Ghahderijani, F.R.,
Hamed, E.,
Salari-esker, F.,
Bashiri, B. Journal of Biomechanics (18732380)185
Running is generally considered a symmetrical activity that involves harmonized functions of upper and lower limbs. However, asymmetry can occur under certain conditions, such as fatigue, as lower limbs perform distinct functional tasks. While running, trunk muscles play a crucial role in transmitting loads between the upper and lower limbs, yet the impact of trunk muscle fatigue on the dominant and nondominant legs has not been well addressed. This study investigated the effects of trunk muscle fatigue on ground reaction force characteristics on dominant and nondominant legs in novice runners. Thirty participants were asked to run along a runway at 3.3 m · s−1 before and after a trunk muscle fatigue protocol. Ground reaction force data were collected bilaterally, and subsequent asymmetries were calculated. Trunk muscle fatigue had different effects on the dominant and nondominant legs. In the dominant leg peak medial force increased, while the nondominant leg showed reduced peak lateral force, peak braking force and peak negative free moment and increased medio-lateral impulse. Trunk muscle fatigue increased asymmetries in peak lateral force, peak braking force and decreased asymmetry in peak negative free moment. These findings suggest that trunk muscle fatigue, due to its different effects on dominant and nondominant legs, deteriorates running asymmetry and may increase injury risk in novice runners. Strengthening and improving the endurance of trunk muscles is recommended for novice runners to prevent strength reduction-related changes in running mechanics and mitigate injury risk. © 2025 Elsevier Ltd
Iranpour, A.R.,
Hemmatinafar, M.,
Nemati, J.,
Salesi, M.,
Hamed, E.,
Imanian, B. PLoS ONE (19326203)20(2 February)
Background The principle of gradual overload is crucial in improving sports performance, yet the effects of combining speed and weight overloads in plyometric training remain understudied. Objective This study investigated the effects of plyometric training with speed and weight overloads on isokinetic strength, explosive power, and agility in volleyball players. Method Forty male volleyball players were randomly assigned to four groups: plyometric training (PT), plyometric training with speed overload (PTS), plyometric training with weight overload (PTW), and plyometric training with both speed and weight overload (PTSW). Each group completed a four-week plyometric training regimen. Performance metrics, including Sarjent’s jump height (SJH), Spike jump height (SPJH), Sheppard test (ShT), muscle voluntary isometric contraction (MVIC), rate of force development (RFD), absolute peak torque (PTQ), relative peak torque (RPT), and average power (AP) of knee extensors and flexors were measured before and after the intervention. Results SJH improved significantly in PTS (P = 0.012), PTW (P = 0.041), and PTSW (P = 0.001) compared to PT. SPJH showed substantial gains in PTS (P = 0.002), PTW (P = 0.001), and PTSW (P = 0.001) compared to PT. Average jump height and highest jump in ShT were also significantly higher in PTS, PTW, and PTSW (P < 0.05). Additionally, RFDext240/s was enhanced considerably in PTS (P = 0.001) and PTSW (P = 0.001). Conclusion Based on the results, plyometric training with speed and weight overloads (PTSW) demonstrated superior enhancements in isokinetic strength, explosive power, and jumping performance. This combined approach is highly effective and significantly benefits male volleyball players, aiming to enhance their physical abilities. © 2025 Iranpour et al.
Scientific Reports (20452322)14(1)
The foot structure is associated with different running mechanics. The central nervous system is responsible for using the muscles through synergies during locomotion. The purpose of the present study was to examine the effect of foot structure on the electromyography factors and the synergy of the selected muscles of the lower extremity. Tibialis anterior, extensor digitorum longus, peroneus longus, soleus, biceps femoris, vastus lateralis, gastrocnemius lateralis and medialis muscles activity of 60 barefoot recreational runners with different foot structures was recorded while running at a speed of 3.3 m/s. Muscle activity was measured in the running cycle. Besides, muscle synergies were extracted using non-negative matrix factorization algorithm. The results showed that there were differences between groups with different foot type in muscle activity under different phases of running in some muscles. Furthermore, the findings indicated that the number of synergies was similar in different groups and the relative weight of muscles was not different across groups. In conclusion, despite the difference in muscle activity under different phases of the running cycle, muscle synergies are similar among the groups. This can indicate similar control by the central nervous system in runners with different arch structures while running and the observed changes in muscle activity can be attributed to the type of forces exerted on the body, the length-tension relationship, and changes in the direction of the lower limbs in people with different arch structures. © The Author(s) 2024.
