scholarly journals The Influence of Growth, Maturation and Resistance Training on Muscle-Tendon and Neuromuscular Adaptations: A Narrative Review

Sports ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 59
Author(s):  
Nakul Tumkur Anil Kumar ◽  
Jon L. Oliver ◽  
Rhodri S. Lloyd ◽  
Jason S. Pedley ◽  
John M. Radnor

The purpose of this article is to provide an overview of the growth, maturation and resistance training-related changes in muscle-tendon and neuromuscular mechanisms in youth, and the subsequent effect on performance. Sprinting, jumping, kicking, and throwing are common movements in sport that have been shown to develop naturally with age, with improvements in performance being attributed to growth and maturity-related changes in neuromuscular mechanisms. These changes include moderate to very large increases in muscle physiological cross-sectional area (CSA), muscle volume and thickness, tendon CSA and stiffness, fascicle length, muscle activation, pre-activation, stretch reflex control accompanied by large reductions in electro-mechanical delay and co-contraction. Furthermore, a limited number of training studies examining neuromuscular changes following four to 20 weeks of resistance training have reported trivial to moderate differences in tendon stiffness, muscle CSA, muscle thickness, and motor unit activation accompanied by reductions in electromechanical delay (EMD) in pre-pubertal children. However, the interaction of maturity- and training-related neuromuscular adaptions remains unclear. An understanding of how different neuromuscular mechanisms adapt in response to growth, maturation and training is important in order to optimise training responsiveness in youth populations. Additionally, the impact that these muscle-tendon and neuromuscular changes have on force producing capabilities underpinning performance is unclear.

2018 ◽  
Author(s):  
Gerald T. Mangine ◽  
Michael J. Redd ◽  
Adam M. Gonzalez ◽  
Jeremy R. Townsend ◽  
Adam J Wells ◽  
...  

AbstractResistance training may differentially affect morphological adaptations along the length of uni-articular and bi-articular muscles. The purpose of this study was to compare changes in muscle morphology along the length of the rectus femoris (RF) and vastus lateralis (VL) in response to resistance training. Following a 2-wk preparatory phase, 15 resistance-trained men (24.0 ± 3.0 y, 90.0 ± 13.8 kg, 174.9 ± 20.7 cm) completed pre-training (PRE) assessments of muscle thickness (MT), pennation angle (PA), cross-sectional area (CSA), and echo-intensity in the RF and VL at 30, 50, and 70% of each muscle’s length; fascicle length (FL) was estimated from respective measurements of MT and PA within each muscle and region. Participants then began a high intensity, low volume (4 × 3 − 5 repetitions, 3min rest) lower-body resistance training program, and repeated all PRE-assessments after 8 weeks (2 d · wk−1) of training (POST). Although three-way (muscle [RF, VL] × region [30, 50, 70%] × time [PRE, POST]) repeated measures analysis of variance did not reveal significant interactions for any assessment of morphology, significant simple (muscle × time) effects were observed for CSA (p = 0.002) and FL (p = 0.016). Specifically, average CSA changes favored the VL (2.96 ± 0.69 cm2, pp < 0.001) over the RF (0.59 ± 0.20 cm2, p = 0.011), while significant decreases in average FL were noted for the RF (–1.03 ± 0.30 cm, p = 0.004) but not the VL (–0.05 ± 0.36 cm, p = 0.901). No other significant differences were observed. The findings of this study demonstrate the occurrence of non-homogenous adaptations in RF and VL muscle size and architecture following 8 weeks of high-intensity resistance training in resistance-trained men. However, training does not appear to influence region-specific adaptations in either muscle.


BMJ Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. e039939
Author(s):  
Sahdia Parveen ◽  
Sarah Jane Smith ◽  
Cara Sass ◽  
Jan R Oyebode ◽  
Andrea Capstick ◽  
...  

