- Associate professor at the Department of Physical Education and Sports Science of the Aristotle University of Thessal... moreAssociate professor at the Department of Physical Education and Sports Science of the Aristotle University of Thessaloniki, born in Thessaloniki, Greece, in 1974. His is research interests are related to factors that affect the biomechanical and neuromuscular function (fatigue, neuromuscular diseases, sport injuries, gender, age, training and footwear) and the investigation of their underlying mechanismsedit
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This chapter introduces issues regarding motor deficits in people with intellectual disability (ID), focusing on two motor skills that are essential for life, namely, gait and balance. As the average age of the general population... more
This chapter introduces issues regarding motor deficits in people with intellectual disability (ID), focusing on two motor skills that are essential for life, namely, gait and balance. As the average age of the general population increases and people with ID live longer the ability to achieve static and dynamic balance and an increased risk of falling are becoming increasingly important issues. A better understanding of the nature of gait and balance problems, and identification of the causes of falling in persons with ID may help to develop intervention strategies and techniques preventing falls and injuries in the future. There are several important features of the neuromuscular system that affect the efficiency of gait and balance. These include the level of general physical fitness, coordination, and muscle strength and power, which are commonly reduced in populations with ID. Bearing in mind the limitations of these deficits, the attributes of gait and balance are affected and compensatory mechanisms may be engaged. In this chapter, the literature regarding gait and balance in people with ID compared with nonsymptomatic populations is reviewed, helping to identify the causes and mechanisms of deficits in motor performance. Furthermore, apart from intrinsic causes due to the pathophysiology of the disease, there are environmental conditions, such as the level of physical activity that could reverse negative attitudes for the benefit of people with ID in terms of quality of life. It is concluded, that gait and balance can be improved with interventions involving more physical activities, although further randomized clinical trials are required to establish solid training protocols and treatments.
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Shoulder strength is essential for gymnasts in order to succeed in their sport, but little research has examined isometric and isokinetic shoulder moment and flexion/extension ratios. The purpose of this study was to evaluate the relative... more
Shoulder strength is essential for gymnasts in order to succeed in their sport, but little research has examined isometric and isokinetic shoulder moment and flexion/extension ratios. The purpose of this study was to evaluate the relative and absolute reliability of isometric and isokinetic shoulder moment and shoulder flexion/extension ratios. Fifteen international level male gymnasts (age: 19.3 ± 2.3 years) participated in the study. Two identical measurements with one week interval were applied using the isokinetic Humac Norm 770 dynamometer at three angles (45o, 90o, and 135o) for isometric and at three angular velocities (60o/s, 180o/s, and 300o/s) for concentric and eccentric action modes. All measurements were conducted in a range of motion of 10o to 180o, in supine position, bilaterally, with the elbows fully extended. Notwithstanding a small systematic bias (due to testing/learning) from measurement 1 to measurement 2 significant in four parameters, the results supported th...
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Introduction: Polyneuromyopathy constitutes a common complication in critically ill patients of the Intensive Care Unit (ICU) and in the last few years it appears to be identified as a syndrome detectable in the limbs and respiratory... more
Introduction: Polyneuromyopathy constitutes a common complication in critically ill patients of the Intensive Care Unit (ICU) and in the last few years it appears to be identified as a syndrome detectable in the limbs and respiratory muscles. It is associated with the difficulties during weaning from mechanical ventilation. Aim: The present study investigates the reflective reaction of the soleus muscle following an electrical stimulation of the tibial nerve in intubated critically ill patients hospitalized in ICU with no medical history prior to their admission. Methods: Thirteen (13) patients who had been hospitalized for more than five (5) days and had a high APACHE II score (>15) and 13 age-matched control subjects were asked to participate in the present study on a volunteer basis. During the study, as reflective response parameters the range of the H-reflex and M-wave of the soleus muscle, as well as the conduction velocity of the tibial nerve, after electro-stimulation of ...
