TY - JOUR A1 - Sander, Martha Maria A1 - Scheffler, Christiane T1 - Bilateral asymmetry in left handers increased concerning morphological laterality in a recent sample of young adults JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie KW - anthropometry KW - handedness KW - laterality KW - bilateral asymmetry KW - left handers KW - upper extremity KW - reskilling KW - elbow breadth Y1 - 2016 U6 - https://doi.org/10.1127/anthranz/2016/0663 SN - 0003-5548 VL - 73 SP - 335 EP - 342 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Zouhal, Hassane A1 - Abderrahman, Abderraouf Ben A1 - Dupont, Gregory A1 - Truptin, Pablo A1 - Le Bris, Régis A1 - Le Postec, Erwan A1 - Sghaeir, Zouita A1 - Brughelli, Matt A1 - Granacher, Urs A1 - Bideau, Benoit T1 - Effects of Neuromuscular Training on Agility Performance in Elite Soccer Players JF - Frontiers in Physiology N2 - Background: Agility in general and change-of-direction speed (CoD) in particular represent important performance determinants in elite soccer. Objectives: The objectives of this study were to determine the effects of a 6-week neuromuscular training program on agility performance, and to determine differences in movement times between the slower and faster turning directions in elite soccer players. Materials and Methods: Twenty male elite soccer players from the Stade Rennais Football Club (Ligue 1, France) participated in this study. The players were randomly assigned to a neuromuscular training group (NTG, n = 10) or an active control (CG, n = 10) according to their playing position. NTG participated in a 6-week, twice per week neuromuscular training program that included CoD, plyometric and dynamic stability exercises. Neuromuscular training replaced the regular warm-up program. Each training session lasted 30 min. CG continued their regular training program. Training volume was similar between groups. Before and after the intervention, the two groups performed a reactive agility test that included 180° left and right body rotations followed by a 5-m linear sprint. The weak side was defined as the left/right turning direction that produced slower overall movement times (MT). Reaction time (RT) was assessed and defined as the time from the first appearance of a visual stimulus until the athlete’s first movement. MT corresponded to the time from the first movement until the athlete reached the arrival gate (5 m distance). Results: No significant between-group baseline differences were observed for RT or MT. Significant group x time interactions were found for MT (p = 0.012, effect size = 0.332, small) for the slower and faster directions (p = 0.011, effect size = 0.627, moderate). Significant pre-to post improvements in MT were observed for NTG but not CG (p = 0.011, effect size = 0.877, moderate). For NTG, post hoc analyses revealed significant MT improvements for the slower (p = 0.012, effect size = 0.897, moderate) and faster directions (p = 0.017, effect size = 0.968, moderate). Conclusion: Our results illustrate that 6 weeks of neuromuscular training with two sessions per week included in the warm-up program, significantly enhanced agility performance in elite soccer players. Moreover, improvements were found on both sides during body rotations. Thus, practitioners are advised to focus their training programs on both turning directions. KW - laterality KW - football KW - footedness KW - eyedness KW - rotation KW - team sport Y1 - 2019 U6 - https://doi.org/10.3389/fphys.2019.00947 SN - 1664-042X VL - 10 PB - Frontiers Research Foundation CY - Lausanne ER - TY - GEN A1 - Zouhal, Hassane A1 - Abderrahman, Abderraouf Ben A1 - Dupont, Gregory A1 - Truptin, Pablo A1 - Le Bris, Régis A1 - Le Postec, Erwan A1 - Sghaeir, Zouita A1 - Brughelli, Matt A1 - Granacher, Urs A1 - Bideau, Benoit T1 - Effects of Neuromuscular Training on Agility Performance in Elite Soccer Players T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe N2 - Background: Agility in general and change-of-direction speed (CoD) in particular represent important performance determinants in elite soccer. Objectives: The objectives of this study were to determine the effects of a 6-week neuromuscular training program on agility performance, and to determine differences in movement times between the slower and faster turning directions in elite soccer players. Materials and Methods: Twenty male elite soccer players from the Stade Rennais Football Club (Ligue 1, France) participated in this study. The players were randomly assigned to a neuromuscular training group (NTG, n = 10) or an active control (CG, n = 10) according to their playing position. NTG participated in a 6-week, twice per week neuromuscular training