Quadriceps EMG/force relationship in knee extension and leg press

2000 ◽  
Vol 32 (2) ◽  
pp. 459 ◽  
Author(s):  
BJ??RN A. ALKNER ◽  
PER A. TESCH ◽  
HANS E. BERG
Keyword(s):  
Knee Extension ◽  
Leg Press ◽  
Force Relationship

scholarly journals Exploring the acute affective responses to resistance training: A comparison of the predetermined and the estimated repetitions to failure approaches

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256231
Author(s):  
Hadar Schwartz ◽  
Aviv Emanuel ◽  
Isaac Isur Rozen Samukas ◽  
Israel Halperin
Keyword(s):  
Resistance Training ◽  
Knee Extension ◽  
Affective Responses ◽  
Affective Valence ◽  
Task Failure ◽  
Leg Press ◽  
Effort Regulation ◽  
The Mean ◽  
Age Range ◽  
Repetitions To Failure

Background In resistance-training (RT), the number of repetitions is traditionally prescribed using a predetermined approach (e.g., three sets of 10 repetitions). An emerging alternative is the estimated repetitions to failure (ERF) approach (e.g., terminating sets two repetitions from failure). Despite the importance of affective responses experienced during RT, a comparison between the two approaches on such outcomes is lacking. Methods Twenty women (age range: 23–45 years) without RT experience completed estimated one repetition maximum (RM) tests in four exercises. In the next two counterbalanced sessions, participants performed the exercises using 70%1RM. Participants completed ten repetitions in all three sets (predetermined condition) or terminated the sets when perceived to be two repetitions away from task-failure (ERF condition). Primary outcomes were affective-valence, enjoyment, and approach-preference and secondary outcomes were repetition-numbers completed in each exercise. Results We observed trivial differences in the subjective measures and an approximately even approach-preference split. Under the ERF condition, we observed greater variability in repetition-numbers between participants and across exercises. Specifically, the mean number of repetitions was slightly lower in the chest-press, knee-extension, and lat-pulldown (~1 repetition) but considerably higher in the leg-press (17 vs. 10, p<0.01). Conclusions Both approaches led to comparable affective responses and to an approximately even approach preference. Hence, prior to prescribing either approach, coaches should consider trainee’s preferences. Moreover, under the ERF condition participants completed a dissimilar number of repetitions across exercises while presumably reaching a similar proximity to task-failure. This finding suggests that ERF allows for better effort regulation between exercises.

scholarly journals Brain-Behavior Mechanisms for the Transfer of Neuromuscular Training Adaptions to Simulated Sport: Initial Findings From the Train the Brain Project

2018 ◽  
Vol 27 (5) ◽  
Author(s):  
Dustin R. Grooms ◽  
Adam W. Kiefer ◽  
Michael A. Riley ◽  
Jonathan D. Ellis ◽  
Staci Thomas ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Injury Risk ◽  
Cruciate Ligament ◽  
Knee Extension ◽  
Ligament Injury ◽  
Leg Press ◽  
Landing Mechanics ◽  
Anterior Cruciate ◽  
Movement Mechanics ◽  
Risk Reducing

Context: A limiting factor for reducing anterior cruciate ligament injury risk is ensuring that the movement adaptions made during the prevention program transfer to sport-specific activity. Virtual reality provides a mechanism to assess transferability, and neuroimaging provides a means to assay the neural processes allowing for such skill transfer. Objective: To determine the neural mechanisms for injury risk–reducing biomechanics transfer to sport after anterior cruciate ligament injury prevention training. Design: Cohort study. Setting: Research laboratory. Participants: Four healthy high school soccer athletes. Interventions: Participants completed augmented neuromuscular training utilizing real-time visual feedback. An unloaded knee extension task and a loaded leg press task were completed with neuroimaging before and after training. A virtual reality soccer-specific landing task was also competed following training to assess transfer of movement mechanics. Main Outcome Measures: Landing mechanics during the virtual reality soccer task and blood oxygen level–dependent signal change during neuroimaging. Results: Increased motor planning, sensory and visual region activity during unloaded knee extension and decreased motor cortex activity during loaded leg press were highly correlated with improvements in landing mechanics (decreased hip adduction and knee rotation). Conclusion: Changes in brain activity may underlie adaptation and transfer of injury risk–reducing movement mechanics to sport activity. Clinicians may be able to target these specific brain processes with adjunctive therapy to facilitate intervention improvements transferring to sport.

