and recover from physical activity.

Muscle Activation in the Main Muscle Groups of the Lower Limbs in High-Level Dancesport Athletes

2018 ◽  
Vol 33 (4) ◽  
pp. 231-237
Author(s):  
Encarnación Liébana ◽  
Cristina Monleón ◽  
Raquel Morales ◽  
Carlos Pablos ◽  
Consuelo Moratal ◽  
...  
Keyword(s):  
Tibialis Anterior ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Gastrocnemius Medialis ◽  
Leg Muscles ◽  
Relative Activation ◽  
Muscle Groups ◽  
High Level

Dancers are subjected to high-intensity workouts when they practice dancesport, and according to the literature, they are prone to injury, primarily of the lower limbs. The purpose of this study was to determine whether differences exist in relative activation amplitudes for dancers involved in dancesport due to muscle, gender, and type of dance. Measurements were carried out using surface electromyography equipment during the choreography of a performance in the following leg muscles: rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius medialis. Eight couples of active dancesport athletes (aged 20.50±2.75 yrs) were analyzed. Significant gender differences were found in rumba in the tibialis anterior (p≤0.05) and gastrocnemius medialis (p≤0.05). Based on the different activations, it is possible to establish possible mechanisms of injury, as well as tools for preventing injuries and improving sports performance.

scholarly journals Effects of Pitch and Rhythm Priming Tasks on Accuracy and Fluency During Sight-Reading

2019 ◽  
Vol 67 (3) ◽  
pp. 252-269
Author(s):  
Christine R. Russell
Keyword(s):  
Repeated Measures ◽  
Sight Reading ◽  
Exposure Condition ◽  
Pitch Accuracy ◽  
Wind Instrumentalists ◽  
Repeated Measures Design ◽  
Priming Condition ◽  
Main Effect ◽  
Main Effects ◽  
Performance Scale

The purpose of this study was to investigate the effects of pitch and rhythm priming tasks on sight-reading accuracy and fluency. High school wind instrumentalists ( N = 182) were assigned to one of four experimental groups: pre-/posttest rhythm, pre-/posttest pitch, posttest-only rhythm, or posttest-only pitch. Participants sight-read selected stimulus exercises from the Watkins-Farnum Performance Scale and completed two priming treatments and a control condition as part of a repeated-measures design. A three-way repeated-measures MANOVA, with rhythm accuracy, pitch accuracy, and fluency accuracy as dependent measures, revealed a significant main effect due to priming condition. Rhythm accuracy scores were significantly lower after both perceptual and conceptual priming than after a control condition. No significant differences in pitch accuracy or fluency existed based on priming condition. No significant differences were found in rhythm, pitch, or fluency accuracy based on treatment condition (pitch or rhythm) or exposure condition (pre-/posttest or post only). Two-way repeated-measures MANOVAs revealed significant main effects based on time. Pitch accuracy and fluency each significantly improved between pre- and posttest and from the first to third study tasks. Results suggest that performing rhythm alone or pitch alone requires different cognitive processes than does performing both together.

The Relationship between Integrated EMG and Oxygen Uptake during Treadmill and Bicycle Exercise

1976 ◽  
Vol 20 (23) ◽  
pp. 548-551
Author(s):  
T. Fukunaga ◽  
K. Yuasa ◽  
M. Kobayashi ◽  
T. Miyagawa ◽  
H. Fujimatsu ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Correlation Coefficient ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Treadmill Walking ◽  
Emg Activity ◽  
Bicycle Exercise ◽  
Leg Muscles ◽  
Integrated Emg ◽  
Muscle Groups

The aim of this study is to measure the integrated EMG in relation to the oxygen uptake during submaximal treadmill and bicycle exercises. Seven healthy adult subjects performed five minute exercise at three different submaximal work intensities on the same day. The EMG activity in right thigh and leg muscles was measured from m. rectus femoris, m. biceps femoris, m. tibialis anterior and m. gastrocnemius by means of four pairs of surface electrodes sealed with collodion to the skin at a distance of 3 cm apart over the belly of muscles. The EMG activity was not likely modified by the possible fatigue during 5 minutes submaximal exercise in this experiment. In the treadmill walking, there was a rectilinear relationship between integrated EMG activity from four muscle groups and percent of VO2max. On the bicycle exercise the correlation coefficient between them was generally lower than that on the treadmill walking. The product of integrated EMG and volume of the same muscle groups was considerably linearly related to oxygen uptake during treadmill and bicycle exercise (the correlation coefficient was 0.945, p < 0.001 in treadmill and 0.710, p < 0.001 in bicycle).

scholarly journals Age-specific modulation of intermuscular beta coherence during gait before and after experimentally induced fatigue