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Purpose: To examine the effect of drop height on vertical jumping performance in children with respect to sex and maturity status. Methods: Thirty-seven pre-pubertal, 71 circa-pubertal, and 69 post-pubertal boys and girls performed, in a... more
Purpose: To examine the effect of drop height on vertical jumping performance in children with respect to sex and maturity status. Methods: Thirty-seven pre-pubertal, 71 circa-pubertal, and 69 post-pubertal boys and girls performed, in a randomized order, 2 squat jumps, 2 countermovement jumps, and 2 drop jumps (DJ) from heights of 20, 30, 40, 50, 60, and 70 cm. The trial with the best jump height in each test was used for analysis. Results: No significant sex × maturity status × jump type interaction for jump height was observed. However, on average, the children jumped higher in the countermovement jump than in squat jump and DJs (+1.2 and +1.6 cm, P < .001, respectively), with no significant differences between DJs and squat jumps or between DJs when increasing drop heights. Regarding DJs, 59.3% of the participants jumped higher from drop heights of 20 to 40 cm. Conclusions: Children, independent of sex and maturity status, performed best in the countermovement jump, and no pe...
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Purpose: This study examined the underlying mechanisms of postactivation potentiation and the time course of muscular- and neural-related variables. Methods: Fourteen trained males executed 4 sets of six 6-second maximum isometric... more
Purpose: This study examined the underlying mechanisms of postactivation potentiation and the time course of muscular- and neural-related variables. Methods: Fourteen trained males executed 4 sets of six 6-second maximum isometric conditioning plantar flexions, with 15 seconds and 2 minutes of interval between the contractions and sets, respectively. Peak twitch torque (TT), rate of torque development, time to peak torque, half relaxation time, and the neural-related variables of H-reflex and electromyogram, normalized to the maximum M-wave (H/M and RMS/M, respectively), were evaluated, as well as the level of the voluntary activation, assessed by the twitch interpolation technique. All neural-related variables were analyzed for the trial within each set when TT was maximal and for the trial within each set when the neural-related variable itself was maximal. Results: Compared with the baseline measures, TT and rate of torque development significantly increased in all sets (P < ....
This systematic review documents the protocol characteristics of studies that used neuromuscular electrical stimulation protocols (NMES) on the plantar flexors [through triceps surae (TS) or tibial nerve (TN) stimulation] to stimulate... more
This systematic review documents the protocol characteristics of studies that used neuromuscular electrical stimulation protocols (NMES) on the plantar flexors [through triceps surae (TS) or tibial nerve (TN) stimulation] to stimulate afferent pathways. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, was registered to PROSPERO (ID: CRD42022345194) and was funded by the Greek General Secretariat for Research and Technology (ERA-NET NEURON JTC 2020). Included were original research articles on healthy adults, with NMES interventions applied on TN or TS or both. Four databases (Cochrane Library, PubMed, Scopus, and Web of Science) were systematically searched, in addition to a manual search using the citations of included studies. Quality assessment was conducted on 32 eligible studies by estimating the risk of bias with the checklist of the Effective Public Health Practice Project Quality Assessment Tool....
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Drop jump (DJ) performance gain with increasing drop height is well documented in adults, but there is still no clear evidence of such gain in children. This study aimed to examine the differences in DJ performance gain in male adults and... more
Drop jump (DJ) performance gain with increasing drop height is well documented in adults, but there is still no clear evidence of such gain in children. This study aimed to examine the differences in DJ performance gain in male adults and prepubescent boys by comparing drop heights tailored to each individual’s performance and expressed as a percentage of their squat jump (SJ) performance. Fifteen boys (9–11 y) and 15 men (19–27 y) executed DJs from drop heights that were set at 75%, 100%, 125%, and 150% of their best performance in SJ (DJ75, DJ100, DJ125, and DJ150, respectively). Vertical ground reaction force (vGRF), contact time and kinematics of the lower extremities were captured. The results showed that boys jumped significantly lower than adults in DJs, and both age groups presented jumping gain with increasing drop height, up to DJ125. Boys demonstrated longer total contact time, lower angular velocity and vGRF during the propulsive phase, as well as smaller knee flexion at...
