دکتر امیرعلی جعفرنژادگرو

The elderly population faces numerous challenges threatening their quality of life, autonomy, and mobility. Therefore, it is essential to implement activities that address and enhance these issues. This study aimed to examine the effects of rehabilitation exercises on the mechanics of transitional movements among the elderly.

The present study was a systematic review. Articles in Persian and English were searched from December 2020 to May 2024. The study examined the effects of various rehabilitation exercises on the biomechanics of transfer movements in elderly individuals. Specialized databases, including Magiran SID, Scopus، PubMed، ISC، WOS, and Google Scholar were utilized for the review. Initially, 74 relevant articles were selected, and ultimately, 21 articles related to different types of rehabilitation exercises for the elderly were analyzed based on inclusion and exclusion criteria.

The results showed that a variety of rehabilitation exercises can effectively enhance the reduction of peak ground reaction forces during transitional movements. Additionally, it was observed neuromuscular exercises improved the balance index. Conversely, resistance exercises improved both static and dynamic balance and reduced the risk of falling among the elderly.

Prolonged participation in combined exercises, which merge two or more rehabilitation exercises, might yield more beneficial results. However, further research is needed to determine the best type and intensity of exercise for improving the biomechanics of transfer movements in the elderly.

The relationship between doing physical activity and neglecting activities and inactivity causes overweight. Obesity with orthopedic problems is caused by overloading the musculoskeletal structure. The purpose of this research was to compare the plantar pressure values in obese male teenagers compared to healthy peers during walking.

The current research was semi-experimental and applied research. Using G-Power software, the minimum sample size of 15 people was estimated for each group. The statistical sample of this research was 30 teenagers from Ardabil province, who were purposefully placed in two groups icluding 15 obese and 15 healthy people. A foot scan device (RSScan) with a sampling rate of 300 Hz was used to record plantar pressure variables. An attempt was made to walk correctly on the 18-meter path to record the pressure of the soles of the feet. Independent t-test was used for statistical analysis of plantar pressure variables of two groups at a significance level of 0.05.

Peak pressure values in the areas of the toe 1 (P=0.002), toe 2-5 (P=0.003), first metatarsal bone (P=0.052), second metatarsal bone (P=0.028), third metatarsal bone (P=0.009), fourth metatarsal bone (P=0.004), fifth metatarsal bone (P=0.001), midfoot (P=0.001), medial heel (0.001) P =), the lateral heel (P = 0.001) of the left foot was significantly greater in obese group than that healthy group.

According to the obtained results, obese teenagers have more peak plantar pressure than their healthy peers, which makes these people prone to more structural injuries.

It seems that investigating factors that reduce falls and also the effect of physical activities during activities are more effective in reducing falls in the elderly. Because the elderly fall during activity or walking, not in a stationary state where postural control is measured. Therefore, the aim of this study was to compare the effect of strength and balance training on the reactive postural control of healthy elderly people.

The current research is semi-experimental in terms of method and strategy; and in terms of the topic, it was applied research with a pre-test-post-test design. The current research includes two experimental groups (strength training group and balance training group) and one control group. The statistical sample of this research included 36 people (12 people in each group) with an age range of 60 to 75 years. Electromyographic muscle activity was used to evaluate the reactive postural control of the elderly. To analyze the data, two-way analysis of variance and Bonferroni post hoc tests were performed at a significance level of p≥0.05. Statistical software SPSS version 26 and Excel 2019 were used for statistical calculations and drawing graphs.

The results of this study showed that balance training (P=0.001); and strength training (P=0.001). They have a significant effect on the reactive postural control of the elderly. Also, the results of the research showed that there is no significant difference between balance exercises with strength on the reactive postural control of the elderly (p<0.05).

It seems that both balance and strength training have a significant effect on the reactive postural control of the elderly. Also, the results showed that there is no significant difference between balances with strength training on the reactive postural control of the elderly. Therefore, both balance and strength training can be used as an alternative to improve the reactive postural control of the elderly and thus reduce the risk of falls in the elderly.

Peronitis is one of the most common injuries in the ankle joint. The aim of the present study was to review the research conducted in the field of the effects of different types of foot orthoses on the mechanics of the lower limbs of athletes with pronitis from 2023 to 2015.The current study was systematic. The search for studies according to the target from 2015 to 2023 was done in Science direct, PubMed, Web of Science and Magiran databases. A total of 116 articles were received from the mentioned sites. 66 articles were excluded due to their repetition and lack of relevance to the content of the study. 48 articles were excluded from the study due to the lack of research on orthosis and athletes with pronitis. Finally, 12 articles were included in the study due to the keywords of pronitis, athletes and types of orthoses. Studies have shown that the effect of foot orthoses can have a great effect on reducing the forces and pressures of the soles of the feet in athletes with pronitis. Muscle activity increases as a result of using orthosis in sports activities. As a result, the use of orthoses during sports activities can prevent more injuries in athletes with pronitis.

