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One of the effective way to treat and control the neuromuscular organs from injuries of lower limbs in the exercise of backward running. The present research has been set up to determine the effectiveness of this sport and comparing it with forward walking. The aim of this clinical trial is to differentiate between the effectiveness of these two sports on the functional performance tests of lower limbs. To carry out this study 30 normal male has been divided in two groups, in group one forward walking is carried out three 15 minutes session per week for six weeks, and backwards walking has been arranged for group 2 on the same condition. The functional performance tests in this study were vertical jump, single leg hop jump for the distance of 6 meters, in forward and backward running. The findings from this study indicate that there is not meaningful improvement during the six weeks within the 2 different sports. On the basis of these results the 2 procedures of running forward and backward have got the same effect on the increasing the functional performance of lower limbs and both sports can be used active functional rehabilitation.

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Background and Objective: Foot pronation could increase injury occurrence during running. This study was done to investigate the effect of shoes with spikes containing two different stiffness on frequency spectrum of muscles during running in patients with pronated feet.
Methods: This quasi-experimental study was done on15 pronated feet runners with mean age of 27.2±6.4 years. Running was done in two conditions including double density and usual spikes Track and field shoes with between rests of 5 minutes. A wireless 8 channels electromyography system (UK) with bipolar electrodes was used to record the electrical activity of the lower limb muscles. Electrodes were located on tibialis anterior, medial gastrocnemius, vastus medialis, retus femoris, vastus lateralis, biceps femoris, semitendinosus, and gluteus medius muscles in accordance with SENIAM European protocol.
Results: Frequency content of tibialis anterior and gluteus medius at loading phase were significantly greater during running with spikes double density Track and field shoes compared with usual spike shoes (P<0.05). The frequency content of muscles did not demonstrate any significant differences during running with spikes double density Track and field shoes compared with usual spike shoes at both mid-stance and push-off phases.
Conclusion: The double density spikes track and field shoes increased frequency content of tibialis anterior and gluteus medius muscles during loading phase that could be associated with shock absorption.

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Background and Objective: The use of lumbar braces affects kinetics and kinematics. This study evaluated the effects of two types of simple and sensor thoracolumbosacral braces on electromyography activity of selected muscles in patients with kyphosis during running.
Methods: This quasi-experimental study was performed on 15 males with kyphosis. The subjects performed a running task in three conditions: without braces, with simple braces, and with sensor braces. An 8-channel wireless electromyography system was used to record the activity of the muscles of the lower back and lower limbs during running.
Results: There was no significant difference between the tested conditions in response to loading, middle support and swing; however, during push-off, the median frequency of the gastrocnemius muscle was greater when running with a simple brace compared with running without brace (P<0.05). In addition, the median frequency of the semitendinosus muscle was significantly higher while running with sensor brace compared with simple brace (P<0.05).
Conclusion: Using brace, especially sensor brace, can improve muscle activities in patients with kyphosis.

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Background and Objective: Genu varum is a lower limb deformity. This study was done to evaluate the effects of shoe aging on the general and directional contraction of ankle muscles during running in females with genu varum.
Methods: This case-control study was done on 30 female students (15 individuals with genu varum degree 2 and 15 healthy individuals) using new and old sneakers for 6 months in the sports biomechanics laboratory of the University of Mohaghegh Ardabili, Iran. Each subject was given a new pair of sneakers, and after the initial data collection, the subjects were asked to use them in their daily activities for at least an hour a day for 6 months. Electrical muscle activity was recorded using surface electromyography.
Results: There was no significant difference in the general and directional contractions if ankle muscles during the running phases.
Conclusion: Shoe aging has no effect on ankle joint co-contractions.
 

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Background and Objective: Using lumbar orthoses changes the running mechanics. An essential biomechanical factor in rehabilitation and injury prevention is the co-contraction of the knee and ankle joints. Therefore, this study aimed to investigate the effect of 2 types of thoracolumbosacral braces on ankle and knee joint co-contraction in people with kyphosis during running.
Methods: This quasi-experimental study was conducted on 15 men aged 18-25 years suffering from kyphosis greater than 40 degrees in the Biomechanics Laboratory of the University of Mohaghegh Ardabili Health Center during the summer of 2020. Each participant randomly performed 3 running tests in each condition: without a brace, with a sensor brace, and with a simple brace. The test consisted of electromyographic data of the selected lower limb muscles, which also recorded the contraction of the knee and ankle muscles in the right leg when running at a constant speed.
Results: The results showed a reduction of the general knee co-contraction while using a sensory brace compared to without the brace by 6% during the loading phase (P<0.05). Additionally, using a simple brace compared to the condition without a brace, the ankle-directed contraction during the push-off phase decreased by 38% (P<0.05). Directed vastus medialis and lateralis co-contraction while using a sensory brace increased by about 49% compared to without the brace at the loading phase and increased by about 47% at the mid-stance phase without a brace condition compared to the simple brace condition (P<0.05).
Conclusion: General knee co-contraction after using a sensory brace was lower than when a simple brace was used.

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Background and Objective: Fatigue is considered one of the factors effective in changing the electrical activity of muscles so that it is directly linked to increasing the potential of muscular injuries and functional decline in various stages of sports. The present study was conducted to evaluate the frequency of electrical activity of lower limb muscles before and after fatigue during running in individuals with a history of coronavirus disease 2019 (COVID-19) compared to healthy individuals.
Methods: This quasi-experimental research was conducted on 14 women with a history of COVID-19 over the past two months (the experimental group) and 14 women without a history of COVID-19 (the control group) with an age range of 18-30 years using the convenience sampling method in the city of Ardabil. The fatigue protocol started using a sophisticated treadmill at a speed of 6 km/h, and the treadmill speed was accelerated by 1 km/h every 2 minutes. The Borg’s Rating of Perceived Exertion (RPE) 6-20 Scale was used to determine the participants’ final moment of fatigue. A steady-state running fatigue protocol ended at a score higher than 17 on the Borg’s RPE 6-20 scale or 80% of maximum heart rate. Electromyography data were analyzed using the data LITE biometrics software before and after the fatigue protocol.
Results: There was a statistically significant increase in the frequency of the electrical activity of the vastus lateralis (VL) muscle between the post-test of the control group and the experimental group (d=0.410, P=0.035). The pretest-posttest difference of the frequency of electrical activity of the VL muscle after fatigue compared to before fatigue during the loading response phase during running had a statistically significant increase in the experimental group than in the control group (d=0.602, P=0.016). The frequency of the activity of the semitendinosus muscle increased after fatigue compared to before fatigue during the mid-stance phase of running (d=0.261, P=0.005). The impact of fatigue on the frequency of the activity of the VL muscle during the push-off phase of running was statistically significant (d=0.140, P=0.049). The frequency of the activity of the VL muscle increased after fatigue compared to before fatigue during the push-off phase of running in the experimental group.
Conclusion: The increased electrical activity of the lower limb muscles in various phases of running after fatigue in individuals with a history of COVID-19 can be attributed to decreased neuromuscular coordination.