Gait and Posture (18792219)107pp. 330-336
Background: Gait mechanics alternation is one of side effects after anterior cruciate ligament reconstruction (ACLR). Foot roll-off characteristics shows whole gait mechanics and is not well known in ACLR patients. The purpose of present study was to investigate the roll-off process characteristics while walking and running in patients with ACLR history. Research question: Is there any difference in walking and running roll-off characteristics between patients with ACLR history and healthy individuals? Methods: 48 physically active males (24 healthy and 24 with ACLR history) participated in this study. Participants walked and ran on a footscan (Rsscan International) which was mounted in the midway of a 18 m runway at the speeds of 2 m·s−1 and 3.3 m·s−1. Center of pressure (COP) trajectory, timing of stance subphases, foot progression angle and contact time were calculated bilaterally in walking and running. Mixed-design MANOVA was used to examine effect of ACLR on the outcomes. Results: The results showed that ACLR participants had greater foot progression angle (p = .001) and more medially oriented COP trajectory in forefoot push-off phase (FFPOP) of waking (p = .001) and running (p = .001), but showed shorter contact time in running compared to healthy group (p = .02). Involved leg in ACLR group showed greater foot progression angle (p = .001) and more medially directed COP trajectory in FFPOP of walking (p = .001) and running (p = .01) compared to uninvolved side. Also, involved leg had shorter contact time (p = .04) and shorter relative time in the forefoot contact phase (p = .001), and longer relative time in forefoot flat phase (p = .001) during running. Significance: Based on the results, it can be concluded that ACLR affects running and walking roll-off characteristics which can show altered mechanics. Running shows remarkable differences in roll-off process than walking. So, it is recommended to use running in post-ACLR assessments rather than walking. © 2023 Elsevier B.V.
Journal of Bodywork and Movement Therapies (15329283)36pp. 125-132
Introduction: Firefighting is a high-risk job with a high prevalence of work-related musculoskeletal disorders (WMSDs). The aim of his study was to determine the prevalence of WMSDs, estimate the likelihood of subsequent disorders, and investigate the effect of NASM-based training protocol on firefighters function. Method: First, prevalence and region of WMSDs in all 524 male Isfahan firefighters were determined by Medical-history-questionnaire. Then, functional movement screen (FMS) separated firefighters to the 2-dimension FMS score (FMSCS≤14 or FMSCS>14) to show at risk firefighters. Finally, 40 Participants with both FMSCS≤14 and common WMSDs randomly assigned to either an intervention (IG) (n = 20) or control (CG) (n = 20) group. The IG received NASM-based training, while the CG engaged in daily activities. Outcomes included movement efficiency during landing error scoring system-real time, Y balance, single-leg squat, and deep squat, which were assessed in pretest and posttest. Results: The prevalence of disorders was 52.1%, which lower limb, back, upper limb, and neck were the highest prevalence respectively. Only lower limb and back disorders could identify individuals at disorder risk with a likelihood of 89% and 71%, sequentially. Also, movement performance significantly improved in all functional tests in IG relative to CG. Conclusions: Considering high disorder rate in firefighters, the value of our study lies in alleging a systematic model periodically to reduce WMSDs and risk of subsequent disorders. Not only our model determined the prevalence of WMSDs, but it also identified those who are at risk. In addition, our model represents exercise therapy as a solution. © 2023 Elsevier Ltd
Journal Of Rehabilitation Sciences And Research (23456159)10(4)pp. 188-193
Background: This study aimed to investigate stance phase characteristics and asymmetry in females with non-specific low back pain (LBPP) which they adopt different strategies in walking to reduce pain and enhance walking quality. The results of this research can provide new insight into gait characteristics for individuals with LBPP by examining temporal characteristics and asymmetry in their stance phase during walking. Methods: In this cross-sectional study, 36 females were purposefully recruited and divided into two groups: one consisting of 18 individuals with low back pain (LBPP) and the other without LBPP. Data were collected using the Footscan system and analyzed with the Footscan Gait 7 gait generation software. Independent t-tests were employed to compare the outcomes between the two groups. Results: The results indicated that the right (P=0.001) and left (P=0.001) foot progression angles in the low back pain group were higher than those in the healthy group. Additionally, the low back pain group exhibited higher asymmetry in the timings of the initial contact phase (P=0.02) and forefoot contact phase (P=0.02), as well as in foot progression angle asymmetry (P=0.009) compared to the healthy group. Conclusion: Given the higher foot progression angle and observed asymmetries in individuals with low back pain, rehabilitative exercises need to consider these differences when evaluating and planning rehabilitation procedures. 2023© The Authors. Published by JRSR.
