راضیه یوسفیان ملا

The way we walk and the symmetry of various joints in the lower limb, particularly the knee, which is crucial for movement and weight-bearing, can change due to immobility and splinting of the upper limb. Therefore, this research aimed to conduct a symmetry analysis of the three-dimensional maximum mechanical power of the knee joint during walking while using an upper limb splint with a sling in young women.

This study employed a quasi-experimental and cross-sectional design. All research participants provided written consent to participate after being informed about the study's details. Ethical approval was obtained from the Kinesiology Research Center of Kharazmi University. Thirty healthy female subjects met the entry and exit criteria, which included having a dominant right limb and no history of orthopedic or neurological disorders. Participants walked along a force plate in three different conditions: normal, dominant upper limb splinting, and non-dominant upper limb splinting, all while being recorded by motion analysis cameras. Based on the obtained kinetic and kinematic outputs, the mechanical power value of the dominant and non-dominant knee of the subjects was estimated in three situations to compare the three-dimensional average mechanical power of the knee joint in each of the circumstances. Independent t-test was used at a significance level of P≤0.05.

The results showed that none of the values related to the knee joint's three-dimensional production and absorption power in the right and left limbs are significantly different.

The principle of symmetry in the knee joint is established between all three positions of dominant and non-dominant upper limb splinting. Since mechanical power is one of the important biomechanical criteria and contains kinetic and kinematic information at the same time, it may be concluded that the biomechanical symmetry of the knee joint is maintained in immobility states of the upper limb and these joint plays a more controlling role in walking.

 Flatfoot, as a three-dimensional foot deformity can cause alterations in motor function. Different methods, such as exercises, orthotic insoles, and specialized shoes, have been proposed to manage this condition. The present study aimed to compare the effects of orthotic insoles, shoes, and taping on the frequency content of ground reaction forces (GRFs) during walking in athletes with flexible flatfeet.

In this quasi-experimental study, 15 male athletes aged 18-25 years with flexible flatfeet (age: 21.78 ± 2.07 years; height: 1.78 ± 0.07 m; weight: 80.28 ± 8.23 kg) with a history of regular fitness training for at least 6 months participated. The GRF data were collected using a force plate under five walking conditions: shoes (relaxed-fit, breathe-easy Skechers) + insoles (ethylene vinyl acetate), barefoot, shoes, taping, and shoes + taping. The frequency content of the GRFS was then calculated. To compare the frequency content among different walking conditions, repeated measures ANOVA was used. P≤ 0.05 was considered statistically significant.

 The results showed significant differences between the various walking conditions, with the greatest significant reductions in the variables of 99.5% power frequency, median frequency, frequency bandwidth, and mean frequency in the shoes and shoes+ taping conditions (P<0.05). The reduction in frequency content was particularly prominent in the mediolateral direction.

 The use of shoes can result in a greater reduction in the frequency content of GRFs during walking in athletes with flexible flatfeet compared to taping or barefoot walking. Therefore, relaxed-fit, breathe-easy Skechers are recommended for enhancing motor performance in athletes with flexible flatfeet.

Core stability training plays an important role in performance of youth volleyball players and is defined as a critical factor regarding prevention of the physical abilities and important characteristics of the volleyball players such as balance and jump performance. In this research, the effect of a Progressive Core Stability Program regarding Health Protection on maintenance of Balance and Jump Performance of Junior Volleyball Players during Coronavirus Pandemic has been investigated. After the second quarantine period in Iran, two jump tests (Serjent jump test and Three-step jump test) and static balance test (Romberg) were taken from each player. The players then performed a 12-week core stability training program in compliance with health protocols. Following that, post-test evaluation was recorded. There is a significant difference in all research variables (Sarjent jump test, Three-step jump test and Romberg equilibrium test) between pretest and post-test in junior volleyball players after 12 weeks of progressive core stability training with health protocols. Coaches, specialists in sports sciences and trainers can use progressive core stability exercises to maintain vital functions in volleyball players and emphasize their performance during quarantine.

