Bruno Luiz de Souza Bedo

Additional Haptic Information Provided by Anchors Reduces Postural Sway in Young Adults Less Than Does Light Touch

This study investigated the effect of adding haptic information to the control of posture, as well as comparing the effect of both the “light touch” (LT) and “anchor system” (AS) paradigms on postural sway. Additionally, it compared the effect of location and number of points of contact to the control of posture in young adults. The location consisted of using the anchors tied to the finger and held by the hands, and, for LT, the fingertip. For the number of points of contact, participants used two hands, and then separately the dominant hand, and the non-dominant hand, for both anchor and LT paradigms. Participants stood upright with feet-together and in tandem position while performing tasks that combined the use of anchors and LT, points of contact (hand grip and finger), and number of points of contact (two hands and one hand). In this study, the anchors consist of holding in each hand a flexible cable with the other end attached to the ground. The LT consists of slightly touching a rigid surface with the tip of the index finger. The results showed, first, that the anchors improved postural control less than did the LT. Second, they revealed that holding the anchors with the hands or with them tied to the fingertip resulted in a similar reduction in postural sway only in the tandem position. For the feet-together position, the anchors tied to the fingertip were ineffective. Similarly, the use of one or two hands did not affect the contribution of the anchors. However, using two hands in the LT condition was more effective than was one hand. Third, our results showed the presence of a temporal delay between force and center-of-pressure (COP) for the anchors, only in the AP direction with feet-together. In conclusion, overall, the anchors were less effective in reducing postural sway than was the LT. The anchors attached to fingertips were as effective as the hand-held anchors in the tandem position, yet ineffective during foot-together standing. Force-COP timing explains reduced postural sway with LT but not for the anchor; hence, exploratory and supra-postural components may be involved.

Kicking Performance in Young U9 to U20 Soccer Players: Assessment of Velocity and Accuracy Simultaneously

ABSTRACT Purpose: The purpose of this study was to compare the kicking performance of young soccer players in the U9 to U20 age groups. Method: Three hundred and sixty-six Brazilian players were evaluated on an official pitch using three-dimensional kinematics to measure (300 Hz) ball velocity (Vball), foot velocity (Vfoot), Vball/Vfoot ratio, last stride length, and distance between the support foot and the ball. Simultaneously, a two-dimensional procedure was also conducted to compute (60 Hz) the mean radial error, bivariate variable error, and accuracy. Possible age-related differences were assessed through one-way analysis of variance and magnitude-based inferences. Results: Ball velocity increased by 103% (p < .001, η2 = .39) from the U11 age group (48.54 ± 8.31 km/hr) to the U20 age group (98.74 ± 16.35 km/hr). Foot velocity presented a 59% increase (p < .001, η2 = .32) from the U11 age group (49.08 ± 5.16 km/hr) to U20 (78.24 ± 9.49 km/hr). This finding was due to improvement in the quality of foot–ball impact (Vball/Vfoot ratio) from U11 (0.99 ± 0.13 a.u.) to U20 (1.26 ± 0.11 a.u.; p < .001, η2 = .25). Parameters such as mean radial error and accuracy appeared to be impaired during the growth spurt (U13–U15). Last stride length was correlated, low to moderately high, with Vball in all age groups (r = .36–.79). Conclusions: In summary, we concluded that simple biomechanical parameters of kicking performance presented distinct development. These results suggest that different training strategies specific for each age group could be applied. We provide predictive equations to aid coaches in the long-term monitoring process to develop the kick in soccer or search for talented young players.