program that included CoD, plyometric and dynamic stability exercises. Neuromuscular training replaced the regular warm-up program. Each training session lasted 30 min. CG continued their regular training program. Training volume was similar between groups. Before and after the intervention, the two groups performed a reactive agility test that included 180° left and right body rotations followed by a 5-m linear sprint. The weak side was defined as the left/right turning direction that produced slower overall movement times (MT). Reaction time (RT) was assessed and defined as the time from the first appearance of a visual stimulus until the athlete’s first movement. MT corresponded to the time from the first movement until the athlete reached the arrival gate (5 m distance). Results: No significant between-group baseline differences were observed for RT or MT. Significant group x time interactions were found for MT (p = 0.012, effect size = 0.332, small) for the slower and faster directions (p = 0.011, effect size = 0.627, moderate). Significant pre-to post improvements in MT were observed for NTG but not CG (p = 0.011, effect size = 0.877, moderate). For NTG, post hoc analyses revealed significant MT improvements for the slower (p = 0.012, effect size = 0.897, moderate) and faster directions (p = 0.017, effect size = 0.968, moderate). Conclusion: Our results illustrate that 6 weeks of neuromuscular training with two sessions per week included in the warm-up program, significantly enhanced agility performance in elite soccer players. Moreover, improvements were found on both sides during body rotations. Thus, practitioners are advised to focus their training programs on both turning directions. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 575 KW - laterality KW - football KW - footedness KW - eyedness KW - rotation KW - team sport Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-437358 SN - 1866-8364 IS - 575 ER - TY - JOUR A1 - Fritzsch, Claire A1 - Wang, Jing A1 - dos Santos, Luara Ferreira A1 - Mauritz, Karl-Heinz A1 - Brunetti, Maddalena A1 - Dohle, Christian T1 - Different effects of the mirror illusion on motor and somatosensory processing JF - Restorative neurology and neuroscience N2 - Purpose: Mirror therapy can improve motor and sensory functions, but effects of the mirror illusion on primary motor and somatosensory cortex could not be established consistently. Methods: Fifteen right handed healthy volunteers performed or observed a finger-thumb opposition task. Cerebral activations during normal movement (NOR), mirrored movement (MIR) and movement observation (OBS) by means of a video chain were recorded with functional magnetic resonance imaging (fMRI). Activation sizes in movement > static conditions were identified using SPM8 (p < 0.001, unc.) and attributed to predefined areas employing the Anatomy toolbox 1.8. Laterality indices for the responsive areas were calculated on the basis of the number of activated voxels. Results: Relevant bilateral BOLD responses were found in primary motor (M1) and somatosensory (S1 - BA 2, 3b and 3a) cortex, premotor and parietal areas and V5. When comparing MIR to NOR, no significant change of contralateral activation in M1 was found, but clearly at S1 with differences between hands. Conclusion: The mirror illusion does not elicit immediate changes in motor areas, yet there is a direct effect on somatosensory areas, especially for left hand movements. These results suggest different effects of mirror therapy on processing and rehabilitation of motor and sensory function. KW - Movement KW - mirror KW - laterality KW - stroke KW - sensorimotor cortex Y1 - 2014 U6 - https://doi.org/10.3233/RNN-130343 SN - 0922-6028 SN - 1878-3627 VL - 32 IS - 2 SP - 269 EP - 280 PB - IOS Press CY - Amsterdam ER - TY - THES A1 - Krüger, Tom T1 - Zum Einfluss der Lateralität in zyklischen Sportarten bei Nachwuchsathleten T1 - The effect of laterality on young elite cyclic-sports athletes N2 - Die Ausprägung der Lateralität der Körperextremitäten steht in engem Zusammenhang mit der Hemisphärenspezialisierung des menschlichen Gehirns. Die Lateralität und die Dominanz einer Hemisphäre mit ihren Auswirkungen auf die Leistungsfähigkeit ist ein bislang unvollständig untersuchtes Phänomen im Sport. In der vorliegenden Arbeit soll daher die Bedeutung der Seitigkeitsausprägung im Rahmen sportlicher Bewegungsabläufe geprüft werden. Sowohl bei Messungen im "Freiwasser", als auch in der "Kanu–Gegenstromanlage" im Bereich des Kanurennsportes werden seit einigen Jahren sich in Qualität und Quantität unterscheidende Kraft–Zeit–Funktionen der linken und rechten Körperseite beobachtet, die zwar dokumentiert, aber bislang