Refine
Has Fulltext
- no (203) (remove)
Year of publication
Document Type
- Article (178)
- Review (15)
- Other (9)
- Monograph/Edited Volume (1)
Is part of the Bibliography
- yes (203)
Keywords
- football (15)
- athletic performance (13)
- resistance training (12)
- adolescents (10)
- balance (10)
- youth (10)
- strength training (9)
- stretch-shortening cycle (9)
- children (8)
- Exercise (7)
- electromyography (7)
- training (7)
- Gait (6)
- exercise (6)
- monitoring (6)
- performance (6)
- plyometric training (6)
- postural control (6)
- strength (6)
- training load (6)
- young athletes (6)
- Electromyography (5)
- Stretch-shortening cycle (5)
- injury risk (5)
- muscle strength (5)
- power (5)
- Aging (4)
- EMG (4)
- Ground reaction force (4)
- Resistance training (4)
- aging (4)
- elite athletes (4)
- gait (4)
- periodization (4)
- physical fitness (4)
- Balance (3)
- Seniors (3)
- Walking (3)
- agility (3)
- change of direction (3)
- force (3)
- ground reaction force (3)
- injury (3)
- jumping (3)
- loading rate (3)
- movement (3)
- muscle power (3)
- physiology (3)
- postural stability (3)
- soccer (3)
- speed (3)
- sport-specific performance (3)
- striking combat sports (3)
- working memory (3)
- youth sports (3)
- Body composition (2)
- COVID-19 (2)
- Cognitive/motor interference (2)
- Detraining (2)
- EEG (2)
- Jump height (2)
- Kampfsport (2)
- Muscle (2)
- Muscle strength (2)
- Performance (2)
- Postural stability (2)
- Power (2)
- Proactive/reactive balance (2)
- Single/dual tasking (2)
- Steady-state balance (2)
- Team sports (2)
- Trunk muscle strength (2)
- Youth (2)
- adolescent (2)
- attentional demand (2)
- biomechanics (2)
- cardiorespiratory fitness (2)
- child (2)
- cognitive performance (2)
- cognitive-postural dual task (2)
- combat sport (2)
- cross-education (2)
- drop jump (2)
- fatigue (2)
- gait analysis (2)
- global positioning system (2)
- ground reaction forces (2)
- hospitalization (2)
- human physical conditioning (2)
- inertial measurement unit (2)
- jumps (2)
- knee joint angle (2)
- maturity (2)
- modality compatibility (2)
- motor skills (2)
- muscle (2)
- musculoskeletal and neural physiological phenomena (2)
- oarsmen (2)
- on-water performance (2)
- peak height velocity (2)
- physical conditioning human (2)
- physical performance (2)
- plyometric exercise (2)
- plyometrics (2)
- postural sway (2)
- range of motion (2)
- rate of perceived exertion (2)
- rate of torque development (2)
- recovery (2)
- reliability (2)
- rolling averages (2)
- running (2)
- running mechanics (2)
- sensitivity (2)
- somatic variables (2)
- sportliche Leistung (2)
- sprint (2)
- sprints (2)
- talent (2)
- validity (2)
- weighted moving averages (2)
- youth athletes (2)
- youth soccer (2)
- ACWR (1)
- Acceleration (1)
- Acute Recovery and Stress Scale (ARSS) (1)
- Alpha-2 (1)
- Association (1)
- Attention (1)
- Balance Tests (1)
- Biomechanics (1)
- Bow leg (1)
- Central activation (1)
- Children (1)
- Cognition motor (1)
- Cognitive enhancer (1)
- Cognitive fatigue (1)
- Cognitive interference (1)
- Cognitive skills (1)
- Computer Software (1)
- Conditioning activity (1)
- Core stability (1)
- Core strength (1)
- Countermovement jump (1)
- Cross-over fatigue (1)
- Crossover (1)
- Crossover fatigue (1)
- DXA (1)
- Daily life (1)
- Dual tasks (1)
- EXERCISE (1)
- Elderly (1)
- Electric stimulation (1)
- Electroencephalography (EEG) (1)
- Electromyography (EMG) (1)
- Elite sports (1)
- Endocrine (1)
- Endurance (1)
- Executive function (1)
- Exercise therapy (1)
- Exertion (1)
- Exhaustion (1)
- Explosive force production (1)
