Comparison of Knee Kinematics during Single Leg Squat across Physically Active Females with and without Dynamic Knee Valgus

@#Introduction: Introduction: Knee valgus which also known as dynamic knee valgus (DKV), is frequently linked to non-contact lower-limb injuries, especially in females. This retrospective study aims to compare the kinematic variables of lower limb joints in physically active females with normal versus excessive DKV during single leg squat (SLS) at 45° and 60° knee flexion. Methods: Based on the outcomes of drop vertical jump screening test, 34 females were recruited and divided into two groups (i.e., normal and excessive DKV). Participants performed SLS at 45° and 60° knee flexion with three-dimensional motion capture and analysis. The kinematic variables of lower limb joints at both knee flexion of SLS were compared across groups using independent T-test. Results: During 45° SLS with the dominant limb, the normal DKV group performed significantly greater hip adduction angle (4.49±3.25°, t(32) = 2.371, p= 0.024) than the excessive DKV group (1.426±4.23°). During 60° SLS with the dominant limb, the normal DKV group showed knee adduction (0.223±0.07°, t(16.048) = 10.707, p=0.001) while the excessive DKV group showed knee abduction (-4.478±1.81°). Conclusion: Females with excessive DKV showed significantly different lower limb kinematics and motion control strategy compared to females with normal range of DKV. The findings highlighted the importance of DKV screening among physically active females, and the rationale for prescribing individualized exercise intervention to prevent lower limb non-contact injuries.

Reducing the sports injury through function movement biological image data screening / Reduzindo lesões esportivas por meio da triagem de dados biológicos de imagens de movimento / Reducción de las lesiones deportivas mediante la detección de datos biológicos por imágenes en movimiento

