Comparison and Agreement between Simplified and Three-dimensional Methods for Estimating the Front Crawl Stroke Arm Stroke Efficiency

Abstract

Aims: To compare and verify the agreement of the arm stroke efficiency (ȠF) results obtained by simplified (ȠFS) and three-dimensional (ȠF 3D) methods. Background: Arm stroke efficiency (ȠF) estimates how much of the force applied by the swimmers’ upper limbs contribute to their propulsion. To estimate ȠF, in front crawl stroke, three-dimensional (ȠF3D) and simplified (ȠFS) methods are highlighted. Objective: To verify if different methods estimate similar arm stroke efficiency values. Methods: Ten male swimmers (age: 21.5 ± 2.6 years; height: 1.78 ± 0.05 m; competitive swimming experience: 12.2 ± 5.0 years) were tested in three 25 m front crawl stroke bouts at low, moderate, and high intensities. The ȠF data were obtained after collecting swimming images with six synchronized cameras and later analyzed in motion reconstruction software. Results: The mean results of ȠF, respectively for ȠF3D and ȠFS, were: 34.7±2.1% and 47.4±6.4% at a low; 34.8±2.7% and 42.3±3.3% in moderate; and 33.1±2.6% and 32.4±2.9% at high intensity. Along the intensities, ȠF remained similar with ȠF3D and reduced with ȠFS. ȠF was lower with ȠF3D than with ȠFS at low and moderate intensities (p < 0.05) and similar at maximum intensity (p > 0.05). Conclusion: At maximum intensity, the ȠF values agree between the methods. The results obtained by both methods were not fully similar. ȠF3D and ȠFS results agree just at high intensity. The differences between the methods may be due to the different variables used to measure ȠF, stroke rate in the ȠFS and three-dimensional hand velocity in the ȠF3D.