EFEITO DO TREINO NEUROMUSCULAR NA ROTAÇÃO DO JOELHO DURANTE A ATERRISSAGEM EM MULHERES

Introduction: The high rate of injuries of the anterior cruciate ligament (ACL) without involving contact in women is a source of curiosity among scientists, because drop landing assessments may suggest a predisposition to the risk of this injury. In these sense, several training protocols have been used as an intervention and achieved mixed results in the change of this risk factor. Objective: The aim of this project was to evaluate the possible changes of rotation knee in single-leg drop landing after the intervention of a neuromuscular training program. Methods: The study included 18 women aged between 18 and 51 years, who were divided into two groups: neuromuscular training group (NTG) (n=11) and control group (CG) (n=7). In addition, they did not have musculoskeletal injury or pain in the lower limbs. Each participant completed five valid single-leg drop landings from a platform of 40 cm. The motion capture process was carried out with 12 infrared cameras of the OptiTrackTM system to obtain three-dimensional coordinates of markers fixed in the anatomical points of interest. The local coordinate systems of the thigh and leg were defined by means of the respective markers set in the anatomical points. Thus, the knee rotation angles in the sagittal, frontal, and transverse planes were calculated through the sequence of Euler angles and the angular velocities were calculated using the formulations of quaternions. Results: The results showed an increase in the knee rotation speed after the neuromuscular training. Conclusion: We conclude that neuromuscular training resulted in faster rotation at the knee in the 40 milliseconds succeeding the single-leg landing.Introduccion: El gran numero de lesiones del ligamento cruzado anterior sin que implique un contacto en las mujeres es motivo de curiosidad entre los cientificos porque las evaluaciones de aterrizaje pueden sugerir predisposicion al riesgo de esta lesion. En este sentido, varios protocolos de entrenamiento se han utilizado como intervencion y lograron resultados mixtos en el cambio de este factor de riesgo. Objetivo: El objetivo de este proyecto fue evaluar los posibles cambios de rotacion de la rodilla en el aterrizaje unipodal despues de la intervencion de un programa de entrenamiento neuromuscular. Metodos: El estudio incluyo a 18 mujeres de edades comprendidas entre 18 y 51 anos, que fueron divididas en dos grupos: grupo de entrenamiento neuromuscular de ocho semanas (GEN) (n = 11) y grupo control (GC) (n = 7). Ademas, no tenian lesion musculoesqueletica o dolor en las extremidades inferiores. Cada participante realizo cinco aterrizajes unipodales validos desde una plataforma de 40 cm. El proceso de captura de movimiento se llevo a cabo con 12 camaras infrarrojas del sistema OptiTrack(tm) para obtener las coordenadas tridimensionales de los marcadores fijados a los puntos anatomicos de interes. Los sistemas de coordenadas locales del muslo y la pierna se definieron por medio de los respectivos marcadores establecidos en los puntos anatomicos. De esa manera, fueron calculados los angulos de rotacion de la rodilla en los planos sagital, frontal y transversal utilizando las secuencias de los angulos de Euler, y las velocidades angulares utilizando las formulaciones de cuaterniones. Resultados: Los resultados mostraron un aumento en la velocidad de rotacion de la rodilla despues del entrenamiento neuromuscular. Conclusion: Se concluye que el entrenamiento neuromuscular resulto en mayor velocidad de rotacion en la rodilla en los 40 milisegundos posteriores al aterrizaje unipodal.

