Evaluating the Effect of Shoes with Varying Mass on Vertical Ground Reaction Force Parameters in Short-Term Running

International Journal of Exercise Science 15(1): 191-205, 2022. Past investigations have revealed that running shoes affect ground reaction force parameters. However, these studies are unclear as to whether these changes, which occur while running in different shoe types of differing masses, are the result of the structural design or the mass of the shoe. The main aim of this study is to evaluate the effect of shoe mass on vertical ground reaction force parameters: active peak and impulse. Methods. 21 male runners (24.52 years old (± 3.09) and 77.13kg (± 7.9)) participated in the experiment. A baseline shoe (BS) = 283g and four weighted shoes (shoe 2 = 333g, shoe 3 = 433g, shoe 4 = 533g and shoe 5 = 598g) were compared for 8 minutes of running on the instrumented treadmill. Each shoe was compared in a repeated measurement with the BS. Results showed that active peaks and impulses differed significantly (p \u3c .05) between the BS and weighted shoes, except for shoe 2. From the threshold of 433g (shoe 3, which is 1.5 times heavier than the BS), we observed a significant increase in the vertical ground reaction force peak (1.86%) and impulse (1.84%). Other shoes such as shoe 4 and shoe 5, produced increasingly active peaks (N) of 2.08% N and 2.45% N compared to the BS. Increase of shoe masses in shoe 3, shoe 4, and shoe 5 resulted in an increase of impulse up to 1.84% Nm, 1.85% Nm and 2.49% Nm compared to the BS. Our determination of the shoe masses influencing these kinetic parameters may be a step towards reducing running-related injuries that result from accumulated microtrauma

COMPARATIVE STUDY OF SHOE-SURFACE INTERACTION IN TRAIL RUNNING - SUBJECTIVE AND OBJECTIVE EVALUATION

The purpose of this study is to compare and evaluate different running shoes in various surface conditions in two measurement phases. In the subjective test, fourteen trail runners performed the experiment with three running shoes in distinct surface conditions. Three features, comfort, cushioning and traction, were rated by means of questionnaire. In the objective measurement, a traction tester device was configured to simulate the movement and evaluate the rotational traction of the three shoes on different surfaces. The subjective test showed a significant difference with respect to comfort and cushioning. The objective measurement in dry conditions showed a significant decrease (P \u3c 0.05) in rotational traction on different surface types; rotational traction in wet conditions was significantly lower (P \u3c 0.05) than in dry conditions

Determining the effect of gender and racial differences on mental and physical tasks

Occupational stress has attracted the attention of many researchers during recent years. Through studies of stress the level of efficiency of work performance can be increased while the level of human error can be decreased. Investigating stress without considering human factors such as gender and race cannot be effective and reliable. Many studies investigate these factors but findings show conflicts among investigation results. The aim of this research is resulted by gender and racial differences to investigate the effects on performance of mental and physical tasks. A total of 120 (non-smoking) participants consisted of 60 males and 60 female of different races such as Malay, Chinese, Iranian and Black-African. Two tasks were considered in the experiment: ?) Mental, ??) Physical. The experiment consisted of three stages. The first and second stage were held in a non-stressful situation in a library and the third stage was held in a stressful-situation in a mechanical engineering workshop. Considering energy expenditure per tasks were accomplished consecutively in each stage. Heart rate was measured once before and once during each task, each measurement taking approximately thirty seconds. Mean heart rate numbers during thirty second periods were recorded for the analysis of baseline (non-stress) and stress situations. To measure heart rate, “Oxi-meter finger pulse” was applied. To measure nicotine rate in order to determine non-smoking subjects, “Smokerlyzer” was used. A questionnaire was administered to a random group of students before stages in order to determine an appropriate reward for the winner of each skill competition in third stage. The analysis heart rate reactivity, recall task efficiency and typing task efficiency were accomplished through SPSS 18. Mean heart rate in baseline and stress per subject was calculated. Correlation and regression were SPSS methods to analyze (P value < 0.05). Gender differences clearly influenced heart rate reactivity, and mental task in baseline and stressful situation. Results demonstrated that stress decreased mental efficiency in females more than males, also that males adapted faster than females in stressful situations