Wearable inertial sensors in swimming motion analysis: a systematic review

The use of contemporary technology is widely recognised as a key tool for enhancing competitive performance in swimming. Video analysis is traditionally used by coaches to acquire reliable biomechanical data about swimming performance; however, this approach requires a huge computational effort, thus introducing a delay in providing quantitative information. Inertial and magnetic sensors, including accelerometers, gyroscopes and magnetometers, have been recently introduced to assess the biomechanics of swimming performance. Research in this field has attracted a great deal of interest in the last decade due to the gradual improvement of the performance of sensors and the decreasing cost of miniaturised wearable devices. With the aim of describing the state of the art of current developments in this area, a systematic review of the existing methods was performed using the following databases: PubMed, ISI Web of Knowledge, IEEE Xplore, Google Scholar, Scopus and Science Direct. Twenty-seven articles published in indexed journals and conference proceedings, focusing on the biomechanical analysis of swimming by means of inertial sensors were reviewed. The articles were categorised according to sensor’s specification, anatomical sites where the sensors were attached, experimental design and applications for the analysis of swimming performance. Results indicate that inertial sensors are reliable tools for swimming biomechanical analyses.     

6- and 8-year-olds’ performance evaluations: Do they differ between self and unknown others?

The current study investigated kindergarteners and second graders’ ability to monitor and evaluate their own and a virtual peer’s performance in a paired-associate learning task. Participants provided confidence judgments (CJs) for their own responses and performance-based judgments (judgments provided after receiving feedback on their performance) for both their own and a virtual peer’s responses. For the performance-based judgments, children were confronted with their own or the peer’s answer as well as the correct answer. Additionally, participants were asked to credit their own and the peer’s correct and incorrect answers while facing feedback. Results indicate an age-related progression in metacognitive monitoring skills, with second graders differentiating more strongly in their confidence judgments between correct and incorrect responses compared to kindergarteners. Regarding performance-based judgments, children of both age groups provided higher judgments for correctly compared to incorrectly recognized items as well as for their own responses in comparison to the responses of the unknown child. Similarly, when crediting, participants of both age groups gave more credits for correct recognition than for incorrect recognition and for their own responses than for the peer’s responses. The significant interaction between age group and recognition accuracy for the crediting shows that second graders gave more credits for correctly recognized items while kindergarteners gave more credits for incorrect answers than the older children – primarily for their own incorrect answers. In conclusion, the study provides new insights into 6- and 8-year-olds’ evaluations of their own and an unknown child’s performance in a paired-associate learning task by showing that children of both age groups generally judged and credited responses in their own favor. These results add to our understanding of biases in children’s performance evaluations, including metacognitive judgments and judgments provided after receiving feedback.