Sadra Medical Sciences Journal (23224339)11(1)pp. 55-64
Introduction: The path of the center of pressure while walking reflects the general mechanics of the body. Also, the electrical stimulation system triggers movement units, including the lower limbs. The present study investigated the effect of the electrical stimulation system on gait and balance patterns in young athletes. Methods: This research is applied and semi-experimental. In this study, 15 male athletes were selected by convenience sampling. The present study was performed in February 1400 at Shahriar Health Club. Participants were asked to walk at a self-selected speed. In the middle of the walking path, a foot-scanning device was placed, which recorded information about the path of the center of pressure, the relative duration of the stance phases, and the forward angle in both positions with and without the muscle stimulation vest. After checking the normality of the data using the Shapiro-Wilk test, paired sample t-test was used to analyze the data. Results: The results showed that the electrical muscle stimulation system had a favorable effect on the gait pattern of athletes compared to those without a vest. Electrical stimulation led to a slight increase in pressure center oscillations and improved displacement of pressure fluctuations (p=0.001) in the vest mode, which showed the effectiveness of this method. Conclusion: The results of the present study showed that strengthening the muscles of the lower extremities by the electrical muscle stimulation system had favorable effects on athletes' gait pattern and foot pressure fluctuations © 2023, Sadra Medical Sciences Journal.All Rights Reserved.
Background: Bilateral symmetry evaluation in lower limb is used for injury prevention, and is an indicator of returning to post-injury activity. The aim of present study was to investigate the effect of different angular velocities on asymmetry of the hamstring-to-quadriceps strength ratio. Method: Isokinetic concentric hamstring to quadriceps (H:Q) peak torque ratio of the 27 male and female professional basketball players was measured at seven angular velocities (60, 90, 120, 150, 180, 180, 240, 300 deg s−1) on both dominant and non-dominant legs with Biodex Isokinetic Dynamometer. Repeated measure analysis of variance was used to assess the effects of angular velocity and limb side on our outcomes (p ≤ 0.05). Results: The results showed that with increasing angular velocity, the ratio of hamstrings to quadriceps increases (p = 0.001). There was no difference between dominant and non-dominant limbs in the H:Q peak torque ratio (p = 0.254). In addition, velocity of measurement did not affect the bilateral asymmetry of peak torque ratio of the H:Q of both sides (p = 0.852). Conclusions: Based on the results of this study, it can be concluded that measurement velocity does not affect the bilateral asymmetry of the H:Q peak torque ratio of the dominant and non-dominant limbs. In clinical assessments of H:Q bilateral asymmetry, we suggest that physical trainer can assess bilateral asymmetry of H:Q with arbitrary angular velocities. © 2022 Elsevier B.V.