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BACKGROUND Whole-body tracking of visual motion cues is used in balance training to improve weight shifting ability in old age and sports. RESEARCH QUESTION How tracking of a complex (pink noise) and a periodic visual target motion during... more
BACKGROUND Whole-body tracking of visual motion cues is used in balance training to improve weight shifting ability in old age and sports. RESEARCH QUESTION How tracking of a complex (pink noise) and a periodic visual target motion during anteroposterior weight shifting affects postural and muscle responses to unilateral hip vibration. METHODS Twenty-six participants performed 160 anteroposterior weight shifting cycles while tracking the vertical motion of a visual target, concurrently receiving Center of Pressure (CoP) feedback. They were randomly divided to groups; (a) the Constant group tracked a visual target motion constructed by 3 sinusoids of different amplitude, and (b) the Pink group tracked a complex visual target motion constructed by a pink noise generation process. Between the 60th and the 120th cycle, vibration was applied to the right gluteus medius, introducing a sideways CoP deviation. CoP displacement and electromyographic (EMG) responses of soleus, tibialis anterior and peroneus longus were recorded and summarized in blocks of 3 cycles. RESULTS Sideways CoP deviation induced at the onset/offset of unilateral hip vibration was smaller for the Pink than the Constant group. The Pink group demonstrated greater tibialis anterior and peroneus longus EMG activity around the most anterior sway peak while soleus EMG was similar for the two groups. Both groups successfully coupled weight shifting amplitude to the target motion, but the Pink group tracked the target motion with a greater delay compared to the Constant group. SIGNIFICANCE Whole body tracking of complex visual motions evokes perception-based action and increases ankle muscle co-activation making sway more resilient to a proprioceptive perturbation induced by unilateral hip vibration. Complex visual guidance motions should be considered when designing balance rehabilitation regimes, aiming at improving weight shifting ability and dynamic balance control.
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To support clinical decision-making in central neurological disorders, a physical examination is used to assess responses to passive muscle stretch. However, what exactly is being assessed is expressed and interpreted in different ways. A... more
To support clinical decision-making in central neurological disorders, a physical examination is used to assess responses to passive muscle stretch. However, what exactly is being assessed is expressed and interpreted in different ways. A clear diagnostic framework is lacking. Therefore, the aim was to arrive at unambiguous terminology about the concepts and measurement around pathophysiological neuromuscular response to passive muscle stretch. During two consensus meetings, 37 experts from 12 European countries filled online questionnaires based on a Delphi approach, followed by plenary discussion after rounds. Consensus was reached for agreement ≥75%. The term hyper-resistance should be used to describe the phenomenon of impaired neuromuscular response during passive stretch, instead of for example 'spasticity' or 'hypertonia'. From there, it is essential to distinguish non-neural (tissue-related) from neural (central nervous system related) contributions to hyper-...
Research Interests: Medicine, Physical Medicine and Rehabilitation, Spasticity, Humans, Europe, and 10 moreConsensus, Electromyography, Model Based Clinical Decision Support Systems, Clinical Sciences, Neuromuscular diseases, Clinical Decision Support Systems, Delphi Technique, Neurosciences, Neurologic Examination, and Muscle spasticity
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This study aimed to investigate age-related differences in electromyographic (EMG) responses to unexpected Achilles tendon vibration (ATV) perturbations while standing blindfold. ATV with variable and random duration (12-15 s) and rest... more
This study aimed to investigate age-related differences in electromyographic (EMG) responses to unexpected Achilles tendon vibration (ATV) perturbations while standing blindfold. ATV with variable and random duration (12-15 s) and rest periods (20-24 s) was applied on 18 young and 16 older volunteers. The anterior/posterior center of pressure (CoP) and the soleus (SOL) and tibialis anterior (TA) EMG were analyzed for 1 s before and 8 s after the ATV onset and offset. ATV induced a posterior shift of CoP in both groups, with more pronounced shift in the older group. During ATV onset, the older group demonstrated less SOL and more TA EMG increase compared to the young group. During the first 0.5 s of ATV offset, SOL EMG was decreased in both age groups, while TA showed a burst of EMG activity that was greater in the older group. No difference in the latencies of EMG peaks or valleys was observed between the groups. It is concluded that ATV induces greater posterior CoP shift in older adults, and they adopt a recovery strategy, characterized by a decreased SOL activation and an increased TA activation. These differences are possibly attributed to the increased fear of falling, decreased limits of stability and reduced capacity of older people to reweight their sensory inflow when proprioception is distorted.
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The purpose of this study was to compare the acute effects of three different stretching protocols on balance, agility, reaction time and movement time of the upper limbs. Participants were thirty one female high school athletes (age =... more
The purpose of this study was to compare the acute effects of three different stretching protocols on balance, agility, reaction time and movement time of the upper limbs. Participants were thirty one female high school athletes (age = 17.3 ± 0.5 yr.). All participants performed one of the following protocols on different days: (a) 3 min jogging followed by 7 min static stretching (SS), (b) 3 min jogging followed by 7 min dynamic stretching (DS), and (c) 3 min jogging followed by 7 min of rest (NS). After the protocols participants performed the following tests: dynamic balance, 505 agility test, reaction time (time between a sound stimulus and release of a button) and movement time (movement of the upper extremity over a 0.5 m distance). The order of stretching protocols and performance tests were counterbalanced to avoid carryover effects. Repeated measures analysis of variance revealed significant main effects for all variables except reaction time. The DS protocol compared to SS...
