mahdi majlesi

This study examines the impact of fatigue on kinetic variables during landing after performing a spike in professional volleyball players. Fatigue can significantly affect athletic performance and increase the risk of lower limb injuries, particularly in movements that require precise landings.

In this study, 28 professional volleyball players performed a spike over the net and landed on a force plate before and after inducing fatigue. Kinetic variables, including ground reaction forces and loading rates, were evaluated at both stages. A paired t-test was used to examine the effect of fatigue on these variables during the landing task after the spike. All statistical analyses were conducted using SPSS software with a significance level set at P<0.05.

The results showed that fatigue caused a significant reduction in the vertical ground reaction force at initial contact, the maximum posterior force, and the medio-lateral force at initial contact in the dominant leg. Fatigue did not have a significant effect on the other variables.

The results indicated that the ground reaction force in the dominant leg after inducing fatigue was significantly different from before. Given the asymmetry in ground reaction forces between the dominant and non-dominant legs, it is crucial to address this in training programs.

Disruptions in the gait patterns of individuals with Parkinson's disease lead to an increased risk of falls in  these patients. The aim of the present study is to investigate spatiotemporal gait variables during obstacle crossing in both real and virtual reality environments in individuals with Parkinson's disease and compare them with healthy counterparts.

In this study, 15 Parkinson's disease and 17 healthy individuals with similar heights, weights, and ages participated through convenience sampling. In this study, four walking tasks were evaluated: normal walking, obstacle crossing, walking in a virtual reality environment, and obstacle crossing in a virtual reality environment. The spatiotemporal gait variables were recorded in terms of both invariant parameters and relative timing using the Vicon motion analysis system. The data were analyzed using independent t-tests, and repeated measures ANOVA, in the SPSS-25 software (p < 0.05).

The results showed that variables such as step and stride time, single support time, stance and sway time were significantly higher in the Parkinson's group compared to the control group, while cadence and gait speed were lower in the Parkinson's group (p < 0.05). Walking in the virtual reality environment, with or without obstacles, led to decreased speed and increased step and stride time, single support time, and sway. However, relative timing in gait parameters did not change significantly (p < 0.05).

  According to the results, the virtual reality environment did not have a significant impact on the relative timing of gait parameters. However, when it came to obstacle crossing, there was a noticeable reduction in relative timing variables. These findings suggest that there are distinct movement patterns involved in obstacle crossing, while the gait patterns in the virtual reality environment closely resemble those of normal walking. To validate these results, further studies are required.

IObstacle crossing and navigating through complex environments is a challenging task in daily life and has been identified as a major cause of falls in individuals with Parkinson's disease (PD). The aim of this study is to assess the variability in spatio-temporal variables of gait in patients with Parkinson's disease when crossing obstacles.

This descriptive study included 15 men with Parkinson's disease and 17 age-matched healthy men who participated in this study through convenience sampling. Spatio-temporal parameters of gait during normal walking and obstacle crossing were evaluated using a motion analysis system with four cameras (Vicon, Oxford Metrics, Oxford, UK). The results were analyzed using three-way analysis of variance (ANOVA) and SPSS software with a significance level of p < 0.05.

The results showed that cadence and walking speed were lower and swing time, stance time, stride time, step time, single support time, and double support time were higher in the PD group compared to the control group (p < 0.05). The difference between the two groups was significant in the variability coefficient of variables such as double support time, single support time, stride time, step length, and percentage of opposite foot contact with the ground. Crossing obstacles also resulted in increased stride time, stance time, step length, and stride length compared to normal walking, and increased variability in swing time, single support time, stride time, and step time.

Crossing obstacles in individuals with PD resulted in reduced walking speed and increased double support time, which are among the most important risk factors for falls. Additionally, greater variability during normal walking or obstacle crossing, accompanied by decreased cognitive functions in the PD group, indicates an increased risk of falls during challenging activities.

Studying the developmental process, it may be possible to examine the role of sensory and cognitive systems involved in postural control. The aim of this study was to evaluate static postural control in both linear and nonlinear methods in children aged 7 to 12 years and compare them with young-adult.

