نشریه مطالعات طب ورزشی
پیاپی 27 (بهار و تابستان 1399)

Fatigue impairs the neuromuscular control of gait. A flat foot can cause early muscle fatigue and impair the weight-bearing function of the foot. The purpose of this study was to investigate the effect of fatigue on spatial and temporal parameters of gait in people with normal and flexible flat-foot.

In this Quasi-experimental study. 10 people with flexible flat foot and 10 people with normal foot arch participated were selected among 15-18 years male students in Tehran. Gait analysis treadmill was used to measure gait parameters. A running protocol on a treadmill was used to induce fatigue based on the Borg's Perceived Exertion scale. The gait parameters were collected for one minute before and one minute immediately after fatigue induced. Repeated measures and paired t-tests were used to compare the within-group and between-group effects of fatigue on the spatial and temporal parameters of gait in people with normal foot and flat foot.

Based on the results there was a significant difference in post-test scores between groups in the single support variable. However, there were no significant differences in the variables of stride time, step time, double support, stride length, step length, and step width. However, the effect size obtained for most variables indicated a strong interactive effect of flat foot and fatigue on these parameters. Besides, fatigue had a significant effect on the variables by increasing the stride time, step time, double support, stride length, step length, and step width.

According to the results of this study, it seems that fatigue has a significant effect on some temporal and spatial parameters of gait in people with normal and flat-foot.

There are various methods for motion reconstruction using stereophotogrammetric cameras. The most common method is the use of predictive methods by attaching markers to anatomical landmarks. In contrast, functional methods are not depending on anatomical landmarks and use the relative motion of adjacent segments to identify the center of rotation and subsequently motion reconstruction. The goal of this study was to conduct a comparison between the predictive and functional methods to investigate the feasibility of using circle fitting algorithm in human body motion reconstruction. Six healthy subjects have been studied (three times each) using the three marker sets: plug-in-gait, cluster and circle-fitting method. However, some differences between methods were found in some signal characteristics, the results showed a high correlation Among three methods. By expanding functional methods such as circle-fitting, can be controlled many sources of errors in predictive methods and can be made a change in human movement reconstruction.

T Abstract To improve motor function, movement pattern and changes in joint kinematic parameters are investigated in different conditions. Using a treadmill in human gait analysis, makes it possible to record several steps of gait in a limited space and also controlled conditions. The purpose of this study was to investigate the consistency of the kinematic parameters of lower limb joints during walking on the ground and treadmill. Intraclass correlation coefficients (ICC) for kinematic parameters of lower limb joints of 15 healthy young male participants were calculated during walking on the ground and treadmill. The angles of pelvic, hip, and ankle were often in the range of excellent reliability (ICC>0.9) when walking on the ground, while the results were in the range of average reliability (ICC<0.7) when walking on a treadmill. Therefore, in treatment activities or research studies, considering the decrease in consistency of walking trials on the treadmill is important.

The aim of this study was the effect of release massage and stretching exercises on pain, ROM and functional disability of the Neck due to Myofascial Trigger Points of the Trapezius Muscle. 30 patients were divided into three groups including massage group, stretching group and control group. Patients in experimental groups received training for 8 weeks. Pain, ROM and functional disability were measured with a visual analog scale, goniometer and Neck Pain and Disability Scale, respectively. The results showed that stretching exercises and massage led to a significant increase in ROM and a significant decrease in pain and functional disability. Also, significant differences were observed between the two groups for all variables. Based on the results, massage can have more advantages than stretching exercises, but due to the benefits of stretching movements as an exercises approach, these exercises are recommended for trigger points.

The purpose of present study was to determine the effects of action observation and motor imagery on balance, gait length, speed and rhythm in elderly post stroke. Twenty- four elderly post stroke participated voluntarily in the study. Stork test, Timed Up and Go test (TUG) and KINOVEA software were used in pretest and post-test. Mixed ANOVA revealed that static balance, speed and length of step improved significantly compared to pretest. Motor imagery and action observation resulted in a significant improvement in dynamic balance compared to control group. Speed step of motor imagery group was more than action observation and control group significantly and action observation group experienced significantly improvement in step rhythm compared to pretest. Finding suggested that motor imagery and action observation improves balance and gait parameters in elderly post stroke.

Decreased muscle strength in the lower extremities is one of the disorders caused by type 2 diabetes. The purpose of this study was to investigate the effect of six weeks strengthening training on some biomechanical parameters of knee joint in type 2 diabetic patients. 24 patients with type 2 diabetes participated in the study and were divided in control group (N=12) and exercise group (N=12). Before and after six weeks of strengthening exercise program, research variables were measured by isokinetic dynamometer. The results showed that there were significant differences in concentric peak torque of knee flexion and extension and time to concentric peak torque of knee flexion and extension between two groups. It seems that strengthening exercise can improve the power generation capacity and neuromuscular function in patients with type 2 diabetes by increasing knee concentric peak torque and decreasing time to concentric peak torque.