ABSTRACT Introduction Among the many cases of sports injuries, the incidence of musculoskeletal injuries remains high. After a musculoskeletal injury occurs, athletes often need to suspend training and undergo rehabilitation. A suitable sport mode requires athletes to have sufficient joint range of motion, core stability, and balance ability in different positions to complete various complex movements in training and competition. Objective The paper analyzes the impact of warm-up exercises before the test on the test results of functional sports biological image data screening ( FMS TM ) and provides references for unifying test conditions, checking the reliability of FMS TM repeated tests, and discussing the comparability of the research results. Methods The paper used the same password and process to test 12 young male volleyball professional athletes without warm-up and warm-up. The two-dimensional motion analysis system Dartfish Pursuit 8.0 was used to analyze the video data recorded by the two cameras simultaneously. Results In the two tests before and after, the hurdle step score (1.75±0.62 vs. 2.42±0.52) and the total score (13.50±2.20 vs. 16.42±2.15) were significantly higher than those without the warm-up test (P<0.01). Besides, in squats (1.58±0.67 vs. 1.92±0.67), straight lunges (2.00±0.43 vs. 2.50±0.52), active straight leg lifts (1.50±0.67 vs. 2.00±0.60), rotation stability (1.42) ±0.52 vs. 1.92±0.29) showed a significant increase in the score (P<0.05). Conclusions Warm-up exercises before the test can improve the test results. This abnormal movement pattern observed only by visual inspection may not truly reflect the "dysfunction" of the movement. In the case of ignoring the pre-test warm-up factors, feedback on sports performance and formulating training strategies, this conclusion of predicting injury risk and evaluating training effects may have specific limitations in its reference value. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMO Introdução Dentre os diversos casos de lesões esportivas, a incidência de lesões musculoesqueléticas permanece elevada. Após a ocorrência de uma lesão musculoesquelética, os atletas geralmente precisam suspender o treinamento e se submeter à reabilitação. Um modo de esporte adequado requer que os atletas tenham amplitude de movimento articular suficiente, estabilidade central e capacidade de equilíbrio em diferentes posições para completar vários movimentos complexos em treinamento e competição. Objetivo o artigo analisa o impacto dos exercícios de aquecimento antes do teste sobre os resultados dos testes de triagem de dados de imagens biológicas esportivas funcionais (FMSTM) e fornece referências para unificar as condições de teste, verificar a confiabilidade de testes FMSTM repetidos e discutir a comparabilidade dos resultados da pesquisa . Métodos O artigo utilizou a mesma senha e processo para testar 12 jovens atletas profissionais do sexo masculino de voleibol sem aquecimento e com aquecimento. O sistema de análise de movimento bidimensional Dartfish Pursuit 8.0 foi usado para analisar os dados de vídeo gravados pelas duas câmeras simultaneamente. Resultados Nos dois testes antes e depois, a pontuação do hurdle step (1,75 ± 0,62 vs. 2,42 ± 0,52) e a pontuação total (13,50 ± 2,20 vs. 16,42 ± 2,15) foram significativamente maiores do que aqueles sem o teste de aquecimento ( P <0,01). Além disso, em agachamentos (1,58 ± 0,67 vs. 1,92 ± 0,67), estocadas retas (2,00 ± 0,43 vs. 2,50 ± 0,52), levantamentos ativos de perna reta (1,50 ± 0,67 vs. 2,00 ± 0,60), estabilidade de rotação (1,42) ± 0,52 vs. 1,92 ± 0,29) mostrou um aumento significativo na pontuação (P <0,05). Conclusão Os exercícios de aquecimento antes do teste podem melhorar os resultados do teste. Este padrão de movimento anormal observado apenas por inspeção visual pode não refletir verdadeiramente a "disfunção" do movimento. No caso de ignorar os fatores de aquecimento pré-teste, feedback sobre o desempenho esportivo e formulação de estratégias de treinamento, esta conclusão de prever o risco de lesões e avaliar os efeitos do treinamento pode ter limitações específicas em seu valor de referência. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción Entre los muchos casos de lesiones deportivas, la incidencia de lesiones musculoesqueléticas sigue siendo alta. Después de que ocurre una lesión musculoesquelética, los atletas a menudo necesitan suspender el entrenamiento y someterse a rehabilitación. Un modo de deporte adecuado requiere que los atletas tengan suficiente rango de movimiento articular, estabilidad central y capacidad de equilibrio en diferentes posiciones para completar varios movimientos complejos en el entrenamiento y la competencia. Objetivo El documento analiza el impacto de los ejercicios de calentamiento antes de la prueba en los resultados de las pruebas de detección de datos de imágenes biológicas deportivas funcionales (FMSTM) y proporciona referencias para unificar las condiciones de prueba, verificar la confiabilidad de las pruebas FMSTM repetidas y discutir la comparabilidad de los resultados de la investigación. Métodos El documento utilizó la misma contraseña y proceso para evaluar a 12 jóvenes atletas profesionales de voleibol sin calentamiento y con calentamiento. El sistema de análisis de movimiento bidimensional Dartfish Pursuit 8.0 se utilizó para analizar los datos de video grabados por las dos cámaras simultáneamente. Resultados En las dos pruebas antes y después, la puntuación del paso de valla (1,75 ± 0,62 frente a 2,42 ± 0,52) y la puntuación total (13,50 ± 2,20 frente a 16,42 ± 2,15) fueron significativamente más altas que aquellas sin la prueba de calentamiento ( P <0,01). Además, en sentadillas (1,58 ± 0,67 vs 1,92 ± 0,67), estocadas rectas (2,00 ± 0,43 vs 2,50 ± 0,52), levantamientos activos de piernas rectas (1,50 ± 0,67 vs 2,00 ± 0,60), estabilidad de rotación (1,42) ± 0,52 vs. 1,92 ± 0,29) mostró un aumento significativo en la puntuación (P <0,05). Conclusión Los ejercicios de calentamiento antes de la prueba pueden mejorar los resultados de la prueba. Este patrón de movimiento anormal observado solo por inspección visual puede no reflejar realmente la "disfunción" del movimiento. En el caso de ignorar los factores de calentamiento previos a la prueba, la retroalimentación sobre el rendimiento deportivo y la formulación de estrategias de entrenamiento, esta conclusión de predecir un riesgo de lesión y evaluar los efectos del entrenamiento puede tener limitaciones específicas en su valor de referencia. Nivel de evidencia II; Estudios terapéuticos: investigación de los resultados del tratamiento.