The center of pressure (COP) in eight postural task was assessed in 420 girls and boys 7 to 12 years old and 20 young adults. The linear method included sway, deviation, the amplitude of CoP and velocity. To characterize the nonlinear evaluation, sample entropy (SampEn) was measured.

The results showed that 7 and 8-year-old have the most sway, amplitude, speed of CoP and deviations than others (p< 0.05) and adults had the lowest amount. But the SampEn, decreases significantly with age (p< 0.01). The base of support was greater effect on linear and nonlinear than that other conditions, especially in children (p< 0.001). The closed-eyes condition, were not aligned in linear and non-linear evaluation (p< 0.001).

The differences between age groups were significant in the challenging situation than that stable condition, due to changes in postural control strategies. Task demands did not have a significant effect on balance variability in adults, but it did affect children and linear variables.

The study focuses on the design and manufacture of an Eccentric Smith Machine, incorporating specialized mechanical components for enhanced athletic benefits, minimizing injuries, and promoting hypertrophy. The Eccentric Smith Machine comprises three main parts: A stable Smith machine adapted for electrical motor shocks, an electrical component with a panel and motor, and a transmission system using four pulleys and two cables. The mechanical design facilitates acute and smooth bar movement, ensuring safety and ease of use for athletes of varying heights and strengths. The Eccentric Smith Machine demonstrates resilience to electrical motor power, simplicity in usage, and safety advantages. Its adaptability makes it accessible to athletes with diverse physical characteristics, providing a tool for effective and safe resistance training. The designed device has the potential to enhance physical fitness, particularly muscle hypertrophy. It stands as a viable option for athletes, offering a reduced risk of injuries during workouts. The Eccentric Smith Machine presents itself as an alternative for those recovering from minor injuries, contributing to overall workout safety.

The aim of this research was to investigate the effect of acute fatigue on the plantar pressure distribution in professional young male volleyball players. A total of 38 young male volleyball players (aged 16-20 years) volunteered for this study and were randomly divided into two groups: the experimental group (n=20) who performed the functional fatigue protocol, and the control group (n=18) who did not perform the fatigue protocol. The fatigue protocol in this study was of a functional and volleyball-specific nature, consisting of six repetitive cycles of movements until fatigue was reached. Plantar pressure distribution was measured using a foot scanner before and after the application of functional fatigue during walking task. One-way ANOVA was used to investigate between-group differences, and repeated measures ANOVA was used to examine the fatigue effect within each group. The data were analyzed using SPSS software (version 21) at a significance level of p ≤ 0.05. The results showed that after fatigue, between-group differences of plantar pressure distribution increased in both feet. Significant differences between the two groups were observed in the force values of the left small toe, first, second, and third metatarsals, midfoot, and heel medial of the right foot (p < 0.05). The results indicated that fatigue leads to an increase in maximum distributed force. These factors can potentially increase the risk of injury in individuals.

Balance weakness and changes in the walking pattern of deaf children due to vestibular disorders have been clarified by past studies. This study aimed to investigate static balance and walking in sensorineural deaf children with two methods of linear and non-linear assessment of posture control.

This descriptive study was conducted on 20 hearing and healthy boys (10.80±1.46 years old) and 20 boys with deafness greater than 75 dB (11.30±1.89 years old). Static balance was evaluated during tandem stance and with feet together on an unstable surface using a force plate. Kinetic and kinematic variables of gait were also investigated. The independent and dependent t-tests were used to assess the inter-group and between-group differences in SPSS21 software with p < 0.05.

The results of static balance showed a significant difference between groups in linear variables. The amount of sway, path, area, and speed of the center of pressure movement in the deaf was significantly higher than that in the control group (P<0.05). However, entropy (non-linear evaluation) was only significant in the medial-lateral direction of tandem test (P<0.05). Lower gait speed and an increase in the medial-lateral component of the ground reaction force were observed in the deaf (P<0.05).

According to the results, the evaluated linear variables were more sensitive to deafness and vestibular system disorder than the nonlinear variable. Entropy is a sign of variability and irregularity in a person's performance; therefore, deaf people may be more likely to be vulnerable in the medial-lateral direction due to more irregularity in this direction.