ObjectivesThe aim of this study was to establish the impact of dementia education and training on the knowledge, attitudes and confidence of health and social care staff. The study also aimed to identify the most effective features (content and pedagogical) of dementia education and training.DesignCross-sectional survey study. Data collection occurred in 2017.SettingsHealth and social care staff in the UK including acute care, mental health community care trusts, primary care and care homes.ParticipantsAll health and social care staff who had completed dementia education and training meeting the minimal standards as set by Health Education England, within the past 5 years were invited to participate in an online survey. A total of 668 health and social care staff provided informed consent and completed an online survey, and responses from 553 participants were included in this study. The majority of the respondents were of white British ethnicity (94.4%) and identified as women (88.4%).OutcomesKnowledge, attitude and confidence of health and social care staff.ResultsHierarchical multiple regression analysis was conducted. Staff characteristics, education and training content variables and pedagogical factors were found to account for 29% of variance in staff confidence (F=4.13, p<0.001), 22% of variance in attitude (knowledge) (F=3.80, p<001), 18% of the variance in staff knowledge (F=2.77, p<0.01) and 14% of variance in staff comfort (attitude) (F=2.11, p<0.01).ConclusionThe results suggest that dementia education and training has limited impact on health and social care staff learning outcomes. While training content variables were important when attempting to improve staff knowledge, more consideration should be given to pedagogical factors when training is aiming to improve staff attitude and confidence.


Author(s):  
Stefano Longo ◽  
Emiliano Cè ◽  
Angela Valentina Bisconti ◽  
Susanna Rampichini ◽  
Christian Doria ◽  
...  

Abstract Purpose We investigated the effects of 12 weeks of passive static stretching training (PST) on force-generating capacity, passive stiffness, muscle architecture of plantarflexor muscles. Methods Thirty healthy adults participated in the study. Fifteen participants (STR, 6 women, 9 men) underwent 12-week plantarflexor muscles PST [(5 × 45 s-on/15 s-off) × 2exercises] × 5times/week (duration: 2250 s/week), while 15 participants (CTRL, 6 women, 9 men) served as control (no PST). Range of motion (ROM), maximum passive resistive torque (PRTmax), triceps surae architecture [fascicle length, fascicle angle, and thickness], passive stiffness [muscle–tendon complex (MTC) and muscle stiffness], and plantarflexors maximun force-generating capacity variables (maximum voluntary contraction, maximum muscle activation, rate of torque development, electromechanical delay) were calculated Pre, at the 6th (Wk6), and the 12th week (Wk12) of the protocol in both groups. Results Compared to Pre, STR ROM increased (P < 0.05) at Wk6 (8%) and Wk12 (23%). PRTmax increased at Wk12 (30%, P < 0.05), while MTC stiffness decreased (16%, P < 0.05). Muscle stiffness decreased (P < 0.05) at Wk6 (11%) and Wk12 (16%). No changes in triceps surae architecture and plantarflexors maximum force-generating capacity variables were found in STR (P > 0.05). Percentage changes in ROM correlated with percentage changes in PRTmax (ρ = 0.62, P = 0.01) and MTC stiffness (ρ = − 0.78, P = 0.001). In CTRL, no changes (P > 0.05) occurred in any variables at any time point. Conclusion The expected long-term PST-induced changes in ROM were associated with modifications in the whole passive mechanical properties of the ankle joint, while maximum force-generating capacity characteristics were preserved. 12 weeks of PST do not seem a sufficient stimulus to induce triceps surae architectural changes.


2011 ◽  
Vol 46 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Eleftherios Kellis ◽  
Andreas Zafeiridis ◽  
Ioannis G. Amiridis

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 &gt; .05), but it increased the ratio during the LR1 phase (P &lt; .05). The GAS∶TA EMG ratio increased during the LR1 phase after fatigue (P &lt; .05) but remained unchanged during the PR and LR2 phrases (P &gt; .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.


2009 ◽  
Vol 34 (4) ◽  
pp. 609-615 ◽  
Author(s):  
Bareket Falk ◽  
Charlotte Usselman ◽  
Raffy Dotan ◽  
Laura Brunton ◽  
Panagiota Klentrou ◽  
...  