- Fall risk (1)
- Fall risk assessment (1)
- Falls (1)
- Fatigue (1)
- Flat feet (1)
- Football (1)
- Footwear (1)
- Force (1)
- Force production (1)
- Frail elderly (1)
- Free moment (1)
- Functional magnetic resonance imaging (fMRI) (1)
- Gait biomechanics (1)
- Gait kinematics (1)
- Gait kinetics (1)
- Ginkgo biloba extract (1)
- Gym-based/home-based training (1)
- Healthy aging (1)
- ICA (1)
- Injury risk (1)
- Instability (1)
- Intensity Dose -response relationship (1)
- Isokinetic (1)
- Judo-specific pulling movement (1)
- Jugendliche (1)
- Jumping height (1)
- Kinder (1)
- Kindergarten (1)
- Kinematics (1)
- Knee valgus (1)
- Knee valgus motion (1)
- Lateral jumps (1)
- Linear regression analysis (1)
- Loading rate (1)
- MUSCLE (1)
- Maturation (1)
- Maximal isometric force (1)
- Maximal voluntary contraction (MVC) (1)
- Maximalkraft (1)
- Metabolism (1)
- Mild cognitive impairment (1)
- Mobility (1)
- Morote-seoi-nage (1)
- Motion (1)
- Motor function (1)
- Motor performance (1)
- Motor skills (1)
- Movement velocity (1)
- Multiple sclerosis (1)
- Muscle contraction (1)
- Muscle mass (1)
- Muscle power (1)
- Muscle torque (1)
- Oberflächenelektromyografie (1)
- OptoGait (1)
- Optojump system (1)
- Overhead athletes (1)
- Parkinson's disease (1)
- Pediatric gait (1)
- Performance gains (1)
- Physical fitness (1)
- Physical performance (1)
- Plyometric exercise (1)
- Plyometrics (1)
- Post-activation potentiation (1)
- Postactivation potentiation (1)
- Postural Control (1)
- Postural balance (1)
- Postural control (1)
- Power training (1)
- Preventive therapy (1)
- Primary school (1)
- Principal component analysis (1)
- Quadriceps muscle (1)
- Quadriceps strength (1)
- Quarantine (1)
- RGB-D cameras (1)
- RPE (1)
- Reactive movement (1)
- Recovery (1)
- Reflex (1)
- Repeated sprint (1)
- Scanning electron microscopy (1)
- Schnellkraft (1)
- Sensorimotor training (1)
- Short‐term effect (1)
- Shoulder (1)
- Skill (1)
- Speed (1)
- Sport-specific performance (1)
- Strength training (1)
- Stress (1)
- Stress levels (1)
- Sway (1)
- Swimming performance (1)
- Theraband training (1)
- Theta (1)
- Tiredness (1)
- Transcranial magnetic brain stimulation (TMS) (1)
- Velocity (1)
- Vertec device (1)
- WALKING (1)
- Walking speed (1)
- Widerstandstraining (1)
- Work ability (1)
- Young swimmers (1)
- Zebris (1)
- academy (1)
- acute chronic workload ratio (1)
- adolescent athletes (1)
- aerobic metabolism (1)
- aerobic power (1)
- age (1)
- allometry (1)
- alpha-2 (1)
- ankles (1)
- annual training (1)
- anterior cruciate ligament (1)
- anthropometry (1)
- anxiety (1)
- apoptosis (1)
- assessment (1)
- athlete testing (1)
- athlete. (1)
- athletes (1)
- athletic (1)
- attention (1)
- balance strategy (1)
- balance training (1)
- ball speed (1)
- ballistic training (1)
- barbell velocity (1)
- biological age (1)
- biological maturation (1)
- blood (1)
- blood sample (1)
- body density (1)
- body limbs (1)
- body shape (1)
- bone (1)
- boys (1)
- calcaneal eversion (1)
- canoe racing (1)
- cardiomyopathy (1)
- causal mediation analysis (1)
- change of direction speed (1)
- change-of-direction speed (1)
- climbing (1)
- cognitive interference (1)
- cognitive skills (1)
- cognitive/muscular fatigue (1)
- combat sports (1)
- comparison of devices (1)
- concurrent training (1)
- conditioning activity (1)
- conditioning exercise (1)
- conditioning stimulus (1)
- core (1)
- core strength (1)
- data pipeline (1)
- deconditioning (1)
- depression (1)
- detraining (1)
- diabetes (1)
- diabetes mellitus (1)
- diabetic (1)
- digital health (1)