Iranian Journal of Ageing (1735806X)17(2)
Objectives: Knee osteoarthritis is one of the most common musculoskeletal problems in older adults. Pain, stiffness, tenderness, decreased muscle strength and joint range of motion, impaired proprioception, and balance problems lead to impaired physical function, making the person incapable of performing functional activities. Therefore, it is necessary to use strategies to control and reduce the complications of the disease and improve their daily functional activities. The aim of this study was to compare the effect of land exercise therapy and hydrotherapy on functional activities in older women with knee osteoarthritis. Methods & Materials: Fifty-four female patients with knee osteoarthritis within an age range of 60-69 years (height: 159.96 ±5.53, weight: 76.93±9.50) were selected as available, and were randomly divided into two groups of land exercise therapy and hydrotherapy for 8 weeks. To evaluate the patients' functional activities, timed up & go, 30-second chair stand, 40-meter fast paced walk test, stair climb test, and 6-minute walk test were used. SPSS V. 26 and analysis of variance for repeated measures were used for data analysis. Results: The results showed that The results showed that both land exercise therapy and hydrotherapy methods caused intra-group changes in functional tests (P ≤ 0.05) but the difference between the two groups was not significant (P ≥ 0.05), which indicates the same effect of the methods used in the study. Conclusion: Land exercise therapy has had the same effect as hydrotherapy on timed get up & go, 30-second chair stand, 40-meter fast paced walk test, stair climb test, and 6-minute walk test, which means that it has shown effective for the patients’ functional activities. Any of these methods can thus be recommended according to the conditions of each patient. © 2022. Iranian Journal of Ageing.All Rights Reserved
Journal of Biomechanics (18732380)122
During running, trunk muscles act to sufficiently contribute to the energy generation and transmission of the body parts. Improper function of trunk muscles affects running mechanics adversely and could result in altered lower limb energetics. The aim of this study was to examine the effects of trunk muscles fatigue on plantar pressure distribution in novice runners. 46 novice heel-to-toe runners (26 female and 20 male) ran in 3.3 m/s before and after the trunk muscles fatigue along the plantar pressure measuring device. Then, participants performed trunk muscles fatigue protocol. Trunk muscles fatigue protocol consisted of four consecutive cycles of seven exercises (1) rotating trunk with a medicine ball in sitting position, 2) prone static torso extension with a medicine ball, 3) rotate lower torso with a medicine ball in supine position, 4) incline sit-ups with a weight plate, 5) lateral side binding with a weight plate, 6) rotating lumbar extension with weighted plate, and 7) standing trunk rotation with weighted pulley resistant. After trunk muscles fatigue, increases in loading of lesser toes (p = 0.001, ES = 0.379), fourth (p = 0.001, ES = 0.474) and fifth metatarsals (p = 0.004, ES = 0.173) and medial and lateral heel (p = 0.018,0.001, ES = 0.118,0.427) were observed. Also, foot progression angle (p = 0.001, ES = 392) and relative time of initial contact phase (p = 0.003, ES = 0.182) decreased. The trunk muscles fatigue could alter the plantar pressure distribution pattern. Novice runners should consider strengthening of the trunk region muscles to avoid trunk muscles strength reduction-related changes in running mechanics. © 2021 Elsevier Ltd
Gait and Posture (18792219)88pp. 132-137
Background: Running induced-fatigue is an important factor in running related injuries. Runners with different strike types have different running mechanics and suffer from different injury patterns. Underlying mechanism of this difference is not well understood. Research question: The aim of this study was to examine the effects of running-induced fatigue on plantar pressure distribution in runners with different strike types. Methods: 30 rearfoot (age = 21.56 ± 2.28 years; height = 1.67 ± 0.08 m; mass = 61.43 ± 11.57 kg; BMI = 21.77 ± 2.9 kg∙m−2) and 30 forefoot (age = 19.73 ± 1.68 years; height = 1.71 ± 0.08 m; mass = 65.7 ± 13.45; BMI = 22.53 ± 3.39 kg∙m−2) strike male and female recreational runners were recruited to this study. Participants ran in 3.3 m/s barefoot along the plantar pressure measuring device (Footscan®, Rsscan International) before and after running-induced fatigue. Fatigue protocol was performed on a treadmill. Peak plantar pressure and peak plantar force (% body weight), contact time and medio-lateral force ratio were calculated while running. Repeated measures ANOVA test was used to investigate the effect of running-induced fatigue on plantar pressure variables (p ≤ 0.05). Results: After running-induced fatigue, in the rearfoot strike group, increases in loading of medial and lateral portions of the heel, first metatarsal and big toe was observed, and in lesser toes and in the forefoot push off phase, the medio-lateral force ratio decreased. While, in the forefoot strike group first to third metatarsals loading increased and fifth metatarsal loading decreased after fatigue, and medio-lateral force ratio in the foot flat and forefoot push off phase increased. In both groups contact time increased after fatigue. Significance: Our data indicate that running-induced fatigue has different effects on plantar pressure distribution pattern in runners with different strike type. These different effects reflect different adaptation strategies in runners with different strike types, and could explain existence of different injury patterns in runners with different strike types. © 2021 Elsevier B.V.
