TY - GEN A1 - Quarmby, Andrew James A1 - Mönnig, Jamal A1 - Mugele, Hendrik A1 - Henschke, Jakob A1 - Kim, MyoungHwee A1 - Cassel, Michael A1 - Engel, Tilman T1 - Biomechanics and lower limb function are altered in athletes and runners with achilles tendinopathy compared with healthy controls: A systematic review T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe N2 - Achilles tendinopathy (AT) is a debilitating injury in athletes, especially for those engaged in repetitive stretch-shortening cycle activities. Clinical risk factors are numerous, but it has been suggested that altered biomechanics might be associated with AT. No systematic review has been conducted investigating these biomechanical alterations in specifically athletic populations. Therefore, the aim of this systematic review was to compare the lower-limb biomechanics of athletes with AT to athletically matched asymptomatic controls. Databases were searched for relevant studies investigating biomechanics during gait activities and other motor tasks such as hopping, isolated strength tasks, and reflex responses. Inclusion criteria for studies were an AT diagnosis in at least one group, cross-sectional or prospective data, at least one outcome comparing biomechanical data between an AT and healthy group, and athletic populations. Studies were excluded if patients had Achilles tendon rupture/surgery, participants reported injuries other than AT, and when only within-subject data was available.. Effect sizes (Cohen's d) with 95% confidence intervals were calculated for relevant outcomes. The initial search yielded 4,442 studies. After screening, twenty studies (775 total participants) were synthesised, reporting on a wide range of biomechanical outcomes. Females were under-represented and patients in the AT group were three years older on average. Biomechanical alterations were identified in some studies during running, hopping, jumping, strength tasks and reflex activity. Equally, several biomechanical variables studied were not associated with AT in included studies, indicating a conflicting picture. Kinematics in AT patients appeared to be altered in the lower limb, potentially indicating a pattern of “medial collapse”. Muscular activity of the calf and hips was different between groups, whereby AT patients exhibited greater calf electromyographic amplitudes despite lower plantar flexor strength. Overall, dynamic maximal strength of the plantar flexors, and isometric strength of the hips might be reduced in the AT group. This systematic review reports on several biomechanical alterations in athletes with AT. With further research, these factors could potentially form treatment targets for clinicians, although clinical approaches should take other contributing health factors into account. The studies included were of low quality, and currently no solid conclusions can be drawn. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 830 KW - achilles tendinopathy KW - biomechanics KW - neuromuscular KW - kinetics KW - electromyography KW - athletes KW - runners KW - kinematics Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-587603 SN - 1866-8364 IS - 830 ER - TY - JOUR A1 - Quarmby, Andrew James A1 - Mönnig, Jamal A1 - Mugele, Hendrik A1 - Henschke, Jakob A1 - Kim, MyoungHwee A1 - Cassel, Michael A1 - Engel, Tilman T1 - Biomechanics and lower limb function are altered in athletes and runners with achilles tendinopathy compared with healthy controls: A systematic review JF - Frontiers in Sports and Active Living N2 - Achilles tendinopathy (AT) is a debilitating injury in athletes, especially for those engaged in repetitive stretch-shortening cycle activities. Clinical risk factors are numerous, but it has been suggested that altered biomechanics might be associated with AT. No systematic review has been conducted investigating these biomechanical alterations in specifically athletic populations. Therefore, the aim of this systematic review was to compare the lower-limb biomechanics of athletes with AT to athletically matched asymptomatic controls. Databases were searched for relevant studies investigating biomechanics during gait activities and other motor tasks such as hopping, isolated strength tasks, and reflex responses. Inclusion criteria for studies were an AT diagnosis in at least one group, cross-sectional or prospective data, at least one outcome comparing biomechanical data between an AT and healthy group, and athletic populations. Studies were excluded if patients had Achilles tendon rupture/surgery, participants reported injuries other than AT, and when only within-subject data was available.. Effect sizes (Cohen's d) with 95% confidence intervals were calculated for relevant outcomes. The initial search yielded 4,442 studies. After screening, twenty studies (775 total participants) were synthesised, reporting on a wide range of biomechanical outcomes. Females were under-represented and patients in the AT group were three years older on average. Biomechanical alterations were identified in some studies during running, hopping, jumping, strength tasks and reflex activity. Equally, several biomechanical variables studied were not associated with AT in included studies, indicating a conflicting picture. Kinematics in AT patients appeared to be altered in the lower limb, potentially indicating a pattern of “medial collapse”. Muscular activity of the calf and hips was different between groups, whereby AT patients exhibited greater calf electromyographic amplitudes despite lower plantar flexor strength. Overall, dynamic maximal strength of the plantar flexors, and isometric strength of the hips might be reduced in the AT group. This systematic review reports on several biomechanical alterations in athletes with AT. With further research, these factors could potentially form treatment targets for clinicians, although clinical approaches should take other contributing health factors into account. The studies included were of low quality, and currently no solid conclusions can be drawn. KW - achilles tendinopathy KW - biomechanics KW - neuromuscular KW - kinetics KW - electromyography KW - athletes KW - runners KW - kinematics Y1 - 2023 U6 - https://doi.org/10.3389/fspor.2022.1012471 SN - 2624-9367 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - Jafarnezhadgero, Amir Ali A1 - Anvari, Maryam A1 - Granacher, Urs T1 - Long-term effects of shoe mileage on ground reaction forces and lower limb muscle activities during walking in individuals with genu varus JF - Clinical biomechanics N2 - Background: Shoe mileage is an important factor that may influence the risk of sustaining injuries during walking. The aims of this study were to examine the effects of shoe mileage on ground reaction forces and activity of lower limb muscles during walking in genu varus individuals compared with controls. Methods: Fifteen healthy and 15 genu varus females received a new pair of running shoes. They were asked to wear these shoes over 6 months. Pre and post intervention, mechanical shoe testing was conducted and ground reaction forces and muscle activities of the right leg were recorded during walking at preferred gait speed. Findings: Significant group-by-time interactions were found for shoe stiffness, antero-posterior and vertical impact peak. We observed higher shoe stiffness and lower impact peaks after intervention in both groups with larger effect sizes in genu varus. Significant group-by-time interactions were identified for vastus medialis (loading phase) and rectus femoris (loading and push-off). For vastus medialis, significant decreases were found from pre-to-post during the loading phase in the control group. Rectus femoris activity was higher post intervention during the loading and push-off phases in both groups with larger effect sizes in genu varus. Interpretation: Our findings indicate that the observed changes in ground reaction forces are more prominent in genu varus individuals. Together with our findings on shoe stiffness, it seems appropriate to change running shoes after an intense wearing time of 6 months, particularly in genu varus individuals. KW - footwear KW - electromyography KW - loading rate KW - patients Y1 - 2020 U6 - https://doi.org/10.1016/j.clinbiomech.2020.01.006 SN - 0268-0033 SN - 1879-1271 VL - 73 SP - 55 EP - 62 PB - Elsevier CY - Oxford 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 -