Study aim: to evaluate the differences in H-reflex parameters in lying and standing positions in canoeists. Material and methods: twenty seven male canoeists (age 17.2 ± 1.6 year, body mass 73.7 ± 7.6 kg, height 180.9 ± 6.1 cm, training experience 6.5 ± 3.6 years) participated in the study. None of the subjects had any history of neuromuscular disorders. The soleus H-reflex was examined in each subject twice: in lying and standing position. H-reflex was elicited by one-millisecond electrical stimulation of a posterior tibial nerve in the popliteal fossa. A recruitment curve for each subject was obtained by gradually increasing the stimulus intensity. Results: the results obtained in the present study showed statistically significant differences of the variables characterising effects of stimulations performed in lying and standing positions (F4,23 = 8.063; p < 0.001). H/M ratio was 0.50 ± 0.25 and 0.64 ± 0.27 for lying and standing positions, respectively. Our results support previous findings. Conclusions: the lying position is recommended for measurements as more comfortable for subjects and providing a greater level of the elicited H-reflex.
Study aim: The aim of the present study was to determine a strength profile which characterizes young male athletes from different sports and to use the method of allometry to synthetically evaluate the muscular strength with respect to body mass. Material and methods: The study included 85 men who practiced taekwondo (8 subjects), 20 judoists, 10 weightlifters, 35 canoeists and 12 speed skaters. Measurements of maximal muscle torques in 10 groups of flexors and extensors of the elbow, shoulder, hip, knee and trunk were carried out in a testing station for muscle torque measurements under static conditions. In order to determine the relationships between the body mass and muscle torques in each muscle group, the authors used a procedure of linear regression for the data expressed as logarithms. Hence, the allometric relationship scaled with body mass was obtained. Results: The study demonstrated that the mean values of logarithms of maximal muscle torques are significantly different for the representatives of individual sports and they depend on the logarithm of body mass. The analysis of residuals was employed for the evaluation of maximal muscle torques. The highest strength profiles were observed in athletes who practice judo and the lowest in those who represented weightlifting and taekwondo. Conclusion: The authors propose to use an allometric relationship which takes body mass into consideration during evaluation of strength in individual muscle groups, because the values of muscle torques are not in direct proportion to body mass and their mutual proportions change with an increase in body mass.
Study aim: To determine and compare the muscle strength profile and muscle strength symmetry of kayakers and canoeists. Material and methods: A total of 36 male participants participated in the study, including 25 kayakers and 9 canoeists. Measurements of maximum muscle torque were taken under static conditions for 10 muscle groups: flexors and extensors of the elbow, shoulder, knee, hip, and trunk. Muscle torque was allometrically scaled by body mass. To determine the muscle strength profiles of athletes in both disciplines, residual analysis was used. Two methods were utilized to assess and compare the muscle strength symmetry between left and right limbs. The first one is known as intraclass correlation coefficient (ICC). The second one is an asymmetry coefficient proposed by authors. Results: The study showed that kayakers obtained lower rates of asymmetry indicators than canoeists in most muscle groups. An overall asymmetry coefficient amounted to 0.77 ± 0.20 and 0.99 ± 0.31 (p < 0.05) for kayakers and canoeists, respectively. Moreover, it was observed that the kayakers and canoeists had similar strength profile. The symmetry assessment of maximum muscle torque corresponds to the characteristics of the studied disciplines. Conclusions: The intraclass correlation coefficient is recommended as a measure of strength symmetry for muscle groups comparisons. The asymmetry coefficient is recommended for comparison of individuals.
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.