Many studies have investigated the effect of mechanical power on the symmetry and asymmetry of the lower limbs and have discussed the differences in the values of this parameter between the two limbs. Additionally, some studies have investigated and analyzed the types of mechanical power (propulsion and control) in joint movements. However, no study has yet examined and compared the muscle mechanical power among different joints of each limb, particularly the dominant leg. Therefore, the present study aimed to compare the three-dimensional mechanical power of the dominant lower limb during walking.

Thirty female subjects were asked to walk at their chosen speed and barefoot along the path of the motion analyzer cameras and on the force plate so that the three-dimensional mechanical power of each lower limb joint could be recorded using the obtained data. One-way analysis of variance (ANOVA) and Bonferroni's post hoc test were used to compare the values of mechanical muscle power variables at a significance level of P≤0.05.

Among the peaks of mechanical power of the dominant lower limb, the highest peak belonged to A2S, and the lowest belonged to K2T. Additionally, the most significant difference was observed between the average of some parameters such as H1S and other peaks, while the lowest average difference was observed between the averages of H2F and H1T and other mechanical power peaks.

Therefore, it can be concluded that there is a relationship between the peaks of mechanical power of the hip, knee, and ankle joints of the dominant lower limb. Among these peaks, the second peak of the ankle has the highest mechanical power, while the second peak of the knee has the lowest mechanical power.

The present study aimed to determine the extent to which female athletes display asymmetrical or symmetry patterns in lower limb three-dimensional mechanical muscle power during gait. Thirty healthy female professional bodybuilders participated in his study. Their three-dimensional data of both lower extremities during walking was collected using a ten-camera Vicon motion capture system and two Kistler force plates. The peak mechanical muscle power of lower limbs in all three planes was calculated (P≤ 0.05). The results showed that except in the ankle joint, there were significant differences in third mechanical muscle power peaks of the knee and hip joints in sagittal plane (H3S, K3S), first and second mechanical muscle power peaks of knee joint in frontal plane (K1F, K2F), and second mechanical muscle power peak of hip joint in horizontal plane (H2T). In addition, the findings confirmed approximately 25% local asymmetry in the mechanical muscle power in the hip and knee joints between the right and left limbs.

This study aimed to investigate the effect of chronic ankle instability on coordination and variability of coordination of lower limb joints during running. 20 active male subjects (10 subjects with chronic ankle sprain and 10 healthy subjects) started running on the treadmill with connected sensors at a gradual speed. Information about the coordination and variability of 10 steps of each subject in the joints of the lower limbs was extracted in the sagittal plane of all three joints (hip, knee, and ankle) as well as the transverse plane of the ankle. Finally, an independent t-test was used to analyze the statistical analysis at a significant level of (P <0.05). The results showed that coordination at the initiation of the stance phase was significantly lower in the group with chronic ankle sprain than in the healthy group. The coordination of the hip-knee, hip-to-ankle, and knee-to-ankle joints are more different in injured people than in healthy people at the initiation of the stance phase running, so the coordination of these joints is reduced in the sagittal plane of subjects with chronic ankle sprain. Also, the coordination of the knee joints to the ankle in the frontal plane of the injured group is greater than the healthy group. Chronic ankle sprain injury has caused this difference in the pattern of coordination during the stance phase of running, so that the central nervous system of the body, under the influence of fear of re-injury, designs the movement of the ankle joints relative to the knee to minimize the risk of injury.

Objective:

 The aim of this study was to determine the effect of increasing running speed on the displacement and speed of the center of sole pressure.

Methods:

 For this purpose, 28 professional runners with at least 5 years of experience in athletics, from among Tehran province teams in the national league, were selected as volunteers as a sample. After completing the informed consent form, the subjects first walked at a speed of 1.2 meters per hour to get acquainted with the treadmill. Then, slowly, the speed reached 2.5 meters per second, and after 3 minutes of running at this speed, the data were recorded for about thirty seconds. The runners then ran on the treadmill at a speed of 3.5 m / s and then at a speed of 4.5 m / s. Data were collected using special markers and 3D cameras. Analysis of variance with repeated measures and Bonferroni post hoc test were also used to analyze the data.

Results:

 The results showed that increasing the running speed would have a significant effect on the displacement rate and foot pressure of runners. As the running speed increased, so did the displacement and the pressure of the sole of the foot.