Abnormal pressure during daily activities, including walking, is known as a risk factor in knee joint degeneration in knee amputees. The aim of this research was to analyze ground reaction force (GRF) and sample entropy in below-the-knee amputees.

This study was a descriptive-cross-sectional type, and 20 people with below-knee amputations of the right leg (TT group) and 20 people without amputations (control group) participated. VICON motion analysis system was used to evaluate the ground reaction force during walking. Two linear and non-linear methods were used to analyze GRF data. Sample entropy was chosen as a nonlinear analysis method. ANOVA statistical test was used for inter-group comparison of GFR components and dependent t-test was used to check the difference between legs in TT group. All statistical steps were performed by SPSS software with p<0.05.

The amount of GRF force in the control group was significantly higher in the vertical (first and third peak) and anterior-posterior components and lower in the second peak of the vertical component than in the TT group (p<0.05). Also, the entropy value in all GRF components and in both legs of the TT group was significantly lower than the control group (p<0.05).

According to the results, the amount of force exerted on the joints of the TT group is not symmetrically distributed between the two legs, so the probability of developing osteoarthritis in the healthy leg joint will be higher. The reduction of the entropy value is a sign of the absence of natural fluctuations in the GRF, which indicates less adaptation and coordination of the lower body joints during walking.

This study aimed to investigate the effect of acute functional fatigue on plantar pressure distribution and center of pressure (CoP)  in young professional male volleyball players. 38 young volleyball players voluntarily participated in this study and were randomly divided into two experimental and control groups. A plantar pressure scanner measured plantar pressure distribution and CoP during standing and walking. The dependent samples t-test was used to investigate inter-group differences, and the covariance test was used to compare between groups. The data were analyzed by SPSS software (version 21) at a significance level of p≥0.05. The results showed that fatigue had a significant effect on the percentage of plantar pressure distribution in the fore-foot of both feet and the left rear-foot in both control and training groups (p<0.05). Also, the CoP path length and the ellipse area of the CoP after fatigue showed a significant change in the experimental group (p<0.05). The results showed that fatigue increases the contact surface and impulse of the forefoot and the CoP movements. These factors can increase the probability of injury in participants.

In recent years, the effect of cognitive exercises on improving gait parameters has been studied, but the effects of these exercises on coordination inter-joint of the lower limbs have received less attention. Therefore, the aim of this study was to investigate the effect of dual task motor-cognitive training on inter-join coordination during walking in elderly with balance impairment.

30 elderlies with the mean age of 73.8 participated in this study. The elderly's functional balance score (Berg) was lower than 52, and the Mini Mental Status Exam (MMSE) was higher than 23. These individuals were purposefully divided into two groups, the experimental group participated in 24 training sessions after the pre-test and the control group engaged in normal daily activities. To assess the inter-join coordination, the participants had to walk a 12-meter path and the coordination was recorded at the sagittal level in four gait cycle by vector coding. The data were analyzed by repeated measures and one-way ANOVA at the significance level of p < 0.05.

The findings of this study showed that after training, the amount of coupling angle has decreased in most gait cycles. The greatest effect of dual training in the experimental group is in the loading response and push off (p <0.05). Some temporal characteristics of gait, such as walking speed, were also significantly improved by dual task training (p <0.05).

According to the results, it can be concluded that the dual task training had improved the coordination characteristics between the lower limbs joints. This change in coordination with the improvement of some temporal parameters was a sign of increased balance and better posture control in the elderly with balance impairment.

The evaluation of cognitive and motor performance can lead to a recognition of the risk factors associated with falling. The aim of this study was to compare cognitive and motor functions in elderly with and without experience of falling. In so doing, 60 elderly with and without falling experience voluntarily participated in this study. Mini Mental examination Test, working memory capacity test, reaction time, inhibition test, Berg balance test, tandem balance test, 6-minute walking test and balance confidence test were all administered to the groups. To analyze the data thus obtained, and to examine the relationship between the variables for estimated fall, independent samples t-test and regression analysis were run. The significance level was considered as p<0.05. The results showed that elderly people with fall experience had a weaker cognitive and balance-maintenance performance than those without such experience (p<0.05). The results of correlation and regression analyses indicated that Berg balance test, tandem, inhibition and MMSE had the strongest relationship with falling. Based on these results, it can be claimed that fall in elderly is associated with poor balance as well as cognitive decline. Age is one of the predictors of falling, and about 25% of motor activities are related to cognitive capacities.