The purpose of this study was to determine the effect of three different ankle braces using the Maximum Lyapunov exponent on local dynamical stability of individuals with chronic ankle instability during running. Twelve subjects with chronic ankle instability as injured group and 12 healthy individuals participated in this study. Injured group performed 70 strides of treadmill running in shoe and rigid, semi-rigid and soft braces as well as no-brace conditions. The healthy group performed the test only in no-brace condition. Kinematics data were used to calculate the short time (λ_S) and long time (λ_L) maximum Lyapunov exponent. The results showed that λ_S of running in semi-rigid brace is significantly different with running in other braces in chronic ankle instability group; but it was not different with the control group. It seems running in semi-rigid brace in chronic ankle instability group provides stability like healthy control group.

The present study aimed to investigate the effect of one global fatigue stage on coordination and variability between upper extremity joints in elite rowers. Fourteen male rowers of the national team participated in this quasi-experimental study. A rowing ergometer device was used to create general fatigue until exhaustion. An inertial measurement device of units was also used for measuring kinematic parameters in 15 consecutive rowing cycles at the beginning and end of the fatigue protocol. The results showed that a session of global fatigue changes the level of coordination between the shoulder-trunk joints on the horizontal plane and the elbow-shoulder joints on the sagittal plane, as well as the level of variability between shoulder-trunk joints in the horizontal plane, elbow-shoulder joints in the sagittal plane and elbow-trunk joints in the sagittal plate. It can have negative effects on the performance of professional rowers and increases the risk of injuries caused by overuse. Due to results, considering the effect of fatigue on the lower extremities of the elite national rower athletes during the designation of training programs is an important issue.

The present study aimed to investigate the effect of the shoe’s external insole with different inclination percentages on the knee’s external adduction torque and its impulse in individuals with genu varum. Kinetic and kinematic indices of the knee joint during running calculated by inverse dynamic method with barefoot, no insoles shoes, and shoes having 0, 5, and 10 degrees of external slopes insoles. The results showed a significant difference in the amount of torque peak and adduction torque impulse of the knee, between insoles; as the insoles of 5- and 10-degrees external slopes, caused a significant decrease of variables compared to bare foot, no insoles shoes, and zero-degree slope insoles shoes. Thus, external slope insoles are suggested as an effective and non-invasive approach for preventing musculoskeletal disorders such as osteoarthritis related to inconsistency of genu varum in affected people.

The aim of the present study was to investigate the effect of a combined training course on selected biomechanical variables of the elderly active male athlete. 40 active elderly men participated in this study voluntarily in two groups. The experimental group practiced in a combined training program and the control group continued to perform their daily activities during this period. To compare the results before and after exercise in each group, Parametric Paired t test and non-parametric Wilcoxon test were executed using SPSS ver. 21. The results show that a combined training session was not significant in posture control and gait function, but can be effective in improving motor control, balance in active older men and reducing the risk of falls.

The aim of the present study was to compare the kinematics of the foot-ankle complex and knee joints in women with flexible and rigid flatfeet during stance phase of walking. Twenty-nine young women (10 healthy, 10 with flexible flatfeet and 9 with rigid flatfeet) participated in this study. Motion analysis system and a force plate were used to collect research data. The results showed that ankle dorsiflexion was significantly lower in subjects with rigid flatfeet than the other groups. The amount of ankle eversion was significantly higher in subjects with rigid flatfeet than healthy group. Subjects with flexible flatfeet had significantly more knee valgus than other groups. According to the findings, it can be said that subjects with flexible flatfeet were exposed knee injuries as subjects with rigid flatfeet, so it seems necessary to perform treatment in subjects with flexible flatfeet.

The aim of the present study was to investigate the effect of sport metrics training on the performance of young soccer players. 29 soccer players participated as subjects in the present study and divided into experimental and control groups randomly. Subjects' performance was assessed using 50 yards sprint, Illinois and sergeant tests. The experimental group performed soccer-specific SportsMetrics training for six weeks (18 sessions) and the control group continued normal exercises. Data were analyzed by ANCOVA test. The results of ANCOVA showed there are significant differences between the record of speed, agility and power tests in the experimental and control groups after six weeks training (P <0.05). According to the results of the present study, football coaches are suggested to use soccer specific SportsMetrics training to improve the motor performance of players.