scholarly journals Lower Extremity Muscle Strength and Risk of Self-Reported Hip or Knee Osteoarthritis

2004 ◽  
Vol 1 (4) ◽  
pp. 321-330 ◽  
Author(s):  
Jennifer M. Hootman ◽  
Shannon FitzGerald ◽  
Carol A. Macera ◽  
Steven N. Blair
Keyword(s):  
Lower Extremity ◽  
Knee Osteoarthritis ◽  
Knee Extension ◽  
Quadriceps Strength ◽  
Community Dwelling ◽  
Leg Press ◽  
Knee Oa ◽  
Lower Extremity Muscle ◽  
Longitudinal Association

Purpose:The purpose of this study was to investigate the gender-specific longitudinal association between quadriceps strength and self-reported, physician-diagnosed hip or knee osteoarthritis (OA).Methods:Subjects were 3081 community-dwelling adults who were free of OA, joint symptoms and injuries, completed a maximum treadmill exercise test, had isokinetic knee extension and flexion and isotonic leg press strength measurements taken at baseline and returned at least one written follow-up survey. Multivariate logistic regression was used to estimate odds ratios and 95% confidence intervals.Results:Women with moderate or high isokinetic quadriceps strength had a significantly reduced risk (55% to 64%) of hip or knee OA. A similar, nonsignificant trend was noted among men. Moderate isotonic leg press strength was protective for hip or knee osteoarthritis among men only.Conclusions:These results suggest that quadriceps weakness is an independent and modifiable risk factor for lower extremity OA, particularly among women.

scholarly journals Repetition numbers in resistance training: a comparison between the predetermined and the estimated repetitions to failure prescription approaches on affective responses

2020 ◽  
Author(s):  
Hadar Schwartz ◽  
Aviv Emanuel ◽  
Itzhak Rozen Smukas ◽  
Israel Halperin
Keyword(s):  
Resistance Training ◽  
Knee Extension ◽  
Affective Responses ◽  
Affective Valence ◽  
Training Experience ◽  
Task Failure ◽  
Leg Press ◽  
Performance Variability ◽  
Age Range ◽  
Repetitions To Failure

Background: In resistance-training, the number of repetitions is traditionally prescribed using a predetermined approach, whereby the numbers are decided upon before set initiation (e.g., three sets of 10 repetitions). An alternative is the estimated repetitions to failure (ERF) approach, whereby sets are terminated based on one's estimated proximity to task-failure (e.g., two repetitions before failure). The latter approach allows trainees to better account for day-to-day performance variability and may be perceived as a more enjoyable way to train. Methods: Twenty women (age range: 23-45 years) without resistance-training experience first completed estimated 1RM tests in four exercises. In the next two counterbalanced sessions, participants performed three sets of each exercise using 70%1RM. They either completed ten repetitions in all sets (predetermined condition) or terminated the sets when they perceived to be two repetitions before task-failure (ERF condition). Affective-valence, enjoyment, and approach-preference were collected during and after the sessions. Results: We observed trivial differences in the subjective measures and an approximately even approach-preferences split. Number of repetitions performed were mostly similar under both conditions in the chest-press, knee-extension and lat-pulldown (difference of ~1 repetition). However, under the ERF condition participants completed more repetitions in the leg-press (17 vs. 10, p&lt;0.01). Conclusions: Both approaches led to comparable affective responses. However, the fact that participants performed a different number of repetitions across exercises while reaching a similar proximity to task-failure, suggests that the ERF approach may be preferable to account for day-to-day performance variability.