- directed acyclic graphs (1)
- dominant limb (1)
- dose-response relation (1)
- dose-response relationship (1)
- dual task (1)
- dual-task costs (1)
- early sport specialization (1)
- eccentric-plyometric (1)
- elderly (1)
- electroencephalography (1)
- elite (1)
- elite sport (1)
- endurance (1)
- endurance performance (1)
- energetic systems (1)
- evaluation (1)
- exercise intervention (1)
- exercise test (1)
- exercise training (1)
- exhaustion (1)
- explosive force production (1)
- external load (1)
- external training load (1)
- eyedness (1)
- fMRI (1)
- feet (1)
- field test (1)
- fitness (1)
- fitness tests (1)
- flat feet (1)
- flat foot (1)
- flexibility (1)
- footedness (1)
- footwear (1)
- free moment (1)
- function (1)
- functional performance (1)
- gait analysis algorithm (1)
- gait speed (1)
- gender (1)
- gender differences (1)
- girls (1)
- hamstring muscles (1)
- hearing loss (1)
- heart rate (1)
- hematocrit (1)
- high-intensity interval training (1)
- high-intensity-interval training (1)
- hip (1)
- hormones (1)
- human motion (1)
- immune system (1)
- impact loading (1)
- infection (1)
- injury prevention (1)
- intermittent sport (1)
- internal load (1)
- intervention (1)
- jump (1)
- jump height (1)
- jump height/power (1)
- jump performance (1)
- jump performances (1)
- jump training (1)
- jump/sprint exercises (1)
- jumping ability (1)
- kindergarten (1)
- kinetics (1)
- knee (1)
- knee flexion angle (1)
- knee osteoarthritis (1)
- knee valgus angle (1)
- knee valgus motion (1)
- knees (1)
- late childhood (1)
- latency (1)
- laterality (1)
- leg extensors (1)
- limb overuse conditions (1)
- linear sprint (1)
- load carriage (1)
- load-velocity (1)
- long-term (1)
- low-back-pain (1)
- lower limb mechanics (1)
- lower-extremity kinematics (1)
- martial arts (1)
- matched time (1)
- material fatigue (1)
- maturation (1)
- maximal isometric contraction (1)
- maximal isometric torque (1)
- maximum voluntary contraction (1)
- medial longitudinal arch (1)
- mental imagery (1)
- meta-analysis (1)
- methodological quality (1)
- miRNAs (1)
- mitochondrial adaptation (1)
- mobility disability (1)
- motion capture (1)
- motor-performance (1)
- muscle activation (1)
- muscle activity (1)
- muscle coactivation (1)
- muscle fitness (1)
- muscle metabolism (1)
- muscular endurance (1)
- muscular power (1)
- muscular strength (1)
- musculature (1)
- myofascial (1)
- neuromuscular rolling (1)
- non-dominant limb (1)
- of-direction speed (1)
- optimal load (1)
- overreaching (1)
- overtraining (1)
- oxygen consumption (1)
- passive stretching (1)
- patients (1)
- peak torque (1)
- pelvic alignment (1)
- pervasive healthcare (1)
- physical activity (1)
- physical activity program (1)
- physical fitness expertise (1)
- physiological strain (1)
- postural balance (1)
- power training (1)
- preactivation (1)
- pressure (1)
- prevention (1)
- progression (1)
- proprioception (1)
- public dataset (1)
- race (1)
- race time (1)
- randomized controlled-trial (1)
- rate of force development (1)
- region/point elastic gym floor (1)
- relationship (1)
- relationships (1)
- responses (1)
- return-to-sport (1)
- rotation (1)
- rugby league players (1)
- running velocity (1)
- schedule (1)
- scholastic demands (1)
- school baseball players (1)
- sedentary (1)
- self massage (1)
- self-massage therapy (1)
- self-myofascial release (1)
- sensorimotor training (1)
- sensory input (1)
- sex-differences (1)
- shoe (1)
- short latency response (1)
- shoulder girdle (1)
- shoulder strength (1)
- skeletal joints (1)
- ski jumping (1)
- soccer players (1)
- specific assessment (1)