Applied Ergonomics (18729126)88
Trunk muscles play an important role during load lifting and contract to control trunk stability. The aim of present study was to investigate immediate effects of using various insole wedges on activation and co-contraction indices of selected trunk muscles during load lifting. Thirty able-bodied males completed load lifting task using nine various insole wedges. The results showed these significant differences: for normalized mean amplitude of RA muscle between posterior and anterior-medial wedges and for QL muscle between posterior and lateral wedges, for normalized peak amplitude of RA muscle between posterior and anterior-medial wedges, for median frequency of LES muscle between anterior-medial and anterior-lateral wedges, and for co-contraction of RA/TES, RA/LES and RA/MU between posterior and anterior-medial wedges (P = 0.001). These findings should be considered during designation of shoe or insole for work environments. Future studies need to assess other biomechanical aspects of using various insole wedges during work-related tasks. © 2020 Elsevier Ltd
Hajilou, B.,
Anbarian, M.,
Hamed, E.,
Mirzapour, M. Journal of Biomechanics (18732380)103
The purpose of this study was to investigate the effect of fatigue on selected lower extremity muscles synergy during running using non-negative matrix factorization algorithm method. Sixteen male recreational runners participated in this study. The surface electromyographic activity of rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), semitendinosus, gastrocnemius medialis (GM), soleus (SO) and tibialis anterior (TA) were recorded on treadmill at 3.3 m s−1 before and after the fatigue protocol. Synergy pattern and relative muscle weight were calculated by non-negative matrix factorization (NNMF) algorithm method. The results showed that using the VAF method, five muscle synergies were extracted from the emg data during running. After the fatigue, the number of muscular synergies did not show a change, but relative weight of the muscles changed. Fatigue did not have any effect on the structure of muscular synergy, but changed the relative weight of muscles. These changes could be the strategy of the central nervous system to maintain optimal function of the motor system. © 2020 Elsevier Ltd
Human Factors and Ergonomics in Manufacturing and Service Industries (15206564)28(4)pp. 213-219
The level of muscle activity can be decreased with optimized foot wedge condition. The aim of this study was to evaluate the effect of different foot wedge conditions on the activity of selected lower extremity muscles during load lifting. Nine able-bodied male subjects participated in this study. Electromyography activity of the vastus medialis (VM), vastus lateralis (VL), medialis gastrocnemius (MG), and soleus (SOL) muscles was recorded during dynamic load lifting using the squat technique in 5 conditions: i) non-wedge (NW), ii) 1 cm heel height increasing (PW1), iii) 3 cm heel height increasing (PW3), iv) 1 cm in front of the feet (AW1), and v) 1 cm inside the feet (MW1). The results showed that the VM activity decreases in the MW1 compared to other conditions and significantly compared to the PW1 and PW3 conditions (p <.05). Decreases in the VL activity in the AW1 as well as in descending and ascending phases of MW1 were observed (p <.05). Also in the descending phase, the SOL activity in AW1 decreased significantly compared to NW condition (p <.05). However, there was no significant difference in MG activity between different conditions (p >.05). It seems that placing wedges in the anterior and medial area of the feet may decrease quadriceps muscles activity and probably can delay reaching time to fatigue during load lifting. These findings may be helpful in designing special shoes for ergonomics fields and work environments. © 2018 Wiley Periodicals, Inc.
Gait and Posture (18792219)48pp. 52-56
This study aimed to assess the effects of running-induced fatigue on plantar pressure parameters in novice runners with low and high medial longitudinal arch. Plantar pressure data from 42 novice runners (21 with high, and 21 with low arch) were collected before and after running-induced fatigue protocol during running at 3.3 m/s along the Footscan® platform. Peak plantar pressure, peak force and force-time integral (impulse) were measured in ten anatomical zones. Relative time for foot roll-over phases and medio-lateral force ratio were calculated before and after the fatigue protocol. After the fatigue protocol, increases in the peak pressure under the first-third metatarsal zones and reduction under the fourth-fifth metatarsal regions were observed in the low arch individuals. In the high arch group, increases in peak pressure under the fourth-fifth metatarsal zones after the running-induced fatigue was observed. It could be concluded that running-induced fatigue had different effects on plantar pressure distribution pattern among novice runners with low and high medial longitudinal foot arch. These findings could provide some information related to several running injuries among individuals with different foot types. © 2016 Elsevier B.V.