In previous studies, the effect of lateral wedge insole on gait variables in people with medial knee osteoarthritis has been studied. However, No study was found to examine the effect of insole slope. This study was sought to assess the effect of increasing the angle of lateral wedge insole on spatiotemporal gait parameters in patients with medial knee osteoarthritis.Ten individuals with medial knee osteoarthritis and 10 healthy subjects with similar age, height and mass were selected. The spatiotemporal gait parameters of subjects were calculated in four walking conditions (walking barefoot, walking while wearing shoes with 0°, 5°, 11° insoles). Repeated measures and t-test was used in case of intragroup comparison and MANOVA in case of intergroup comparison. The main effect of insole had a significant effect on walking speed (p = 0.000). Walking speed in wearing shoes with 0° and 5° insoles were significantly higher than other condition. The intragroup analysis showed that walking speed, Double Support time, percent of foot off, and stride and step length in walking barefoot were significantly less than walking while using insoles in both groups. The speed of walking, stride and step length in barefoot conditions showed a significant difference between the two groups (p < 0.05). These findings imply that the use of insole was a similar effect in affected and non- affected limb. To increase the efficiency of gait, according to the results, recommended using laterally wedged insoles in people with medial knee OA.

 Stair ascent and descent is an essential movement task in daily life in which individuals are subjected to repetitive impact forces. The purpose of this study was to evaluate the intensity of Electromyographic (EMG) activity in lower extremity muscles of healthy young men during stair ascent and descent task wearing different type of shoes and carrying loads.

 Nine men with a mean age of 25.94±3.26 years, mean height of 174±7.4 cm, and mean weight of 70.95±8.25 kg were selected. Four stairs were fabricated and the electromyographic activity of their lower extremity muscles (two muscles in the posterior leg and three quadriceps muscles) in the right side of the body was measured using the 16-channel EMG system MA300 during the task. These tests were conducted in two conditions of with and without load carrying. The load was a cube-shaped box weighing 15% of the body weight. Three cases of footwear were set: barefoot, athletic shoes, and formal shoes. Repeated measure ANOVA was used for data analysis at the significant level of P<0.05.

The load factor had a significant effect on the intensity of muscle activity. The intensity of muscle activity during ascending stairs was higher than that during descending. In stair descent task, the EMG activity of the vastus medialis muscle was greater than that of the vastus lateralis and rectus femoris muscles, which causes the patella to be pulled inward more leading to patellofemoral articular cartilage wear in the long term.

 Stair ascent puts more pressure on the ankle and knee joints. When carrying the load up stairs, the use of proper shoes can greatly reduce the intensity of muscle activity and delay fatigue. It is, therefore, recommended that people with patellofemoral articular cartilage wear should not use the stairs, if possible.

Stair ascent and descent is a challenging task for people with sight loss. Identifying the effects of lack of visual input in people with sight loss while stair ascent and descent can be effective in planning rehabilitation program and improving locomotion pattern. The purpose of the present study is to evaluate the spatiotemporal variables in stair ascent and descent in people with sight loss and comparing them with people with full-sight. In this study, the spatiotemporal variables of stair ascent and descent in people with sight loss were measured using 3D motion analysis device Vicon with frequency of 100HZ. For within group analysis, repeated measure test and for that of between groups, independent sample t-test were used with level of significance of p<0.05. The spatial‐temporal gait parameters during stair ascent and descent were collected. The results showed that the people with sight loss had less speed, cadence and stride length comparing with people with full-sight (p<0.05). Moreover, stride and step time, single and double support time and stance time were significantly more in people with sight loss comparing with the people with full-sight (p<0.05). There was a significant difference in variables such as cadence and stance time between stair ascent and descent (p<0.05) and in both groups the mentioned difference was the same (p>0.05). Decreased speed and cadence and increased stance time represent motion deficiency in people with sight loss. Regarding the mentioned results, people with sight loss have cautious stair locomotion pattern and spatiotemporal variables in closed eye state in people with full-sight had weaker patterns comparing with people with loss sight.