ungeprüft in ihrer Bedeutung als leistungsbeeinflussend angenommen werden. Im Zeitraum von Oktober 1997 bis Oktober 2000 wurden 275 Kajakfahrer und Canadierfahrer im Alter zwischen 11 und 20 Jahren zweimal jährlich (März und Oktober) mit einem umfangreichen trainings- und bewegungswissenschaftlichen sowie biomechanischen Instrumentarium untersucht. Die Athleten gehören zum Nachwuchs- und Anschlusskader des LKV Brandenburg. Schwerpunkt der Fragestellung ist der Zusammenhang von auftretenden Kraftdifferenzen zwischen der linken und rechten oberen Extremität und sportartspezifischen Leistungen unter Laborbedingungen und Feldbedingungen. Es wurden objektive Daten zu ausgewählten Kraftfähigkeiten der oberen Arm–Beuge–Schlinge an einem Kraftdiagnosegerät, Kraftverläufe am Messpaddel während Leistungsüberprüfungen im "Kanu–Gegenstromkanal" und im "Freiwasser" über 250 m und 2.000 m im Jahresverlauf erhoben. Die Ergebnisse zeigen einen Trend der im Altersverlauf ansteigenden Differenz der Mittelwertunterschiede in der Maximalkraft zwischen dem linken und rechten Arm. Bei bestehenden Maximalkraftdifferenzen zwischen linker und rechter oberer Extremität in der Längsschnittgruppe liegen die Leistungen mit dem rechten Arm deutlich über den Kraftleistungen des linken Arms und sind nicht zufällig. Mit steigendem Maximalkraftniveau nimmt überraschenderweise auch die Differenz der Maximalkraft zwischen der linken und rechten oberen Extremität trotz bilateralen Trainings zu. Die Ergebnisse der EMG–Analyse bestätigen, dass die Maximalkraft leistungsbestimmend für die Bootsleistungen ist. In den EMG–Signalverläufen werden die unterschiedlichen Belastungen der Labor– und Feldbedingungen mit individuellen Charakteristika nachgezeichnet. Deutlich unterscheiden sich die Kraftverläufe im "Freiwasser" gegenüber den Kraftverläufen in der "Kanu–Gegenstromanlage". Bei der vorliegenden Untersuchung handelt es sich um eine erste empirische Arbeit zur Auswirkung von Seitigkeitsunterschieden in zyklischen Sportarten auf der Expertiseebene. In der Untersuchung wurden methodische Verfahren eingesetzt, die dem derzeitigen Forschungsstand in der Trainings- und Bewegungswissenschaft entsprechen. Neben varianzanalytischen Verfahren der Auswertung zur Darstellung von Mittelwertunterschieden und Zusammenhänge prüfenden Verfahren wurden ebenso explorative EMG–Analysen angewandt. Die Ergebnisse aus dem Längsschnitt belegen bei ausschließlich rechtshändigen Probanden, dass die Schlussfolgerung von bevorzugter Extremität auf ein höheres Kraftniveau nicht eineindeutig ist. Zwischen den oberen Extremitäten bei Kanurennsportlern bestehen nicht nur zufällige Kraftunterschiede, trotz des bilateralen Trainings. Kontrovers diskutiert wird die Beziehung von bevorzugter Extremität und der Höhe der Kraftentfaltung. Im Alltagsverständnis wird häufig angenommen, dass ein höheres Maximalkraftniveau in der Extremität vorliegen muss, die auch die bevorzugte (z.B. Schreibhand) ist (WIRTH & LIPHARDT, 1999). Diese Eindeutigkeit konnte in der durchgeführten Untersuchung nicht bestätigt werden. Wie die Ergebnisse dieser Untersuchung deutlich zeigen, nimmt mit der höheren Maximalkraft aber auch die Differenz der Kraftleistungen zwischen dem linken und rechten Arm bei bilateral ausgerichtetem Training zu. FISCHER (1988; 1992) wies nach, dass sich ein Training auf der subdominanten Seite in einem kontralateralen Leistungstransfer auf der dominanten Seite positiv auswirkte. Erkenntnisse von KUHN (1986) und HOLLMANN & HETTINGER (2000) unterstützen nachhaltig die Ergebnisse. Die EMG–Ergebnisse zeigen die individuelle Reaktion auf die Belastungsanforderungen. Die elektromyographischen Daten beziehen sich auf den neuromuskulären Komplex. Somit sprechen hohe Amplitudenwerte einerseits für eine hohe Innervation der beteiligten motorischen Einheiten an der Bewegungsausführung und andererseits für einsetzende Ermüdungserscheinungen im Muskel. In Bezug auf die Ermüdung der oberen Extremitätenmuskeln der rechten und linken Seite beschreiben WILLIAMS, SHARMA & BILODEAU (2002) keine signifikanten Unterschiede zwischen der dominanten und nichtdominanten Handseite. N2 - The development of body extremity laterality is closely linked to hemisphere specialization of the human brain. Laterality, the dominance of one hemisphere, and the effect of these two phenomena on sports performance capacity have yet to be described in detail. The question arises as to whether performance differences between paired extremities and the attendant extent of this difference might determine performance levels. In flat water canoeing, measurements in flat water as well as in the canoe counter current system reveal force time functions of the left