Comparison of Open Kinetic Chain Knee and Hip Extension to Closed Kinetic Chain Leg Press Performance

1995 ◽  
Vol 4 (2) ◽  
pp. 99-107 ◽  
Author(s):  
John LaFree ◽  
Amy Mozingo ◽  
Teddy Worrell
Keyword(s):  
Analysis Of Variance ◽  
Repeated Measures ◽  
Intraclass Correlation ◽  
Peak Torque ◽  
Knee Extension ◽  
Muscle Performance ◽  
Kinetic Chain ◽  
Leg Press ◽  
Significant Difference ◽  
Hip Extension

The purposes of this study were to determine the relationship of isokinetic quadriceps and hip extensor peak torque to isokinetic leg press peak torque and to determine the influence of hip position (seated vs. supine) on leg press peak torque. Forty subjects (20 males and 20 females) were tested bilaterally on the isokinetic dynamometer. Subjects were tested during knee extension, hip extension, seated leg press, and supine leg press. Intraclass correlation coefficient and standard error of measurement values revealed acceptable reliability for all tests. An analysis of variance revealed significant dominant versus nondominant differences in all tests except hip extension. A repeated measures analysis of variance revealed no significant difference between seated and supine leg press peak torque. Finally, stepwise regression revealed a significant relationship between knee extension and leg press peak torques, with hip extension adding only minimally to the explained variance. These data suggest that knee extension and leg press peak torque assess similar muscle performance characteristics. Further research involving electromyographic analysis is recommended to determine the influence of other muscles on leg press force performance.

scholarly journals Effects of Adding Single Joint Exercises to a Resistance Training Programme in Trained Women

Sports ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 160 ◽  
Author(s):  
Matheus Barbalho ◽  
Victor Coswig ◽  
Rodolfo Raiol ◽  
James Steele ◽  
James Fisher ◽  
...  
Keyword(s):  
Bench Press ◽  
Training Programme ◽  
Knee Extension ◽  
Additional Benefit ◽  
Muscle Performance ◽  
Anthropometric Measures ◽  
Repetition Maximum ◽  
Leg Press ◽  
Resistance Training Programme ◽  
Arm Circumference

Background: The present study’s aim was to compare the changes in muscle performance and anthropometric measures in trained women performing RT programs composed only of MJ exercises or programmes that involve the addition of SJ exercises. Methods: Seventeen trained women were randomised to MJ or MJ+SJ. Both groups performed the same MJ exercises following a nonlinear periodisation model for 8 weeks. The only difference was that the MJ+SJ group also performed SJ exercises. The participants were tested for 10 repetition maximum (10 RM), flexed arm circumference, and both biceps and triceps skinfold. Results: Both groups significantly increased 10 RM load for the bench press (12.6% MJ and 9.2% MJ+SJ), triceps (15.6% MJ and 17.9% MJ+SJ), pull down (9.8% MJ and 8.3% MJ+SJ), biceps (14.0% MJ and 13.0% MJ+SJ), leg press (15.2% MJ and 12.8% MJ+SJ) and knee extension (10.2% MJ and 9.1% MJ+SJ). The decreases in triceps (−5.1% MJ and −5.3% MJ+SJ) and biceps (−6.5% MJ and −5.7% MJ+SJ) skinfolds were also significant as were the increases in arm circumference (1.47% MJ and 1.58% MJ+SJ). In all tests there was nothing significantly different between groups. Conclusions: The use of SJ exercises as a complement to a RT programme containing MJ exercises brings no additional benefit to trained women.

scholarly journals Efeitos da Suplementação de Leucina Associada ao Treinamento Resistido Sobre a Força Muscular em Sujeitos Jovens

2017 ◽  
Vol 19 (2) ◽  
pp. 63 ◽  
Author(s):  
Alan Pablo Grala ◽  
Marcos Antonio Rolim Teixeira ◽  
Tatiana Cipriano Nishitani ◽  
André Fusco Melozi ◽  
Jeferson Lucas Jacinto ◽  
...  
Keyword(s):  
Muscle Strength ◽  
High Intensity ◽  
Low Dose ◽  
Training Session ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Short Term ◽  
Leucine Supplementation ◽  
Leg Press ◽  
The One