- specific strength training (1)
- specificity (1)
- spezifisches Krafttraining (1)
- sport profile (1)
- sports (1)
- sprinting (1)
- stability (1)
- standing position (1)
- static/dynamic postural control (1)
- stroke (1)
- structured (1)
- surface electromyography (1)
- taekwondo electronic scoring system (1)
- taekwondo-specific testing (1)
- task difficulty (1)
- tasks (1)
- team sport (1)
- tendon stiffness (1)
- test-retest reliability (1)
- therapy (1)
- theta (1)
- time (1)
- time-efficient exercise (1)
- torque (1)
- track and field (1)
- training adaptation (1)
- training intensity (1)
- training specificity (1)
- twitch torque (1)
- unstable walkway (1)
- vertical jump height (1)
- vestibular (1)
- virus (1)
- virus infection (1)
- water sports (1)
- weight lifting (1)
- weight loss (1)
- weight training (1)
- weightlifting (1)
- whole-body vibratoin (1)
- women (1)
- work (1)
- young (1)
- young adults (1)
- young soccer players (1)
- youth sport (1)
Institute
- Department Sport- und Gesundheitswissenschaften (104)
- Strukturbereich Kognitionswissenschaften (59)
- Extern (17)
- Department Psychologie (6)
- Humanwissenschaftliche Fakultät (6)
- Hasso-Plattner-Institut für Digital Engineering GmbH (3)
- Fakultät für Gesundheitswissenschaften (2)
- Fachgruppe Soziologie (1)
Hintergrund:
Eine gut ausgeprägte Rumpfstabilität ist eine wichtige Voraussetzung für die Mobilität der oberen und unteren Extremitäten während des sportlichen Bewegungsvollzugs. Vor diesem Hintergrund könnte die Rumpfkraft ein leistungsdeterminierender Faktor bei der Ausführung judospezifischer Bewegungen darstellen. Das Ziel der vorliegenden Studie war es, statistische Zusammenhänge zwischen der Rumpfkraft und kinetischen Parametern bei Anriss-Bewegungen von Judoka zu untersuchen.
Methode:
An der Untersuchung nahmen 21 leistungsorientierte Judoka mit einem mittleren Alter von 22 ± 4 Jahre und einem Trainingsumfang von 15 ± 4 Stunden pro Woche teil. Das maximale isokinetische Drehmoment (PIT) der Rumpfflexoren (PITFlex), -extensoren (PITEx) und -rotatoren (PITRot) wurde unter Verwendung eines isokinetischen Dynamometers (IsoMed 2000) erfasst. Zusätzlich wurden kinetische Parameter (mechanische Arbeit [W], dynamisch-realisierte Maximalkraft [Fmax]) bei Anriss-Bewegung im Stand und bei Anriss- mit Eindrehbewegung (d. h. Morote-seoi-nage) mithilfe eines judospezifischen Mess- und Informationssystems (JERGo©) erhoben.
Ergebnisse:
Die statistische Analyse zeigte signifikante Korrelationen (0,62 ≤ r P ≤ 0,72) zwischen den maximalen isokinetischen Drehmomenten (PITFlex, PITEx, PITRot) und der Anriss-Bewegung im Stand (W). Zudem konnten signifikante Zusammenhänge (0,59 ≤ r P ≤ 0,65) zwischen den isokinetischen Tests (PITEx, PITRot) und Fmax auf der Hubarmseite bei der Anriss-Bewegung im Stand gefunden werden. Für die Anriss- mit Eindrehbewegung ergaben sich signifikante Korrelationen (0,47 ≤ r P ≤ 0,88) zwischen den isokinetischen Tests (PITFlex, PITEx, PITRot) und Leistungskennwerten der judospezifischen Bewegung (W und Fmax), unabhängig von der untersuchten Armseite. Es wurden vergleichbare Korrelationskoeffizienten zwischen PIT der Rumpfflexoren, -extensoren und -rotatoren und judospezifischen Leistungskennwerten festgestellt. Weiterhin identifizierte die Regressionsanalyse den Kennwert PIT bei Rumpfextension als besten Prädiktor für die mechanische Arbeit bei Anriss-Bewegung im Stand (46,9 %). Bei der Anriss- mit Eindrehbewegung konnte PIT der Rumpfrotatoren auf die Hubarmseite als bester Prädiktor für die mechanische Arbeit (69,4 %) ermittelt werden.
