The evoked vocal response of the bullfrog- A study of communication by sound

Evoked vocal response of bullfrog - communication by soun

Inter-limb coordination dynamics: effects of visual constraints and age

This study aimed to verify the effect of visual afference (eyes open – EO vs. eyes closed – EC) on inphase (IP) and anti-phase (AP) homolateral inter-limb coordination performance in relation to age. Forty individuals (12 youths, age=12±1 years; 16 young adults, age=24±3 years; 12 older adults, age=59±11 years) performed IP and AP synchronized (80, 120, and 180 bpm) hand and foot flexions and extensions. Variability of IP and AP movements was obtained by calculating the within-subject standard deviation of each condition. Significant interactions between coordination mode × age and coordination mode × age × visual afference showed joint effects on IP and AP variability, while no main effects emerged. In the IP-EO condition, posthoc analysis showed higher (p=.0003) variability in older adults (24.8±6.6 s) with respect to young adults (10.5±10.9 s), whereas in the IP-EC condition, older adults showed higher (p=.03) variability (23.4±10.7 s) with respect to both youths (13.7±8.6 s) and young adults (24.1±12.2 s). In both AP conditions, older adults showed lower (p<.002) variability values (EO=9.5±12.1 s; EC=4.6±7.5 s) with respect to the other age groups, with only the youth group showing differences between EO (16.6±12.1 s) and EC (23.6±8.4 s) conditions. Findings show that the age-related worsening of inter-limb coordination is independent of the use of visual afferences. In contrast, at developmental age, visual perception seems to play a differential role depending on the coordinative task complexity (IP/AP). It becomes crucial only in the AP condition, with a lower variability in the EO than in the EC condition indicating youths’ tendency to rely more on visual information for stabilizing complex inter-limb coordination performance

Poster Session III, July 15th 2010 — Abstracts Inertial sensors in sports: application to vertical jumps

Abstract Countermovement jump (CMJ) height is typically estimated by applying the equation of free-fall to the motion of the centre of mass (CM) during the flight phase. In field setting, this is generally done using optical cells/contact mats. The reliability of the estimate is strongly affected by the subject's expertise in executing the jump. Wearable inertial measurement units (IMU), containing 3D accelerometers and gyroscopes, can provide similar information regardless to execution constraints. However, the interpretation of signals still requires the development of computational techniques and of models embodying the specific motor task. This study aims to verify whether IMU can be used to assess CMJ performance. Twenty-eight college students (67±13 kg, 1.73±0.09 m) performed 5 CMJ, with a 3-min rest in between. A wireless IMU (Sensorize, Italy) was placed using an elastic belt around the trunk at L5 level. Sensor accelerations, influenced by trunk bending, were expressed in a global reference system using the gyroscopes. Flight time (T) was identified when the vertical acceleration (az) was lower than gravity. Subsequent numerical integration of az provided velocity and height of the centre of mass at take-off. These quantities and the ballistic law of motion were used to estimate jump height (H). A stereophotogrammetric system (Vicon MX, UK) and a force plate (Bertec, USA) were used to obtain reference values for H (Hr) and T (Tr). ANOVA for repeated measurements ( p 0.05 ) and Pearson's correlation coefficient evaluated statistical differences between H and Hr and T and Tr, respectively. Intra-individual reliability was assessed by means of the Intraclass Correlation Coefficient (ICC). IMU and reference values were highly correlated (H: r = 0.9 ; T: r = 0.9 ) and presented no statistical difference for both H and T. Relevant differences were 2±8% and 4±3% for H and T, respectively. High intra-subject IMU reliability was found (ICCJ=0.834, ICCT=0.868). This study showed how the combination of a 3D accelerometer and gyroscope can lead to an accurate and repeatable estimate of jump height. CMJ height estimate does not suffer from any assumption about the performed task and it is not affected by the subject's expertise (reliable for elderly and young populations). Furthermore, since the IMU is worn by the athlete, vertical jumps can be performed on any surfaces such as grass, sand, springboards, etc

Effect of Number of Players and Maturity on Ball-Drills Training Load in Youth Basketball

This study aimed to assess the basketball ball-drills workload analyzing: (1) the effect of varying the number of players involved on physiological and technical demands; (2) the temporal changes in players’ responses across bouts; and (3) the relationship of players’ workload with their maturation status and training age. Twelve young male basketball players (mean ± SD; age 13.9 ± 0.7 years; height 1.76 ± 0.06 m; body mass 65.7 ± 12.5 kg; HRmax 202 ± 8 beat·min−1) completed three bouts of 4 min interspersed by 2 min of passive recovery of two vs. two and four vs. four ball-drills. The mean percentage of HRmax (%HRmax) and ratings of perceived exertion (RPE) were collected. Technical actions (TAs) (dribbles, passes, shots, interceptions, steals, rebounds, and turnovers) were calculated through notational analysis. Players’ genitalia development (GD) and pubic hair (PH) growth were assessed using Tanner scale. Results showed a higher %HRmax (p = 0.018), RPE (p = 0.042), dribbles (p = 0.007), shots (p = 0.003), and rebounds (p = 0.006) in two vs. two compared to four vs. four condition. Furthermore, a statistical difference was found for %HRmax (p = 0.005) and number of passes (p = 0.020) between bouts. In addition, no correlation between GD, PH, and training age with %HRmax, RPE, and TAs was found. These findings suggest that variations of the number of players involved affect ball-drills workload and that ball-drills training intensity varies across bouts. Finally, ball-drills elicit an adequate training stimulus, regardless of players’ maturation status and training age