Conclusion:

 The results confirm the effect of increasing running speed on the amount of movement and speed of foot pressure.

Running is known as one of the most popular sports for which there is no time and space limit. Recently, due to lifestyle changes, the use of treadmills for walking and running has increased. However, the biomechanical differences in coordination between running on a treadmill at different speeds have not been sufficiently addressed. The aim of this study was to investigate the effect of increasing running speed on three-dimensional changes of lower extremity joint angles in the open motor chain and swing phase.

28 elite runners participated in this study. Subjects ran on an equipped treadmill while kinematic running data was recorded for 30 seconds through a three-dimensional 12-camera motion recording system at speeds of 2.5, 3.5 and 4.5 m / s. Data were normalized based on the subjects' body mass as well as 101 time points in the running cycle. The normality and homogeneity of variance of the dependent variable were tested using Bartlett and Leven’s tests. Repeated measurement test was performed to measure the angles of the pelvis, knee and ankle between the dominant and non-dominant lower limb joints in the running swing phase.

In the range of motion of hip, knee and ankle joint, there were significant differences among all the three speed rates of 2.5, 3.5 and 4.5 on all planes.

Changes in the angle and range of motion of the hip, knee and ankle joints are significantly greater in the swing phase as the running speed increases. Due to the fact that in high-speed running, the stability of the body decreases, the central nervous system commands to increase the range of motion of the angle of the mentioned joints to regulate the structure of the body and reduce the instability in response to the applied disorders. The results also show that the ankle joint, as the closest joint in contact with the ground, helps to run faster and more efficiently by increasing changes in the angle and range of motion of the ankle joint during running, and by reducing the time of foot contact with the ground at each step. It can be concluded that this point is effective in increasing speed.

Propose:

The presence of lower limb abnormalities in cross-fit athletes may cause a great impact on possible injuries and the skill and performance of movements. The aim of the present study was to investigate the effect of using PU insole on static - dynamic balance and the plantar index of elite male and female cross-fit athletes.

Thirty-two professional male and female cross-fit athletes were divided into two groups of control and intervention groups.  Variables of plantar index, static balance and dynamic balance were then evaluated. The intervention group used the PU insole in their shoes for 10 weeks, but the control group did not receive any intervention during this period. Both groups were re-evaluated after ten weeks. Paired t-test was used to compare the differences between pre-test and post-test and independent t-test was used to compare the effect of insole on static balance, dynamic and foot index of elite cross-fit men and women athletes.

Dynamic balance variables were statistically significant between female in the control and intervention groups in the pre-test (p=0.000) and post-test stages (p=0.002), and in the intervention group only in the female post-test (p=0.003) and male.

Considering the positive effect of insoles on static balance of female athletes in cross-fit, it is expected that athletes enhance their static and dynamic balance by performing correct exercises and continuous use of insoles.

Attention can be paid to the biomechanical characteristics of running since the speed of running varies. The aim of the present study was to investigate the effects of increasing running speed on the three-dimensional kinematics of the lower limb joints in the stance phase.

The research was quasi-experimental. 27 volunteer subjects ran on a treadmill and the kinematic and kinetics data were collected through a three-dimensional system at three speed levels (2.5, 3.5, and 4.5) m/s. kinematics and kinetics data were recorded by 12 cameras (120 Hz) and force platform (150 Hz), respectively.   The stance phase was derived according to the ground reaction Force value of the force platform. Hip, knee and ankle kinematics including peak of the absolute angles in three dimensions and three speeds were calculated for further analysis. Repeated measurement with Bonferroni post Hoc tests were employed to investigate the differences between the variables in three dimensions using SPSS software (P <0.05).

The results showed that during increasing speed, significant differences were observed in frontal (2.5 & 3.5, 2.5 & 4.5 m/s) and sagittal (2.5 & 3.5. 2.5 & 4.5, 3.5 & 4.5 m/s) planes in hip as well as only in transverse (2.5 &4.5, 3.5 & 4.5 m/s) plane for knee. No significant differences were obvious in peak of ankle joints during increasing speed in all three planes.

The results of the present study showed that hip and knee joints are more susceptible to changes of kinematics behavior during running progressively. Ankle joint seems to be more stable during the progressive running situation. Coaches and athletes may also enhance their performance using the results of the present study.