Schlussfolgerung:
Die Ergebnisse zeigen, dass die Rumpfkraft, insbesondere bei der Rumpfrotationsbewegung, mit Variablen der judospezifischen Leistungskennwerte bei der Anriss- mit Eindrehbewegung assoziiert ist. Dies impliziert, dass vor allem durch rumpfrotationskräftigende Übungen Einfluss auf die Anriss- mit Eindrehbewegung (d. h. Morote-seoi-nage) genommen werden könnte.
Background: Habitual walking speed predicts many clinical conditions later in life, but it declines with age. However, which particular exercise intervention can minimize the age-related gait speed loss is unclear.
Purpose: Our objective was to determine the effects of strength, power, coordination, and multimodal exercise training on healthy old adults' habitual and fast gait speed.
Methods: We performed a computerized systematic literature search in PubMed and Web of Knowledge from January 1984 up to December 2014. Search terms included 'Resistance training', 'power training', 'coordination training', 'multimodal training', and 'gait speed (outcome term). Inclusion criteria were articles available in full text, publication period over past 30 years, human species, journal articles, clinical trials, randomized controlled trials, English as publication language, and subject age C65 years. The methodological quality of all eligible intervention studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. We computed weighted average standardized mean differences of the intervention-induced adaptations in gait speed using a random-effects model and tested for overall and individual intervention effects relative to no-exercise controls.
Results: A total of 42 studies (mean PEDro score of 5.0 +/- 1.2) were included in the analyses (2495 healthy old adults; age 74.2 years [64.4-82.7]; body mass 69.9 +/- 4.9 kg, height 1.64 +/- 0.05 m, body mass index 26.4 +/- 1.9 kg/m(2), and gait speed 1.22 +/- 0.18 m/s). The search identified only one power training study, therefore the subsequent analyses focused only on the effects of resistance, coordination, and multimodal training on gait speed. The three types of intervention improved gait speed in the three experimental groups combined (n = 1297) by 0.10 m/s (+/- 0.12) or 8.4 % (+/- 9.7), with a large effect size (ES) of 0.84. Resistance (24 studies; n = 613; 0.11 m/s; 9.3 %; ES: 0.84), coordination (eight studies, n = 198; 0.09 m/s; 7.6 %; ES: 0.76), and multimodal training (19 studies; n = 486; 0.09 m/s; 8.4 %, ES: 0.86) increased gait speed statistically and similarly.
Conclusions: Commonly used exercise interventions can functionally and clinically increase habitual and fast gait speed and help slow the loss of gait speed or delay its onset.
Aim The purpose of this study was to examine physical fitness and psycho-cognitive performance and their associations in young and middle-aged workers with primarily physical versus mental work demands. Subjects and methods Healthy young and middle-aged workers (73 men, age = 33 +/- 7 years; 75 women, age = 35 +/- 9 years) were recruited from German small-to-medium-sized enterprises (< 250 employees) and classified into groups with primarily mental (MD) or physical demands (PD) at work. Participants were tested for cardiorespiratory fitness, trunk flexor/extensor muscular endurance, handgrip strength, balance, leg muscle power, perceived stress, cognitive performance, and work ability. Results Ninety-four workers were allocated to the MD (53% females) and 54 to the PD (46% females) groups. The MD group showed significantly better balance, trunk extensor muscular endurance, and cognitive performance (p < 0.035, 0.35 <= d <= 0.55) and less stress compared with the PD group (p < 0.023, d = 0.38). Group-specific Spearman rank correlation analysis (r(S)) revealed significant small-to-medium-sized correlations between physical fitness and cognitive performance (- 0.205 <= r(S) <= 0.434) in the MD and PD groups. Significant small-to-medium-sized correlations were found for physical fitness and stress/work ability (0.211 <= r(S) <= 0.301) in the MD group only. Further, associations of trunk extensor muscular endurance and work ability were significantly higher in the MD group (r(S) = 0.240) compared with the PD group (r(S) = - 0.141; z = 2.16, p = 0.031). Conclusions MD workers showed better physical fitness measures (balance, trunk extensor muscular endurance) and cognitive performance and lower levels of perceived stress compared with PD workers. Small-to-medium-sized associations between physical fitness and psycho-cognitive performance measures indicate that gains in physical fitness may at least partly contribute to psycho-cognitive performance and/or vice versa, particularly in MD workers.