There are three types of footstrike patterns that runners use including rearfoot strike, mid- or forefoot strike. The aim of the present study was to investigate the effects of running with different patterns on loading rate, impulse, and free moment values in three dimensions during stance phase.

A total of 13 healthy men (age: 26.6±2.8 years; weight: 78.4±7.2 kg) were included in the present trial and semi-experimental study. Ground reaction force data was recorded using a Kistler force platform (sampling rate: 1000 Hz). Two-way ANOVA with a significance level of ɑ=0.05 was used for statistical analysis.

The results of the current study showed that the vertical ground reaction force during the mid-stance phase of the rearfoot strike without shoe was more than that of the rearfoot strike with shoe. External force in the heel contact phase showed a significant decrease while running forefoot strike versus running with a rearfoot strike pattern. The vertical loading rate was higher when running with shoes compared to without shoe in the rearfoot strike pattern.

According to the results, it can be concluded that the rearfoot strike pattern has reduced the amount of external component and thus the amount of foot pronation relative to the forefoot strike pattern, which can reduce the risk of injury.

The visual system collects the information of the surroundings of the individual and plays a significant role in taking and maintaining balance and stability and planning the course of the movement. This study aimed to compare muscle activity of gait among blind and persons with full-sight and investigate the effects of closing the eyes on muscle activity of gait in persons with full-sight. In the present study 20 male (blind and persons with full-sight) were participated. Muscle activity of gait was measured in blind subjects without a cane and in normal subjects with and without vision. The differences between the two groups and the two walking conditions were determined through repeated measure ANOVA at a significance level of 0.05.

Excessive foot pronation is one of the major risk factors for anterior cruciate ligament's injuries.The purpose of the present study was to investigate the immediate effects of anti-pronation foot orthoses with various angles on ground reaction force components during walking.
A total of 15 healthy volunteers (age: 28.2±8.8 years; height: 179.5±8.4 cm; weight: 76.3±13.5 kg; BMI: 23.7±9.1 kg/m2) participated in the study. A Vicon motion analysis system, including four cameras, and two Kistler force plates were used to measure the ground reaction force components in walking with shoes without foot orthoses as well as walking with shoes and three different foot orthoses (10º, 15º, and 20º of lateral inclinations).
In foot orthoses with 20º inclination, the ground reaction force in vertical and medial-lateral directions at initial heel contact was greater than those without foot orthoses by 5% (p=0.02) and 110% (p=0.02), respectively. Impulse, loading rate, and free moment were not different between walking with different foot orthoses compared with those of walking without foot orthoses (p>0.05).
The application of anti-pronation foot orthoses (20º inclination) can reduce the loading rate at propulsion; however, it may impose loads to the knee which consequently place the knee on genu varum position, facilitating medial knee osteoarthritis.

Foot orthoses are often used to correct altered gait patterns. However, effect of long term use of arch support foot orthoses on walking mechanics is not well understood. The aim of this study was to evaluate the effects of long term use of arch support foot orthoses on the asymmetry indices of ground reaction forces during stance phase of walking in male children with flexible flat feet.

Fifteen male volunteered children (with their parents’ permission) with flexible flat feet were evaluated. Walking ground reaction forces and kinematic data before and after four months use of foot orthoses were recorded by force plate and Vicon motion system, respectively. Then, the asymmetry indices of ground reaction force components were calculated.

The results show that asymmetry index of the medio-lateral component of ground reaction force in loading response and push off phases during pre-test were higher than 4% (normal value). Also asymmetry index of its time to peak during the mid-stance phase in the pre-test were higher than normal value. Moreover, findings did not show any significant differences in asymmetry indices of other ground reaction force components and their time to peak, impulses and vertical loading rate between pre-test and post-test conditions.