EFECTO DEL ENTRENAMIENTO NEUROMUSCULAR EN LA ROTACIÓN DE LA RODILLA DURANTE EL ATERRIZAJE EN LAS MUJERES

Introduction: The high rate of injuries of the anterior cruciate ligament (ACL) without involving contact in women is a source of curiosity among scientists, because drop landing assessments may suggest a predisposition to the risk of this injury. In these sense, several training protocols have been used as an intervention and achieved mixed results in the change of this risk factor. Objective: The aim of this project was to evaluate the possible changes of rotation knee in single-leg drop landing after the intervention of a neuromuscular training program. Methods: The study included 18 women aged between 18 and 51 years, who were divided into two groups: neuromuscular training group (NTG) (n=11) and control group (CG) (n=7). In addition, they did not have musculoskeletal injury or pain in the lower limbs. Each participant completed five valid single-leg drop landings from a platform of 40 cm. The motion capture process was carried out with 12 infrared cameras of the OptiTrackTM system to obtain three-dimensional coordinates of markers fixed in the anatomical points of interest. The local coordinate systems of the thigh and leg were defined by means of the respective markers set in the anatomical points. Thus, the knee rotation angles in the sagittal, frontal, and transverse planes were calculated through the sequence of Euler angles and the angular velocities were calculated using the formulations of quaternions. Results: The results showed an increase in the knee rotation speed after the neuromuscular training. Conclusion: We conclude that neuromuscular training resulted in faster rotation at the knee in the 40 milliseconds succeeding the single-leg landing.Introduccion: El gran numero de lesiones del ligamento cruzado anterior sin que implique un contacto en las mujeres es motivo de curiosidad entre los cientificos porque las evaluaciones de aterrizaje pueden sugerir predisposicion al riesgo de esta lesion. En este sentido, varios protocolos de entrenamiento se han utilizado como intervencion y lograron resultados mixtos en el cambio de este factor de riesgo. Objetivo: El objetivo de este proyecto fue evaluar los posibles cambios de rotacion de la rodilla en el aterrizaje unipodal despues de la intervencion de un programa de entrenamiento neuromuscular. Metodos: El estudio incluyo a 18 mujeres de edades comprendidas entre 18 y 51 anos, que fueron divididas en dos grupos: grupo de entrenamiento neuromuscular de ocho semanas (GEN) (n = 11) y grupo control (GC) (n = 7). Ademas, no tenian lesion musculoesqueletica o dolor en las extremidades inferiores. Cada participante realizo cinco aterrizajes unipodales validos desde una plataforma de 40 cm. El proceso de captura de movimiento se llevo a cabo con 12 camaras infrarrojas del sistema OptiTrack(tm) para obtener las coordenadas tridimensionales de los marcadores fijados a los puntos anatomicos de interes. Los sistemas de coordenadas locales del muslo y la pierna se definieron por medio de los respectivos marcadores establecidos en los puntos anatomicos. De esa manera, fueron calculados los angulos de rotacion de la rodilla en los planos sagital, frontal y transversal utilizando las secuencias de los angulos de Euler, y las velocidades angulares utilizando las formulaciones de cuaterniones. Resultados: Los resultados mostraron un aumento en la velocidad de rotacion de la rodilla despues del entrenamiento neuromuscular. Conclusion: Se concluye que el entrenamiento neuromuscular resulto en mayor velocidad de rotacion en la rodilla en los 40 milisegundos posteriores al aterrizaje unipodal.