Purpose
The objective of the investigation was to determine the concomitant effects of upper arm blood flow restriction (BFR) and inversion on elbow flexors neuromuscular responses.
Methods
Randomly allocated, 13 volunteers performed four conditions in a within-subject design: rest (control, 1-min upright position without BFR), control (1-min upright with BFR), 1-min inverted (without BFR), and 1-min inverted with BFR. Evoked and voluntary contractile properties, before, during and after a 30-s maximum voluntary contraction (MVC) exercise intervention were examined as well as pain scale.
Results
Inversion induced significant pre-exercise intervention decreases in elbow flexors MVC (21.1%, Z2p = 0.48, p = 0.02) and resting evoked twitch forces (29.4%, Z2p = 0.34, p = 0.03). The 30-s MVC induced significantly greater pre- to post-test decreases in potentiated twitch force (Z2p = 0.61, p = 0.0009) during inversion (75%) than upright (65.3%) conditions. Overall, BFR decreased MVC force 4.8% (Z2p = 0.37, p = 0.05). For upright position, BFR induced 21.0% reductions in M-wave amplitude (Z2p = 0.44, p = 0.04). There were no significant differences for electromyographic activity or voluntary activation as measured with the interpolated twitch technique. For all conditions, there was a significant increase in pain scale between the 40-60 s intervals and post-30-s MVC (upright< inversion, and without BFR< BFR).
Conclusion
The concomitant application of inversion with elbow flexors BFR only amplified neuromuscular performance impairments to a small degree. Individuals who execute forceful contractions when inverted or with BFR should be cognizant that force output may be impaired.
Electroencephalographic (EEG) research indicates changes in adults' low frequency bands of frontoparietal brain areas executing different balance tasks with increasing postural demands. However, this issue is unsolved for adolescents when performing the same balance task with increasing difficulty. Therefore, we examined the effects of a progressively increasing balance task difficulty on balance performance and brain activity in adolescents. Thirteen healthy adolescents aged 16-17 year performed tests in bipedal upright stance on a balance board with six progressively increasing levels of task difficulty. Postural sway and cortical activity were recorded simultaneously using a pressure sensitive measuring system and EEG. The power spectrum was analyzed for theta (4-7 Hz) and alpha-2 (10-12 Hz) frequency bands in pre-defined frontal, central, and parietal clusters of electrocortical sources. Repeated measures analysis of variance (rmANOVA) showed a significant main effect of task difficulty for postural sway (p < 0.001; d = 6.36). Concomitantly, the power spectrum changed in frontal, bilateral central, and bilateral parietal clusters. RmANOVAs revealed significant main effects of task difficulty for theta band power in the frontal (p < 0.001, d = 1.80) and both central clusters (left: p < 0.001, d = 1.49; right: p < 0.001, d = 1.42) as well as for alpha-2 band power in both parietal clusters (left: p < 0.001, d = 1.39; right: p < 0.001, d = 1.05) and in the central right cluster (p = 0.005, d = 0.92). Increases in theta band power (frontal, central) and decreases in alpha-2 power (central, parietal) with increasing balance task difficulty may reflect increased attentional processes and/or error monitoring as well as increased sensory information processing due to increasing postural demands. In general, our findings are mostly in agreement with studies conducted in adults. Similar to adult studies, our data with adolescents indicated the involvement of frontoparietal brain areas in the regulation of postural control. In addition, we detected that activity of selected brain areas (e.g., bilateral central) changed with increasing postural demands.