Muscle strength and activation were compared in boys and men during maximal voluntary elbow flexion and extension contractions. Peak torque, peak rate of torque development (dτ/dτmax), rate of muscle activation, and electromechanical delay (EMD) were measured in 15 boys (aged 9.7 ± 1.6 years) and 16 men (aged 22.1 ± 2.8 years). During flexion, peak torque was significantly lower in boys than in men (19.5 ± 5.8 vs. 68.5 ± 11.0 Nm, respectively; p < 0.05), even when controlling for upper-arm cross-sectional area (CSA), and peak electromyography activity. Boys also exhibited a lower normalized dτ/dτmax (7.2 ± 1.7 vs. 9.5 ± 1.6 (Nm·s–1)·(Nm–1), respectively; p < 0.05) and a significantly longer EMD (75.5 ± 28.4 vs. 47.6 ± 17.5 ms, respectively). The pattern was similar for extension, except that group differences in peak torque were no longer significant when normalized for CSA. These results suggest that children may be less able to recruit or fully utilize their higher-threshold motor units, resulting in lower dimensionally normalized maximal torque and rate of torque development.


2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Taiwo Akeem Lawal

Abstract Background The care of children with fecal incontinence is suboptimal with inadequate support and training opportunities. The postgraduate training of pediatric surgeons on the management of fecal incontinence is inadequate since each training center is not likely to see enough number of cases yearly. Supplemental training through workshops on fecal incontinence may help to bridge the gap. The aim of this cross sectional study was to evaluate the impact of previous attendance of a workshop on fecal incontinence management practices among pediatric surgeons. Results A total of 41 respondents participated. Eleven (26.8%) respondents had attended a workshop in the past and seven (17.1%) had done a Malone antegrade continent enema (MACE) on patients. A higher proportion of respondents who had practiced for over 15 years had attended a workshop on fecal incontinence compared to those who had not attended one (90.9% vs. 33.3%, p = 0.001). The proportion of respondents who had attended a workshop on fecal incontinence and had performed a MACE (18.2%) was higher than the proportion of those who had not attended a workshop and had performed a similar procedure on patients (3.3%), p = 0.047. Conclusions One quarter of pediatric surgeons in the country surveyed had attended a workshop on fecal incontinence. Prior attendance of a workshop on fecal incontinence is significantly related to experience and significantly influenced the performance of a MACE procedure. Supplementation of the training of pediatric surgeons through workshops on fecal incontinence will help to improve capacity in pediatric colorectal surgical care.


2018 ◽  
Vol 39 (05) ◽  
pp. 355-365 ◽  
Author(s):  
Cassio Ruas ◽  
Lee Brown ◽  
Camila Lima ◽  
G. Gregory Haff ◽  
Ronei Pinto

AbstractThe aim of this study was to compare three specific concentric and eccentric muscle action training protocols on quadriceps-hamstrings neuromuscular adaptations. Forty male volunteers performed 6 weeks of training (two sessions/week) of their dominant and non-dominant legs on an isokinetic dynamometer. They were randomly assigned to one of four groups; concentric quadriceps and concentric hamstrings (CON/CON, n=10), eccentric quadriceps and eccentric hamstrings (ECC/ECC, n=10), concentric quadriceps and eccentric hamstrings (CON/ECC, n=10), or no training (CTRL, n=10). Intensity of training was increased every week by decreasing the angular velocity for concentric and increasing it for eccentric groups in 30°/s increments. Volume of training was increased by adding one set every week. Dominant leg quadriceps and hamstrings muscle thickness, muscle quality, muscle activation, muscle coactivation, and electromechanical delay were tested before and after training. Results revealed that all training groups similarly increased MT of quadriceps and hamstrings compared to control (p<0.05). However, CON/ECC and ECC/ECC training elicited a greater magnitude of change. There were no significant differences between groups for all other neuromuscular variables (p>0.05). These findings suggest that different short-term muscle action isokinetic training protocols elicit similar muscle size increases in hamstrings and quadriceps, but not for other neuromuscular variables. Nevertheless, effect sizes indicate that CON/ECC and ECC/ECC may elicit the greatest magnitude of change in muscle hypertrophy.


Author(s):  
Paul William Hendrickse ◽  
Tomas Venckunas ◽  
Justinas Platkevicius ◽  
Ramutis Kairaitis ◽  
Sigitas Kamandulis ◽  
...  