The aim of this study was to investigate the effect of increasing running speed on motor ‎chain and kinetic ratio of lower limb joints‎.

The statistical population of this study consisted of healthy people and ordinary runners. A ‎group of 28 healthy male subjects, including runners who ran more than 20 km per week, ‎were selected via convenience sampling method as research sample. They were also fully ‎acquainted with running on a treadmill. Three-dimensional kinetics parameters of the lower ‎limb joints, hip, knee, and ankle, torque and the kinetic ratio of the minimum, maximum and mean values of these ‎joints at three different speeds 2/5,3/5 and 4/5 was measured by two important instruments, ‎the camera and the force plate. Shapiro-wilks test was used to check the normality of data ‎distribution and data analysis was performed using analysis of variance with repeated ‎measurements or repeated measure through SPSS software, version 22‎.

Based on the results obtained in this study, the torque ratio of hip to knee and thigh to ankle ‎joints was not significant in any of the anatomical plates and axes at three speeds (p≥0.05). ‎Also, the ratio of torque of knee joints to ankle in three speeds and three planes did not ‎show a significant difference ( p≥0.05)‎.

According to the results obtained in this study, it seems that with the knowledge of the ‎moment changes of the lower limb joints, practical solutions can be provided to reduce the ‎amount of damage when running, especially on a treadmill, to these 3 joints. ‎

The aim of this study was to investigate the effect of a combined and core stability training program with protective measures on selected variables of physical fitness of junior and young volleyball players during the coronavirus pandemic.

15 male volleyball players [18±1.06 yrs.] after the end of the first quarantine period and then after a 12 weeks period of combined and core stability training program emphasizing on physical fitness exercises in compliance with all health protocols, as pre-test and post-test of selected key factors, performed physical fitness including lower limb strength, upper limb and abdomen endurance, as well as flexibility tests. Descriptive statistics, Shapirovik test and paired t-test were used for statistical analysis (p≤ 0.05).

The results of the present study showed that there was a statistically significant difference in the variables of upper limb and trunk muscle endurance as well as muscle flexibility, but in the lower limb strength variable, this difference was not observed in both pre-test and post-test levels.

Volleyball coaches and players can benefit from combination and core stability training with health protocols to maintain and improve fitness during the coronavirus epidemic.

Investigating the relationship and correlation between kinetic parameters, especially between the maximum force and the flight time variable play an important role in increasing the jump height and preventing various injuries in volleyball players. Therefore, the aim of the present study was to investigate the relationship between maximum concentric and eccentric forces and flight time in block jump skill of young professional volleyball players.

21 young male volleyball players performed the block jump skill with the maximum jump height on the force plate system. The maximum of concentric and eccentric forces and flight time were investigated and extracted. Pearson correlation method was used to estimate the relationship between concentric, eccentric maximum force and flight time and linear regression method was employed to determine the load factor order of concentric and eccentric maximum forces.

The results showed that there is no significant correlation between any of the research variables (maximum eccentric force, concentric force and flight time). The factor load of the maximum concentric force is much higher than the maximum eccentric force in the flight time variable and the maximum eccentric force has a negative relationship, while the maximum concentric force shows a positive relationship with the flight time.

It is suggested that coaches, players and volleyball practitioners pay special attention to the different phases of jumping with the aim of optimizing performance and better designing training programs.

 Accurate velocity analysis is essential when performing the block jumping technique on the net by various spikers because it will improve this performance and prevent injury. This study aimed to compare the jump and landing velocity of the Iranian national team’s young elite spikers when performing block jump skills. 

 A total of 21 young elite male volleyball players of the Islamic Republic of Iran (11 wing spikers and 10 middle spikers) participated in the present study. Subjects performed block jumping skills. Force data in the X, Y, and Z directions were obtained directly from the force plate’s output. Then, the area under the force-time curve was calculated as an impulse. The rate of changes in mean, maximum, and minimum velocities and the resultant in each direction (X, Y, and Z) were obtained by dividing every subjects’ impulse data in each direction to his mass. Descriptive statistics, the Shapiro-Wilk test (checking the normality of data distribution), and independent t-test were used to analyze and compare the two groups’ variables (P≤0.05).

