Performance analysis of the flip turn in swimming: The relationship between pressures and performance times

This study examined the effects of pressure and other kinetic variables on freestyle flip turn performance. It was hypothesized that an increase in average and peak pressure, and a decrease in the magnitude difference between left and right foot pressure, would result in an improved performance of a swimmer as they performed a flip turn. Ten University level (varsity) swimmers performed five freestyle flip turns using their competition technique. Data were collected from a pressure pad mounted to the vertical wall of the pool and from an underwater camera in the sagittal plane. A negative correlation of .58 and .67 was seen for average and peak pressures respectively when compared to five-meter performance times. Average contact area throughout the push-off phase compared to average and maximum load was .94 and .88. An increase in average contact area from 40 cm2 to 50 cm2 resulted in a 26% increase in maximum load. No difference in performance was seen for varying maximum knee flexion angles. Differences between pressure magnitudes between left and right foot did not impact the five-meter performance time. Therefore, increased average contact area throughout the push-off phase caused higher average and maximum loads, and to a lesser extent average and peak pressures. Increases in pressure and load resulted in an improved five-meter performance time. It is concluded that flip turn performance increases through higher contact area with the feet when pushing off the wall

Start performance and its relation to competition times in Paralympic swimmers

The purpose of this study was to investigate the relationship between the variability of the 100m freestyle final race time to start performance in a population of Paralympic swimmers using the coefficient of variation (CV). A secondary purpose of study was to investigate the correlation between start performance and competition results in this population of athletes. A total of 321 data points were collected on start performances and 231 data points were collected from competition results. It was found that there was a within-athlete CV in final times of 2.6% and a within-athlete CV in start performances of 18.2%. These two parameters were moderately correlated having an r2 of 0.57. The athletes improved their performances across five-consecutive seasons by 6.4%. In addition, it was found that a strong correlation existed between the 5m start time compared to the final race time in the 100m freestyle (r2=0.78). The results showed that the variability of start performance was moderately correlated to the variability of the final times and there was a strong correlation between start performance and competition results

Attitudes and behaviours of Canadian National Team coaches regarding the use of technology in their coaching practice

Previous literature has proposed that successful adoption measures involve positive attitudes regarding using technology, high levels of technological self-efficacy beliefs, low levels of perceived complexity, and high levels of perceived relative advantage. The purpose of this study is to investigate these antecedents of technology adoption among national team Canadian coaches. Twenty-five current and retired Summer and Winter Canadian national team coaches participated in this investigation. They completed four questionnaires: a general information form, the Affinity for Technology Interaction Scale (ATI), the Computer Self-Efficacy Measure (CSEM), and the Perceived Relative Advantage and Perceived Complexity Scales (PRA/PCo). Canadian national team coaches who responded were found to have a moderate affinity for technology when engaging with technology in their coaching practice. They also reported to have very high self-efficacy when it comes to using technology. They were shown to have a moderately high conviction in their ability to use technology. Coaches also viewed technology as giving them a high relative advantage over not using technology. Finally, they generally viewed technology as not very complex to operate. Most Canadian national team coaches who responded showed favourable views regarding using technology, had belief in their ability, and seemed capable of overcoming challenges in using technology. Future investigations should also identify elite coaches who do not use innovations and focus on sport specific challenges in adopting or implementing technology, as well as identifying barriers coaches face when acquiring or using new technology

Effect of shoe inserts on kinematics, center of pressure, and leg joint moments during running

The purposes of this project were to assess the effect of four different shoe inserts on the path of the center of pressure (COP), to quantify the effect of these inserts on selected knee joint moments during running, and to assess the potential of COP data to predict the effects of inserts/orthotics on knee joint moments.; Kinematics for the lower extremities, resultant ankle and knee joint moments, and the path of the COP were collected from the right foot of 15 male subjects while running heel-toe with five different shoe inserts (full or half with 4.5-mm postings).; Individual movement changes with respect to the neutral insert condition were typically small and not systematic. Significant changes for the path of the COP were registered only for the full lateral insert condition with an average shift toward the lateral side. The mediolateral shift of the COP was not consistent for the full medial and the two half-shoe inserts. The subject-specific reactions to the inserts' intervention in the corresponding knee joint moments were typically not consistent. Compared with the neutral insert condition, subjects showed increases or decreases of the knee joint moments. The correlation between the individual COP shifts and the resultant knee joint moment was generally small.; The results of this study showed that subject-specific reactions to the tested inserts were often not as expected. Additionally, reactions were not consistent between the subjects. This result suggests that the prescription of inserts and/or orthotics is a difficult task and that methods must be developed to test and assess these effects. Such methods, however, are not currently available

Comparison of two methods in the estimation of vertical jump height

Vertical jumps are vital aspects in many sports. Many technologies are available to determine and calculate jump height. One such portable and easy-to-use technology is an Inertial Measurement Unit (IMU) that uses accelerometers, gyroscopes and magnetometers. The purpose of this study was to compare vertical jump heights calculated from the data captured with an IMU versus true jump height calculated using a gold standard 3-Dimensional Motion Capture system. Ten subjects completed five jumps for six different conditions including vertical counter-movement jumps and jumps involving rotations on the ground and using a trampoline. An average Pearson correlation coefficient of 0.87 was found between the IMU and motion capture for all conditions. Condition correlations ranged from 0.76 to 0.94. Bland-Altman analyses showed that the IMU underestimated the vertical jump height compared to the motion capture by 5.0 to 9.2 cm across all conditions. Results suggest an IMU can be used to measure jump height in a laboratory setting with a reasonable accuracy, even during vertical jumps that include rotations

The Accuracy of a Real Time Sensor in an Instrumented Basketball

AbstractIntegrating sensing devices into sports equipment such as tennis racquets, basketballs and soccer balls has great potential for measuring performance, training athletes and encouraging participation. These innovative, interactive tools provide real time feedback systems for collecting and analysis sports data and could provide effective support for coaches and athletes. The 94fifty™ is an instrumented basketball that has the same specifications as a standard basketball with the addition of a sensor that provides data on shot arc, shot speed, and number of dribbles in real time through a smartphone or tablet device app. The purpose of this investigation was to determine the sensor accuracy in the 94Fifty on measures of shot arc and dribbling in relation to Dartfish™ video analysis software.To measure the shot arc, five adult basketball players were recorded performing 28 shots from various positions for a total of 140 trials. For dribbling 260, 4-12 year old children were video recorded dribbling for 10 seconds each. We compared results using Cronbach's alpha. Shot angle reliability coefficients between the 94Fifty software and Dartfish video analysis alpha = 0.998. No differences were found in the dribbling count between the video analysis and the 94Fifty sensing basketball. While Cronbach's alpha was very high for shot arc, a detailed analysis reveals discrepancies in arc angle on individual shots where 78 out of 140 angles were the same, 59 were within +/-1 degree and three were +/-3.5 degrees.Participants universally enjoyed receiving feedback on their performance. This new technology could redefine the way players are trained and could encourage creative approaches to practice planning and implementation