Comparison Of Some Kinematic Parameters In The 100 M Free Style Swimming Performances Of Different Age Groups

Abstract

The purpose of the present study was to determine the effect of stroke length and stroke frequency on 100-m freestyle swimming performance. Participants comprised a total of twenty-four swimmers from Antalya Kulac Swimming Club. These swimmers were allocated to two groups. Group 1 consisted of twelve swimmers with a training duration of seven years and Group 2 consisted of twelve swimmers with a training duration of three years. The athletes' 100m freestyle swimming performance (as 4x25m) were recorded with two digital (50 Hz) cameras and the kinematic parameters stroke frequency, stroke length and speed were analyzed at each 25 m. There was a statistically significant difference between the two groups in the second 25-m and fourth 25 m stroke length values of 100-m freestyle swimming performance(p <.05). The stroke length values of swimmers in Group 2 followed an irregular form for every 25 m while Group 1 swimmers increase their 100-m freestyle swimming performance by using SL without losing the stroke frequency value at all. In order to increase the swimming speed, swimmers in Group 2 have compensated for the decrease in stroke length by increasing the stroke frequency.

Keywords: Stroke length” stroke frequency” swimming biomechanics” swimming velocity

1.Introduction

Swimming Performance as with cycling, running and other cyclic sports, is also directly related to

physiological, technical and physical capacity. However, as the water locomotion requires more energy

per unit than the locomotion on land, the technical level becomes more important to increase propulsive

force and reduce active drag (Barghamadi et al., 2012; Greco et al., 2007).

The swimming velocities (V) depend on stroke length (SL) and stroke frequency (SF). SF refers

to number of arm cycles (strokes) in per unit time, while SL refers to the displacement of the body in each

arm cycles. These two parameters showed a significant correlation in the definition of swimming

performance of swimmers at different performance levels in short and long tests (Greco et al., 2007,

Bartlett, 1997). The freestyle swimming is the fastest swimming style among other styles. The decrease in

swimming speed during performance is due to the decrease in stroke length. For that reason a swimmer

who does not have a longer SL will have to swim with more SF to get same swimming velocities. In

previous studies it was determined that elite swimmers preferred longer SL for conservation of their

velocities (Barbosa et al., 2010; Carla et al., 2011; McCabe et al., 2011).

Elite swimmers usually perform with stroke length, while stroke frequency and velocities continue

to decrease throughout the competition. The general conclusion about the change of stroke length and

stroke frequency in a competition is that stroke length and velocities are decreasing during the race.

Similarly, there are different opinions about stroke frequency that it can remain steady, decrease or

increase. However, the decisive factor of the average speed of the swimmer is the stroke length relative to

the stroke frequency. Thus, the velocity decline during the race is explained completely by the loss in the

stroke length. Therefore, the best way to identify the stroke parameters that make up the velocities is to

examine the changes in stroke length for a given performance (Keskinen , 1997).

2.Problem Statement

Examination of the effect of stroke length and frequency parameters on the 100-m freestyle

swimming performance will provide information for trainers about which parameters are used more and

which parameters should be developed more for athletes with different training ages.

3.Research Questions

How do the changes in stroke frequency and length parameters improve along with regular

training and what is the contribution to 100-m freestyle swimming performance?

4.Purpose of the Study

The aim of present study was to examine the changes in stroke length and stroke frequency during

100m free swimming performance depending on the training age and to determine which parameter was

effective for performance.

5.Research Methods

6.Findings

7.Conclusion

When the swimming performance is examined in a comprehensive way, it is obvious that

competition among participants is influenced by individual differences (stroke frequency, stroke length

and swimming velocity). These differences are based on the interaction between the biomechanical

requirements of the skill (swimming technique) and skill level of athletes. For instance, long distance

swimmers have longer SL and lower SF values (Craig et al., 1985).

It can be said that differences in height and stroke length contribute to differences in stroke length,

as the swimming speed is generated by the stroke length multiplied by the stroke frequency. In present

study, the reason of having larger stroke length values of group 1 swimmers may be resulting from their

anthropometric characteristics.