 The difference between the mean velocities on the X and Z planes and the mean rates between the two groups was significant. The other velocity variables in the two groups were not significant (P˂0.05).

 The results of the present study can help coaches, players, and volleyball professionals to pay more attention to the velocity of execution during block jump technique, especially between middle and wing spikers in different directions during the match and design of the training program.

Within the volleyball game skills, Block and Attack are presenting the highest correlation with success, independent of the game phase. Monitoring block jump actions in middle and wing attackers are crucial to improve performance and avoid injuries during this skill, therefore the aim of this study was to investigate the 3-Dimensional analysis of selected kinetics and impulse variables between middle and wing volleyball attackers during block jump based on integration method. 21 healthy junior volleyball players of the national team (11 wing attackers and 10 middle attackers) were selected to participate in this study. The athletic task was Block Jump, performed by middle and wing volleyball attackers. The 3-Dimentional average, maximum and minimum of GRF (Average Force (X, Y, Z), Maximum Force (X, Y, Z), and Minimum Force (X, Y, Z)) were obtained from Force plate system output directly and 3-Dimentional impulse (X, Y, Z) were calculated by integrating force with respect to time. Also, time between two minimum and maximum GRF’s peaks (Time between Two Peaks) were calculated for each jump. Average Mean and Standard Deviation were used for descriptive analysis. Shapiro-Wilk test was used for the normality of data. If so, an Independent t-test was performed to compare any differences of variables in three-dimension between two attackers’ groups during block jump. The results highlight that middle attackers have greater average force in Anteroposterior (X) and vertical (Z) directions during block jumps, but wing attackers show larger impulse in vertical (Z) direction as well as greater time duration between minimum and maximum force peaks (p < 0.05). These specific differences in variables of two groups may be useful for physical trainers coaches and specialists who will be able to manage task constrains to design proper training programs for optimal performance and minimizing related injuries.

Arm Swing during gait is proven as an interaction tool between arms, legs, and trunk, and has important implications for the normal gait pattern in the lower extremity. The aim of the present study was to investigate the effect of changes in upper limb movement pattern on gait biomechanical variables.

The scientific database, including Scopus, PubMed, Google Scholar, Ovid, Science Direct, ProQuest, Mesh, DOAJ, Medline, and Clinical Key, were searched for the studies with relevant keywords published from 1990 to 2019. The researches were selected based on the inclusion and exclusion criteria.

Findings of the present study indicated that changes in upper extremity patterns have different effects on kinematics, Spatio temporal, and kinetic variables of gait.

The variables related to velocity, frequency, and step length in relation to kinematic and Spatio temporal domains as well as torque variable in kinetic domain changed the most when these patterns changed.

Upper extremity movements and hands can alter or interfere with walking patterns, but they are usually ignored in gait analyses. The present study aimed to investigate the effect of upper extremity splinting on walking speed and cadence.

A total of 30 healthy individuals (Mean±SD: 29.56±5.34years, BMI: 24.06±3.25 kg/cm2) were asked to walk in front of the Vicon motion analysis system at their usual speed and then at the same speed with the dominant and then non-dominant hand position on the splint. Then, using MATLAB software, data were extracted and analyzed using descriptive statistics (Mean and SD), Shapirovik test (to check the normality of data distribution), and paired t-test to compare walking speed and cadence.

The results of the t-test showed a significant difference between the normal swing and dominant hand position in the splint as well as the natural swing and the non-dominant hand position in the splint in the moving average variable walking speed. However, in terms of cadence, despite the mean decrease, there was no significant difference between any of the conditions and patterns compared to the natural pattern. (p≤0.05).

According to the results of the study, it can be suggested that sling should not be used to maintain normal walking speed in unnecessary cases in different patients, because these individuals may experience changes in walking patterns, imbalances, and falls due to increased walking speed.