and right body side that differ in quality and quantity. These differences have been documented for a number of years. However, so far their influence on performance has been presumed to exist and no attempt has been made to explain them. During the period from October 1997 to October 2000, 275 kayakers and canoeists between the ages of 11 and 20 were examined twice annually (March and October) using extensive training scientific, kinetic and biomechanical equipment. The athletes were members of a state-wide canoeing club. The main focus of the study was the correlation between (a) force differences arising between the left and right upper extremity and (b) athletic performance under laboratory conditions and field conditions. The following data was gathered: selected strength capacities of the upper arm flexor at a static strength measurement system (Wick & Krüger, 1998), force curves at the measuring paddle during exercise tests using the canoe counter current system and canoeing times in flat water over 250 m and 2,000 m during the course of the year. The results of the static maximum force test showed that the difference in maximum force between the left and right arm increases with age. In the cross-sectional group, maximum force differences were observed between the left and right upper extremity; in terms of strength performance the right arm was clearly superior to the left arm. Despite bilateral training, contrary to what might be expected, the difference in maximum force between the left and right upper extremity increases with rising maximum force level. The proportional relationship remains unaffected by this. The evaluation of force parameters from the longitudinal and cross-sectional standpoint does not provide any clear indication of performance dominance of a specific extremity. The differences of the force parameters between the left and right upper extremity as measured in the canoe counter current system and in flat water are not stable. An analysis of EMG results confirmed that the maximum force has a decisive effect on canoeing performance. Force curves in flat water differ markedly from force curves in the canoe counter current system. The present investigation is a first empirical paper on the effect of laterality differences on expert athletes in cyclic sports. The methodologies applied during the investigation correspond to the present state of research in the fields of training science and human kinetics. Variance-analytical methods of evaluation for the representation of average value differences, procedures that search connections and explorative EMG analyses were used. Results from the longitudinal section indicate that with exclusively right-handed subjects the preferred extremity cannot biuniquely be shown to have a higher force level. This result is confirmed by the cross-sectional findings. Despite bilateral training, force differences are observed between the upper extremities of canoeists. However, there is ongoing controversy about the relationship between preferred extremity and the extent of force development. The preferred extremity (e.g. the writing hand) is commonly believed to possess the higher maximum force level (Wirth & Liphardt, 1999). Nonetheless, this assumption could not be confirmed during the present investigation. However, the results of this investigation clearly show that as maximum force increases, the difference in strength performance between the left and right arm increases, including when bilateral training is applied. Fischer (1988; 1992) showed that training the subdominant side positively affected the dominant side. This is attributable to contralateral achievement transfer. These results are strongly supported by the findings of Kuhn (1986) and Hollmann & Hettinger (2000). The proportional difference remains stable over time with the athletes studied. This too supports the concept that the preferred extremity benefits from positive transfer effects. The electromyographic data pertains to the neuromuscular complex. Thus high amplitude values suggest on one hand a high innervation of the motor units involved in the performance of the movement and on the other hand the first signs of muscle fatigue. Williams, Sharma & Bilodeau (2002) found no significant differences between fatigue levels in the upper extremity muscles of the dominant and non-dominant extremity. KW - Kanurennsport KW - Lateralität KW - Elektromyographie KW - Maximalkraft KW - Schnellkraft KW - Hemisphaerendominanz KW - Dominanz KW - laterality KW - dominance of hemisphere KW - cyclic sports KW - flat water canoeing KW - electromyography KW - maximum force Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-5810 ER -