Research Interests: Mechanical Engineering, Bioinformatics, Mathematics, Materials Science, Life Sciences, and 15 moreMedicine, Muscle strength, Proprioception, Humans, Biomedical Research, Knee, Flexibility, Male, Adult, Analysis of Variance, Curriculum and Pedagogy, Muscle contraction, Medicine and Science In Sports and Exercise, Knee Joint, and Quadriceps Muscle
Limited research exists in the literature regarding the biomechanics of the jump-landing sequence in individuals that experience symptoms of muscle damage. The present study investigated the effects of knee localized muscle damage on... more
Limited research exists in the literature regarding the biomechanics of the jump-landing sequence in individuals that experience symptoms of muscle damage. The present study investigated the effects of knee localized muscle damage on sagittal plane landing biomechanics during drop vertical jump (DVJ). Thirteen regional level athletes performed five sets of 15 maximal eccentric voluntary contractions of the knee extensors of both legs at 60°/s. Pelvic and lower body kinematics and kinetics were measured pre- and 48 h post-eccentric exercise. The examination of muscle damage indicators included isometric torque, muscle soreness, and serum creatine kinase (CK) activity. The results revealed that all indicators changed significantly following eccentric exercise (p < 0.05). Peak knee and hip joint flexion as well as peak anterior pelvic tilt significantly increased, whereas vertical ground reaction force (GRF), internal knee extension moment, and knee joint stiffness significantly dec...
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PURPOSE To examine the effect of a 10-week plyometric training (PT) on the kinematic and kinetic properties of prepubescent girls during squat jump, countermovement jump, and drop jumps. METHODS Twenty-four untrained girls (aged 9-11 y)... more
PURPOSE To examine the effect of a 10-week plyometric training (PT) on the kinematic and kinetic properties of prepubescent girls during squat jump, countermovement jump, and drop jumps. METHODS Twenty-four untrained girls (aged 9-11 y) were assigned to a training group (TG) and a control group. The TG followed twice a week PT for 10 weeks. Squat jump, countermovement jump, and drop jumps performed from heights of 20, 35, and 50 cm were tested before and after PT. Jump height, kinematic, and kinetic parameters were evaluated using a motion analysis system and a force plate. RESULTS Jumping height in all jump types increased significantly after PT for the TG (P < .001). After training, the TG presented increased power (P < .001) and knee angular velocity (P < .001), higher knee flexion at the deepest point during the braking phase (P < .001), longer contact time (P < .001), and unchanged stiffness and reaction strength index (P > .05). No differences were observed i...
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Understanding the modulations of motor control in the presence of perturbations in task conditions of varying complexity is a key element towards the design of effective perturbation-based balance exercise programs. In this study we... more
Understanding the modulations of motor control in the presence of perturbations in task conditions of varying complexity is a key element towards the design of effective perturbation-based balance exercise programs. In this study we investigated the effect of mechanical perturbations, induced by an unstable surface, on muscle activation and visuo-postural coupling, when actively tracking target motion cues of different complexity. Four postural tasks following a visual oscillating target of varying target complexity (periodic-sinusoidal vs. chaotic-Lorenz) and surface (stable-floor vs. unstable-foam) were performed. The electromyographic activity of the main plantarflexor and dorsiflexor muscles was captured. The coupling between sway and target was assessed through spectral analysis and the system’s local dynamic stability through the short-term maximum Lyapunov exponent. We found that external perturbations increased local instability and deteriorated visuo-motor coupling. Visuo-m...
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The aim of this study was to investigate the effect of fatigue on electromyographic (EMG) parameters of healthy young adults during obstacle crossing of two different heights. Twelve untrained male adults (23 ± 5 years of age) were... more
The aim of this study was to investigate the effect of fatigue on electromyographic (EMG) parameters of healthy young adults during obstacle crossing of two different heights. Twelve untrained male adults (23 ± 5 years of age) were fatigued running on a treadmill with increasing speed and inclination and walked over an obstacle with a height set at 10% and 20% of each individual's lower limb length. Maximal plantar flexor torque and EMG of the medial gastrocnemius, soleus, and tibialis anterior muscles of the trailing limb were assessed during obstacle crossing. Data were captured before, immediately after and 5 minutes after a fatigue session. Fatigue induced significant reduction on the plantar flexor torque output immediately after and 5 minutes after exhaustion. After fatigue gait speed was not affected, the minimum distance between the obstacle and the trailing or leading foot remained unchanged, and the trailing foot contacted the ground closer to the obstacle immediately ...