Determinants of the effectiveness of fast break actions in elite and sub-elite Italian men\u27s basketball games

The aim of this study was to examine the determinants of successful and unsuccessful fast-break (FB) actions in elite and sub-elite basketball games. Fifteen 1st-division (elite) and fifteen 3rd-division (sub-elite) Italian men’s championship games were analysed across two seasons (2012/2013 and 2013/2014). A binary logistic regression analysis was performed, and the fast-break outcome (successful vs. unsuccessful) was adopted as the dependent variable separately in both elite and sub-elite games. FB execution (initiation, advance and completion phases), typology (primary and secondary break) and the number of players involved (equal number or superiority) were used as independent variables. The results showed that the rate of success of FB actions was 63.5% and 59.7% in elite and sub-elite games, respectively. Moreover, successful FBs were more likely to be completed in the lane in relation to unsuccessful ones in both elite and sub-elite games (p\u3c0.05). Finally, descriptive statistics showed that both elite and sub-elite teams executed FBs similarly. This study highlighted that completion zone was the only predictor of a successful fast break in basketball, while the typology and number of players involved did not predict fast break effectiveness. Moreover, elite and sub-elite teams executed fast break actions similarly. These findings might be useful for basketball coaches to optimize the training of FB actions

Energy expenditure and perceived exertion during active video games in relation to player mode and gender

Active video games (AVG) increase energy expenditure (EE) with respect to sedentary video games. Although several AVG consoles allow playing in single-player (SP) or multiplayer (MP) mode, few studies investigated differences in relation to game modality in men and women. Therefore, the aim of this study was to evaluate gender-related psycho-physiological responses during Zumba Fitness Rush (ZFR) played in SP vs. MP mode. Twenty-four college students (women: 14, men: 10; age: 24.6±2.0 years; body weight: 60.2±12.5 kg; body height: 167.8±11.5 cm; BMI: 21.2±2.1 kg·m-2) participated in two experimental sessions: SP (a subject playing ZFR alone) and MP (two subjects playing ZFR simultaneously). Heart rate (HR), oxygen consumption (VO2) and EE (MET and kcal∙min-1) were continuously measured and averaged every 10 seconds, while Rating of Perceived Exertion (RPE) was recorded 30 minutes after the end of each session. A two (gender: women vs. men) by two (modality: SP vs. MP) ANOVA for repeated measures was applied. No differences emerged in relation to gender and game mode for %HRmax, VO2, MET, and RPE. Conversely, a main effect (p=.0007) for gender was found in EE, with significantly (p<.004) higher values in men in SP (women: 5.5±0.6 kcal·min-1; men: 8.3±1.4 kcal·min-1) and MP (women: 5.3±0.7 kcal·min-1; men: 7.6±1.9 kcal·min-1). Present findings suggest that ZFR could be classified as a moderate physical activity, proving to be an alternative form to traditional exercise. Although an effect of number of players could be expected, different player modes did not affect EE, probably because the rhythm of the music imposes a time constraint, independently of the presence of other players

Effect of Number of Players and Maturity on Ball-Drills Training Load in Youth Basketball

This study aimed to assess the basketball ball-drills workload analyzing: (1) the effect of varying the number of players involved on physiological and technical demands; (2) the temporal changes in players’ responses across bouts; and (3) the relationship of players’ workload with their maturation status and training age. Twelve young male basketball players (mean ± SD; age 13.9 ± 0.7 years; height 1.76 ± 0.06 m; body mass 65.7 ± 12.5 kg; HRmax 202 ± 8 beat·min−1) completed three bouts of 4 min interspersed by 2 min of passive recovery of two vs. two and four vs. four ball-drills. The mean percentage of HRmax (%HRmax) and ratings of perceived exertion (RPE) were collected. Technical actions (TAs) (dribbles, passes, shots, interceptions, steals, rebounds, and turnovers) were calculated through notational analysis. Players’ genitalia development (GD) and pubic hair (PH) growth were assessed using Tanner scale. Results showed a higher %HRmax (p = 0.018), RPE (p = 0.042), dribbles (p = 0.007), shots (p = 0.003), and rebounds (p = 0.006) in two vs. two compared to four vs. four condition. Furthermore, a statistical difference was found for %HRmax (p = 0.005) and number of passes (p = 0.020) between bouts. In addition, no correlation between GD, PH, and training age with %HRmax, RPE, and TAs was found. These findings suggest that variations of the number of players involved affect ball-drills workload and that ball-drills training intensity varies across bouts. Finally, ball-drills elicit an adequate training stimulus, regardless of players’ maturation status and training age