Ball Impact Position in Recreational Male Padel Players: Implications for Training and Injury Management.

Racket sports such as padel are characterized by the repetition of unilateral gestures, which can lead to negative adaptations like asymmetries or overuse musculoskeletal injuries. The purpose of this study was to determine the differences in ball impact positions (i.e., forward or backward of the center of gravity) in nine stroke types in a sample of forty-eight recreational male padel players. The sample included 14,478 shots corresponding to 18 matches from six tournaments. Forty-eight male padel players were classified into two groups according to their level: trained (n = 24) and novice (n = 24). Type of stroke and ball impact position were registered using a computerized motion tracking video system. The ball impact position was computed from the distance (cm) between the coordinates of the ball and the player's center of gravity. Results show that trained players hit the ball in a more backward position (from 11 to 25 cm, compared to novice) in serve and offensive strokes (volleys, trays, and smashes) but used more forward strokes (from 7 to 32 cm, compared to novice) in defensive shots (groundstrokes, wall strokes, and lobs). Because the current differential variables are trainable and demonstrated to be of relevance for performance, the findings of this study may assist padel coaches in designing proper training plans to improve effectiveness and to prevent musculoskeletal injuries regarding the type of stroke and ball impact position. Such knowledge may constitute a very important factor affecting technique, biomechanics, and injury management in padel players of different competitive levels.

The Effect of the Return of Serve on the Server Pair's Movement Parameters and Rally Outcome in Padel Using Cluster Analysis.

Purpose: The pressure exerted on racket sports players by the service has been well documented. Whilst the return of serve has been suggested through qualitative interviews as being of similar importance there is a dearth of quantitative data to support this contention. This study analyzed time, speed, and distance parameters related to the outcome of the return of serve (ROS) in Padel, a sport similar to tennis but played on a court bounded by walls and played in doubles format only. Methods: Matches (n = 18) at two tournaments, sanctioned by the Valencian Federation, in 2012 were recorded and processed using Tracker software. ROS shot type (flat or lob), ball location, players' positions on court and movement parameters between the ROS and the third shot of the server were captured 25 times per second. Results: Both lob and flat ROS produced six main clusters, as well as a small proportion of shots deemed outliers. The clusters differentiated shots played by two different level players (National and Regional), whether the ROS was played following a first or second serve, whether the serving pair adopted a conventional or Australian formation and whether the rally ended in a short number of shots (seven or less) or not. Conclusion: It was suggested that the aim of the ROS in Padel was to prevent the serving pair winning the rally quickly, since the advantage of the serve diminished after around 6 to 8 shots. This was best achieved by good depth on lobs, regardless of the direction, and pace on low shots, predominately aimed toward the server. This approach should be further modified to include the time between serve and ROS and consideration could be given to classifying attacking and defending positions.

Effects of Different Backpack Loads in Acceleration Transmission during Recreational Distance Walking.

It is well established nowadays the benefits that physical activity can have on the health of individuals. Walking is considered a fundamental method of movement and using a backpack is a common and economical manner of carrying load weight. Nevertheless, the shock wave produced by the impact forces when carrying a backpack can have detrimental effects on health status. Therefore, the aim of this study was to investigate differences in the accelerations placed on males and females whilst carrying different loads when walking. Twenty nine sports science students (16 males and 13 females) participated in the study under 3 different conditions: no weight, 10% and 20% body weight (BW) added in a backpack. Accelerometers were attached to the right shank and the centre of the forehead. Results showed that males have lower accelerations than females both in the head (2.62 ± 0.43G compared to 2.83 + 0.47G) and shank (1.37 ± 0.14G compared to 1.52 ± 0.15G; p<0.01). Accelerations for males and females were consistent throughout each backpack condition (p>0.05). The body acts as a natural shock absorber, reducing the amount of force that transmits through the body between the foot (impact point) and head. Anthropometric and body mass distribution differences between males and females may result in women receiving greater impact acceleration compared to men when the same load is carried.

Effect of overground vs treadmill running on plantar pressure: influence of fatigue.

The differences produced when running on a treadmill vs overground may call into question the use and validity of the treadmill as a piece of equipment commonly used in research, training, and rehabilitation. The aim of the present study was to analyze under pre/post fatigue conditions the effect of treadmill vs overground on plantar pressures. Twenty-seven recreational runners (17 men and 10 women) ran on a treadmill and overground at two speeds: S1=3.33 m/s and S2=4.00 m/s, before and after a fatigue protocol consisting of a 30-min run at 85% of their individual maximal aerobic speed (MAS). Contact time (CT in seconds), peak pressure (PP in kPa), and relative load (RL in %) were analyzed under nine foot zones of the left foot using an in-shoe plantar pressure device. A two-way repeated measures ANOVA showed that running on a treadmill increases CT (7.70% S1 and 9.91% S2), modifies the pressure distribution and reduces PP (25.98% S1 and 31.76% S2), especially under the heel, medial metatarsals, and hallux, compared to running overground. Moreover, on both surfaces, fatigue (S2) led to a reduced stride frequency (2.78%) and reduced PP on the lateral heel and hallux (15.96% and 16.35%, respectively), and (S1) increased relative load on the medial arch (9.53%). There was no significant interaction between the two factors analyzed (surface and fatigue). Therefore, the aforementioned surface effect, which occurs independently of the fatigue state, should be taken into account when interpreting the results of studies that use the treadmill in their experimental protocols, and when prescribing physical exercise on a treadmill.

