scholarly journals Acute Influence of Leg Press Exercise on Hamstring Muscles Functional Stress

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Ribeiro José Ricardo Claudino ◽  
Tocafundo Lincoln Eugênio ◽  
Moutinho André Luiz Silva ◽  
Morales Anderson Pontes ◽  
Jorge Felipe Sampaio ◽  
...  
Keyword(s):  
Leg Press ◽  
Hamstring Muscles ◽  
Functional Stress

Passive resistance of hamstring muscles in children with severe multiple disabilities?

2000 ◽  
Vol 42 (8) ◽  
pp. 541-544 ◽  
Author(s):  
S Holt ◽  
S Baagøe ◽  
F Lillelund ◽  
S P Magnusson
Keyword(s):  
Multiple Disabilities ◽  
Passive Resistance ◽  
Hamstring Muscles

A influência aguda de uma sessão de Jump Fit no desempenho dos exercicios resistidos

2009 ◽  
Vol 7 (3) ◽  
pp. 118
Author(s):  
Roberto Simão
Keyword(s):  
Leg Press ◽  
Post Hoc

Existem evidências de que o treinamento de resistência antecedendo os exercícios resistidos (ER) pode influenciar no desempenho deste último. O objetivo deste estudo foi verificar a influência de uma aula de Jump Fit sobre o número de repetições em uma seqüência nos ER. A amostra foi de sete mulheres (23,7 ± 2,2 anos; 162,1 ± 5,7 cm; 54 ± 5,3 kg, praticantes de ER e Jump Fit. O estudo envolveu quatro visitas com intervalo de 48 horas entre as mesmas. Na primeira visita, foram avaliados a freqüência cardíaca em repouso, medidas antropométricas e o teste de 10 repetições máximas (10 RM). Após 48 horas realizamos um re-teste de 10 RM. Nos dois dias seguintes, após a obtenção das cargas, os indivíduos foram submetidos a duas sessões de treinamento, organizada em duas formas seqüenciais (SEQ A e SEQ B): SEQA – leg press 450, cadeira extensora e cadeira flexora, sendo três séries com cargas de 10RM, e intervalos de dois minutos entre as séries e exercícios. A SEQB – consistia primeiramente na aula de Jump Fit e em seguida a realização dos ER na mesma ordenação da SEQA. A realização das seqüências foi definida pelo balance cross-over design. Para verificar o comportamento do número de repetições, realizou-se uma ANOVA fatorial de duas entradas, seguida do teste post-hoc de Tuckey (p < 0,05). Comparando o número total de repetições dos ER sem a execução prévia do Jump Fit e após o Jump Fit, todas as séries comparadas apresentaram redução no número de repetições, com exceção da 1a série da flexão do joelho. Verificamos que a aula de Jump Fit influencia negativamente no desempenho dos ER.Palavras-chave: treinamento aeróbio, treinamento de força, treinamento concorrente, fadiga.

Evaluation of the functional tension of foreign medical student’s organisms in adapting to educational activities

2020 ◽  
pp. 755-755
Author(s):  
N. K. Smagulov ◽  
A. A. Adilbekova ◽  
N. V. Gitenis
Keyword(s):  
Mathematical Modeling ◽  
Foreign Students ◽  
Educational Process ◽  
Educational Activities ◽  
Modeling Methods ◽  
Functional Stress

The use of mathematical modeling methods allowed us to develop criteria for functional stress for assessing and predicting the level of functional stress of foreign students in the process of adaptation to the educational process.

scholarly journals Meta-Analysis Examining the Importance of Creatine Ingestion Strategies on Lean Tissue Mass and Strength in Older Adults

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1912
Author(s):  
Scott C. Forbes ◽  
Darren G. Candow ◽  
Sergej M. Ostojic ◽  
Michael D. Roberts ◽  
Philip D. Chilibeck
Keyword(s):  
Resistance Training ◽  
Meta Analysis ◽  
Creatine Supplementation ◽  
Strength Increase ◽  
Lean Tissue ◽  
Tissue Mass ◽  
Resistance Training Program ◽  
Lean Tissue Mass ◽  
Leg Press ◽  
Meta Analyses

Creatine supplementation in conjunction with resistance training (RT) augments gains in lean tissue mass and strength in aging adults; however, there is a large amount of heterogeneity between individual studies that may be related to creatine ingestion strategies. Therefore, the purpose of this review was to (1) perform updated meta-analyses comparing creatine vs. placebo (independent of dosage and frequency of ingestion) during a resistance training program on measures of lean tissue mass and strength, (2) perform meta-analyses examining the effects of different creatine dosing strategies (lower: ≤5 g/day and higher: >5 g/day), with and without a creatine-loading phase (≥20 g/day for 5–7 days), and (3) perform meta-analyses determining whether creatine supplementation only on resistance training days influences measures of lean tissue mass and strength. Overall, creatine (independent of dosing strategy) augments lean tissue mass and strength increase from RT vs. placebo. Subanalyses showed that creatine-loading followed by lower-dose creatine (≤5 g/day) increased chest press strength vs. placebo. Higher-dose creatine (>5 g/day), with and without a creatine-loading phase, produced significant gains in leg press strength vs. placebo. However, when studies involving a creatine-loading phase were excluded from the analyses, creatine had no greater effect on chest press or leg press strength vs. placebo. Finally, creatine supplementation only on resistance training days significantly increased measures of lean tissue mass and strength vs. placebo.

