Motion Adaptive Electromechanical Delay Measurement: Flatwater Kayak Stroke Implication

Abstract

ABS TRACT Objective: Electromechanical delay (EMD) is a substantial component of athletic performance as it is potent in reactive time and power production. A novel EMD measurement method was applied during flatwater kayak stroke in this study. In flatwater kayaking, stroke rate (number of strokes per minute, tempo), which may be increased by lower EMD, is a major parameter in boat speed. The purpose of this study is to investigate EMD in catch phase of flatwater kayak stroke. Material and Methods: A male and a female kayak athlete volunteered to participate the study. Kayak stroke was conducted on kayak ergometer. Muscle activation onset and mechanical response was assessed by electromyogram (EMG) and 3-axis accelerometer, respectively. EMG sensors were placed on M. Latissimus Dorsi (LD), M. Pectoralis Major (PM), Anterior Deltoid (AD) and Posterior Deltoid (PD). The accelerometer was placed on fifth metacarpophalangeal joint. EMD was calculated as the latency between EMG onset and accelerometer onset. Results: Two data recordings, which were 20 seconds long for each subject, were ensured. The EMD values calculated for the male and female subject’s LD were 51.25 ms±3.01 and 61.13 ms±2.94; and PD were 37.25 ms±3.57 and 49.37 ms±4.43 ms, respectively. Conclusion: The findings of this study conducted during dynamic kayak stroke elicit results in spectrum of reported EMD values in clinical studies. With use of the present method, EMD for various sports and movement patterns may be investigated.