Muscle Coordination Research Articles

Correlation of Balance, Coordination, and Power of Leg Muscles to the Quality of Shooting Ability in Futsal Games

Shooting technique is a basic determining technique in futsal to get victory points. The ability to measure shooting techniques requires important component elements, one of which is balance, coordination, and leg muscle power. This study aims to determine the correlation of balance, coordination, and leg muscle power to the quality of shooting ability using the instep in futsal games. This research is a correlational research. This study was conducted with subjects totaling 20 athletes from the Escape FC team. The instruments used in this study were coordination tests using the Soccer Wall Volley Test, balance using the Modifield Bass Test, leg muscle power using Standing Broad or Long Jump and shooting skills using the target area of the shooting skill test. Data analysis techniques in this study using simple correlation test analysis using the product moment correlation formula and multiple correlation using regression line equations. Based on the results of this study showed: (1) the relationship between coordination on futsal shooting ability using instep R of 0.623 with sig value. of 0.003, (2) the relationship between balance and futsal shooting ability using instep R of 0.472 with sig value. of 0.002, (3) the relationship between leg muscle power and futsal shooting ability using instep R of 0.045 with sig value. of 0.000. (4) the relationship between coordination, balance, and leg muscle power on the ability to shoot futsal using the instep R of 0.809, R2 of 0.654 with a sig value. amounted to 0.001. So it can be concluded that the relationship between coordination, balance, and leg muscle power with the ability to shoot futsal using the instep in futsal sports is significant.

Age-related changes in muscle coordination patterns of stepping responses to recover from loss of balance

IntroductionReactive stepping capacity to recover from a loss of balance declines with aging, which increases the risk of falling. To gain insight into the underlying mechanisms, we investigated whether muscle coordination patterns of reactive stepping differed between healthy young and older individuals. MethodsWe performed a cross-sectional study between 15 healthy young and 14 healthy older adults. They recovered from 200 multidirectional platform translations that evoked reactive stepping responses. We determined spatiotemporal step variables and used muscle synergy analysis to characterize stance- and swing-leg muscle coordination patterns from the start of perturbation until foot landing. ResultsWe observed delayed step onsets in older individuals, without further spatiotemporal differences. Muscle synergy structure was not different between young and older individuals, but age-related differences were observed in the time-varying synergy activation patterns. In anterior-posterior directions, the older individuals demonstrated significantly enhanced early swing-leg synergy activation consistent with non-stepping behavior. In addition, around step onset they demonstrated increased levels of synergy coactivation (mainly around the ankle) in lateral and anterior directions, which did not appear to hamper foot clearance. ConclusionAlthough synergy structure was not affected by age, the delayed step onsets and the enhanced early synergy recruitment point at a relative bias towards non-stepping behavior in older adults. They may need more time for accumulating information on the direction of perturbation and making the corresponding sensorimotor transformations before initiating the step. Future work may investigate whether perturbation-based training improves these age-related deficits.

Osteogenesis imperfecta in children: treatment experience

Osteogenesis imperfecta (OI) is a genetic disorder primarily characterized by an impairment in the synthesis of type I collagen, leading to bone fragility, frequent fractures, scoliosis, short stature, and other symptoms. The disease is mostly inherited from parents to children, and its severity can vary significantly. This article describes the approach to treatment and therapy outcomes for 10 children with osteogenesis imperfecta. Objective — сomplex examination of pediatric patients with OI, treatment with bisphosphonates and further support by multidisciplinary team of specialists for therapy evaluation. Materials and methods. The treatment was aimed to minimize the frequency of fractures and improve the quality of life of patients. Key aspects of the treatment included: medicinal treatment (bisphosphonates were used to reduce bone resorption, thereby increasing bone mass and reducing bone fragility, as well as vitamin D and calcium, administered to support normal bone mineralization); physical therapy (included exercises to develop muscle strength, coordination, and joint mobility, minimizing the risk of injury); and management by a multidisciplinary team (consultations with an orthopedist, psychologist, and other specialists as needed). Results and discussion. The treatment results were positive, showing a reduction in the frequency of fractures and improvements in functionality and quality of life. Conclusions. Over the course of 11 months, the significant reduction in medical complications and improvements in the overall health status of the study participants have been noticed, demonstrating the importance of a comprehensive approach to the treatment of osteogenesis imperfecta.

Non-Invasive Alcohol Concentration Measurement Using a Spectroscopic Module: Outlook for the Development of a Drunk Driving Prevention System.

