• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.81-86
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• 2010

Despite the importance of cycling postures during cycling performances, there has been a very little research investigating cycling postures and pedaling rate for particularly concerning domestic cyclists. The aim of this study was to analyze correlations and effects between cycling postures and pedaling rate in track cycling. Twelve male racing cyclists (six racing and university cyclists) participated in this research. For this study, seven infrared cameras (Qualisys ProReflex MCU-240s) were used for collecting data and these were processed via QTM (Qualisys Tracker Manager) software. It appeared that pedaling rate had correlations with regard to a shoulder angle (R=-.601) and displacement between shoulder joints(R= -.637), but a knee (R=-.601) and ankle angle (R=.667). Moreover, two multiple regression equations of pedaling rate for cycling postures were significant and R2 of the first order equation y (pedaling rate) = 0.039x (knee angle) - 1.068 was less than the second order equation y = 0.006x2 - 1.287x + 69.674. In conclusion, cycling postures affected the pedaling rate. Further study should be researched on postures in relation to air resistance in a wind tunnel.

• The Journal of Korean Physical Therapy
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• v.18 no.3
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• pp.37-45
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• 2006

Purpose: This study analyzed changes in spinal neuron and action potential of motor unit depending on voluntary contraction on spinal neuron adaptation. Methods: It selected 80 university students in their twenties and divided into experimental groups of 25% MVIC (I), 50% MVIC (II), 75% MVIC (III) and 100% MVIC (IV) depending on maximum voluntary isometric contraction (MVIC) and performed isometric exercise of plantar flexor muscle to each experimental group with given contraction for 20 times. It measured Mmax, H/Mmax, Hmax latency, V/Mmax, V wave latency before and after exercise, compared method and volume of contraction. Results: H/Mmax ratio showed significant difference in comparison among groups (p<0.01) and there was difference in I and IV groups. V/Mmax ratio showed significant difference in comparison among experimental groups (p<0.05) and there was difference in I and IV groups. When voluntary contraction level was maximum, changes were greatest. However, no significantly difference was to Mmax, H latency and V wave latency. Conclusion: These results suggest that amplitude changes of voluntary contraction level, spinal neuron and supra-spinal neuron had a dose connection that the more contraction level, the better central activation seem to decrease highly for a short time.