scholarly journals NEURAL ACTIVITY PROFILES ASSOCIATED WITH ACL INJURY-RISK MECHANICS IN ECOLOGICAL SPORT SPECIFIC VIRTUAL REALITY

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0015
Author(s):  
Dustin R. Grooms ◽  
Jed A. Diekfuss ◽  
Alexis B. Slutsky-Ganesh ◽  
Cody R. Criss ◽  
Manish Anand ◽  
...  
Keyword(s):  
Motor Control ◽  
Neural Activity ◽  
Injury Risk ◽  
Neural Control ◽  
Acl Injury ◽  
Initial Contact ◽  
Leg Press ◽  
Visual Spatial ◽  
Peak Knee ◽  
Acl Injury Risk

Background: Anterior cruciate ligament (ACL) injury is secondary to a multifactorial etiology encompassing anatomical, biological, mechanical, and neurological factors. The nature of the injury being primarily due to non-contact mechanics further implicates neural control as a key injury-risk factor, though it has received considerably less study. Purpose: To determine the contribution of neural activity to injury-risk mechanics in ecological sport-specific VR landing scenarios. Methods: Ten female high-school soccer players (15.5±0.85 years; 165.0±6.09 cm; 59.1±11.84 kg) completed a neuroimaging session to capture neural activity during a bilateral leg press and a 3D biomechanics session performing a header within a VR soccer scenario. The bilateral leg press involved four 30 s blocks of repeated bilateral leg presses paced to a metronome beat of 1.2 Hz with 30 s rest between blocks. The VR soccer scenario simulated a corner-kick, requiring the participant to jump and head a virtual soccer ball into a virtual goal (Figure 1A-E). Initial contact and peak knee flexion and abduction angles were extracted during the landing from the header as injury-risk variables of interest and were correlated with neural activity. Results: Evidenced in Table 1 and Figure 1 (bottom row), increased initial contact abduction, increased peak abduction, and decreased peak flexion were associated with increased sensory, visual-spatial, and cerebellar activity (r2= 0.42-0.57, p corrected < .05, z max > 3.1, table & figure 1). Decreased initial contact flexion was associated with increased frontal cortex activity (r2= 0.68, p corrected < .05, z max > 3.1). Conclusion: Reduced neural efficiency (increased activation) of key regions that integrate proprioceptive, visual-spatial, and neurocognitive activity for motor control may influence injury-risk mechanics in sport. The regions found to increase in activity in relation to higher injury-risk mechanics are typically activated to assist with spatial navigation, environmental interaction, and precise motor control. The requirement for athletes to increase their activity for more basic knee motor control may result in fewer neural resources available to maintain knee joint alignment, allocate environmental attention, and handle increased motor coordination demands. These data indicate that strategies to enhance efficiency of visual-spatial and cognitive-motor control during high demand sporting activities is warranted to improve ACL injury-risk reduction. [Figure: see text][Table: see text]

scholarly journals Early Maximal Strength Training Improves Leg Strength and Postural Stability in Elderly Following Hip Fracture Surgery

2021 ◽  
Vol 12 ◽  
pp. 215145932110151
Author(s):  
Ole Kristian Berg ◽  
Jens-Meinhard Stutzer ◽  
Jan Hoff ◽  
Eivind Wang
Keyword(s):  
Hip Fracture ◽  
Muscle Strength ◽  
Strength Training ◽  
Postural Stability ◽  
Maximal Strength ◽  
Leg Press ◽  
Hip Fracture Surgery ◽  
Downward Spiral ◽  
Conventional Physiotherapy ◽  
Fracture Surgery

Introduction: Hip fractures predominantly occur in the geriatric population and results in increased physical inactivity and reduced independency, largely influenced by a downward spiral of ambulatory capacity, related to loss of skeletal muscle strength and postural stability. Thus, effective postoperative treatment, targeting improvements in muscle strength, is sought after. Materials & Methods: Twenty-one hip fracture patients (>65 yr) were randomized to 8 weeks of either conventional physiotherapy control group (CG), or leg press and hip abduction maximal strength training (MST) 3 times per week. MST was performed applying heavy loads (85-90% of 1 repetition maximum; 1RM) and 4-5 repetitions in 4 sets. Maximal strength (bi- and unilateral 1RM), postural stability (unipedal stance test; UPS), and DEXA-scan bone mineral content/ density (BMC/BMD) were measured before and after the 8-week rehabilitation. Results: Both MST and conventional physiotherapy improved bilateral leg press 1RM by 41 ± 27 kg and 29 ± 17 kg, respectively (both p < 0.01), while unilateral leg press 1RM only increased after MST (within group and between groups difference: both p < 0.05). MST also resulted in an increase in abduction 1RM in both the fractured (5 kg, 95%CI: 2-7; p < 0.01) and healthy limb (6 kg, 95%CI: 3-9; p < 0.01), while no such improvement was apparent in the CG (between groups difference: p < 0.01). Finally, MST improved UPS of the fractured limb (p < 0.05). No differences were observed in BMC or BMD following the 8 weeks. Discussion: Early postoperative MST improved lower extremities maximal muscle strength more than conventional physiotherapy and was accompanied by improvements in postural stability. Conclusion: Implementing MST in early rehabilitation after hip fracture surgery should be considered as a relevant treatment to curtail the downward spiral of reduced ambulatory capacity typical for this patient group, possibly reducing the risk of recuring falls and excess mortality. Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03030092