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The aim of this study was to examine the acute effect of backward running (BwR) during warm-up on a 20-m sprint of boys’ performance, compared to forward running (FwR). Fourteen recreationally active preadolescent boys (aged 12.5 ± 0.5... more
The aim of this study was to examine the acute effect of backward running (BwR) during warm-up on a 20-m sprint of boys’ performance, compared to forward running (FwR). Fourteen recreationally active preadolescent boys (aged 12.5 ± 0.5 years) were examined in 3 protocols: warm-up (control condition), warm-up with 3 × 10 m additional BwR sprints and warm-up with 3 × 10 m additional FwR sprints. Participants were evaluated 4 minutes after each protocol on a 20-m sprint and intermediate distances, as well as the rate of perceived exertion (RPE). Sprint speed across 10-20 m was significantly higher for the BwR warm-up compared to the regular warm-up (p < 0.05) and a significantly higher RPE after the BwR and FwR protocols compared to the control condition was recorded (p < 0.05). No significant difference was detected across the distances 0–5, 5–10, 0–10 and 0–20 m. Although adding 3 × 10-m sprints of BwR or FwR after the warm-up did not enhance performance in a 20 m sprint of pre...
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In recent decades, the interest for exercise-induced fatigue in youth has substantially increased, and the effects of growth on the peripheral (muscular) and central (neural) mechanisms underpinning differences in neuromuscular fatigue... more
In recent decades, the interest for exercise-induced fatigue in youth has substantially increased, and the effects of growth on the peripheral (muscular) and central (neural) mechanisms underpinning differences in neuromuscular fatigue between healthy children and adults have been described more extensively. The purpose of this review is to retrieve, report, and analyse the findings of studies comparing neuromuscular fatigue between children and adults. Objective measures of the evaluation of the physiological mechanisms are discussed. Major databases (PubMed, Ovid, Scopus and Web of Science) were systematically searched and limited to English language from inception to September 2017. Collectively, the analyzed studies indicate that children experience less muscular and potentially more neural fatigue than adults. However, there are still many unknown aspects of fatigue regarding neural (supraspinal and spinal) and peripheral mechanisms that should be more thoroughly examined in ch...
Research Interests: Skeletal muscle biology, Aging, Adolescent, Humans, Child, and 3 moreExercise, Adult, and Muscle Fatigue
Xenofondos, A, Bassa, E, Vrabas, IS, Kotzamanidis, C, and Patikas, D. Muscle twitch torque during two different in volume isometric exercise protocols: fatigue effects on postactivation potentiation. J Strength Cond Res 32(2): 578-586,... more
Xenofondos, A, Bassa, E, Vrabas, IS, Kotzamanidis, C, and Patikas, D. Muscle twitch torque during two different in volume isometric exercise protocols: fatigue effects on postactivation potentiation. J Strength Cond Res 32(2): 578-586, 2018-The purpose of this study was to quantify the effect of the contraction duration of 2 isometric exercise protocols on the postactivation potentiation of 14 well-trained men (age: 22.6 ± 2.8 years, height: 180.3 ± 5.9 cm, and body mass: 72.3 ± 37.9 kg). The protocols consisted of 4 × 6 maximal plantar flexions, of 3-second (P3) or 6-second (P6) duration, performed in random order, with a 2-minute and 15-second intervals between the sets and repetitions, respectively. The torque during maximal isometric voluntary contraction (MIVC), the peak twitch torque (TT), and the rate of torque development (RTD) after each MIVC were analyzed for the first and the last trial of each set, the average of all trials of each set, and the trials within each set tha...
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Our purpose was to examine the H-reflex during balance recovery after a simulated forward fall from 2 different inclination angles. The Soleus H-reflex of 15 healthy adults was measured in 2 different leaning positions (exerting a... more
Our purpose was to examine the H-reflex during balance recovery after a simulated forward fall from 2 different inclination angles. The Soleus H-reflex of 15 healthy adults was measured in 2 different leaning positions (exerting a horizontal force at 15% and 30% of body weight, respectively), with no release (Int0) and at 2 different intervals (Int1, Int2) after the release (∼45 and ∼65ms, respectively). During Int2 the H-reflex which was evoked before the onset of the Soleus EMG was significantly higher than the H-reflex induced 20 ms earlier (Int1). No significant difference was observed between Int0 and Int1 and between the 2 leaning positions. These findings indicate that Ia afferent input is facilitated before muscle activation during forward falling. This could be important for the timely activation and increased rate of force development required during this task. This article is protected by copyright. All rights reserved.