NEUROMUSCULAR TRAINING EFFECT ON KNEE ROTATION DURING DROP LANDING IN WOMEN

Introduction: The high rate of injuries of the anterior cruciate ligament (ACL) without involving contact in women is a source of curiosity among scientists, because drop landing assessments may suggest a predisposition to the risk of this injury. In these sense, several training protocols have been used as an intervention and achieved mixed results in the change of this risk factor. Objective: The aim of this project was to evaluate the possible changes of rotation knee in single-leg drop landing after the intervention of a neuromuscular training program. Methods: The study included 18 women aged between 18 and 51 years, who were divided into two groups: neuromuscular training group (NTG) (n=11) and control group (CG) (n=7). In addition, they did not have musculoskeletal injury or pain in the lower limbs. Each participant completed five valid single-leg drop landings from a platform of 40 cm. The motion capture process was carried out with 12 infrared cameras of the OptiTrackTM system to obtain three-dimensional coordinates of markers fixed in the anatomical points of interest. The local coordinate systems of the thigh and leg were defined by means of the respective markers set in the anatomical points. Thus, the knee rotation angles in the sagittal, frontal, and transverse planes were calculated through the sequence of Euler angles and the angular velocities were calculated using the formulations of quaternions. Results: The results showed an increase in the knee rotation speed after the neuromuscular training. Conclusion: We conclude that neuromuscular training resulted in faster rotation at the knee in the 40 milliseconds succeeding the single-leg landing.Introduccion: El gran numero de lesiones del ligamento cruzado anterior sin que implique un contacto en las mujeres es motivo de curiosidad entre los cientificos porque las evaluaciones de aterrizaje pueden sugerir predisposicion al riesgo de esta lesion. En este sentido, varios protocolos de entrenamiento se han utilizado como intervencion y lograron resultados mixtos en el cambio de este factor de riesgo. Objetivo: El objetivo de este proyecto fue evaluar los posibles cambios de rotacion de la rodilla en el aterrizaje unipodal despues de la intervencion de un programa de entrenamiento neuromuscular. Metodos: El estudio incluyo a 18 mujeres de edades comprendidas entre 18 y 51 anos, que fueron divididas en dos grupos: grupo de entrenamiento neuromuscular de ocho semanas (GEN) (n = 11) y grupo control (GC) (n = 7). Ademas, no tenian lesion musculoesqueletica o dolor en las extremidades inferiores. Cada participante realizo cinco aterrizajes unipodales validos desde una plataforma de 40 cm. El proceso de captura de movimiento se llevo a cabo con 12 camaras infrarrojas del sistema OptiTrack(tm) para obtener las coordenadas tridimensionales de los marcadores fijados a los puntos anatomicos de interes. Los sistemas de coordenadas locales del muslo y la pierna se definieron por medio de los respectivos marcadores establecidos en los puntos anatomicos. De esa manera, fueron calculados los angulos de rotacion de la rodilla en los planos sagital, frontal y transversal utilizando las secuencias de los angulos de Euler, y las velocidades angulares utilizando las formulaciones de cuaterniones. Resultados: Los resultados mostraron un aumento en la velocidad de rotacion de la rodilla despues del entrenamiento neuromuscular. Conclusion: Se concluye que el entrenamiento neuromuscular resulto en mayor velocidad de rotacion en la rodilla en los 40 milisegundos posteriores al aterrizaje unipodal.

Comparison of the Kinematic Patterns of Kick Between Brazilian and Japanese Young Soccer Players.

Background Kicking performance is the most studied technical action in soccer and lower limbs kinematics is closely related to success in kicking, mainly because they are essential in imparting high velocity to the ball. Previous studies demonstrated that soccer leagues in different countries exhibit different physical demands and technical requirements during the matches. However, evidencewhether nationality has any influence in the kinematics of soccer-related skills has not yet been reported. The nationality of the players is an aspect that might be also relevant to the performance in kicking. Objectives The aim of this study was to compare the lower limbs kinematic patterns during kicking, between Brazilian and Japanese young top soccer players. Patients and Methods Seven Brazilian (GA) and seven Japanese (GB) U-17 players performed 15 side-foot kicks each, with a distance of 20 m away from the goal, aiming a target of 1 × 1 m in upper corner, constrained by a defensive wall (1.8 × 2 m). Four digital video cameras (120 Hz) recorded the performance for further 3D reconstruction of thigh, shank and foot segments of both kicking and support limbs. The selected kicking cycle was characterized by the toe-off of the kicking limb to the end of the kicking foot when it came in contact with the ball. Stereographical projection of each segment was applied to obtain the representative curves of kicking as function of time for each participant in each trial. Cluster analysis was performed to identify the mean GA and GB curves for each segment. Silhouette coefficient (SC) was calculated, in order to determine the degree of separation between the two groups’ curves. Results Comparison between the median confidence intervals of the SC showed no differences between groups as regards lower limb patterns of movements. Task accuracy was determined by the relative frequency that the ball reached the target for all attempts and no differences were found (GA: 10.48 ± 14.33%; GB: 9.52 ± 6.51%; P = 0.88). Conclusions We conclude that lower limb kinematic patterns, in support and ball contact phases, are similar in young Brazilian and Japanese soccer players during free kicks when adopting the side-foot kick style.