Riesgo para la salud de la natación en piscinas cloradas (I) / Health risks of swimming in chlorinated swimming pools (I)

No disponible

No disponible

Effects of three feedback conditions on aerobic swim speeds.

THE PURPOSE OF THIS STUDY WAS TWOFOLD: (a) to develop an underwater chronometer capable to provide feedback while the athlete is swimming, as well as being a control tool for the coach, and (b) to analyse its feedback effect on swim pace control compared with feedback provided by the coach and with no feedback, in 25 m and 50 m swimming pools. 30 male swimmers of national level volunteer to participate. Each swimmer swam 3 x 200 m at aerobic speed (AS) and 3 x 200 m just under the anaerobic threshold speed (AnS), each swam repetition with a different feedback condition: chronometer, coach and without feedback. Results (a) validate the chronometer system developed and (b) show that swimmers pace control is affected by the type of feedback provided, the swim speed elected and the size of the swimming pool. Key pointsProviding concurrent feedback to swimmers improves theis swimming pace control.It is more important to provide feedback to control swim pace when the swimming pool is 50m long.Technological development as this chronometer system, could offload coach work, so coach can focus its time and attention on other performance aspects or other swimmers.Technological developments are more accepted by coaches when they don't interfere on swimmers execution, that is, whet it is not necessary to implement the swimmer with cables and apparatus.

Tests mecánicos versus biomecánicos para simular impactos en gimnasia / Mechanical versus biomechanical test to simulate gymnast impacts

En la mayoría de los casos, el material y equipamiento deportivo es analizado y homologado mediante una serie de criterios normativos que emplean test mecánicos. En gimnasia, la recepción es una de las acciones más peligrosas y frecuentemente realizadas, la cual es ejecutada sobre una colchoneta homologada mediante estos test. Sin embargo, las lesiones siguen siendo altas, planteándose como objetivo en este estudio: analizar el efecto de las propiedades de la colchoneta sobre el gimnasta, así como la validez delos test mecánicos para predecir tales efectos. Para ello, se contó con la participación de cinco gimnastas, analizándoselas fuerzas de impacto, la aceleración (tibia y cabeza),y el rango de movimiento en las articulaciones coxo-femoral, rodilla, tibio-tarsiana y subastragalina, tras saltar sobre una muestra de seis colchonetas. Los resultados muestran como el gimnasta adapta su ejecución en función de las características de la colchoneta, con magnitudes de impacto medias de 4450 ± 195.34 N, valores máximos de deceleración de 15.57 ± 0.54 g en tibia y 4.72 ± 0.55 g encabeza, rangos de flexión medios de 72.18 ± 5.8º en la articulación coxo-femoral, 87.07 ± 6.29º en rodilla, 6.81± 10.23º en tibio-tarsiana, y rangos medios de pronación/supinación en la subastragalina de 15.96 ± 7.75º/ 13.56± 5.67º, respectivamente. Se observó cómo no todas las variables analizadas estuvieron correctamente contempladas en los test normativos, especialmente el mecanismo de prono-supinación en la articulación subastragalina. Esto permite pensar que los criterios normativos en las colchonetas podrían ser revisados considerando los efectos que la recepción produce en el gimnasta, fundamentalmente los relacionados con la estabilidad (o deformación de la colchoneta) y la absorción de los impactos, evitándose de este modo futuras lesiones (AU)

Certain material and sport equipment are analyzed by means of mechanical test suggested by standard criteria.In gymnastics, landing is one of the most important and dangerous actions that a gymnast takes, which are executed on a mat accredited by means of this test. Nevertheless, injuries continue being high, for this reason we considered as objective in this study: to analyze the effect of themat properties on gymnast, as well as the mechanical test validity to predict this effects. Five gymnasts participated in this study, and we analyzed impact forces, acceleration(shank and head), and range of motion on the knee, hip, tibiotarsal and subastragaloid joints, after landing on six mat. Results show as gymnast modulated his execution based on mat characteristics, with average reaction force of4450 ± 195.34 N, maximum deceleration of 15.57 ± 0.54g at the shank and 4.72 ± 0.55 g at the head, and average flexion movement of 72.18 ± 5.8º at the hip joint, 87.07 ±6.29º at the knee joint, 6.81 ± 10.23 at the ankle joint, and average of eversion/inversion movement of 15.96 ± 7.75º/13.56 ± 5.67º at the subastragaloid joint, respectively. Not all the biomechanical variables analysed were faithfully reproduced in the mechanical tests, especially the eversion/inversion movement at subastragaloid joint. This allows thinking that standard criteria on mats could be reviewed to consider the effects that landing cause on gymnast, related to stability (or mat deflection) and shock absorption essentially, avoiding several injuries during gymnast landing in a future (AU)