Prediction of Kick Count in Triathletes during Freestyle Swimming Session Using Inertial Sensor Technology

Abstract

Monitoring sports training performances with automatic, low cost, low power, and ergonomic solutions is a topic of increasing importance in the research of the last years. A parameter of particular interest, which has not been extensively dealt with in a state-of-the-art way, is the count of kicks during swimming training sessions. Coaches and athletes set the training sessions to optimize the kick count and swim stroke rate to acquire velocity and acceleration during swimming. In regard to race distances, counting kicks can influence the athlete’s performance. However, it is difficult to record the kick count without facing some issues about subjective interpretation. In this paper, a new method for kick count is proposed, based on only one triaxial accelerometer worn on the athlete’s ankle. The algorithm was validated on data recorded during freestyle training sessions. An accuracy of 97.5% with a sensitivity of 99.3% was achieved. The proposed method shows good linearity and a slope of 1.01. These results overcome other state-of-the-art methods, proving that this method is a good candidate for a reliable, embedded kick count.

Advanced Research in Electronics: The Perspective of Women

“…The implemented measurement method has been tested and compared with gold standard methods (video recording). The obtained results improve on the state-of-the-art methods, proving that the work described in [3] is suitable as a reliable and accurate method for obtaining the kick count during swimming training.…”

“…In [3], an interesting application of programmable electronics to sport activities is presented. During swimming training, it is relevant to monitor stroke and kick count in athletes.…”

“…However, while stroke number can be detected by using a wearable "swim stroke meter", the number of kicks is usually detected with the effort of dedicated staff by acquiring video images. In [3], the authors propose a new method for obtaining the kick count, which is based on one triaxial accelerometer worn on the athlete's ankle to maximize the athlete's comfort. An algorithm for the evaluation of the number of kicks has been developed and validated.…”

A Higher Kick Frequency Swimming Training Program Optimizes Swim-to-Cycle Transition in Triathlon

“…The investigation of biomechanical parameters during the swim segment was conducted using 2 sport watch trackers (Garmin Forerunner 735XT, Olathe, KA) placed at wrist and ankle location. The Garmin Forerunner 735XT tracker integrates a triaxial accelerometer and magnetometer with a sampling frequency of 25 and 1 Hz, respectively, and has already been validated as a wearable kick-count device for triathletes (5). Moreover, the entire test trial was recorded using an underwater camera (GoPro HERO71, San Mateo, CA) held parallel to the direction of swimming to further ascertain biomechanical parameters.…”