Showing 5 results for Stiffness
Mr. Ali Smaeeli, Dr. Amirali Jafarnezhadgero, Mr. Mansour Jabri,
Volume 0, Issue 0 (11-2019)
Abstract
Background and Aim: This study focuses and reviews the researches that examines the effect of footwear types on torsional, vertical and limb stiffness during running.
Methods: The search for articles in English languages between 2000 and 2024 (until May) was carried out in WOS, Scopus, PubMed, Springer databases and grey literature from Google Scholar. The inclusion criteria included the number of participants being more than one and the availability of the full text of the articles. Exclusion criteria included studies whose participants were under 18 years of age. Review studies and studies that studied an activity other than running.
Results: 586 relevant articles were selected. After examining the articles, 17 articles were selected. Vertical stiffness and limb stiffness in barefoot conditions are significantly greater than in conventional shoes. The torsional stiffness in the ankle and hip joints in conventional shoe conditions was reported to be higher than in barefoot and minimal shoe conditions. In contrast, the torsional stiffness of the knee joint in conventional shoe conditions was lower than in barefoot and minimal shoe conditions.
Conclusion: These findings provide further insight into the susceptibility of runners to different injury mechanisms as a function of footwear.
Dr Elham Shirzad, Dr Ali Asghar Ravasi, Mojtaba Eshrestaghi,
Volume 13, Issue 9 (4-2015)
Abstract
Stiffness is an index for determination of elastic properties of body and its optimum range is different in various
motion patterns. The Spring-mass model is used for calculating stiffness. In this method, the whole leg is modeled
with a linear simple spring. The aim of this study is determination of lower body stiffness and evaluation of its
correlation with agility, as dominant motion pattern in racket sports. 12 national-level male racket-players (age:
25±4 years & weight: 80±7 kg) participated voluntarily in this study. Leg and vertical stiffness were measured
during running on treadmill and hopping test. Pearson’s correlation coefficients were used to examine the
relationships between stiffness and agility test records. Statistical significance was set at P< 0.05. There wasn’t
significant correlation with agility in this study. The reason could be of the contrast influence of knee and ankle
stiffness on performance. This problem requires separate evaluation of joint stiffness.
Mr Amir Reza Sedighi, Dr Mehrdad Anbarian,
Volume 18, Issue 20 (11-2020)
Abstract
The purpose of this study was to determine the immediate effect of three types of shoe insoles, on electromyography activity of selected lower extremity muscles during running on treadmill. The electromyography activity of the rectus femoris, vastus lateralis, vastus medialis, biceps femoris, tibialis anterior and gastrocnemius lateralis muscles of 14 male athletes were recorded in non-insole, wearing soft, semi-rigid and rigid insoles conditions during running on treadmill. Electromyography activity of the rectus femoris muscle in the loading phase was lower in soft insole condition than other conditions. In the pre-swing/early swing phase, there was difference of the rectus femoris muscle activity in the soft/non-insole and soft/semi-rigid conditions. In this phase, the biceps femoris muscle had different activity in the semi-stiff/non-insole and semi-rigid/rigid conditions. In the mid-swing phase, there was a difference in the activity of the rectus femoris and the tibialis anterior muscles in the non-insole/semi-rigid condition, and the gastrocnemius lateralis muscle in the non-insole condition with other conditions. There was difference also for biceps femoris muscle activity in the semi-rigid/non-insole condition in the pre-activation phase. The vastus lateralis and gastrocnemius lateralis muscles activity in the soft insole condition was lower than that of the semi-rigid condition. It seems that the intensity and contraction pattern of the muscles change while using different shoe insoles with different variety of stiffness during running. It could be useful in choosing a shoe insole with a suitable stiffness material level for clinical and training purposes.
Effat Hosseinzadeh, Mansour Eslami,
Volume 18, Issue 20 (11-2020)
Abstract
Introduction: The ability to attain high level of speed is an essential component of success in many sports fields. However, physical qualities that underpin this ability remain unclear. The purpose of this study was to investigate the role of leg stiffness and vertical stiffness in predicting sprint running. Methods: 50 healthy females were selected among physical education students. The required kinetic and kinetic data were collected in three dimensions. The kinetic and kinematic variables rrunning skill was used to measure both stiffness variables. A multivariate regression model was used to examine the possibility of predicting running speed using leg stiffness and vertical stiffness. Findings: The results of multiple regression showed that there is a significant relationship between the two-leg stiffness and vertical stiffness with mean running speed (R = 0.671), and these two variables can predict 42% of Average speed variation (Adj. R square=0.426). Conclusion: The results of the present study showed that the ability of individuals to sprint running is likely to be significantly dependent on leg stiffness and vertical stiffness. The results of this study can provide important information for designing training programs and talent detection for trainers and specialists in this field.
Dr Adel Donyaei, Mustafa Rahimi, Fatemehsadat Nabavi,
Volume 20, Issue 24 (3-2023)
Abstract
vitamin D deficiency is associated with many cardiovascular disorders. Arterial stiffness responses also depend on nutritional and exercise. Therefore, the study aimed to investigate the relationship between arterial stiffness response after glucose uptake and exercise with baseline levels of vitamin D in inactive men and women.
The present study was an analysis correlation study, and the subjects were 88 inactive men and women with an age range of 20 to 45 years. Vitamin D, body composition, and arterial stiffness, were measured. Subjects then ran for 30 minutes at 65% of maximum heart rate. Also, 75g of glucose was given to the subjects after 30 minutes of activity, 60 minutes after the of glucose consumption and arterial stiffness was measured. Data were analyzed using Pearson correlation test and analysis of variance with repeated measures at a significant level (P≤0.05).there was a negative and significant relationship between baseline levels of vitamin D and changes in CAVI in women (p=0.001 and r=-0.559) and in men a positive and significant relationship (p=0.005 and r=0.413).It seems that basal levels of vitamin D can be effective in the vascular response; due to little research, more research is need.
