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Showing 16 results for Jafarnezhadgero

1
Hamed Ebrahimpour , Amir Ali Jafarnezhadgero, Ebrahim Piri , Ehsan Fakhri Mirzanag,
Volume 0, Issue 0 (2-2024)
Abstract


Seyed Majid Alavi Mehr, Amir Ali Jafarnezhadgero , Mahdi Majlesi ,
Volume 21, Issue 1 (3-2019)
Abstract

Background and Objective: 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.
Methods: 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.
Results: 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.
Conclusion: 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.
Aidin Valizadehorang , Farshad Ghorbanlou, Amir Ali Jafarnezhadgero ,
Volume 22, Issue 2 (6-2020)
Abstract

Background and Objective: One of the most common malalignments of the knee joint is valgus. This study was done to determine the effect of using graded knee brace at two angles of 60 and 30 degrees on the ground reaction force components in males with genu valgus during landing.
Methods: This clinical trial study was done on twenty males with genu valgus with age range of 21.70±2.12 years. The graded knee brace was used in two flexion angles of 60 and 30 degrees. Landing from a platform with 40 cm height on a force plate was done during three conditions including without brace, with a brace at flexion angles of 30 and 60 degrees.
Results: A significant reduction was observed in the vertical force during contact phase while landing with brace at a 60-degree angle compared with landing without brace by 15.21% (P<0.05). Also, the peak of medio-lateral force during the heel contact phase while landing with knee brace at 30 degree was significantly greater than that landing with knee brace at 60 degree by 27.18 % (P<0.05).
Conclusion: By reducing the knee flexion angle, the forces of the lower extremities increase and this issue could possibly increase the risk of injury in the knee joint. Therefore, the use of this type of brace is recommended for individuals with genu valgum at a 60 degrees limiting angle.
Arefeh Mokhtari Malekabadi, Amir Ali Jafarnezhadgero , Mohsen Barghamadi , Abbas Memarbashi ,
Volume 23, Issue 1 (3-2021)
Abstract

Background and Objective: Proprioceptors of the plantar surfaces of the foot have less efficiency and the stimulation and reinforcement of them may be lead to reduction of falling risk. One of the methods to reinforce proprioceptor receptors in these individuals is using textured foot orthoses. The aim of this study was to evaluate the effect of textured foot orthoses on frequency spectrum of lower extremity muscles, stance time and comfort in individuals over age of 55 years during walking.
Methods: This quasi-experimental study was done on the 14 females and 14 males age ranged of 56-70 years with the ability to walk independently and with physical and mental health status. Subjects were compared during five conditions including without foot orthoses and using four foot orthoses (including small and large foot orthoses with two types of flexible and rigid), flexible and rigid large textured foot orthoses. The 8 electrodes were located on tibialis anterior, medial gastrocnemius, vastus medialis, vastus lateralis, biceps femoris, semitendinisus, gluteus, and erector spinae in 3 lumbar vertebrae region muscles.
Results: Frequency content of tibialis anterior and vastus medialis was significantly increased in males than female (P<0.05). Vastus medialis frequency during walking with large foot orthoses was more than walking without foot orthoses (P<0.05). The comfort level was different during flexible large textured foot orthoses condition compared with flexible small textured foot orthoses condition (P<0.05). The stance time was not significant between all conditions.
Conclusion: Increased frequency content of the vastus medialis muscle can increase the absorption and decrease the vertical loading rate imposed on the foot, which in turn reduces the risk of injury of the lower limb in older adults.
Saeed Norinasab, Amir Ali Jafarnezhadgero , Marefat Siahkouhian , Aydin Valizadeh Orang ,
Volume 23, Issue 1 (3-2021)
Abstract

Background and Objective: Genu varus deformity is associated with changes of lower limb muscle co-contraction and running economy. This study was done to evaluate the effect of using of brace in three different knee flexion angles on running economy and lower limb muscular co-contraction in individuals with genu varus.
Methods: This quasi-experimental study was done on active soccer male students including 15 healthy subjects (average age of 22.86±1.55 years) and 15 subjects with genu varus (average age of 22.13±1.80 years). The amount of electrical activity of the muscles (tibialis anterior, medial gastrocnemius, vastus medialis, vastus lateralis, rectus femoris, biceps femoris, semi-tendinosus) were recorded by electromyography system during four conditions of with and without using knee brace. After that, directed and general co-contraction was computed during running. The angles of brace were 15, 30, and 60 degrees. The values of VO2 max were recorded using of gas analyzer system to compute running economy.
Results: The ratio of respiratory exchange was significantly more in the genu varus group than healthy group (P<0.05). However, the acute effect of brace was not significant on running economy and ratio of respiratory exchange. The main effect of brace was significant for general co-contraction of knee joint during the loading phase (P<0.05). Paired wise comparison revealed significant greater general knee co-contraction during brace conditions (P<0.05). However, the general knee co-contraction during loading phase reduced while using brace 15 degree. The main effect of “brace” for ankle joint general co-contraction during the push-off phase was significant (P<0.05). Paired wise comparison revealed significant greater general ankle co-contraction during brace conditions at push-off phase (P<0.05).
Conclusion: Knee brace did not change running economy. However, the using of brace 15 degree improved general knee joint co-contraction during loading phase.
Amin Naghdizadeh, Amir Ali Jafarnezhadgero , Marefat Siahkohian , Saeed Noorinasab, Mitra Zivarikabir,
Volume 23, Issue 2 (7-2021)
Abstract

