جستجوی مقالات مرتبط با کلیدواژه « symmetry index » در نشریات گروه « پزشکی »

The impact of the weight of backpacks with different weights on the foot, which is the link between the human body and the ground, has received less attention from researchers. Therefore, the aim of this study was to compare ground reaction force distribution between dominant and non-dominant legs among female students while carrying different loads.

The present study was semi-experimental and laboratory. Twenty female students at age of 14-17 participated as subject in this semi-experimental study. Participants carried backpacks with 10%, 15%, and 20% of body weight during walking. Ground reaction force data of subjects in both dominant and non-dominant legs was collected by a foot pressure system. Repeated measure ANOVA was run to analyze the obtained data. All the analyzes were performed at a significance level of 0.05 using SPSS 22 software.

The results showed that the symmetry index between dominant and non-dominant legs in lateral heel (P=0.045), second and fifth metatarsals (P=0.023), toes 2-5 (P=0.000) were significantly greater in carrying backpack 20% of body weight as compared to 10% of body weight.

According to the results, it seems that increasing weight of backpack can rise the symmetry index between dominant and non-dominant legs that indicate difference and dissimilarity in performance of dominant and non-dominant legs in students.

The purpose of the present study was to examine the effect of unilateral and bilateral backpack carrying with different weights on the spatio-temporal gait symmetry in healthy adults.

Totally, 17 healthy females with the mean age of 21.73 years volunteered to participate in the study. Participants completed carrying unilateral and bilateral backpack with loads of 0, 5, 10, and 15% of their body weight. Then, their gaits were assessed using a 3D motion analysis system with six cameras. Also, the spatio-temporal parameters of the gait and step time and step length symmetry indices were calculated using Velocity-Based Treadmill (VBT) algorithm and coding in MATLAB. Data were analyzed using paired sample t-test and repeated measures ANOVA (p<0.05).

The results of the present study showed that with increasing backpack weight, stance, swing and double support duration increased and the step length and cadence decreased. Evaluation of the symmetry index showed that the symmetry decreases with increasing load exerted to the body and leads to asymmetry of lower extremity. It was also found that unilateral backpack carrying affects the symmetry index more than bilateral backpack carrying; the difference when carrying backpack with 15% of the body weight was found to be significant.

According to the results obtained in the present study, it is recommended that to improve symmetry, the backpack weight should not exceed 10% of their body weight and backpack should be carried bilaterally.

Due to the fact that walking is the main activity of humans to relocate, understanding its complexity and its different angles has long been the focus of various studies. One of the main issues in this regard is gait symmetry. Accordingly, the aim of the present study was investigating the concept of gait symmetry and the methods for evaluating it.
A search among the related articles published from 2000 to 2015 in valid scientific databases, according to the research criteria, resulted in 71 scientific articles selected for the present review study.
Review of the previous studies showed that generally, from kinematical and kinetical point of view, walking in participants with and without abnormalities was asymmetrical and this condition is represented in all measured kinematic and kinetic parameters except in a few studies. Also, the methods of evaluating gait symmetry could generally be categorized into symmetry indices and statistical methods. In this situation, symmetry indices, despite their ease of application, could not represent the spatial-time complexity of walking cycle because of single-variable evaluations. In addition, the main limitation of statistical methods is that they do not present a qualitative value. Thus, for neither of these two methods is normal data available.
With respect to the fact that during walking lower limbs have an asymmetrical behavior in normal/healthy individuals, which is due to their different functional tasks in control and propulsion, the assumption of gaining perfect symmetry after rehabilitation and intervention does not seems to be true. However, it is crucial to carry out further investigations in order to obtain the normal range of gait asymmetry in different participants and to understand fundamental factors affecting gait asymmetry.

Weight bearing asymmetry is one of the basic causes of disturbance in maintaining balance of hemiparesis patients that could complicate standing and participation in activities of daily living in these patients. The purpose of this study was to investigate the immediate effects of constraint induced movement therapy technique using wedge on symmetry index as well as the short-term effects of this technique on functional balance of chronic hemiparesis patients.

In this quasi-experimental study, twenty-one hemiparesis patients by mean age of 54.28 (±10.06) and the mean passed duration of injury 50.14 (±36.48) months were selected by simple non-probability method. The symmetry index was measured in three conditions: non-wedge, wedge 5ºand wedge 7.5º. Also, functional balance of patients was measured with Functional Reach (FR) and Timed Up and Go (TUG) tests before and after using of short-term constraint induced movement therapy technique.

According to the results of this study, symmetry index difference was significant in both wedge 5º and wedge 7.5º conditions compared with no-wedge condition (p<0.001), while it was not significant between wedge 5º and wedge 7.5º conditions. The mean scores of FR (P=0.012) and TUG (P=0.006) showed significant changes after using the constraint induced movement therapy technique

Constraint induced movement therapy technique caused immediate improvement of weight bearing symmetry and improvement of functional balance in short-term interval.

Muscle fatigue is a factor that caused muscle injuries. Ability to perform movement without error and controllability has important role in reduction of injuries. Reproduce ability of motion is reduced after muscle fatigue. Evaluation of motor control can produce suitable conditions for assessment of these changes and help us treatment guide lines for prevention of injuries. The aim of this study was to evaluate motor control changes following onset of fatigue in patients with anterior knee pain as a physiological aspect. Fifteen voluntary female (10 healthy, 5 patients with bilateral syndromes) participated in this study. During dynamic fatigue test (open and closed chain movements), muscle activities were recorded from bilateral vastus medialis, vastus lateralis and rectus femoris (20 healthy and 10 patients quadriceps muscles) by surface electromyography (sEMG). Five dynamic cycles of motions were selected before and immediately after fatigue and then average of three middle cycles were compared for Symmetry Index (SI) as motor control assessment. Also Median Frequency (MDF) were computed as an indicator for onset of fatigue. MDF reduced significantly in both groups. This reduction was markedly showed in patients group. Reduction of SI was significant after fatigue test. Comparison of SI between groups indicated that before fatigue there was significant difference but after fatigue test was not significant. Dynamic motions can produce muscle fatigue and reduction of MDF. High central control system used different synergies following pain and functional impairment. Synergy patterns change after dynamic motions fatigue and cause reduction of SI. This change is dependent to pain and functional impairment and has not a stable pattern.