INTRODUCTION: Analyzing athletes’ parameters, such as forces during swimming, is essential to enhance performance (1,2). The use of wearable sensors could facilitate this process due to their cost-effectiveness, ease of use, and ecological approach. In this research, we investigated how hand thrust forces vary according to two swimming tests (tethered vs. free) and between the two hands (dominant vs. non-dominant). We hypothesized larger forces in terms of average force (Fmean), impulse (I), and peak force (Fpeak) in tethered compared with the free swimming and in the dominant compared with the non-dominant hand. METHODS: Eleven skilled swimming athletes (age = 15.4 ± 0.5y.; body mass = 58.0 ± 7.1Kg; stature = 168.4 ± 5.0 cm) performed a 10-second tethered front crawl only arms test (Tet), and 10 seconds free front crawl only arms test (Free) wearing two wearable pressure sensors, one for each hand. The thrust force of each hand was estimated as the product of differential pressure (palmar minus dorsal side) and hand surface. Considering circle-shaped hand kinematics, only the horizontal component of hand thrust force was used for the analysis. Average force (FMEAN), impulse (I), average peak (FPEAK), and instantaneous (by means of Statistical Parametric Mapping, SPM) were analyzed as a function of swimming condition and dominant/non-dominant hand. The symmetry index (SI) was analyzed as a function of swimming conditions. RESULTS: Results indicated larger Fmean, Fpeak, and I during Tet compared to the Free condition (F > 4.23, p < .05; Fmean: Tet = 34.0 ± 9.7 N vs. Free = 28.7 ± 7.8 N; Fpeak: Tet = 74.6 ± 22.0 N vs. Free = 66.8 ± 15.2 N; I: Tet = 28.0 ± 5.3 Ns vs. Free = 22.0 ± 5.3 Ns). Whereas SI was non-significant. SPM highlighted a larger Fmean in Tet condition only at the beginning of the stroke (entry phase, from 7 to 28% of the cycle). In addition, non-significant differences were observed for Fmean between the hands (p > .05), and SPM confirmed these results (p > .05). However, larger Fpeak and I in the dominant compared with the non-dominant hand were found (F > 11.11, p < .05; Fpeak: dominant = 65.3 ± 15.9 N vs. non-dominant = 62.7 ± 14.4 N; I: dominant = 26.3 ± 8.0 Ns vs. non- dominant = 23.5 ± 5.6 Ns). CONCLUSION: The swimmer appears to exert larger hand propulsion in tethered- than free- swimming. However, our findings of the symmetry model and the hand-propelling balance during tethered- and free-swimming were not conclusive, and further investigations could help in better understanding this phenomenon (3). REFERENCES: 1) Takagi et al., (2021). Sports Biomechanics. 2) Zamparo et al., (2020). European Journal of Applied Physiology 3) Knihs et al., (2022). Strength & Conditioning Journal
Gabriele Russo, Vittorio Coloretti, Silvia Fantozzi, Matteo Cortesi (2023). HAND THRUST DURING FREE AND TETHERED SWIMMING: AN ANALYSIS OF ASYMMETRY. Cologne : European College of Sport Science.
HAND THRUST DURING FREE AND TETHERED SWIMMING: AN ANALYSIS OF ASYMMETRY
Gabriele Russo
;Vittorio Coloretti;Silvia Fantozzi;Matteo Cortesi
2023
Abstract
INTRODUCTION: Analyzing athletes’ parameters, such as forces during swimming, is essential to enhance performance (1,2). The use of wearable sensors could facilitate this process due to their cost-effectiveness, ease of use, and ecological approach. In this research, we investigated how hand thrust forces vary according to two swimming tests (tethered vs. free) and between the two hands (dominant vs. non-dominant). We hypothesized larger forces in terms of average force (Fmean), impulse (I), and peak force (Fpeak) in tethered compared with the free swimming and in the dominant compared with the non-dominant hand. METHODS: Eleven skilled swimming athletes (age = 15.4 ± 0.5y.; body mass = 58.0 ± 7.1Kg; stature = 168.4 ± 5.0 cm) performed a 10-second tethered front crawl only arms test (Tet), and 10 seconds free front crawl only arms test (Free) wearing two wearable pressure sensors, one for each hand. The thrust force of each hand was estimated as the product of differential pressure (palmar minus dorsal side) and hand surface. Considering circle-shaped hand kinematics, only the horizontal component of hand thrust force was used for the analysis. Average force (FMEAN), impulse (I), average peak (FPEAK), and instantaneous (by means of Statistical Parametric Mapping, SPM) were analyzed as a function of swimming condition and dominant/non-dominant hand. The symmetry index (SI) was analyzed as a function of swimming conditions. RESULTS: Results indicated larger Fmean, Fpeak, and I during Tet compared to the Free condition (F > 4.23, p < .05; Fmean: Tet = 34.0 ± 9.7 N vs. Free = 28.7 ± 7.8 N; Fpeak: Tet = 74.6 ± 22.0 N vs. Free = 66.8 ± 15.2 N; I: Tet = 28.0 ± 5.3 Ns vs. Free = 22.0 ± 5.3 Ns). Whereas SI was non-significant. SPM highlighted a larger Fmean in Tet condition only at the beginning of the stroke (entry phase, from 7 to 28% of the cycle). In addition, non-significant differences were observed for Fmean between the hands (p > .05), and SPM confirmed these results (p > .05). However, larger Fpeak and I in the dominant compared with the non-dominant hand were found (F > 11.11, p < .05; Fpeak: dominant = 65.3 ± 15.9 N vs. non-dominant = 62.7 ± 14.4 N; I: dominant = 26.3 ± 8.0 Ns vs. non- dominant = 23.5 ± 5.6 Ns). CONCLUSION: The swimmer appears to exert larger hand propulsion in tethered- than free- swimming. However, our findings of the symmetry model and the hand-propelling balance during tethered- and free-swimming were not conclusive, and further investigations could help in better understanding this phenomenon (3). REFERENCES: 1) Takagi et al., (2021). Sports Biomechanics. 2) Zamparo et al., (2020). European Journal of Applied Physiology 3) Knihs et al., (2022). Strength & Conditioning JournalI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