Evidence-based testing of the hamstring muscles using wireless surface emg

2011 ◽  
Vol 45 (4) ◽  
pp. 358-358
Author(s):  
K. Kotila ◽  
T. Sveinsson ◽  
A. Arnason
Keyword(s):  
Surface Emg ◽  
Evidence Based ◽  
Hamstring Muscles

scholarly journals Knee Muscle Strength Recovery in the Early Period After ACL Reconstruction

2014 ◽  
Vol 2 (11_suppl3) ◽  
pp. 2325967114S0014
Author(s):  
Gulcan Harput ◽  
Hasan Erkan Kılınc ◽  
Hamza Özer ◽  
Gül Baltacı ◽  
Carl G. Mattacola
Keyword(s):  
Acl Reconstruction ◽  
Early Period ◽  
Quadriceps Strength ◽  
Isometric Strength ◽  
Time Points ◽  
Hamstring Muscles ◽  
Significant Difference ◽  
Isometric Torque ◽  
Over Time ◽  
Time Point

Objectives: The aim of this study was to investigate quadriceps and hamstrings isometric strength at 4, 8 and 12 week time points following ACL Reconstruction (ACLR) and to document the strength changes of these muscles over time. The primary hypothesis was that there would be significant increases in quadriceps and hamstring muscle strengths between the 4th, 8th and 12th weeks following ACLR. The secondary hypothesis was that the quadriceps index would be higher than hamstring index at 12th week after ACLR. Methods: Thirty patients (Mean ± SD [age, 29.1±2.3yrs; weight, 77.3±13.2kg; height, 172.1±7.1cm; BMI, 21.2±3.5kg/m2, time to surgery: 7.1±7.2 months]) who underwent ACLR with Hamstring Tendon Autograft (HTG) were enrolled in this study. The isometric strength of quadriceps and hamstring muscles was measured on an isokinetic dynamometer at 60° knee flexion angle at 4th, 8th and 12th weeks after surgery. The recovery of quadriceps and hamstring muscles strength following rehabilitation was expressed as a Quadriceps Index (QI) and Hamstring Index (HI) and calculated with the following formula:[(maximum voluntary isometric torque of the involved limb / maximum voluntary isometric torque by uninvolved limb) × 100]. Torque output of the involved and uninvolved limbs and quadriceps and hamstring indexes were used for the statistical analysis. A repeated measures of ANOVA was used to determine the strength changes of quadriceps and hamstrings over time. Results: Quadriceps and Hamstrings strengths significantly increased over time for both involved (Quadriceps: F (2,46)=58.3, p<0.001, Hamstring: F (2,46)=35.7, p<0.001) and uninvolved limb (Quadriceps: F(2,46)=17.9, p<0.001, Hamstring: F(2,46)=56.9, p=0.001 ). Quadriceps strength was higher at 12th week when compared to the 8 and 4 week time points for the involved limb (p<0.001), and it was higher at 8th week when compared to 4 week time point for the involved limb (p<0.001). For the uninvolved limb, quadriceps strength was also higher at 12th week when compared to the 8 (p=0.02) and 4 week time point (p<0.001), and higher at 8 week when compared to the 4 week time point (p=0.02). Hamstring strength was higher at 12 week when compared to the 8 and 4 week time points (p<0.001) and it was higher at 8 week when compared to 4 week time point for the involved limb (p<0.001). For the uninvolved limb hamstring strength was also higher at 12 week when compared to 4 week time point (p=0.01). There was no significant difference between the 4 and 8 week time points (p>0.05) or between the 8 and 12 week time points (p=0.07). Quadriceps and hamstring indexes significantly changed from 4th weeks (QI:57.9, HI:54.4 ) to 8th weeks (QI:78.8, HI:69.9 ) and from 8th weeks to 12th weeks (QI:82, HI:75.7 ) (p<0.001); however, there was no difference between indexes at the 12-week time point (p=0.17). Conclusion: Isometric strength of quadriceps and hamstring muscles for the involved and uninvolved limb increased during the early period of ACLR. The results of this study could be a baseline for clinicians while prescribing a rehabilitation protocol for ACLR patients with HTG to better appreciate expected strength changes of the muscles in the early phase.

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