Gait is a fundamental movement pattern influenced by various structures. This study aimed to determine the effect of sand-based training on ground reaction force frequency spectrum in individuals with anterior cruciate ligament (ACL) reconstruction and pronated feet during gait.

This clinical trial was conducted on 28 male students with pronated feet and ACL injuries aged 22-25 years at Mohaghegh Ardabili University. Participants were randomly assigned to two groups of 14: A control group and a sand-based training group. The ground reaction force variables were measured using a force plate in the pre-test and post-test.

The number of necessary harmonics in the free moment component decreased by 15.95% in the post-test (16.48±4.14) compared to the pre-test (19.11±2.15) of the control group (P<0.05). The number of necessary harmonics in the mediolateral direction of the ground reaction force decreased by 23.34% in the post-test (15.59±3.92) compared to the pre-test (19.23±2.66) of the training group (P<0.05). Additionally, the number of necessary harmonics in the anteroposterior direction of the ground reaction force increased by 33.04% in the post-test (21.61±2.55) compared to the pre-test (14.47±4.11) of the training group (P<0.05).

Sand-based training was able to improve the gait mechanics of individuals with ACL reconstruction and pronated feet.

Co-contraction can be defined as the simultaneous activation of agonist and antagonist muscles around a joint. Co-contraction plays a fundamental role in movement control during physiological motor learning-related activities. The aim of the present study was to investigate the relationship between maximum heart rate (MHR) during an exhaustive fatigue protocol and co-contraction of the ankle joint muscles in overweight individuals compared to normal-weight individuals.

The sample consisted of two groups of 12 individuals (n=24), divided into overweight and normal-weight groups. The activity of the ankle joint muscles, including the tibialis anterior and gastrocnemius, was recorded during running using electromyography (EMG). MHR was also recorded using a Polar device. Pearson’s correlation coefficient was used to determine the correlation between variables at a significance level of 0.05.

The results indicate that changes in general and directed co-contraction of the ankle joint muscles in both phases of running did not change significantly before and after the induction of the fatigue protocol. Furthermore, no significant correlation was seen between MHR during the exhaustive fatigue protocol and changes in general and directed co-contraction in phase one and two of running
(P > 0.05).

This study revealed that MHR during exhaustive exercise does not significantly affect ankle muscle co-contraction. The lack of correlation between these two variables suggests that the neuromuscular response to fatigue may be independent of cardiovascular stress and body weight status.

Research has shown that exercises using the Wim Hof Method can positively affect the immune system. Therefore, this study aims to systematically review the impact of meditation, breathing exercises, and cold exposure using the Wim Hof Method on the autonomic nervous system.

This study is a systematic review. The number of articles in this field is limited. The search, conducted in both Persian and English, covered the period from 2013 to 2024 and included databases such as WoS, Civilica, ISC, PubMed, Scopus, and Google Scholar. Ultimately, 5 relevant articles were reviewed and analyzed.

One study revealed that exercises incorporating this method effectively reduced perceived stress levels in participants. Additionally, two articles provided compelling evidence that young individuals practicing the Wim Hof Method experienced significant recovery from flu-like symptoms induced by bacterial endotoxins, such as shivering and headaches. Two other studies indicated that exercises associated with the Wim Hof Method positively influence the autonomic nervous system, suggesting potential benefits in managing autoimmune diseases.

These exercises were notably effective in reducing symptoms of autoimmune diseases. The results indicate that performing meditation, breathing exercises, and cold exposure using the Wim Hof Method has a significant impact on the body's autonomic nervous system and may help improve or manage autoimmune diseases.

Pronated foot, one of the joint foot deformities, can affect running biomechanics and risk of lower extremity injury. Fatigue due to heavy tasks can also change the biomechanical parameters of locomotion. Under the fatigue conditions, the biomechanical differences in individuals with pronated feet are more easily identified. Thus, the main objective of the present study was to examine the effects of fatigue while using double-density spike shoes on muscle activities of the lower extremities in patients with pronated feet while running.