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The purpose of the study was to investigate the effects of resistance training (RT) and sensorimotor training combined with RT (SM-RT) on balance, 1 repetition maximum (RM), rate of force development (RFD) and squat jump (SJ) height.... more
The purpose of the study was to investigate the effects of resistance training (RT) and sensorimotor training combined with RT (SM-RT) on balance, 1 repetition maximum (RM), rate of force development (RFD) and squat jump (SJ) height. Twenty amateur soccer players were equally divided into two groups assigned as SM-RT group (age 22±1.7 years, body mass 79.9±6.3 kg, body height 1.81±0.06 m) and RT group (age 21.3±1.3 years, body mass 77.4±9.3 kg, body height 1.78±0.04 m). Both groups were trained over a 6-week period with two session units per week. SM-RT group performed sensorimotor training (balance on balance board) followed by a high intensity RT at 8-5 RM leg-press. The RT group performed the resistance program only. Both groups showed significantly increased 1 RM leg-press strength, RFD, SJ height and balance abilities (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05), whereas no significant between-group differences were observed in any of the outcome variables (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;0.05). It was concluded, that SM-RT was not superior compared to RT for both balance and strength enhancement. These findings have implications in time management during training for soccer players.
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The aim of this study was to investigate the effect of fatigue on electromyographic (EMG) parameters of healthy young adults during obstacle crossing of two different heights. Twelve untrained male adults (23 ± 5 years of age) were... more
The aim of this study was to investigate the effect of fatigue on electromyographic (EMG) parameters of healthy young adults during obstacle crossing of two different heights. Twelve untrained male adults (23 ± 5 years of age) were fatigued running on a treadmill with increasing speed and inclination and walked over an obstacle with a height set at 10% and 20% of each indi-vidual's lower limb length. Maximal plantar flexor torque and EMG of the medial gastrocnemius, soleus, and tibialis anterior muscles of the trailing limb were assessed during obstacle crossing. Data were captured before, immediately after and 5 minutes after a fatigue session. Fatigue induced significant reduction on the plantar flexor torque output immediately after and 5 minutes after exhaustion. After fatigue gait speed was not affected, the minimum distance between the obstacle and the trailing or leading foot remained unchanged, and the trailing foot contacted the ground closer to the obstacle immediately after fatigue. Regarding the EMG, medial gastrocnemius became after fatigue more active during swing phase when increasing the obstacle height, whereas this was not the case before or 5 minutes after fatigue. No other significant difference was observed for any of the examined muscles. It is concluded that the assessed fatigue protocol induced only minimal changes in the EMG activity of the examined muscles during obstacle crossing. Therefore, it is suggested that the neuromuscular system of healthy young individuals is able to respond to the decreased force capacity after fatigue during obstacle crossing of heights up to the 20% of the limb length.
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The purpose of this study was to compare the acute effects of three different stretching protocols on balance, agility, reaction time and movement time of the upper limbs. Participants were thirty one female high school athletes (age =... more
The purpose of this study was to compare the acute effects of three different stretching protocols on balance, agility, reaction time and movement time of the upper limbs. Participants were thirty one female high school athletes (age = 17.3 ± 0.5 yr.). All participants performed one of the following protocols on different days: (a) 3 min jogging followed by 7 min static stretching (SS), (b) 3 min jogging followed by 7 min dynamic stretching (DS), and (c) 3 min jogging followed by 7 min of rest (NS). After the protocols participants performed the following tests: dynamic balance, 505 agility test, reaction time (time between a sound stimulus and release of a button) and movement time (movement of the upper extremity over a 0.5 m distance). The order of stretching protocols and performance tests were counterbalanced to avoid carryover effects. Repeated measures analysis of variance revealed significant main effects for all variables except reaction time. The DS protocol compared to SS performed significantly better in balance, agility and movement time. Additionally, the DS protocol compared to NS performed significantly better in agility. According to the results of the study, a DS protocol is more appropriate than SS for activities that require balance, rapid change of running direction (agility) and movement time of the upper extremities.