Relationship between Sprint Capacity and Acceleration of Wrists in Wheelchair Basketball Players: Design and Reliability of a New Protocol.

The application of new technologies in wheelchair basketball (WB) is important for the advancement and improvement of athletic performance. The purposes of this study are twofold: (a) to develop a methodological design in order to assess WB players' performance, using wireless inertial measurement units (WIMU®) and a laser system (BioLaserSport® with computer vision), in a 20 m sprint test on court and (b) to assess bilateral symmetry as a performance indicator and for injury prevention purposes, the study of which in previous research is unknown. For both aims, the relation of the acceleration of the players' wrists to the speed achieved by the player in the wheelchair was explored. Ten elite WB players participated in an on-court 20 m sprint test during real training. BioLaserSport® with computer vision was used to assess the average velocity (Va) and maximum velocity (Vmax) of the WB players, and two WIMU® were used for the total acceleration (AcelT) of the players' wrists. A very high correlation was obtained in the assessment of the Va (0.97) and AcelT of both wrists (0.90 and 0.85). There was a significant relationship between the average AcelT of the dominant wrist and the Va on-court sprint velocity (p < 0.05). Two players did not show good wrist symmetry. In conclusion, a new methodological protocol was developed, making it possible to assess the bilateral symmetries in elite WB players in on-court real training and the relation between the acceleration of players' wrists and players' wheelchair speed. Coaches can use this protocol to assess performance or for injury prevention, as it shows very good reliability, with high ICC values.

Relationship between Sprint Velocity and Peak Moment at Shoulder and Elbow in Elite Wheelchair Basketball Players.

Specific wheelchair basketball (WB) skills on the court have been poorly analyzed in relation to improving players' performance according to their functional class. The purpose of this study was to evaluate the associations between maximum velocity (Vmax) and peak moment (PM) in the shoulder and elbow joints in specific WB skills and to compare performance between the main two groups by functional class. Twelve male WB players, divided in categories A (functional classes 1.0-2.5) and B (class 3.0-4.5), performed a sprint test battery composed by four tests (with and without ball) and isokinetic tests. A significant relationship between PM of the internal and external shoulder rotation and the flexion and extension elbow with Vmax (p < 0.05) was found. During a 5 m backward sprint test, category B was faster in the last three meters than category A (p < 0.05) and also for the rest of the test but p = NS. Category B showed higher PM than category A for internal shoulder rotation (ISR) at 60 °/s and at 180 °/s on the dominant side (DS) (p < 0.05). In conclusion, ISR on the DS was found different for both groups and showed significant relationship with Vmax in all of the tests performed. Moreover, at higher speeds the elbow flexion and extension in DS were correlated with Vmax in all the actions with ball (passing, bouncing, and braking) reflected the importance of these joints movements in acquiring speed when performing sport specific WB skills.

Maximum velocity during loaded countermovement jumps obtained with an accelerometer, linear encoder and force platform: A comparison of technologies.

The maximum velocity (Vmax) reached during countermovement jumps (CMJ) has been considered a performance indicator to evaluate vertical jump ability. The aim of this study was to compare Vmax during loaded CMJ (CMJloaded) using three different technologies to show a criterion for selecting the more appropriate depending on its use. Nine recreationally active men performed a CMJloaded test. Five jumps were made in each of 6 series with a 20- kg barbell + 0, + 5, + 10, + 15, + 20 and + 25 kg, with 2 seconds rest between the jumps and 5 minutes rest between the series to explore a wide range of speeds. Vmax was obtained from force platform, inertial device and linear encoder technologies. Bland-Altman plots and mean differences were used to compare devices. Reproducibility was tested using the intraclass correlation coefficient (ICC) for single measures and typical error (TE). All technologies showed high levels of reproducibility, ICC higher than 0.75 and TE lower than 10 %. There were non-significant differences in Vmax between each pair of technologies (linear encoder 2.11 ±â€¯0.24 m·s-1, accelerometer 2.11 ±â€¯0.26 m·s-1, force platform 2.12 ±â€¯0.24 m·s-1) reporting a very low bias. However the limits of agreement between the different technologies evaluated were high (±â€¯0.33 m·s-1). In conclusion, the accelerometer, linear encoder and force platform were suitably reliable to be used to measure Vmax during loaded vertical jumps but their values were not interchangeable.

Nutritional Habits and Performance in Male Elite Wheelchair Basketball Players During a Precompetitive Period.