Hamed, E.,
Anbarian, M.,
Salari-esker, F.,
Hajilou, B.,
Sanjari, M.A. Scientific Journal of Kurdistan University of Medical Sciences (1560652X)19(1)pp. 88-98
Background and Aim: Foot orthoses are widely prescribed to treat a range of lower extremity problems. Long-term biomechanical effects of foot orthosesare not clearly documented in the literature. The aim of this study was to examine long-term effects of foot orthoses on leg muscles activity in individuals with pesplanus during walking. Materials and Method: In this clinical trial we selected 45 subjects after clinical examination. The subjects were divided into three equal groups: experimental pesplanus, control pesplanus and a healthy control group (with normal feet). In the pre-test stage, electrical activity of leg muscles including tibialis anterior, peroneus longus, medial gastrocnemius and soleus were recorded at stance phase of walking, while all subjects walked barefoot along a 14m line. Experimental pesplanus group wore the custom-made orthoses for a period of six months. Then experimental pesplanus and control pesplanus groups underwent post-test. One-way ANOVA was used for data analysis. Results: After six months of utilizing foot orthoses, the tibialis anterior activity significantly decreased in contact sub-phase (P=0.006). The medial gastrocnemius activity showed a significant decrease in midstance sub-phase in the post-test (P=0.007). Also, the soleus muscle had decreased activity in contact (P=0.033) and midstance (p=0.023) sub-phases in the post-test. Conclusion: According to the results of this study, we found that long term use of foot orthoses could change muscle activation and result in secondary adaptation.
Koomesh (23453699)14(4)pp. 422-430
Introduction: Patellfemoral pain syndrome is one of the most common knee joint problems that affect athletes and non-athletes. Knee brace is often used as a treatment method for patellar realignment. The aim of the present study was to determine the effects of a patella support brace on myoelectric activity of selected knee muscles during single leg landing in healthy females. Materials and Methods: 19 healthy female students (Mean age: 23.6±1.98 years, height: 163.5±5.88 cm, weight: 62.3±3.6 kg) participated in this study. Myoelectric activity of biceps femoris, semitendinosus, vastus medialis and vastus lateralis were collected during single leg landing in with and without using the patella support brace conditions. Results: Use of the patella support brace had no significant effect on myoelectric activity for the semitendinosus (p=0.668), vastus medialis (VM) (p=0.915) and vastus lateralis (VL) (P=0.134), while myoelectric activity for biceps femoris (p=0.005) and ratio of VM/VL myoelectric activity significantly increased (p=0.045). Conclusion: Our results revealed that biceps femoris activity and vastus medialis/vastus lateralis ratio increased after using patella support brace during single leg landing. Further studies on kinematic and kinetic variables are needed to describe these changes in muscular activity when using the patella support brace.
Journal of Mazandaran University of Medical Sciences (17359260)23(103)pp. 94-103
Background and purpose: Impaired function of trunk extensor endurance is known as a risk factor and clinical sign for low-back pain. The aim of this study was to determine the relationship between selected back muscles fatigue index and hyperlordosis. Materials and methods: This case-control study was carried out in 12 males diagnosed with hyperlordosis and 12 with normal lumbar curve. Participants were randomly assigned into case and control groups. Surface electromyography activity of iliocostalis, longissimus thoracis, multifidus and gluteus maximus muscles were recorded during performing Sorensen test until exhaustion. Independent ttest and Pearson correlation coefficient were used for data analyses (P<0.05). Results: Median frequency slope decreased significantly for iliocostalis lumborum (P=0.022) and multifidus (P=0.004) muscles. Gluteus maximus muscle had a high correlation with endurance time among hyperlordotic group (r=0.87, P=0.005). Conclusion: Lower median frequency in the iliocostalis lumborum muscle in hyperlordosis group resulted in reduction of median frequency in the multifidus muscle. According to our findings, the gluteus maximus and the iliocostalis lumborum muscles were important determinant of endurance time in case and control groups, respectively. Therefore, iliocostalis lumborum and multifidus muscles training program should be considered in individuals with increased lumbar lordosis while Gluteus maximus training is beneficial for subjects with normal lumbar curve.
