Abstract
Background & Objectives: Athletes generally seek to improve their performance, and to achieve this goal, they use conditioning training programs that include core stability exercises. Fatigue is one of the causes that can lead to decreased coordination and impaired muscle function, and the muscles of the core area of ​​the body are of great importance by creating a stable surface for the execution of coordinated movements of the limbs. Changes in muscle function caused by fatigue reduce their ability to generate strength and, as a result, the occurrence of abnormalities and injuries. Fatigue affects gait parameters such as increasing stride width to improve balance and increase heel strike speed. Fatigue differs between men and women. Despite the studies that have been conducted on the relationship between central stability and performance and according to the results of such research, researchers have not yet managed to clearly understand the impact or lack of influence of central stability on the performance of athletes. This study compared the effect of central muscle fatigue on the kinematic parameters of walking between men and women.
Methods: The present research method was interventional (quasi–experimental) due to the application of fatigue. The selection of subjects was targeted based on the inclusion and exclusion criteria. In the current research, the effect of central body muscle fatigue on walking was investigated through repeated measurement design (pretest–posttest) in two groups of subjects. The statistical population of this research includes all young men and women aged 18 to 25 with 3 years of regular sports experience who participated in the exam based on a public call in the universities of Mashhad City, Iran, in the academic year of 2022–2023. Based on the inclusion and exclusion criteria, the samples of this research included 15 female and 15 male qualified volunteers who were identified from the statistical community and then purposefully selected as research subjects. The inclusion criteria comprised the body mass index between 20–25 kg/m². The exclusion criteria also include non–participation in the posttest and non–satisfaction of the person to participate in the research. In the exclusion criteria section, people with a history of the trunk or lower limb surgery, severe spinal deformities (scoliosis, kyphosis, etc.), meniscus damage and knee ligament tears, ankle joint instability, lower limb misalignment, including genu valgum, genu varum, geno recurvatum, flat soles and hollow soles, suffering from back pain during the tests, having a history of any acute injury in the 60 days before the tests used, which had a negative effect in this research, and use of assistive devices for walking. Three attempts of walking without shoes were performed before and three attempts after the fatigue protocol. The subject was asked to walk a distance of two meters to the sides and in front of the location of the cameras. To analyze the data in SPSS software, a paired t test was used to examine intragroup comparisons, and an independent t test was used for intergroup comparisons at a significance level of 0.05.
Results: According to the paired t test results, no significant difference was observed between the male and female groups (p>0.05) in the pretest and posttest scores of core muscle fatigue on gait kinematic parameters. By examining the results of the independent t test between the male and female groups, there was a significant difference only in the pretest scores of step (p=0.012) and stride (p=0.025), and no significant difference was observed in the pretest and posttest scores of step time, stride time, cadence, and speed (p>0.05).
Conclusion: While there may be differences in the effects of fatigue on kinematic parameters between women and men, the general results show that the impact of fatigue on walking performance may not be significantly different between the two sexes. Since the parameters of step, stride, step time, stride time, cadence, and speed were constant in both the pretest and posttest stages, this result is correct only for the cases examined in the test, and different results may be obtained in other conditions.