Physical condition and an optimized diet are relevant to enhance performance and recovery. The diet composition and meal frequency of eleven elite wheelchair basketball players were estimated using a 3-day food-weighing diary in two months during the precompetitive-period. Performance was determined through a 20 m sprint test. The players consumed 4.2 ± 0.8 meals/day in May and 4.5 ± 0.9 meals/day in June, resulting in total energy intakes of 2492 ± 362 kcal/d and 2470 ± 497 kcal/d, respectively. The macronutrient distribution was 3.8 ± 1.3 g/kg carbohydrates, 1.7 ± 0.6 g/kg protein, and 36 ± 5% of energy derived from fat in May, and 4.2 ± 1.9 g/kg carbohydrates, 1.5 ± 0.5 g/kg protein and 32 ± 5% of energy derived from fat in June. The maximum velocity of the sprint test improved from 4.77 ± 0.31 m/s in May to 5.19 ± 0.23 m/s in June. Our results revealed carbohydrate intake below and fat intake above recommendations, but improvements of dietary patterns. Further nutritional advice is necessary to ensure health and performance improvements.

Sprint Performance of Elite Wheelchair Basketball Players: Applicability of a Laser System for Describing the Velocity Curve.

The purpose of this study was to develop a methodology to accurately analyze sprint performance of elite wheelchair basketball (WB) players in their own training context using a laser system and to analyze the velocity curve performed by the players regarding their functional classification and their playing position. Twelve WB players, from the Spanish men's national team, took part in an oncourt 20-m-sprint test. BioLaserSport® was used to obtain time, mean velocities (Vm), maximum velocities (Vmax), and distances at 90%, 95%, and 98% of their Vmax. Vm and Vmax reached high values in Classes II and III and in the guard playing position. The protocol developed with the laser system makes it possible to obtain a precise velocity curve in short sprints and allows easy analysis of decisive kinematic performance variables in WB players, showing immediate feedback to coaches and players. The normalized data allow an interpretation of how much, where, and when Vmax occurs along the test.

Marginal Micronutrient Intake in High-Performance Male Wheelchair Basketball Players: A Dietary Evaluation and the Effects of Nutritional Advice.

Wheelchair basketball has evolved into a high-performance sport over several years, and small variations in player performance can determine the difference between winning and losing. Therefore, adequate micronutrient intake may influence this difference if performance-promoting macronutrient intake and physical fitness are equal between teams. Seventeen elite male wheelchair basketball players belonging to the Spanish National Team participated in this study. Macro- and micronutrient intake were determined using a food-weighing diary over three consecutive days during three training camps in two consecutive years. Current Dietary Reference Intake levels were used to determine the adequacy of intake of seventeen micronutrients of particular interest for athletes. After categorizing the consumed foods into fourteen food groups according to the National Nutrient Database for Standard References (USDA) these groups were used to identify the best predictors of the adequacy of intake for each micronutrient. Total energy intake correlated positively with the adequacy of all micronutrient intake levels, except for vitamins A and E. Five B vitamins and phosphorus, selenium, and iron showed 100% adequacy. All other micronutrient intake levels were found to be inadequate, e.g., vitamin E (51% adequacy) and calcium (73%). The fruit, fish and cereal food groups were found to be predictors of adequate intake of most micronutrients. Together with energy intake (p = .009, η2 = 0.49), the intake of the fruit (p = .032, η2 = 0.39) and egg (p = .036, Kendall's W = 0.42) food groups increased significantly over time, along with improved iodine (p = .008, W = 0.61) and magnesium (p = .030, W = 0.44) adequacy levels. Because the adequacy of micronutrient intake correlates positively with energy intake (R = 0.64, p < .001), a varied diet that includes cereals, fish and fruits is especially important for players with low levels of energy intake. Supplements may be a possible solution if adequate micronutrient intake cannot be achieved through regular dietary intake alone. However, dietary analyses should be conducted on a regular basis throughout the year to improve the nutritional knowledge of the athletes and assure adequate micronutrient intake.

Analysis of speed performance in soccer by a playing position and a sports level using a laser system.

The purpose of this study was to determine the kinematic variables that identify the quality of velocity in soccer players at different competitive levels and playing positions. This study had two independent variables: 1) a competitive level (competitive and non-competitive players); and 2) a playing position, with four levels (central defenders, wide defenders/midfielders, central midfielders and forwards). Forty-two soccer players took part in a 30 m sprint-test, which was measured using a laser sensor-type 1 (LDM301-Jenoptik) at 2000 Hz. Absolute and relative times, average velocities and absolute and relative maximum velocities over 10 m sections were analyzed at 200 Hz with BioLaserSport(®). There were no significant differences in average velocity between competitive and non-competitive players; however, the former reached a greater maximum velocity in the 10-20 m section. Average velocity in the 0-10 m section identified specificity among playing positions in competitive players. The forwards were the fastest followed by the central midfielders, the wide defenders/midfielders and the central defenders. No differences were found among the non-competitive players. Average velocity over the 0-10 meter section may be an important indicator when assigning a playing position for competitive players. These results support the use of more accurate systems, such as a laser system, to identify soccer players' speed qualities (including maximum velocity) during short sprints.