Despite the high asymmetry values of the peak medio-lateral component and it’s time to peak in children with flexible flat feet during pre-test; long-term use of the foot orthoses did not show any significant effect on the improvement of the asymmetry index of these components. However, long-term wearing of the foot orthoses reduced asymmetry index of the peak positive free moment amplitude.

The asymmetry index during walking can be used for clinical treatment. This study was done to determine the immediate and long-term effects of foot orthoses on asymmetry of ground reaction forces frequency spectrum in male children with flat foot during walking. This clinical trial study was done on fifteen children with flat foot. Subjects were randomly divided into without foot orthoses, immediate and long term usage of foot orthoses groups. The kinematic and kinetic data during three without foot orthoses, immediate and long term use of foot orthoses conditions were recorded by the motion analysis and force platform systems, respectively. Asymmetry index of medio-lateral frequency spectrum component during walking without foot orthoses, immediate and long term use of orthoses in median frequency and band width were greater than 4 percent. There were not any significant differences in asymmetry index of ground reaction force frequency spectrum components, asymmetry index of essential harmony numbers, asymmetry index of essential harmony total powers, and asymmetry index of fundamental harmony number in vertical, anterior-posterior,  and medio-lateral axes between without foot orthoses, immediate and long term use of foot orthoses conditions. However, asymmetry index of essential harmony total power in medio-lateral axis during immediate use of foot orthoses tend to be reduced than that walking without foot orthoses. However, this difference was not significant. Despite the high asymmetry index of the ground reaction force frequency spectrum in the medio-lateral component during walking without foot orthoses, immediate and long-term effects of foot orthoses in the median and bandwidth frequency variables, the acute or long term use of foot orthoses did not show any significant effect on improvement of asymmetry index of ground reaction force frequency spectrum components.

Foot orthoses are often used to correct altered gait patterns. The purpose of this study was to investigate how foot orthoses can modify the magnitude of three dimensional ankle, knee, and hip joints kinematics during stance phase of walking in children with flexible flat feet. Three dimensional kinematic data were collected from 15 male children (age: 10.3 ± 1.5 years) suffering from flexible flat feet. In order to obtain the kinematics data, a Vicon motion capture system was used. Arch support foot orthoses were used as an intervention. ANOVA repeated measure test was used for statistical analysis (α =0.05). The results of data analysis showed that shoe insole can decrease the peak knee (P0.05). The foot orthoses used in this study were observed to have positive systematic effects on kinematic data during stance phase of walking. Therefore, using of this orthoses was recommended for male children with flexible flat feet. Moreover, the findings of this study may be used as a guidance for future researches in this field

The link between gait kinematics and hearing loss is not well understood. The aim of this study was to compare lower limb kinematics during walking in children with hearing loss compared with healthy control ones. Fifteen deaf children with bilateral hearing impairment and fifteen matched healthy control children, were purposefully selected. A four camera Vicon system (Oxford Metrics,UK) was used to record lower-body kinematic data. In this study, the asymmetric index of lower limb kinematics was calculated during the stance and swing phases of walking. In this study, independent t-test was used for statistical analysis. The significance level was set at P The results showed that the values of the right ankle plantar flexion angle in the stance and swing phases of walking in the deaf group were higher than that the healthy group by 37% (P=0.002) and 93%, respectively. Also, the initial peak of the left knee flexion angle during stance phase of walking in the deaf group was lower than that in the healthy group. The values of the ankle dorsiflexion asymmetric index in the deaf group were greater than that in the healthy group during both stance (P=0.11) and swing (P=0.015) phases of the walking. Lower initial peak knee flexion and higher asymmetry index during walking in children with hearing loss could be associated with increased the rate of injuries in these individuals. These results could be used in the rehabilitation protocol of children with hearing loss.