The statistical population of the present study consists of healthy people with pronate feet in Ardabil province. A statistical sample of 22 people aged 20-25 was selected by purposive sampling and participated in the present study. Statistical samples were divided into groups. There were 11 young men and 11 young women with pronate. The navicular bone sagging method divided the smooth and healthy plant groups. Electromyographic activities of the selected muscles before and after the fatigue protocol were recorded. The statistical analysis was performed using the SPSS software and running ANOVA (p≤0.05).

Results demonstrated significant shoe, fatigue-by-group interactions for biceps femoris muscle activity before the heel contact phase. Furthermore, significant shoes, fatigue, and group interactions were found for vastus medialis muscle activity after the heel contact phase (p<0.05). On the other hand, findings showed a significant effect of fatigue-by-shoes interactions on vastus lateralis (p=0.021) muscle activity after the heel contact phase during running. On the other hand, the result showed that tibialis anterior muscle activity after the heel contact phase was significant (p=0.017).

The results showed that using Double Density Spike Shoes can improve the risk factors for injury in people with Pronated Feet.

Individuals with a history of anterior cruciate ligament (ACL) injury are at a higher risk of re-injury compared to healthy individuals. ACL-injured patients exhibit weaker longitudinal arches and increased foot pronation compared to healthy individuals. This study aimed to determine the effect of short-term use of anti-pronation insoles on plantar pressure variables following ACL reconstruction (ACLR) with a pronated foot during gait.

This quasi-experimental study was conducted on 15 male participants who had undergone ACLR with a pronated foot (mean age= 23.2±4.5 years) and 15 healthy males (mean age= 22.7±4.3 years) in Ardabil, Iran during 2022. Plantar pressure values during gait with and without the use of anti-pronation insoles were recorded and compared using a foot scanner (sampling rate: 300 Hz).

The effect of the group factor on the big toe plantar pressure variable was statistically significant (P<0.05). Pairwise comparison results demonstrated a significant increase in pressure in the ACLR group (154.63±41.71 N/cm²) compared to the healthy group (126.54±26.57 N/cm²) (P<0.05). Intragroup comparison results revealed a significant decrease in pressure on the second to fifth toes (215.73±60.74 N/cm²) and the first plantar (420.58±107.56 N/cm²) when using anti-pronation insoles compared to the non-insole condition (the second to fifth toes (201.57±76.21 N/cm²) and the first plantar (400.78±118.20 N/cm²) in the ACL reconstruction group (P<0.05).

The use of anti-pronation insoles can effectively reduce plantar pressure after ACLR in individuals with a pronated foot during gait.

 Asymmetrical gait mechanics after anterior cruciate ligament reconstruction (ACLR) are associated with the development of post-traumatic knee osteoarthritis. Current measures of gait mechanics have focused on peak magnitudes of knee kinematics, kinetics, and joint contact forces; nonetheless, they have seldom considered the plantar pressure and muscular frequency content in individuals with ACLR and pronate feet (PF). The present study aimed to compare ACLR and PF with healthy controls during walking.

The present study was conducted based on a quasi-experimental and laboratory design. The sample of this study comprised 13 people with ACLR and PF and 13 subjects from the healthy group. The mean age scores of patients in the two groups of healthy and sick participants were 22.9±4.1 and 23.2±4.5 years, respectively. During the test, subjects walked barefoot on an 18-m runway. Peak plantar pressure variables in both groups were recorded by a foot scan system (sampling rate: 300 Hz). The electromyography activity of the tibialis anterior, gastrocnemius medialis, vastus lateralis, vastus medialis, rectus femoris, biceps femoris, semitendinosus, and gluteus medius were recorded during walking.

The results demonstrated that the peak midfoot region plantar pressure values (P=0.018) were higher in the ACLR/PF group than in the healthy group during walking. In addition, the results highlighted a significant difference in the muscle frequency content of the rectus femoris (P=0.012, d=0.68) and vastus latelarlis (P=0.042) during the loading response and push-off phase in the ACLR/PF group compared to the healthy group during walking.

Peak plantar pressure values at the midfoot region and rectus femoris and vastus lateralis muscular frequency content in the ACLR/PF group differed from that of the healthy group during walking.

Biomechanics is the knowledge that shows what forces enter the motion system of the human body and how it causes human movement. Therefore, the aim of this Meta-Analysis study was to review the studies conducted in the field of the effects of training on sand surface on biomechanics and physical fitness factors of human body during translational motions. The current study was a library and systematic review, the search for articles in Persian and Latin was from the beginning of the year 2000 to the end of 2023, which was done in the specialized databases of PubMed, WOS, Scopus, ISC and Google Scholar search engine. 568 related articles were selected based on inclusion and exclusion criteria. Standardized mean differences (SMDs) were calculated using random-effects models. The findings of eight articles indicated the improvement of mucle activity during training on sand. Examining the findings of one article indicated positive effects of kinematic variabls during training on sand. A number of two articles also reported that the reduction of the ground reaction forces and impact shock. In addition, five articles reported the improvement of sports performance in athletes, the increase of physical fitness factors. In general, training on sand surface can have significant positive effects on people's daily and sport life. Further study is warranted.