Introduction:
In children, the impact of hearing loss on biomechanical gait parameters is not well understood. Thus, the objectives of this study were to examine three-dimensional lower limb joint torques in deaf compared to age-matched healthy (hearing) children while walking at preferred gait speed.
Methods:
Thirty prepubertal boys aged 8-14 were enrolled in this study and divided into a group with hearing loss (deaf group) and an age-matched healthy control. Three-dimensional joint torques were analyzed during barefoot walking at preferred speed using Kistler force plates and a Vicon motion capture system.
Results:
Findings revealed that boys with hearing loss showed lower joint torques in ankle evertors, knee flexors, abductors and internal rotators as well as in hip internal rotators in both, the dominant and non-dominant lower limbs (all p < 0.05; d = 1.23-7.00; 14-79%). Further, in the dominant limb, larger peak ankle dorsiflexor (p < 0.001; d = 1.83; 129%), knee adductor (p < 0.001; d = 3.20; 800%), and hip adductor torques (p < 0.001; d = 2.62; 350%) were found in deaf participants compared with controls.
Conclusion:
The observed altered lower limb torques during walking are indicative of unstable gait in children with hearing loss. More research is needed to elucidate whether physical training (e.g., balance and/or gait training) has the potential to improve walking performance in this patient group. (C) 2019 Elsevier Ltd. All rights reserved.
This study aimed to investigate the effects of eight weeks of barefoot running exercise on sand versus control on measures of walking kinetics and muscle activities in individuals with diagnosed pronated feet. Sixty physically active male adults with pronated feet were randomly allocated into an intervention or a waiting control group. The intervention group conducted an 8-weeks progressive barefoot running exercise program on sand (e.g., short sprints) with three weekly sessions. Pre and post intervention, participants walked at a constant speed of 1.3 m/s +/- 5% on a 18 m walkway with a force plate embedded in the middle of the walkway. Results showed significant group-by-time interactions for peak impact vertical and lateral ground reaction forces. Training but not control resulted in significantly lower peak impact vertical and lateral ground reaction forces. Significant group-by-time interactions were observed for vastus lateralis activity during the loading phase. Training-induced increases were found for the vastus lateralis in the intervention but not in the control group. This study revealed that the applied exercise program is a suitable means to absorb ground reaction forces (e.g., lower impact vertical and lateral peaks) and increase activities of selected lower limb muscles (e.g., vastus lateralis) when walking on stable ground.
Background: High-intensity muscle actions have the potential to temporarily improve the performance which has been denoted as postactivation performance enhancement.
Objectives: This study determined the acute effects of different stretch-shortening (fast vs. low) and strength (dynamic vs. isometric) exercises executed during one training session on subsequent balance performance in youth weightlifters.
Materials and Methods: Sixteen male and female young weightlifters, aged 11.3±0.6years, performed four strength exercise conditions in randomized order, including dynamic strength (DYN; 3 sets of 3 repetitions of 10 RM) and isometric strength exercises (ISOM; 3 sets of maintaining 3s of 10 RM of back-squat), as well as fast (FSSC; 3 sets of 3 repetitions of 20-cm drop-jumps) and slow (SSSC; 3 sets of 3 hurdle jumps over a 20-cm obstacle) stretch-shortening cycle protocols. Balance performance was tested before and after each of the four exercise conditions in bipedal stance on an unstable surface (i.e., BOSU ball with flat side facing up) using two dependent variables, i.e., center of pressure surface area (CoP SA) and velocity (CoP V).
Results: There was a significant effect of time on CoP SA and CoP V [F(1,60)=54.37, d=1.88, p<0.0001; F(1,60)=9.07, d=0.77, p=0.003]. In addition, a statistically significant effect of condition on CoP SA and CoP V [F(3,60)=11.81, d=1.53, p<0.0001; F(3,60)=7.36, d=1.21, p=0.0003] was observed. Statistically significant condition-by-time interactions were found for the balance parameters CoP SA (p<0.003, d=0.54) and CoP V (p<0.002, d=0.70). Specific to contrast analysis, all specified hypotheses were tested and demonstrated that FSSC yielded significantly greater improvements than all other conditions in CoP SA and CoP V [p<0.0001 (d=1.55); p=0.0004 (d=1.19), respectively]. In addition, FSSC yielded significantly greater improvements compared with the two conditions for both balance parameters [p<0.0001 (d=2.03); p<0.0001 (d=1.45)].