Higher excessive hip adduction and internal rotation is one of the risk factors for lower limb injuries. The aim of the present study was to evaluate the immediate effects of hip external rotator and hip abductor muscular taping on three-dimensional lower limb joint kinematics during stance phase of running. A total of 24 healthy male participants (age: 24.6±2.5 year; Weight: 74.8±6.2; and Height: 177.1±7.9 cm) were volunteered to participate in the study. Three-dimensional lower limb kinematics were measured using a motion analysis system during running with and without femoral rotational and abductoral taping. Paired sample t-test was used for statistical analysis. Significant level was set at 0.05. Application of femoral tapes increased and decreased peak eversion angle during loading response (P=0.001) and mid-stance (P=0.001) phases, respectively. Compared with no tape, femoral tape significantly reduced peak knee adduction angle during the entire stance phase (P<0.05). Moreover, both peak hip adduction and internal rotation during taping condition were about 1° and statistically lower than that of no tape condition (P<0.05). Femoral rotational and abductoral taping could alter lower limb joint kinematics (reduction of ankle eversion during mid-stance, reduce peak knee adduction and peak hip adduction, and internal rotation during stance phase of running. However, effect size values in all cases were low. Therefore, further study is warranted in this field and on different patients.

Gait asymmetry is a useful index that can provide an important role in clinical treatment. Since the link between asymmetry index of gait ground reaction force frequency content and hearing loss is not well evaluated, the aim of this study was to compare the asymmetry index of gait ground reaction force frequency spectrum in deaf and hearing male children of Hamedan city.
Material and In this descriptive study, 30 male children from Hamedan city in 2017 were selected and equally divided into a healthy group and a group with hearing loss problems (deaf group). Frequency content of ground reaction forces were analyzed during barefoot walking. Then, asymmetry indices were computed for essential number of harmonics, band width, median frequency, frequency with a power of 99.5%, and amplitudes of harmonics for three-dimensional groud reaction forces. Independent t-test was used for data analysis. Hearing loss was associated with increased asymmetry index of anterior-posterior median frequency (by 10%; p=0.011) and anterior-posterior frequency band width (by 6%; p=0.022). Similar asymmetry index of vertical and medio-lateral frequency content were found in both groups (p>0.05). The greatest asymmetry index value of ground reaction force frequency content in deaf children was in anterior-posterior direction. Also, the highest differences in asymmetry indices were in median frequemcy, band width, and harmonic amplitude during walking. In order to improve above mentioned asymmetry indices, using treatment interventions in deaf children are suggested

The link between frequency content of gait ground reaction forces and hearing loss is not well understood. The objective of this study was to investigate the effects of hearing loss on gait ground reaction force frequency content. Thirty male children were equally divided into a healthy group and a group with hearing loss problems (Deaf group). Frequency content of ground reaction forces were analyzed during barefoot walking. Independent samples t-test was used for between group comparisons. The significance level was set at p<0.05 for all analyses. The results indicated that hearing loss was associated with increased anterior-posterior frequency band amplitude in right limb (by 53%; p=0.020) and number of anterior-posterior essential harmonics in left limb (by 37%; p=0.000). Similar vertical and medio-lateral frequency content were observed in both groups (p>0.05). The results reveal that gait ground reaction force frequency content in deaf children may have clinical values for rehabilitation of these subjects.

Individuals with flat foot may have sensorimotor impairments that affect coordination at the lower limb joints. The purpose of the present study was to compare joint coupling angles of the lower limbs during walking with and without arch support foot orthoses in children with flexible flat foot.
A total of 15 male teenagers (age: 10.3±1.5 year) with flexible flat foot, after obtaining their parents’ permission, volunteered to participate in the study. Three-dimensional kinematic data were collected while subjects walk with and without arch support foot orthoses. The intra-joint coupling angles were calculated using a vector coding technique. Paired sample t-test was used for statistical analysis. Alpha level was set at P
The results demonstrated that there are significant differences in ankle-knee intra-joint coupling angles in both sagittal (P=0.002) and frontal (P=0.035) planes between the control and experimental groups during loading response phase, while the results also demonstrated that foot orthotic device reduce horizontal knee–hip coupling angle significantly during loading response (P=0.008), mid stance (P=0.009), and push off (P During orthoses condition, knee flexion angle was greater than that of sagittal ankle joint motion. This indicated positive effects of orthoses in injury prevention. The arch support foot orthoses that was used in the present study in male children with flat foot caused the highest alterations in lower limb intra-joint coupling angles in loading response phase. However, further study is needed to prove thie claim.