Excessive pronation of the foot during the stance phase of the gait cycle leads to increased flexibility of the foot, causing instability. The aim of the study was to evaluate the effect of using motion control shoes in runners with pronated feet on the absolute angles of the hip and leg joints in the sagittal plane before and after fatigue during running.

In this study, 13 female beginners with pronated feet were selected as the experimental group. CAST markers were used to identify the pelvic, thigh, leg, and foot segments. Motion analysis was performed using six Basler video cameras with a sampling rate of 200 Hz. A low-pass Butterworth filter with a 4th order (10 Hz frequency cutoff) was used for filtering.

The maximum absolute angle of the lower leg in the sagittal plane during 35% of the initial support phase of running when using motion control shoes after fatigue was about 6.05 degrees, compared to the condition when using control shoes before fatigue. The minimum absolute angle of the thigh in the sagittal plane during 50% of the initial support phase of running when using motion control shoes after fatigue decreased by about 4.09 degrees compared to the condition when using control shoes before fatigue.

Motion control shoes reduce the rearfoot angle after fatigue in runners.

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.

Anterior cruciate ligament reconstruction (ACLR) is a common treatment method used after ACL injuries. Patients undergo ACLR to return to their active lifestyles.   However, returning to their previous activity level may result in a retear of their reconstructed knee or an injury to their contralateral anterior cruciate ligament. Therefore, the purpose of this study was to evaluate the acute effect of using anti pronation insoles on muscle frequency content in individuals with ACLR and pronated feet during walking

This study was semi-experimental and laboratory based. The sample   consisted of 13 healthy males and 13 males with ACLR and pronated feet. A bipolar EMG system with 8 pairs of electrodes was used to record the activity of the tibialis anterior, medial gastrocnemius, vastus medius, vastus lateralis, rectus femoris, biceps femoris, semitendinosus and gluteus medius during walking with and without antipronation foot orthoses. Muscular median frequency during loading, mid-stance, and push-off phases were used for further analysis. Two-way ANOVA with repeated measures was used for statistical analysis.

The results indicated that the ACLR group with pronated feet had higher median frequency in the rectus femoris (p=0.004) and medial gastrocnemius (P=0.017) during the loading phase compared to the healthy group. Additionally, the results showed that the frequency content of the vastus lateralis during the mid-stance phase was higher with foot orthoses compared to without (p=0.002). However, there was no change in the frequency content of this muscle in the ACLR group with pronated feet after using foot orthoses (p>0.05). 

 The quadriceps muscles have eccentric contractions during the loading phase. It appears that individuals with both ACLR and pronated feet use an increased median frequency of the rectus femoris as a compensatory mechanism for improved shock absorption. The use of foot orthoses has limited effects on muscular frequency content in individuals with both ACLR and pronated feet.

Low back pain is a common problem in world and one of the most common causes of physical disability. The aim of this review study was to investigate the effects of rehabilitation exercises with a central muscle stabilization approach on kinetic, kinematic and electromyographic variables during walking, running, trunk flexion and extension movements in patients with back pain.

Search process for Persian and English articles from the beginning of January 2000 to August 2023 were performed in Google Scholar, ISC, Scopus, Pub Med, WOS, and SID databases. Finally, based on selection criteria, 19 articles were selected for final analysis through detailed reviews. The participants had non-specific back pain. Studies that included exercise protocols and control group were used in the present study. The dependent variables were kinematics and kinetics and muscle activity during transitional movements. Downs and Black questionnaires were used to evaluate the quality of the articles.

The results of four articles showed that rehabilitation exercises with muscle endurance approach can improve the electrical activity of muscles and reduce back pain. The results of seven articles showed that strengthening, stretching and massage exercises can be effective in improving pain through correcting the person's vertical alignment. Other articles in a period of at least eight weeks showed that strengthening the central muscles of the body can lead to neuromuscular adaptation and increase muscle fibers recruitment in patients with back pain.

The present review have shown  that rehabilitation exercises with the approach of strengthening the central muscles of the body can lead to improving the flexibility of the trunk muscles, correcting the person's vertical alignment and reducing the back pain.