Abstract
Quantitative evaluation of synergic action among the different body segments is fundamental to swimming performance. The aim of the present study was to develop an easy-to-use tool for stroke-by-stroke evaluation of a swimmer’s integrated timing of stroking, kicking, and breathing. Twelve swimmers were evaluated during one trial of 100 m front-crawl swimming at self-selected speed. Five three-axial inertial sensors were mounted on the head, wrists, and ankles. Algorithms for the wrist entry into the water, the lower limb beat during the downward action, and the exit/entry of the face from/into the water were developed. Temporal events identified by video-based technique, using one sagittal moving camera, were assumed as the gold standard. The performance was evaluated in terms of the root-mean-square error, 90th percentile of absolute error, coefficient of variation, Bland–Altman plots, and correlation analysis. Results of all temporal events showed high agreement with the gold standard, confirmed by a root-mean-square error of less than 0.05 s for absolute temporal parameters and less than 0.7% for the percentages of the stroke cycle duration, and with correlation coefficients higher than 0.856. The protocol proposed was not only accurate and reliable, but also user-friendly and as unobtrusive as possible for the swimmer, allowing a stroke-by-stroke analysis during the training session.
Highlights
Swimming performance is strictly related to the synergic action among the different body segments
Since 1970, video cameras have been exploited for swimmer kinematics analysis from different points of view [6,7,8,9]: timing and distance evaluation, velocity of center of mass, 2D/3D coordinates of anatomical landmarks, and
The limits of agreement (LoA) between the inertial measurement units (IMUs) and TLC had a range of −0.054 to 0.053 s for WRISTENTRY, −0.072 to 0.265 s for HEADEXIT, −0.054 to 0.074 s respective typical error of measurement (TEM) for IMU and TLC were 0.083 and 0.083 s for WRISTENTRY, 0.147 and 0.085 s for HEADEXIT, 0.081 and 0.073 s for HEADENTRY, and 0.240 and 0.232 s for LEGDOWNBEAT
Summary
Swimming performance is strictly related to the synergic action among the different body segments. The analysis of a singular body segment does not completely characterize the actions, and the movement of the limbs cannot be considered independently [1,2]. Depending on swimming speed and athletic skill, swimmers change their coordination between limbs and breathing action [3]. The variability characterization of the synergic action is a way to understand the performance profile [4]. Quantitative evaluation of synergic action and variability is fundamental to provide reliable information to coaches and athletes. Since 1970, video cameras have been exploited for swimmer kinematics analysis from different points of view [6,7,8,9]: timing and distance evaluation, velocity of center of mass, 2D/3D coordinates of anatomical landmarks, and
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