AbstractWhile concurrent training is regularly used in older populations, the inverse relationship between fibre size and oxidative capacity suggests that endurance training in resistance-trained individuals may result in some loss of resistance training-induced gains in muscle mass, which may be more pronounced in older people. We investigated the impact of superimposed endurance training in younger (28.5 ± 4.8 years; n = 8) and older (67.5 ± 5.5 years; n = 7) highly resistance-trained men. Participants underwent a 10-week endurance cycling training programme consisting of five 6-min intervals at 75% max heart rate (HRmax) separated by 4-min intervals at 90% HRmax. The anatomical cross-sectional area (ACSA) of the thigh muscles, as determined with MRI, was 24% smaller in older compared to younger participants (p < 0.001). Although maximal oxygen consumption (VO2max) was also lower in the older group (p < 0.001), VO2max per kg body mass did not differ significantly between younger and older participants. Histological analyses of biopsies of the m. vastus lateralis showed that endurance training induced an increase in succinate dehydrogenase activity in both younger and older participants (p ≤ 0.043), and an increase in the number of capillaries around type I fibres (p = 0.017). The superimposed endurance training did not induce a significant decrease in thigh ACSA, fibre cross-sectional area, or knee extensor maximum voluntary isometric force. These observations indicate that adding endurance training to resistance training can lead to positive endurance-related adaptations without negative consequences for muscle size and strength in older and younger resistance-trained people.


2016 ◽  
Vol 27 (1) ◽  
pp. 50-61 ◽  
Author(s):  
Angela Shin-yih Chen ◽  
Yu-hsiang Hou ◽  
I-heng Wu

Purpose – This paper aims to explore the relationships between emotional intelligence (EI), conflict management styles and job performance in a Chinese cultural context. Design/methodology/approach – The present paper uses a cross-sectional research design. Paper-based questionnaires were distributed to employees working in the R & D department of a science and technology institute in Taiwan. In total, 300 questionnaires were distributed and 248 valid questionnaires were analyzed, with a return rate of 81.4 per cent. Findings – The results show that EI has a positive impact on job performance. Furthermore, agreeable conflict style positively moderated between EI and job performance, whereas active conflict style has negative moderating effect. Research limitations/implications – Due to the research design, sample and data collection method, the research results may lack representativeness. Therefore, researchers are encouraged to use a different approach in the future. Practical implications – Organizations should strengthen employees’ EI and conflict management abilities to improve job performance. Organizations can apply the results of this study in accordance with their policy on recruitment, selection and training. Originality/value – Organizations should strengthen employees’ EI and conflict management abilities to improve job performance. Organizations can apply the results of this study in accordance with their policies on recruitment, selection and training.


2016 ◽  
Vol 11 (7) ◽  
pp. 959-964
Author(s):  
Fábio J. Lanferdini ◽  
Rodrigo R. Bini ◽  
Pedro Figueiredo ◽  
Fernando Diefenthaeler ◽  
Carlos B. Mota ◽  
...  

Purpose:To employ cluster analysis to assess if cyclists would opt for different strategies in terms of neuromuscular patterns when pedaling at the power output of their second ventilatory threshold (POVT2) compared with cycling at their maximal power output (POMAX).Methods:Twenty athletes performed an incremental cycling test to determine their power output (POMAX and POVT2; first session), and pedal forces, muscle activation, muscle–tendon unit length, and vastus lateralis architecture (fascicle length, pennation angle, and muscle thickness) were recorded (second session) in POMAX and POVT2. Athletes were assigned to 2 clusters based on the behavior of outcome variables at POVT2 and POMAX using cluster analysis.Results:Clusters 1 (n = 14) and 2 (n = 6) showed similar power output and oxygen uptake. Cluster 1 presented larger increases in pedal force and knee power than cluster 2, without differences for the index of effectiveness. Cluster 1 presented less variation in knee angle, muscle–tendon unit length, pennation angle, and tendon length than cluster 2. However, clusters 1 and 2 showed similar muscle thickness, fascicle length, and muscle activation. When cycling at POVT2 vs POMAX, cyclists could opt for keeping a constant knee power and pedal-force production, associated with an increase in tendon excursion and a constant fascicle length.Conclusions:Increases in power output lead to greater variations in knee angle, muscle–tendon unit length, tendon length, and pennation angle of vastus lateralis for a similar knee-extensor activation and smaller pedal-force changes in cyclists from cluster 2 than in cluster 1.


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