The aim of this study was to Analysis of Selected Kinetic-Temporal Variables of Lower Extremity of Elite junior volleyball players during Block Jump Skill. 30 junior volleyball players of National Team of the Islamic Republic of Iran stand on Force platform and performed block jump skill, peak vertical forces, Time of peaks, Time elapsed between peaks, time of contact, end of the landing, total landing time, Ratio between peaks and between the time of the peaks were calculated. There are significant positive correlations between Times of peaks, Time elapsed between peaks and peak vertical forces and negative correlations exist between other variables of the research. So in volleyball players great stress would be placed on lower extremity at the moment of landing. Because of increasing time of the second peak will decrease the impact force, although it is not appropriate for volleyball goals.

In the present era, prevalence of cancer is increasing all over the world. So far, a variety of methods have been used to cure and stop cancer, but this disease resistance to current anticancer drugs has created a new need to new pharmaceutical compounds and drug delivery system. Immune deficiency can lead to tumor growth and progression. Therefore, cancer immunotherapy is amongst methods that prevent tumor growth. Exosomes are normal nano- carriers which have been distributed widely in the body fluids and are involved in various diseases processes, including tumorigenic. Exosomes have various advantages. They are non-toxic and non- immunogenic, they are capable of being designed to determine specific target and deliver drug. Therefore, they are used as a strong nano-structure to present anti-cancer drugs with the aim to treat cancer. This method has advanced to ease its usage in medical programs and biotechnology techniques. In this review paper, we investigate the development of Exosomes-based drug delivery systems over time and its advantages and functions. Effectiveness studies on exosome nano-particles using cancer cells and biological models as well as clinical trial are also discussed.

Improving community health is the most important concerns of judicial authorities in every society. Previous research has yielded conflicting results in terms of changes in the rates of social harms in Ramadan (in comparison with the rest of the year). Therefore, the primary objective of this study was to investigate the relationship between Ramadan and the number of accidents or injuries reported by emergency wards of hospitals in Kermanshah, Iran, during a seven year period (2001 through 2008). The study also aimed at examining the possible differences between men and women in this regard.
The current study had a retrospective, quasi-experimental nature. All male and female patients (whose age ranged from 15 to 45 years) who were admitted to emergency departments of Taleghani and Imam Reza hospitals of Kermanshah due to car accident injuries and three other injuries caused by gunshot, fighting, and fall from height during Ramadan and non-Ramadan months of the years 2001 through 2008 were included in our study. Convenient sampling was used for data collection. Kolmogorov-Smirnov test, paired samples t-test and ANOVA were exploited for data analysis. In this study, The ethical issues were all considered and the authors declared no conflict of interest.
For both males and females, a large number of accidents were generally recorded in non-Ramadan months compared with Ramadan (0.001). Nonetheless, no statistically significant differences were found between mean scores obtained for Ramadan and non-Ramadan months in either group (0.743 and 0.773 for women and men, respectively). On the other hand, the mean values of men’s injuries were higher than those of women’s in all cases (0.05 α≤).
The results of this study showed that, on average, the number of accidents and other injuries in non-Ramadan months is greater than that of Ramadan (though the difference is not statistically considerable). Furthermore, the number of injuries in women during Ramadan and other months of the studied years were lower than that of men.

The present study was carried out to study the role of static balance and anthropometric indices in the shooting sports and its impact on the performance of the shooters with the aim of informing the shooting sports specialists and correcting weaknesses in male and female shooters. Anthropometric characteristics, weight, height (standing and sitting positions), two hands, arm length, leg length, the actual length of the foot, knee width, resting and contracting arm circumference, arm circumference, hip circumference, the mid-thigh, the knee, the leg, the ankle, BMI, percent body fat, WHR, and two tests for balance, i.e. Sharpened Romberg and stork, were evaluated for 32 shooters (16 women and 16 men from among the pool of 45 shooters of the National Shooting Team) and 32 controls (16 females and 16 males). The results showed that comparison of the stork balance with anthropometric indices revealed significant difference only in weight variable in female participants and the width of the knee in male participants. No sifnificant relationship was observed between Sharpened Romberg test indices and any of the anthropometric indices in females (except for weight) and males either. Shooters were observed to have better balance compared with that of the control group. Moreover, comparison of anthropometric indices of the adult male and female elite shooters showed that there is a significant difference among all the anthropometric indices. It can be concluded that the Iranian elite shooters have a significantly higher static balance in comparison with that of the control group.