In previous studies it was well documented that Olympic swimmers have longer stroke length than

other swimmers and that they have effective indexes for producing propulsive effectiveness force in

stroke length (Wakayoshi, et al., 1993; Wakayoshi, et al., 1995). Higher propulsive forces associated with

more effective swimming techniques and coordination will allow faster and longer stroke length. Fewer

stroke frequency rates will allow for less energy consumption while providing continuity in generating

propulsion power for arm and leg movements (Hellard et al., 2007; Seifert et al., 2007,Kucia-Czyszczon

et al., 2013, Seifert et al., 2004).

In present study, it can be seen that swimmers with more training ages increase their 100-m freestyle

performance by using stroke length without losing stroke frequency value at all. The stroke length values

of swimmers in group 2 were irregular for every 25 m and in last 25 m there was a 20.93% decline from

the initial value. The stroke frequency is increased to compensate for the decrease in the stroke length and

therefore the speed. However, some results indicate that biomechanical factors (90.3%) explained most of

100-m front crawl swimming performance variability in adolescent male swimmers, followed by

anthropometrical (45.8%) and physiological (45.2%) parameters(Lätt et al.,2010) .

As a result, swimming performance is highly correlated with energy profile and technical level.

Fewer variations in swimming speed, greater stroke length and arm coordination are important factors in

improving the swimming economy.

References

1. Barbosa T, M.Bragada J, A.Reis V, M.Marinho D, A.Carvalho , C.Silva A, J. (2010). Energetics and biomechanics as determining factors of swimming performance: Updating the state of the art, Journal of Science and Medicine in Sport. , 13, 262-269
2. Barghamadi , M.Behboodi , Z.Toor D, S. (2012). Biomechanical factors in 200m freestyle swimming and their relationship with anthropometric characteristics, Iranian Journal of Health and Physical Activity. , 3(2), 49-54
3. Bartlett, R. (1997). Introduction to sports E & FN Spon. , biomechanics. London
4. Carla B, M.Psycharakis , S.Sanders , R. (2011). Kinematic differences between front crawl sprint and distance swimmers at sprint pace, Journal of Sports Sciences. , 29(2), 115-123
5. Craig A, B.Skehan P, L.Pawelczyk J, A.and Boomer W, L. (1985). Velocity, stroke rate, and distance per stroke during elite swimming Sci. Sports Exerc. ., 17(625–634), competition. Med
6. Kucia-Czyszczon , K.Dybinska , E.Ambrozy , T.Chwala , W. (2013). Factors determining swimming efficiency observed in less skilled swimmers, Acta of Bioengineering and Biomechanics. , 15(4), 115-124
7. Hellard , P.Dekerle , J.Avalos , M.Caudal , N.Knopp , M. (2007). Kinematic measures and stroke rate variability in elite female 200-m swimmers in the four swimming techniques: Athens 2004 Olympic semi-finalists and French National 2004 Championship semi-finalists, Journal of Sports Sciences, Taylor & Francis: SSH Journals,1-12.
8. Greco C, C.Pelarigo J, G.Figueira T, F.Denadai B, S. (2007). Effects of gender on stroke rates, critical spee and velocity of a 30-min swim in young swimmers, Journal of Sports Science and Medicine. , 6, 441-447
9. Keskinen K, L. (1997). Evaluation of technique performance in freestyle swimming, Kinesiology. , 2(1)
10. Sanders , R. (2011). Kinematic differences between front crawl sprint and distance swimmers at sprint pace, Journal of Sports Sciences. , 29(2), 115-12
11. Seifert , L.Chollet , D.Chatard J, C. (2007). Kinematic Changes during a 100-m Front crawl: Effects of Performance Level and Gender, Medicine&Science in Sports&Exercise, 1784-1793.
12. Seifert, L.Chollet, D.Brady, B. G. (2004). Effect of swimming velocity on arm coordination in the front crawl: A dynamic analys. (Journal of Sports Sciences, 22, 651–660)
13. Wakayoshi , K.Yoshida , T.kuta , Y.Mutoh , Y.Miyashita , M. (1993). Adaptations to six months of aerobic swim training: Changes in velocity, stroke rate, stroke length and blood lactate. International Journal of Sports Medicine, 14, 368-372
14. Wakayoshi , K.D’acquisto L, J.Cappaert JM, Troup. (1995). Relationship between oxygen uptake, stroke rate and swimming velocity in competitive swimming. International Journal of Sports Medicine, 1, 19-23