Background and Objective: Genu varus is a deformity in frontal plane that in weight bearing position whiles the medial malleolus’s touch each other, the medial knee epicondyles far from each other. Genu varus is very prevalent in soccer players. This study was done to evaluate the effect of using knee brace and lateral wedge on muscular activity amplitude in male soccer players with genu varus during running.
Methods: This quasi-experimental study was done on 15 right-footed male soccer players with genu varus and 15 healthy soccer players. A wireless electromyography system with eight pairs of bipolar Ag/AgCl surface electrodes (20 mm center-to-center distance; input impedance of 100 MΩ; and common-mode rejection ratio of >110 dB) was used to record the activity of the tibialis anterior, gastrocnemius medialis, biceps femoris, semitendinosus, vastus lateralis, vastus medialis, and rectus femoris, and gluteus medius muscles of the right leg. Electromyography data were recorded by sampling rate of 1000 Hz in selected muscles during running at five conditions including: control, 10 degrees lateral wedge, 15 degrees lateral wedge, simultaneous using 30 degrees brace and 10 degrees lateral wedge, and simultaneous using 30 degree brace and 15 degrees lateral wedge.
Results: Treatment intervention had reduction effect on muscular amplitude of biceps femoris and vastus lateralis during push-off phase (P<0.05). Muscular amplitude of biceps femoris and vastus lateralis during loading phase was reduced due to Treatment intervention (P<0.05).
Conclusion: Simultaneous using of lateral wedge and knee brace reduce the electromyography activity of vastus lateralis and biceps femoris muscles. This reduction may be associated with passive support of knee brace that in result could decrease the external knee adductor mowment.



Amir Ali Jafarnezhadgero , Ehsan Fakhri, Aydin Valizadeh Orang , Raziyeh Alizadeh,
Volume 23, Issue 3 (10-2021)
Abstract

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.

Farshad Ghorbanlou , Amir Ali Jafarnezhadgero ,
Volume 23, Issue 4 (12-2021)
Abstract

Background and Objective: Genu valgum is one of the most common lower limb malformations that affects on walking mechanics. This study was done to evaluate the effect of corrective exercise with Thera-band on the lower limb muscles’ co-contraction in males with genu valgum during walking.
Methods: In this clinical trial study, 24 male students with genu valgus with age range of 20-30 years were randomly divided into two control (n=12) and intervention (n=12) groups. Using the caliper, the intensity of the genu valgum was measured by assessing the distance between the medial malleolus of the subjects. Corrective exercises were performed for 8 weeks using Thera-band in interventional group. The electrical activity of selected muscles was recorded by electromyography system (biometrics ltd, UK).
Results: In the interventional group, the knee joint flexor/extensor directed co-contraction was increased significantly during the heel contact phase in the post-test than that in the pre-test (P<0.05). There was also a significant increase in knee joint general co-contraction during heel off phase (P<0.05). In the interventional group, directed co-contraction of vastus lateralis / vastus medialis muscles during the swing phase was significantly increased during the post-test in compared to the pre-test (P<0.05). During post-test, knee joint flexor/extensor directed co-contraction during the heel, knee joint general
co-contraction during heel off phase and directed co-contraction of vastus lateralis / vastus medialis muscles during the swing phase were more in the interventional group in compared to control group (P<0.05).
Conclusion: The increase of general co-contraction in the knee joint during the heel off phase reflects an improvement in activity of the knee support muscles after corrective exercises and increases balance and stability. There was also an increase in the knee joint flexor / extensor direction co-contraction, which increase the distribution of the load and pressure between the femur and tibia in the knee joint.
Milad Piran Hamlabadi , Amir Ali Jafarnezhadgero ,
Volume 24, Issue 1 (3-2022)
Abstract