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Paulo Cezar Rocha dos Santos ◽  
Claudine J. C. Lamoth ◽  
Fabio Augusto Barbieri ◽  
Inge Zijdewind ◽  
Lilian Teresa Bucken Gobbi ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Treadmill Walking ◽  
Beta Band ◽  
Sit To Stand ◽  
Corticospinal Tracts ◽  
Before And After ◽  
Oscillatory Coupling ◽  
Experimentally Induced

Abstract We examined the effects of age on intermuscular beta-band (15–35 Hz) coherence during treadmill walking before and after experimentally induced fatigue. Older (n = 12) and younger (n = 12) adults walked on a treadmill at 1.2 m/s for 3 min before and after repetitive sit-to-stand, rSTS, to induce muscle fatigability. We measured stride outcomes and coherence from 100 steps in the dominant leg for the synergistic (biceps femoris (BF)-semitendinosus, rectus femoris (RF)-vastus lateralis (VL), gastrocnemius lateralis (GL)-Soleus (SL), tibialis anterior (TA)-peroneus longus (PL)) and for the antagonistic (RF-BF and TA-GL) muscle pairs at late swing and early stance. Older vs. younger adults had 43–62% lower GL-SL, RF-VL coherence in swing and TA-PL and RF-VL coherence in stance. After rSTS, RF-BF coherence in late swing decreased by ~ 20% and TA-PL increased by 16% independent of age (p = 0.02). Also, GL-SL coherence decreased by ~ 23% and increased by ~ 23% in younger and older, respectively. Age affects the oscillatory coupling between synergistic muscle pairs, delivered presumably via corticospinal tracts, during treadmill walking. Muscle fatigability elicits age-specific changes in the common fluctuations in muscle activity, which could be interpreted as a compensation for muscle fatigability to maintain gait performance.

Is Tensiomyography-Derived Velocity of Contraction a Sensitive Marker to Detect Acute Performance Changes in Elite Team-Sport Athletes?

2020 ◽  
Vol 15 (1) ◽  
pp. 31-37
Author(s):  
Lucas A. Pereira ◽  
Rodrigo Ramirez-Campillo ◽  
Saul Martín-Rodríguez ◽  
Ronaldo Kobal ◽  
César C.C. Abad ◽  
...  
Keyword(s):  
Training Session ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Team Sport ◽  
Technical Training ◽  
Effect Sizes ◽  
Squat Jump ◽  
National Team ◽  
Before And After ◽  
Sensitive Marker

Purpose: To examine the variations in the velocity of contraction (Vc) assessed using tensiomyography, vertical jumping ability, and sprinting speed induced by 4 different exercise protocols (ie, strength, sprint, plyometric, and technical training sessions) in 14 male national-team rugby players (age 21.8 [2.6] y, weight 83.6 [8.5] kg, and height 177.4 [6.7] cm). Methods: Physical tests were conducted immediately before and after 4 distinct workouts in the following order: tensiomyography in the rectus femoris and biceps femoris muscles, squat and countermovement jumps, and 30-m sprint velocity. To analyze the differences in the assessed variables before and after each training session, the differences based on magnitudes were calculated. Results: After strength and plyometric workouts, the players presented possible to almost certain impairments in sprint and jump performance and in the Vc of the rectus femoris (effect sizes 0.26–0.64). After the sprint-training session, possible to very likely decreases were observed in the squat jump, 30-m sprint, and Vc of the biceps femoris (effect sizes 0.21–0.44). By contrast, after the technical training, athletes demonstrated a possible increase in the squat jump and Vc in both muscles examined (effect sizes 0.13–0.20). Conclusions: The main finding of this research is that, for the vast majority of results, the direction of changes observed in Vc were the same as those observed in performance assessments. This suggests that Vc might be used as a sensitive marker of acute variations in speed and power performance of elite team-sport athletes.

scholarly journals Stumbling Over Obstacles in Older Adults Compared to Young Adults

2005 ◽  
Vol 94 (2) ◽  
pp. 1158-1168 ◽  
Author(s):  
A. M. Schillings ◽  
Th. Mulder ◽  
J. Duysens
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Age Groups ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Risk Of Falling ◽  
Leg Muscles ◽  
Long Latency Responses ◽  
Long Latency ◽  
Movement Strategies

