Horizontal jumping biomechanics among elite female handball players with and without anterior cruciate ligament reconstruction: an ISU based study.

BACKGROUND: Handball is a strenuous body-contact team sport that places high loads on the knee joint. Anterior cruciate ligament (ACL) tear is one of the most devastating injuries that any handball player can suffer, and female athletes are at particular risk due to their intrinsic anatomical, hormonal, neuromuscular and biomechanical characteristics. The purpose of this study was to analyze the horizontal jumping biomechanics of female elite handball players with or without previous ACL reconstruction. METHODS: Twenty-one female participants (6 with previous ACL reconstruction and 15 uninjured controls) were recruited. Two horizontal hopping tasks were evaluated using inertial sensor unit (ISU)-based technology to assess jumping biomechanics through a direct mechanics-based approach. RESULTS: The athletes with previous ACL reconstruction demonstrated a significant (P < 0.05) reduction in the unilateral triple hop for distance compared with the healthy controls. Furthermore, during the initial propulsive phase of the unilateral cross-over hop, the control participants generated significantly (P < 0.05) higher force values in the mediolateral direction (the X axis) with their dominant limb compared with the ACL-reconstructed (ACL-R) limb of previously injured participants. CONCLUSIONS: Three-dimensional horizontal jumping biomechanics analyses using ISU-based technologies could provide clinicians with more accurate information regarding the horizontal jumping biomechanical patterns among elite handball female athletes. Furthermore, several mechanical alterations could still be observed among those players who had undergone previous ACL reconstruction, even when several years have passed since the original ACL injury.

Horizontal jumping biomechanics among elite male handball players with and without anterior cruciate ligament reconstruction. An inertial sensor unit-based study.

OBJECTIVES: Anterior cruciate ligament (ACL) tears are one of the most devastating injuries that any handball player can suffer during landing and pivoting actions. The aim of this study was to analyze the horizontal jumping biomechanics among male elite handball players with or without previous ACLR. DESIGN: Descriptive study. SETTING: Spanish elite male handball players. PARTICIPANTS: Twenty-six male participants (6 ACL-R and 20 uninjured controls) were recruited. MAIN OUTCOME MEASURES: Two horizontal hopping tasks were evaluated using an inertial sensor unit (ISU)-based technology to assess jumping biomechanics through a direct mechanics-based approach. RESULTS: Non-significant differences were found in relation to any of the biomechanical or performance related analyzed variables. CONCLUSIONS: Previously ACL-R elite male handball players who have returned to the top level of sports participation do not seem to possess lasting biomechanical and/or performance deficits 6 years after the original surgical ligament repair.

Predicción de la altura óptima de caída en drop jumps usando antropometría y pruebas motoras / Predicting optimum drop height in drop jumps through anthropometry and motor tests

El objetivo de este estudio ha sido predecir la altura optima de caída (AOC) en los ejercicios pliométricos Drop Jump (DJ) a partir de variables cinemáticas y antropométricas, mediante un modelo de regresión múltiple lineal. Participaron en el estudio 13 sujetos, 6 hombres y 7 mujeres de la liga vallecaucana de atletismo. Inicialmente se determinó la altura de vuelo y longitud de los saltos efectuados con las pruebas físicas Countermovement Jumps (CMJ), Abalakov (ABK), salto largo sin/con impulso de brazos, el tiempo en carreras de 30 y 100 m. Se determinó la composición corporal en % y Kg. (músculo, grasa, óseo y residual) por ecuaciones de regresión (Yuhasz, Mateigka, De Rose, etc.) Además, se valoró utilizando la plataforma de contacto la AOC a partir de los índices de fuerza reactiva (RSI), coeficiente de calidad del salto (CQ), capacidad reactiva del músculo (CR) que se determinan usando los tiempos de contacto y vuelo. La información se analizó con estadística descriptiva e inferencial principalmente con análisis de correlación, regresión lineal múltiple y pruebas no paramétricas para el modelo de regresión. En la AOC con utilización de brazos, el salto largo explicó por sí solo un 99,6% de la variabilidad en la AOC. La variable anterior combinada con el tiempo en 100 m. permitió explicar un 99,8% de la variabilidad en la AOC. Al añadir a la ecuación anterior el porcentaje de asa muscular se pudo explicar un 99,9% de la variabilidad en la AOC. Añadiendo a la ecuación el porcentaje graso se explicó 99,9% de la variabilidad en la AOC.

The aim of this study was to find out if it is possible to predict the land optimal height (AOC) of the plyometric jump (DJ) from kinematic and anthropometric variables using a multiple linear regression model. Thirtee subjects, 13, 6 male and 7 female athletics runners and jumpers of Liga Vallecaucana de Atletismo First, the height of the flight y long jump during the performance of the “countermovement jump” (CMJ), Abalakov, long jump with/without arms impulse, time in 30, 100 m were determined. Then, the corporal composition in % and Kg. (muscle, fat, bone and residual tissue), using Yuhasz, Mateigka, and De rose equations. So, with the contact platform calculate the several index: reactive strength index (RSI), quality coefficient (CQ) and muscle reactive output (CR) using flight and contact times. The information was analize with descriptive and inferential statistics meanly correlation, regression linear and non parametric tests for the regression model. In the AOC using arms, long jump explain 99,6% of the variability. the Prediction power was increased to 99,8% including in the model 100 m time. The inclusion of the muscle mass, as a third variable, raised the prediction power to 99,9% of land optimal height variability. Adding to the corporal fat (%) to the model, the prediction power was 99,9% too.