Abstract
Human locomotion on water depends on the force produced by the swimmer to propel the body forward. Performance of highly complex motor tasks like swimming can yield minor variations that only nonlinear analysis can be sensitive enough to detect. The purpose of the present study was to examine the nonlinear properties of the hand/feet forces and describe their variations across the four competitive swimming strokes performing segmental and full-body swimming. Swimmers performed all-out bouts of 25 m in the four swimming strokes, swimming the full-body stroke, with the arm-pull only and with the leg kicking only. Hand/foot force and swimming velocity were measured. The Higuchi’s fractal dimension (HFD) and sample entropy (SampEn) were used for the nonlinear analysis of force and velocity. Both the arm-pull and leg kicking alone were found to produce similar peak and mean hand/foot forces as swimming the full-body stroke. Hand force was more complex in breaststroke and butterfly stroke; conversely, kicking conditions were more complex in front crawl and backstroke. Moreover, the arm-pull and kicking alone tended to be more complex (higher HFD) but more predictable (lower SampEn) than while swimming the full-body stroke. There was no loss of force production from segmental swimming to the full-body counterpart. In conclusion, the number of segments in action influences the nonlinear behavior of the force produced and, when combining the four limbs, the complexity of the hand/foot force tends to decrease.
Subject
Physiology (medical),Physical Therapy, Sports Therapy and Rehabilitation
Reference70 articles.
1. Ahmadi, S., Sepehri, N., Wu, C., & Szturm, T. (2019). Comparison of selected measures of gait stability derived from center of pressure displacement signal during single and dual-task treadmill walking. Medical Engineering & Physics, 74, 49–57.
2. Arellano, R. (1999). Vortices and Propulsion. Applied Proceedings of the XVII International Symposium on Biomechanics in Sports: SWIMMING, 53–65.
3. Barbosa, T. M., Chen, S., Morais, J. E., Costa, M. J., & Batalha, N. (2018). The changes in classical and nonlinear parameters after a maximal bout to elicit fatigue in competitive swimming. Human Movement Science, 58, 321–329.
4. Variation of Linear and Nonlinear Parameters in the Swim Strokes According to the Level of Expertise
5. Comparison of Classical Kinematics, Entropy, and Fractal Properties As Measures of Complexity of the Motor System in Swimming