Falls are a major problem in older adults. Many falls occur because of stumbling. The aim of the present study is to investigate stumbling reactions of older adults and to compare them with young adults. While subjects walked on a treadmill, a rigid obstacle unexpectedly obstructed the forward sway of the foot. In general, older adults used the same movement strategies as young adults (“elevating” and “lowering”). The electromyographic responses were categorized according to latencies: short-latency (about 45 ms, RP1), medium-latency (about 80 ms, RP2), and long-latency responses (about 110 ms, RP3; about 160 ms, RP4). Latencies of RP1 responses increased by about 6 ms and of RP2 by 10–19 ms in older adults compared with the young. Amplitudes of RP1 were similar for both age groups, whereas amplitudes of RP2–RP4 could differ. In the early-swing elevating strategy (perturbed foot directly lifted over the obstacle) older adults showed smaller responses in ipsilateral upper-leg muscles (biceps femoris and rectus femoris). This was related to shorter swing durations, more shortened step distances, and more failures in clearing the obstacle. In parallel, RP4 activity in the contralateral biceps femoris was enhanced, possibly pointing to a higher demand for trunk stabilization. In the late-swing lowering strategy (foot placed on the treadmill before clearing the obstacle) older adults showed lower RP2–RP3 responses in most muscles measured. However, kinematic responses were similar to those of the young. It is concluded that the changes in muscular responses in older adults induce a greater risk of falling after tripping, especially in early swing.

scholarly journals Functional assessment of muscle response in lower limbs of tumbling gymnasts through tensiomyography

2016 ◽  
Vol 64 (3) ◽  
pp. 505
Author(s):  
Nicolás Rojas-Barrionuevo ◽  
Mercedes Vernetta-Santana ◽  
Jesús López-Bedoya
Keyword(s):  
Delay Time ◽  
High Performance ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Response Speed ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Muscle Response ◽  
Antagonist Muscles ◽  
Before And After

Introduction: Jumping capacity, a distinctive technical skill of tumbling gymnasts, is associated to a successful performance in training and competition; hence the need for an individualized, precise and localized assessment of the most demanded muscle structures.Objective: To assess muscle response of the flexo-extension structure in the knee joint and the extension of the ankle joint in a sample of 12 high-performance male gymnasts.Materials and methods: An acrobatic training protocol including sets of forward somersault in tumbling track was conducted. The contraction time, delay time and deformation of muscle belly were evaluated, and the muscular response speed was calculated using tensiomyography before and after the training intervention in different periods of time.Results: Significant differences were found (p<0.05) according to the muscle group involved, where rectus femoris and biceps femoris presented greater enhancement and shortening of the contraction and delay time. Major differences appeared between agonist-antagonist muscles (vastus lateralis-biceps femoris) (p<0.05) due to a decrease in the contraction and delay speed in vastus medialis (p<0.001).Conclusions: Tensiomyography allows estimating the states of activation-enhancing of the musculature responsible of jumping in tumblers, as well as planning the training based on the state of muscle fatigue.

scholarly journals The Effects of Turmeric Intake Alone or in Combination with Resistance Training on Liver Enzymes in Adult Men

2021 ◽  
Vol 30 (2) ◽  
pp. 183-191
Author(s):  
Seung-Joon Paek ◽  
Sang-Hyun Lee ◽  
Jung Su Park ◽  
Jun-Soo Kim ◽  
Dong-Ho Park
Keyword(s):  
Resistance Training ◽  
Interaction Effect ◽  
Liver Enzymes ◽  
Glutamic Oxaloacetic Transaminase ◽  
Significant Interaction Effect ◽  
Adult Men ◽  
Main Effect ◽  
Before And After ◽  
Glutamyl Transferase ◽  
Main Effects

PURPOSE: This study aimed to investigate the effect of turmeric intake alone or in combination with resistance training on liver enzymes in adult men who regularly consumed alcohol at least twice a week.METHODS: Twelve men (age: 36.0±5.26 years, weight: 99.9±17.9 kg, and height: 184.0±6.5 cm) were randomly assigned to the turmeric intake (2-3 g/day) alone (TI, n=6) group or the TI plus resistance training (60 minutes of RT 3 times a week) (TI+RT, n=6) group for 8 weeks. Blood was collected before and after 8 weeks of treatment. The analyzed variables included glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), γ-glutamyl transferase (γ-GTP), and GOT/GPT ratio.RESULTS:There was no significant interaction effect in all variables, but the main effect was found in all variables only in TI+RT group. The Cohen’s d effect size on the main effects of the TI+RT group on GOT (d=0.548), GPT (d=0.835), γ-GTP (d=0.623), and GOT/GPT ratio (d=0.800) ranged from 0.548-0.835, respectively. However, body composition such as percent body fat (%, <i>p</i>>.05) and muscle mass (kg, <i>p</i>>.05) did not show the main effect on time points as well as the interaction effect (<i>p</i>>.05).CONCLUSIONS:Although the 8-week TI treatment did not show any statistically significant change, TI treatment showed a tendency to decrease in GOT, GPT, and γ-GTP, and the GOT/GPT ratio tends to increase. Therefore, there was a synergic effect of the TI plus RT treatment or the sum of the two treatments for 8 weeks.

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