1.CLASSIFICATION OF STROKE TYPES IN RELATION TO STROKE RATE AND STROKE LENGTH IN 100M FRONT-CRAWL RACE
YUJI MATSUDA ; YOSUKE YAMADA ; TOSHIFUMI AKAI ; YASUSHI IKUTA ; TERUO NOMURA ; SHINGO ODA
Japanese Journal of Physical Fitness and Sports Medicine 2010;59(5):465-474
The purposes of this study were as follows: 1) to classify competitive swimmers on the basis of their stroke rate (SR) and stroke length (SL) by applying a factor analysis and a cluster analysis, 2) to derive discriminant functions by applying a multiple discriminant analysis of the stroke characteristics, and 3) to compare the race patterns of groups classified according to the results of the cluster analysis. 94 male swimmers who had participated in 100-m freestyle events held at the All Japan Swimming Championship from 2000 to 2004 were selected as subjects. The average value of their swimming velocity, SR, and SL in four swimming phases (15-25 m, 25-45 m, 57.5-75 m, and 75-95 m) were measured from videos captured. The subjects were classified according to their SR and SL by applying a factor analysis and a cluster analysis. Results showed that the competitive swimmers could be classified into Type1-4. Type1 showed high values of SR throughout the race, Type2 showed high values of SR in the first half and high values of SL in the second half, Type3 showed high values of SL in the first half and high values of SR in the second half, and Type4 showed high values of SL throughout the race. Although there was no difference in swimming records among the four groups, each group had different race patterns. These results suggest that the knowledge of race patterns might be useful to swimmers or coaches for planning race strategies.
2.STUDY ON THE ERROR THAT WAS ACCOMPANIED WITH BODY GIRTH
MITSUTSUGU ONO ; MOTOKO KOBAYASHI ; TERUO KAISE ; KAZUKO NAKAGAWA ; TAKAHIRA NOMURA ; MICHIAKI IKEDA ; HILOSHI KURATA ; AKIHITO YANAGIMOTO ; KUNIHIKO HARADA ; TERUYA AMAMIYA
Japanese Journal of Physical Fitness and Sports Medicine 1971;20(3):159-168
10 male and 8 female skillful tester on physical fitness measurements were attended. They were measured one another the body girth and blood pressure of themselves. The result obtained on the same person by the different tester were not always coincident. The following issues were obtained.
(1) Mean value of individual error finding on the systolic pressure was about 4mmHg, on the diastolic pressure was about 6mmHg. Mean value of the difference between the maximum and minimum value of the systolic pressure reported on the same person was 15.4mmHg in male group. That of the diastolic value was 21.4mmHg in male group. For the female group, that of the systolic pressure was 17.0mmHg, that of the diastolic pressure was 23.0mmHg.
(2) Mean value of individual error (as under, be showed by“error”) obtained on the chest girth was 1.43cm in male group, 1.05cm in female group. Mean value of the difference between the maximum and minimum value (as under, be showed by“breadth”) was 5.99cm in male, 4.08cm in female.
(3) “Error”observed on the overarm extended girth was 0.73cm in male, 0.79 cm in female, “breadth”was 2.96cm in male, 2.99cm in female.
(4) “Error”finding on the overarm flexed girth was 0.60cm for both sex, “breadth”was 2.81cm in male, 2.43cm in female.
(5) For the forearm girth, “Error”was 0.40cm in male. 0.24cm in female, “breadth”was 1.81cm in male, was 1.35cm in female.
(6) For the thigh girth, “Error”was 0.90cm in male, 0.69cm in female, “breadth”was 3.91cm in male, 2.93cm in female.
(7) On the calf girth measurement, in male and female group, “Error”was 0.44 and 0.40cm, “breadth”was 1.51 and 1.48cm respectively.
From above mentioned findings, we considered that“Error”is possible to regard as unavoidable error, “breadth”might be probable error.