In disability swimming, a functional classification system is used in which swimmers with varying impairments compete against each other in one of 10 classes. In classification research, the criterion most often used to judge validity (fairness) is statistical difference in race performance between adjacent classes. Additional criteria are proposed here. First, the world-record swimming speed should decrease in a predictable manner with decreasing functional class. Second, classes should be clearly discriminated by race performances. To aid in evaluating these criteria, a comparison of the competitiveness (depth of the field) of the classes is made. The criteria were not strictly met in all classes. However, the sprint freestyle events approached fairness, especially for men. The exceptions were more due to a lack of maturity of the sport than to fundamental unfairness. Because of the more complex nature of breaststroke, more problems were observed related to classification fairness in this event.
Daniel J. Daly and Yves Vanlandewijck
Conor D. Osborough, Carl J. Payton and Daniel J. Daly
The purpose of this study was to determine the relationships between swimming speed (SS), stroke length (SL), and stroke frequency (SF) for competitive single-arm amputee front crawl swimmers and assess their relationships with anthropometric characteristics. Thirteen highly trained swimmers (3 male, 10 female) were filmed underwater from a lateral view during seven increasingly faster 25-m front crawl trials. Increases in SS (above 75% of maximum SS) were achieved by a 5% increase in SF, which coincided with a 2% decrease in SL. At SSmax, interswimmer correlations showed that SF was significantly related to SS (r = .72; p < .01) whereas SL was not. Moderate but nonsignificant correlations suggested that faster swimmers did not necessarily use longer and slower strokes to swim at a common submaximal speed when compared with their slower counterparts. No correlations existed between SL and any anthropometric characteristics. Biacromial breadth, shoulder girth, and upper-arm length all significantly correlated with the SF used at SSmax. These findings imply that as a consequence of being deprived of an important propelling limb, at fast swimming speeds SF is more important than SL in influencing the performance outcome of these single-arm amputee swimmers.
Daniel J. Daly, Laurie A. Malone, David J. Smith, Yves Vanlandewijck and Robert D. Steadward
A video race analysis was conducted at the Atlanta Paralympic Games swimming competition. The purpose was to describe the contribution of clean swimming speed, as well as start, turn, and finish speed, to the total race performance in the four strokes for the men’s 100 m events. Start, turn, and finish times, as well as clean swimming speed during four race sections, were measured on videotapes during the preliminary heats (329 swims). Information on 1996 Olympic Games finalists (N = 16) was also available. In Paralympic swimmers, next to clean swimming speed, both turning and finishing were highly correlated with the end race result. Paralympic swimmers do start, turn, and finish slower than Olympic swimmers but in direct relation to their slower clean swimming speed. The race pattern of these components is not different between Paralympic and Olympic swimmers.
Daniel J. Daly, Stefka K. Djobova, Laurie A. Malone, Yves Vanlandewijck and Robert D. Steadward
A video race analysis was conducted on 100-m freestyle performances of 72 male and 62 female finalists at the Sydney 2000 Paralympic Games. Races were won or lost in the second half of each 50-m race lap and differences in speed between swimmers were more related to stroke length than stroke rate. Within-race speed changes were more related to changes in stroke rate. Stroke rate changes were also responsible for speed changes between qualifying heats and finals in the first part of races, while stroke length was responsible for better speed maintenance at the end of races. Results indicate that Paralympic finalists use race speed patterns similar to able-bodied elite swimmers.
Susana M. Soares, Ricardo J. Fernandes, J. Leandro Machado, José A. Maia, Daniel J. Daly and João P. Vilas-Boas
It is essential to determine swimmers’ anaerobic potential and better plan training, understanding physiological effects of the fatigue.
To study changes in the characteristics of the intracyclic velocity variation during an all-out 50-m swim and to observe differences in speed and stroking parameters between these changes.
28 competitive swimmers performed a 50-m front-crawl all-out test while attached to a speedometer. The velocity–time (v[t]) curve off all stroke cycles was analyzed per individual using a routine that included a wavelet procedure, allowing the determination of the fatigue thresholds that divide effort in time intervals.
One or 2 fatigue thresholds were observed at individual level on the v(t) curve. In males, when 1 fatigue threshold was identified, the mean velocity and the stroke index dropped (P < .05) in the second time interval (1.7 ± 0.0 vs 1.6 ± 0.0 m/s and 3.0 ± 0.2 vs 2.8 ± 0.3 m/s, respectively). When 2 fatigue thresholds were identified, the mean velocity of the first time interval was higher than that of the third time interval (P < .05), for both male (1.7 ± 0.0 vs 1.6 ± 0.1 m/s) and female (1.5 ± 0.1 vs 1.3 ± 0.1 m/s) swimmers.
One or 2 fatigue thresholds were found in the intracyclic velocity-variation patterns. Concurrently, changes in velocity and stroke parameters were also observed between time intervals. This information could allow coaches to obtain new insights into delaying the degenerative effects of fatigue and maintain stable stroke-cycle characteristics over a 50-m event.
Inês Marques-Aleixo, Ana Querido, Pedro Figueiredo, João Paulo Vilas-Boas, Rui Corredeira, Daniel Daly and Ricardo J. Fernandes
This study examined the differences in intracycle velocity variation and arm coordination in front crawl in swimmers with Down syndrome in three breathing conditions. International swimmers with Down syndrome (N = 16) performed 3 × 20 m front crawl at 50 m race speed: without breathing, breathing to the preferred side, and breathing to the nonpreferred side. A two dimensional video movement analysis was performed using the APASystem. Breathing conditions were compared using Repeated Measures ANOVA. Swimming velocity was higher without breathing and intracyclic velocity variation was higher while breathing. Swimmers tended to a catch up arm coordination mode for both breathing conditions and a superposition mode when not breathing. These data reflect arm coordination compromising swimming performance, particularly when comparing with non disabled swimmers in literature. The physical and perhaps cognitive impairment associated with Down syndrome may result in a disadvantage in both propulsion and drag, more evident when breathing.