Front-crawl stroke-coordination and symmetry: A comparison between timing and net drag force protocols

Abstract

This study compared stroke-coordination and symmetry using traditional timing methods and net drag force profiles. Twenty elite front-crawl swimmers Federation Internationale de Natation (FINA ranking 908 ± 59) were tested to identify the influence of both gender and breathing. A total of six randomised free-swimming trials were conducted: (i) three breathing, (ii) three non-breathing. Net drag forces were measured using an assisted towing device and the magnitude and location of minimum and maximum was determined to create a stroke symmetry index. Within the breathing condition, there were significant differences between the two symmetry index methods. Using the timing index, all 10 female participants, and seven males, illustrated symmetrical timing. For the net drag force profile, only three females and zero males exhibited a symmetrical minimum net drag force; and only four females and two males demonstrated a symmetrical maximum net drag force index. No differences existed within the non-breathing condition. There was a small (5.2%) difference in the location of maximum net drag force, when stratifying by gender. During the breathing condition, gender also influenced the percentage of overlap for the breathing stroke by 25.2%, and 14.6 % for the non-breathing stroke. A combination of the traditional timing based and net drag force based profile can guide future swimming technique intervention strategies.

Quantification of upper limb kinetic asymmetries in front crawl swimming

“…In the current study, the majority of the participants presented force asymmetry and there was a large inter-individual variability, with symmetry indexes ranging from 3.3% to 48.5% confirming our first hypothesis. These results agree with some of the previous literature (Formosa et al, 2013) and highlight the predictable force imbalance, over the course of repeated crawl movements and years of training (Tourny-Chollet et al, 2009). Over time, unilateral breathing and the development of greater strength of the dominant upper limb may lead to a differentiation in the swimmers ability to exert balanced forces.…”

“…However, the upper limbs alternating movements do not necessarily ensure symmetry, particularly regarding upper limb coordination (Seifert, Chollet, & Allard, 2005), hand speed (Keskinen, 1994), hand path (Aujouannet, Bonifazi, Hintzy, Vuillerme, & Rouard, 2006a) and propulsive forces (Formosa, Sayers, & Burkett, 2013;Formosa et al, 2011;Yeater, Martin, White, & Gilson, 1981). So, it is not clear if the reported asymmetries can alter the optimal function or simply are within the limits of normal variation.…”

“…For instance, high level swimmers have an enhanced control of body roll (Cappaert, Pease, & Troup, 1995) and a greater medio-lateral hand motion augmenting the potential to develop propulsive forces (Payton, Hay, & Mullineaux, 1997). Nevertheless, the majority of high level swimmers demonstrate asymmetrical propulsion (Formosa et al, 2013).…”

“…Swimming velocity is dependent of both propulsive and drag forces, being the ability to obtain high values of propulsive force considered essential to enhance swimming performance (Formosa et al, 2013). Moreover, its importance varies according to the distance to be swum; that is, the importance of forces exerted in water is higher over short distances, while for long distances technical ability plays a major role (Morouço, Keskinen, Vilas-Boas, & Fernandes, 2011).…”

Cascaded evolutionary multiobjective identification based on correlation function statistical tests for improving velocity analyzes in swimming

“…Focusing on technology innovation through equipment development in the sports field, some researches in biomechanics applied to swimming were concentrated in measuring swimmers velocity. Considered one of the most important physical grants in swimming, velocity is frequently related to propulsive and resistive forces [2][3][4], coordination and symmetry of the athletes [5].…”