Epidemiological characteristics and risk factors of nonfatal injury among middle school students in Zhejiang Province / 预防医学

Objective@#To understand the epidemiological characteristics of nonfatal injury and its influencing factors among middle school students in Zhejiang Province,and to provide evidence for prevention and control of nonfatal injury of adolescents. @*Methods@#Using multi-stage stratified cluster sampling method,24 157 middle school students from 442 schools in 30 counties（cities,districts）of Zhejiang Province were selected to investigate socio-demographic characteristics,the occurrence of nonfatal injury and injury-related behaviors from April to May of 2017. Logistic regression model was used to analyze influencing factors for nonfatal injury among middle school students.@*Results@#The incidence of nonfatal injuries in 23 462 secondary school students in the past 12 months was 20.86%. The incidence of nonfatal injury was 24.15% in boys,which was higher than 17.33% in girls（P<0.05）. The incidence of nonfatal injury was 20.17% in urban students and 21.19% in rural students,and the difference between them was not statistically significant（P>0.05）. The incidence of nonfatal injury was 22.17% in junior high school students,19.42% in senior high school students and 19.51% in vocational high school students,and there was statistically significant difference between them（P<0.05）. The results of the multivariate logistic regression analysis showed that boys（girls：OR=0.805,95%CI：0.728-0.890）,poor academic performance（OR=1.149,95%CI：1.018-1.298）,smoking（OR=1.260,95%CI：1.083-1.466）,drinking（OR=1.410,95%CI：1.279-1.553）,more physical activity（OR：1.244- 1.527,95%CI：1.098-1.767）,loneliness（OR：1.336-1.500,95%CI：1.219-1.682）,sadness（OR=1.308,95%CI：1.186-1.441）,absenteeism（OR=1.390,95%CI：1.182-1.634）,running away from home（OR=1.242,95%CI：1.076- 1.435）,fighting（OR=1.771,95%CI：1.594-1.967）and being bullied（OR=2.071,95%CI：1.869-2.294）were risk factors for nonfatal injury in middle school students.@*Conclusion@#The incidence of nonfatal injuries among secondary school students was 20.86%. Male students were the high risk group. The incidence of nonfatal injury was related to gender,smoking,drinking,negative emotions and violence.

Analysis of Landing Error Scoring System during Drop Vertical Jump on Anterior Cruciate Ligament Injury Risk Factors in Elite Fencers / 대한스포츠의학회지

PURPOSE: The aim of this study was to identify the differences of gender and detail items by using landing error scores during drop vertical jumping that can be used in the field for elite fencers and to use them as basic data for prevention of injury. METHODS: The subjects were 42 elite fencers. Independent sample t-test was used to compare the landing error scoring system (LESS) score between the groups. In order to compensate for errors that may occur in multiple comparisons, they are corrected through the Bonferroni collection. The significant differences between the groups were evaluated using Cohen effect difference, and one-way analysis of variance was performed for differences in epee, fleuret, and sabre. RESULTS: The comparison of landing error scores between male and female fencer groups showed that the knee valgus angle at initial contact, lateral trunk flexion angle at initial contact, stance width-narrow, foot position-toe out, symmetric initial foot contact, in the total score of LESS items, female fencer group was higher and statistically significant difference was found. CONCLUSION: In the case of fencing players, there is no significant difference in the LESS scores according to the items. However, when comparing gender, female fencers have higher LESS scores than male fencers; female fencers should be more careful in preventing injuries.

The research on biomechanics of sports injuries / 医用生物力学

All professional or amateur athletes sustain different kinds of acute or overused injuries, which vary with sports events. Biomechanics plays the key role in determining risk factors and elucidating injury mechanisms for sports injuries. Three kinds of research methods, experimental test, modeling and computer simulation and statistical simulation, are generally used in biomechanical studies of sports injuries. This paper firstly reviews the epidemiology of sports injuries, and then comprehensively summarizes the related researches on injury biomechanics, in purpose of providing theoretical basis for studies on sports injury biomechanics, prevention of sports injuries, and clinical treatments and rehabilitation.

Analysis of Landing Error Scoring System during Drop Vertical Jump on Anterior Cruciate Ligament Injury Risk Factors in Female Ballet Dancers and Female Soccer Players / 대한스포츠의학회지

The incidence of anterior cruciate ligament (ACL) injuries among female ballet dancers is much lower than among female soccer players, there is currently little research examining the landing error scoring system (LESS) of female ballet dancers and female soccer players. The purpose of this study was to investigate the LESS during drop vertical jump on ACL injury risk factors in female ballet dancers and female soccer players. Thirteen professional female ballet dancers and elite female soccer players participated in the study. Independent sample t-test was used to compare the LESS score between the groups with Bonferroni collection. The elite female soccer player group showed significantly higher stance width-wide, foot position-toe out, symmetric initial foot contact, overall impression and total LESS score than those of the professional ballet dancers.

