A New Index of Coordination for the Crawl: Description and Usefulness

This study analyzes stroke phases and arm and leg coordination during front crawl swimming as a function of swim velocity and performance level. Forty-three swimmers constituted three groups based on performance level. All swam at three different swim velocities, corresponding to the paces appropriate for the 800 m, 100 m, and 50 m. The different stroke phases and the arm and leg coordination were identified by video analysis. Arm coordination was quantified using a new index of coordination (IdC), which expresses the three major modalities opposition, catch-up and superposition. Opposition, where one arm begins the pull phase when the other is finishing the push phase; catch up, which has a lag time (LT) between propulsive phases of the two arms; and superposition, which describes an overlap in the propulsive phases. The IdC is an index which characterizes coordination patterns by measure of LT between propulsive phases of each arm. The most important results showed that duration of the propulsive phases (B + C) increased significantly with increasing velocity: 43.1 ± 3.3 % for V800; 46.5 ± 3 % for V100 and 49 ± 3 % for V50. The arm and leg synchronization was modified in the sense of an increase in six-beat kick. The IdC increased significantly with velocity: IdCV800 = - 7.6 ± 6.4 %; IdCV100 = - 3.2 ± 5.1 % and IdCV50 = - 0.9 ± 5.6 %. IdC increased also significantly with performance level: IdCG3 = - 6.07 ± 5.3 %; IdCG2 = - 3.9 ± 4.2 % and IdCG1 = - 1.76 ± 5.6 % for the mean of the 3 velocity. The two extreme IdC were IdCG3V800 = - 9.4 ± 5.4 % and IdCG1V50 = + 2.53 ± 4.4 %.

Key words:

Motor coordination - biomechanics - performance - crawl - swimming

References

• 1 Chatard J C, Collomp C, Maglischo E, Maglischo C. Swimming skill and stroking characteristics of front crawl swimmers.  Int J Sports Med. 1990;  11 156-161
• 2 Costill D L, Maglischo E W, Richardson A B. Swimming. Oxford; Blackwell Scientific Publications 1992
• 3 Counsilman J E. Hand speed and acceleration.  Swimming technique. 1981;  18 22-26
• 4 Hollander A P, De Groot G, Van Ingen Schenau G J, Kahman R, Toussaint H M. Contribution of the legs to propulsion in front crawl swimming. In: Ungerechts BE, Wilke K, Reischle K (eds) Swimming Science V. Champaign, IL; Human Kinetics Publishers 1988: 39-44
• 5 Keskinen K L, Komi P V. Stroking characteristics of front crawl swimming during exercise.  J Appl Biomech. 1993;  9 219-226
• 6 Kolmogorov S V, Duplisheva A. Active drug, useful mechanical power output and hydrodynamic force coefficient in different swimming strokes at maximal velocity.  J Biomech. 1992;  25 311-318
• 7 Kolmogorov S V, Rumyantseva O A, Gordon B J, Cappaert J M. Hydrodynamic characteristics of competitive swimmers of different genders and performance levels.  J Appl Biomech. 1997;  13 88-97
• 8 Maglischo E W. Swimming Even Faster. Montain View, CA; Mayfield Publishing Company 1993: 363-388
• 9 Maglischo C W, Maglischo E W, Higgins J, Luedtke D, Schleihauf R E, Thayer A. A biomechanical analysis of the U.S. Olympic freestyle distance swimmers. In: Ungerechts BE, Wilke K, Reischle K (eds) Swimming Science V. Champaign, IL; Human Kinetics Publishers 1988: 351-359
• 10 Monteil K M, Rouard A H, Dufour A B, Cappaert J M, Troup J P. Front crawl stroke phases: discriminating kinematic and kinetic parameters. In: Troup JP, Hollander AP, Strass D, Trappe SW, Cappaert JM, Trappe TA (eds) Biomechanics and medicine in swimming VII. London; E & FN Spon 1996: 44-50
• 11 Rouard A H, Billat R P. Influence of sex and level of performance on freestyle stroke: an electromyography and kinematic study.  Int J Sport Med. 1990;  11 150-155
• 12 Schleihauf R E, Higgins J, Hinricks R, Luedtke D, Maglischo C W, Maglischo E W, Thayer A. Models of aquatic skill in sprint front crawl stroke.  NZ J Sports Med. 1986;  14 7-12
• 13 Toussaint H M, Beek P J. Biomechanics of competitive front crawl swimming.  Sport Med. 1992;  13 8-24
• 14 Vaday M, Nemessuri M. Motor pattern of free-style swimming. In: Lewillie L, Clarys JP (eds) Biomechanics in swimming I. Bruxelles; Université Libre de Bruxelles 1971: 167-173