Conclusion: Fast stretch-shortening cycle exercises appear to be more effective to improve short-term balance performance in young weightlifters. Due to the importance of balance for overall competitive achievement in weightlifting, it is recommended that young weightlifters implement dynamic plyometric exercises in the fast stretch-shortening cycle during the warm-up to improve their balance performance.
Background: The standard method to treat physically active patients with anterior cruciate ligament (ACL) rupture is ligament reconstruction surgery. The rehabilitation training program is very important to improve functional performance in recreational athletes following ACL reconstruction.
Objectives: The aims of this study were to compare the effects of three different training programs, eccentric training (ECC), plyometric training (PLYO), or combined eccentric and plyometric training (COMB), on dynamic balance (Y-BAL), the Lysholm Knee Scale (LKS), the return to sport index (RSI), and the leg symmetry index (LSI) for the single leg hop test for distance in elite female athletes after ACL surgery.
Materials and Methods: Fourteen weeks after rehabilitation from surgery, 40 elite female athletes (20.3 ± 3.2 years), who had undergone an ACL reconstruction, participated in a short-term (6 weeks; two times a week) training study. All participants received the same rehabilitation protocol prior to the training study. Athletes were randomly assigned to three experimental groups, ECC (n = 10), PLYO (n = 10), and COMB (n = 10), and to a control group (CON: n = 10). Testing was conducted before and after the 6-week training programs and included the Y-BAL, LKS, and RSI. LSI was assessed after the 6-week training programs only.
Results: Adherence rate was 100% across all groups and no training or test-related injuries were reported. No significant between-group baseline differences (pre-6-week training) were observed for any of the parameters. Significant group-by-time interactions were found for Y-BAL (p < 0.001, ES = 1.73), LKS (p < 0.001, ES = 0.76), and RSI (p < 0.001, ES = 1.39). Contrast analysis demonstrated that COMB yielded significantly greater improvements in Y-BAL, LKS, and RSI (all p < 0.001), in addition to significantly better performances in LSI (all p < 0.001), than CON, PLYO, and ECC, respectively.
Conclusion: In conclusion, combined (eccentric/plyometric) training seems to represent the most effective training method as it exerts positive effects on both stability and functional performance in the post-ACL-surgical rehabilitation period of elite female athletes.
Previous studies have not considered the potential influence of maturity status on the relationship between mental imagery and change of direction (CoD) speed in youth soccer. Accordingly, this cross-sectional study examined the association between mental imagery and CoD performance in young elite soccer players of different maturity status. Forty young male soccer players, aged 10-17 years, were assigned into two groups according to their predicted age at peak height velocity (PHV) (Pre-PHV; n = 20 and Post-PHV; n = 20). Participants were evaluated on soccer-specific tests of CoD with (CoDBall-15m) and without (CoD-15m) the ball. Participants completed the movement imagery questionnaire (MIQ) with the three- dimensional structure, internal visual imagery (IVI), external visual imagery (EVI), as well as kinesthetic imagery (KI). The Post-PHV players achieved significantly better results than Pre-PHV in EVI (ES = 1.58, large; p < 0.001), CoD-15m (ES = 2.09, very large; p < 0.001) and CoDBall-15m (ES = 1.60, large; p < 0.001). Correlations were significantly different between maturity groups, where, for the pre-PHV group, a negative very large correlation was observed between CoDBall-15m and KI (r = –0.73, p = 0.001). For the post-PHV group, large negative correlations were observed between CoD-15m and IVI (r = –0.55, p = 0.011), EVI (r = –062, p = 0.003), and KI (r = –0.52, p = 0.020). A large negative correlation of CoDBall-15m with EVI (r = –0.55, p = 0.012) and very large correlation with KI (r = –0.79, p = 0.001) were also observed. This study provides evidence of the theoretical and practical use for the CoD tasks stimulus with imagery. We recommend that sport psychology specialists, coaches, and athletes integrated imagery for CoD tasks in pre-pubertal soccer players to further improve CoD related performance.