A proposta do presente estudo foi avaliar os efeitos da suplementação de leucina associada ao treinamento resistido (TR) de alta intensidade sobre a força muscular em sujeitos jovens não treinados. Para tanto, 24 indivíduos jovens não treinados, de ambos os sexos, foram divididos em dois grupos (N = 12/grupo): Leucina (4g de leucina + 8g dextrose) e Placebo (12g dextrose). Ambos os grupos foram submetidos a um programa de TR de alta intensidade (3 séries de 12 repetições máximas; 2x/semana) com duração de 6 semanas, e consumiram seus respectivos suplementos imediatamente após cada sessão de treino. As sessões de treino consistiram na realização dos exercícios de leg press e cadeira extensora, a fim de maximizar o recrutamento do músculo quadríceps. Ambos os grupos foram submetidos ao teste de uma repetição máxima (1RM) nos exercícios de leg press e cadeira extensora, nos momentos pré e pós-treinamento. Ao término do treinamento, houve um significante (P < 0,05) aumento do 1RM em ambos os exercícios, mas nenhuma diferença foi observada entre os grupos. Além disso, a progressão da carga de treino foi similar (P > 0,05) entre os grupos, após 4 e 6 semanas de treinamento. Estes resultados indicam que a suplementação de uma baixa dose semanal de leucina (4g/dia; 2x/semana) associada ao TR em curto prazo não promove efeitos adicionais sobre a força muscular em indivíduos jovens não treinados.Palavras-chave: Músculo Esquelético. Suplementação Alimentar. Leucina.AbstractThe purpose of the study herein was to examine the leucine supplementation effects associated with high-intensity resistance training (RT) on muscle strength in young untrained subjects. Twenty-four young untrained subjects fromboth sexes were divided into two groups (N = 12/ group): Leucine (4g leucine + 8g dextrose) and Placebo (12g dextrose). Both groups underwent a 6-wk high-intensity RT program (3 sets of 12 maximal repetitions; 2x/week), and consumed their respective supplements immediately after each training session. The training sessions consisted of performing leg press and knee extension exercises, in order to maximize the recruitment of the quadriceps muscle. Both groups performed the one-repetition maximum (1RM) test in the leg press and extensor chair exercises at pre- and post-training. After RT program, there was a significant (P < 0.05) increased 1RM in both exercises, but no difference was observed between the groups. In addition, the training load progression was similar (P > 0.05) between the groups after 4 and 6 weeks of training. These results indicate that low dose supplementation of leucine (4g/day; 2x/week) associated with a short-term RT program does not promote additional effects on muscle strength in untrained young subjects.Keywords: Skeletal Muscle. Supplementary Feeding. Leucine.

scholarly journals Comparison of single- and multi-joint lower body resistance training upon strength increases in recreationally active males and females: a within-participant unilateral training study

2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Alexander Goncalves ◽  
Paulo Gentil ◽  
James Steele ◽  
Jürgen Giessing ◽  
Antonio Paoli ◽  
...  
Keyword(s):  
Resistance Training ◽  
Resistance Exercise ◽  
Knee Flexion ◽  
Knee Extension ◽  
Lower Limbs ◽  
Lower Body ◽  
Post Intervention ◽  
Leg Press ◽  
Rehabilitation Professionals ◽  
Body Resistance

The present study compared strength increases resulting from either single-joint (SJ) or multi-joint (MJ) lower body resistance exercise. A within-participants design was utilised. Ten recreationally active participants (males; n=5, and females; n=5) had their lower limbs randomly allocated to perform both unilateral MJ (leg press; LP) and unilateral SJ (knee extension; KE, and seated knee flexion; KF) exercises. Participants trained 2 d.week-1 for 6 weeks. Pre- and post-intervention maximal strength (1-repetition maximum; 1RM) was measured for leg press, knee extension, and seated knee flexion exercises. Statistically significant strength increases occurred for both SJ and MJ groups, with significantly greater increases in 1RM for the MJ compared to the SJ group (p < 0.001 for all exercises). This study supports the use of MJ exercise for strength increases across lower body MJ and SJ movements, suggesting a time-efficient, and simple approach to resistance training may be efficacious. This might serve to promote greater adherence in the lay population as well as serving useful for rehabilitation professionals and strength and conditioning coaches in managing resistance exercise around skill/sport specific training.

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