Risk factors for shoulder injuries with or without past history in collegiate rugby players / 体力科学

To examine risk factors for shoulder injuries with or without history of the injuries using the stratification analysis for collegiate rugby players. 71 elite rugby players from one university rugby club joined in the preseason medical screening related to their shoulder joints, including basic demographics, history of injuries, and physical findings at that time. Subsequently, the occurrence of shoulder injuries was recorded during four playing seasons. Analysis was stratified with or without history of the injuries; player without the past history of injury, 47 players; player with the past history of injury, 24 players. As a result of all players with the past history, 13 players sustained the shoulder injuries. Internal rotational range of motion [IR ROM] (OR, 1.5; 95%CI, 1.13-1.96; p=0.004), external rotational range of motion [ER ROM] (OR, 1.9; 95%CI, 1.21-2.87; p=0.005), horizontal flexion range of motion [HF ROM] (OR, 1.3; 95%CI, 1.03-1.64; p=0.025), IR muscle strength (OR, 0.4; 95%CI, 0.20-0.65; p=0.001) and rugby experience (OR, 1.2; 95%CI, 1.02-1.46; p=0.032) were associated with the shoulder injuries. On the other hand, 10 players sustained injuries of the players without the past history of injury. IR muscle strength (OR, 0.3; 95%CI, 0.11-0.72; p=0.008) and rugby experience (OR, 1.4; 95%CI, 1.11-1.66; p=0.003) were associated with the shoulder injuries. This study clearly showed that IR, ER, HF ROM, IR muscle strength and rugby experience were important initial risk factors for shoulder injuries. Moreover, IR muscle strength and rugby experience were important recurrence risk factors for shoulder injuries.

Diferenças na cinemática entre dois tipos de aterrissagens em atletas de voleibol masculinos / Difference in kinematical behavior between two landing tasks in male volleyball athletes

As lesões no ligamento cruzado anterior (LCA) são frequentes no âmbito esportivo. O estudo dos mecanismos de lesão demonstrou que a maioria das lesões é oriunda tanto de aterrissagens unilaterais quanto bilaterais. Apesar de estudos terem demonstrado diferenças no comportamento cinemático de membros inferiores entre homens e mulheres, não há evidências de como homens se comportam em diferentes condutas. O objetivo neste estudo foi comparar a cinemática angular e temporal dos membros inferiores, manifestaem aterrissagens de saltos com propulsão bilateral, realizadas sobre um e dois membros inferiores. Aterrissagens unilaterais e bilaterais no plano frontal e sagital de quinze atletas masculinos de voleibol foram registradas e processadas por meio de técnicas videogramétricas. Os resultados indicam que, na aterrissagem unilateral, os atletas apresentaram menor flexão do quadril e joelho, assim como maior valgismo do joelho, quando comparada coma aterrissagem bilateral. A diferença no tempo de aterrissagem entre as duas condutas não foi estatisticamente significante. Em conclusão, os resultados deste estudo apóiam a premissa de que a cinemática dos membros inferiores se altera em função da configuração da conduta motora realizada em homens. Estudos futuros são necessários para explorar o impacto das diferenças cinemáticas encontradas na tensão ligamentar e relacioná-las comos mecanismos de lesões no LCA em homens.

Anterior cruciate ligament (ACL) injuries are common in sports. Studies investigating injury mechanisms have demonstrated that most injuries arise from landing tasks. Despite the demonstration of differences between male and female kinematics, there are no studies showing how males behave during different landing tasks. The objective of this study was to compare theangular and temporal kinematics of the lower limbs between two different landing tasks. Double leg and single leg landings were recorded in the frontal and sagittal plane in 15 male volleyball athletes by videogrammetry. Reduced hip and knee flexion and increased knee valgus were observed in the single leg landing task compared to the double leg landing task. No significantdifference in landing time was observed between the two tasks. In conclusion, the results support the premise that lower limb kinematics change according to the task performed. Further studies are necessary to explore the impact of these kinematic differences on knee loading and to relatethem to ACL injury mechanisms in men.