Background and Objective: Back pain is a common orthopedic disease that affects up to 80% of the population at some point in life. Brace is one of the tools that used to reduce pain. The relationship between brace application and gait parameters in people with low back pain is not well understood. This study was done to determine the effects of simple and sensor thoracolumbosacral braces on gait kinetics in patients with low back pain.
Methods: This quasi-experimental study was performed on 15 men and women with low back pain in the biomechanics laboratory of Mohaghegh Ardabili University Health Center in nort-west of Iran during 2020. Each participant performed three gait conditions including without brace, with sensory brace and with simple brace. Ground reaction forces were recorded and compared by a force plate while walking.
Results: The average walking speed during no brace, simple brace and sensor braces were not significant different. Also, results did not demonstrate any significant effect of simple or sensor braces on ground reaction force amplitudes, their time to peak, and free moment values.
Conclusion: Simple and sensory thoracolumbosacral brace did not effect on gait kinetics in low back patients.
Afshiin Orouji, Seyed Sadrodin Shojaodin , Amir Letafatkar , Amir Ali Jafarnezhadgero ,
Volume 24, Issue 1 (3-2022)
Abstract

Background and Objective: The scientific evidence related to the effectiveness of rehabilitation on electromyographical activity of trunk muscles is limited. This study was performed to determine the effect of movement-pattern training on frequency of selected trunk muscles during single-leg landing in individuals with non-specific chronic low back pain.
Methods: In this clinical trial study, 28 patients with non-specific chronic low back pain were randomly divided into intervention and control groups. The control group did not receive treatment. The intervention group performed treatment as a movement-pattern training. Subjects performed single leg landing from 30 cm height. Trunk muscle activity was assessed using an 8-chanel EMG system. The assessments were completed in pre-test and after six weeks.
Results: Frequency content of right rectus abdominus and right lumbar erector spinae in intervention group were lower than control group (P<0.05). In other muscles ant there was not any significant significant differences between interventional and control groups.
Conclusion: The movement-pattern training can be used in rehabilitation of individuals with non-specific chronic low back pain.
Amir Ali Jafarnezhadgero , Milad Piran Hamlabadi ,
Volume 24, Issue 2 (7-2022)
Abstract

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.


Amir Ali Jafarnezhadgero , Seyede Maryam Anvari , Saeedeh Naseri ,
Volume 24, Issue 2 (7-2022)
Abstract

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.
 
Milad Piran Hamlabadi , Amir Ali Jafarnezhadgero ,
Volume 24, Issue 3 (10-2022)
Abstract

Background and Objective: One of the ways to correct kyphosis is to use braces. This study was done to determine the effects of two types of simple and sensor thoracolumbosacral braces on ground reaction force components during walking in males with kyphosis.
Methods: In this quasi-experimental study, 15 males with kyphosis did three walking trials on the force platform without a brace, with a simple brace and with a sensor brace. Ground reaction force data were collected using Bertec force plates.
Results: There was no difference in peal forces, free moment and loading rate values during walking with and without braces.
Conclusion: Using a brace does not affect walking kinetics in males with kyphosis.
 
Milad Piran Hamlabadi , Amir Ali Jafarnezhadgero ,
Volume 25, Issue 3 (10-2023)
Abstract

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.


Ebrahim Piri , Amir Ali Jafarnezhadgero , Hamed Ebrahimpour ,
Volume 25, Issue 4 (12-2023)
Abstract

Foot pronation, as one of the prevalent foot abnormalities, can influence the biomechanics of the lower limbs. The use of various foot orthoses, including insoles and braces, is very common in eliminating this problem. The results obtained regarding the effect of orthoses on pain and biomechanics of individuals with foot pronation are different. The present review study was conducted to evaluate the effects of foot orthoses and shoes on the biomechanics of the lower limbs and balance in individuals with foot pronation. The articles were searched in Persian and Latin languages during 2004-22 in the databases of PubMed, Web of Science (WOS), Scopus, Islamic Science Citation (ISC), and Google Scholar search engine. Moreover, the types of the searched studies were original research, review studies, and clinical trials. Using keywords of Foot pronation, Foot orthoses, Medical soles, and Motion-control shoes, 52 relevant articles were selected, and 22 articles regarding the effects of orthoses and shoes on foot pronation were finally analyzed. Eight articles also reported that reducing forces imposed on the joints, absorbing shock, preventing pronation-related running injuries, and improving muscle activity occurred when using orthosis. Furthermore, 4 articles reported improving sports performance in athletes, reducing the ground reaction forces, and changing the frequency of muscle activity. Finally, 2 articles showed that motion-control shoes prevented intensifying the injury due to increased fatigue and subsequently increased mechanical loading during running. The results of the present study demonstrated that foot orthoses and motion-control shoes could have positive effects on balance, improving the activities of the lower limbs and reducing foot pronation and force imposed on the foot and lower limb joints.


Amir Ali Jafarnezhadgero , Zeynab Noroozi , Ebrahim Piri ,
Volume 26, Issue 1 (3-2024)
Abstract

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.



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مجله دانشگاه علوم پزشکی گرگان Journal of Gorgan University of Medical Sciences
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