Alcohol acts as a central nervous system depressant and falls under the category of psychoactive drugs. It has the potential to impair vital bodily functions, including cognitive alertness, muscle coordination, and induce fatigue. Taking the wheel after consuming alcohol can lead to delayed responses in emergency situations and increases the likelihood of collisions with obstacles or suddenly appearing objects. Statistically, drivers under the influence of alcohol are seven times more likely to cause accidents compared to sober individuals. Various techniques and methods for alcohol measurement have been developed. The widely used breathalyzer, which requires direct contact with the mouth, raises concerns about hygiene. Methods like chromatography require skilled examiners, while semiconductor sensors exhibit instability in sensitivity over measurement time and has a short lifespan, posing structural challenges. Non-dispersive infrared analyzers face structural limitations, and in-vehicle air detection methods are susceptible to external influences, necessitating periodic calibration. Despite existing research and technologies, there remain several limitations, including sensitivity to external factors such as temperature, humidity, hygiene consideration, and the requirement for periodic calibration. Hence, there is a demand for a novel technology that can address these shortcomings. This study delved into the near-infrared wavelength range to investigate optimal wavelengths for non-invasively measuring blood alcohol concentration. Furthermore, we conducted an analysis of the optical characteristics of biological substances, integrated these data into a mathematical model, and demonstrated that alcohol concentration can be accurately sensed using the first-order modeling equation at the optimal wavelength. The goal is to minimize user infection and hygiene issues through a non-destructive and non-invasive method, while applying a compact spectrometer sensor suitable for button-type ignition devices in vehicles. Anticipated applications of this study encompass diverse industrial sectors, including the development of non-invasive ignition button-based alcohol prevention systems, surgeon's alcohol consumption status in the operating room, screening heavy equipment operators for alcohol use, and detecting alcohol use in close proximity to hazardous machinery within factories.

Design of Medical Self-Propelled Walking Tricycle as a Post-Stroke Rehabilitation Tool

Patients recovering from a stroke may not be able to use all rehabilitation equipment due to their poor muscle strength and coordination. This study proposes to design a self-propelled walking tricycle that is a non-motorized three-wheel vehicle in a delta configuration without a pedal. This study was conducted by considering the post-stroke patient needs. It was done using two analysis methods, finite element analysis, and rapid upper limb analysis, to justify the reliability of the design. The results show that the maximum stress is 38.8 MPa in the connection area of the seat tube and down tube, while the maximum deformation is 0.399 mm in the seat post. The tricycle is constructed with 153 mm of ground clearance. Therefore, patients can lift their legs and drive the tricycle by swinging their legs repeatedly, like walking. The proposed self-propelled walking tricycle can be considered as a rehabilitation tool that can train the lower extremities. It could be used for strengthening the muscles and improve body coordination for the recovery process.

Ethanolic Extract of <i>Alternanthera Sessilis</i>: A Potential Therapeutic Agent for Behavioral Improvements in Reserpine-Induced Parkinsonian Rats

The present study evaluated the potential of an ethanol extract from Alternanthera sessilis to alleviate reserpine-induced Parkinson's disease (PD) like behavioural manifestations in rats. The animals were grouped into five: a control group, a group receiving only reserpine, a group treated with levodopa and carbidopa, and two groups given different doses of the Alternanthera sessilis extract. Reserpine was used to mimic PD symptoms, while the extract was administered orally at two different concentrations. The behavioral tests were conducted to assess locomotor activity, grip strength, catalepsy, and rearing activity. Locomotor activity was measured using an actophotometer, where interruptions in light beams caused by the rates were recorded over a 10-minute period. Grip strength was evaluated using a rotarod apparatus, measuring the time taken for rats to fall off individual rods. Catalepsy was assessed through a bar test, measuring the time for rats to descend from a horizontal bar to the base. Rearing activity was observed in a round open field arena, with parameters including the occurrence rate of rearing, general movements score, and duration spent in the center of the arena. The results revealed administration of reserpine led to a decrease in body weight, locomotor activity, muscle coordination, catalepsy score, rearing activity, and grip strength compared to the control group. Conversely, treatment with levodopa and carbidopa resulted in increased values for these parameters. Importantly, administration of Alternanthera sessilis extract showed a dose-dependent reversal of the effects induced by reserpine, with significant increases observed in body weight, locomotor activity, muscle coordination, rearing activity, general movement, and grip strength, indicating its potential therapeutic effects. In conclusion, the present study results suggest that the extract from the Alternanthera sessilis plant might protect brain cells and improve symptoms of Parkinson's disease. However, more research is needed to understand how it works and if it can be used safely and effectively clinical trails.

Assessment of Oral Masticatory Muscle Activity With Different Chewing Gums: A Cross-Sectional Study Based on Electromyogram Analysis.

Facial muscles, particularly those involved in mastication, play a pivotal role in the chewing process. Despite their influence on chewing, these muscles undergo alterations during mastication. Examining the relationship between chewed substances and muscle activity can provide insights into various pathological processes and aid in the development of therapeutic chewing techniques. This study aimed to evaluate the impact of different commercially available chewing gums on the activity of key masticatory muscles. Twenty-two participants were recruited for the study. They were instructed to chew four commercially available gums: group 1 comprised sugar gum with a strong flavor; group 2 included gum containing sorbitol; group 3 consisted of gum containing xylitol; and group 4 provided sugar gum with a mild flavor. Electromyogram (EMG) recordings were utilized to assess muscle activity. Various aspects of muscle activity, including chewing time, maximum muscle potential, and coordination between different muscles, were evaluated. Data tabulation and analysis were performed using IBM SPSS software version 23.0 (IBM Corp., Armonk, NY). Analysis revealed that in terms of temporalis symmetry, group 2 exhibited the highest mean deviation, while for masseter symmetry, group 3 demonstrated the highest mean deviation. The total deviation for the temporalis and masseter muscles was 72.16% and 65.55%, respectively, indicating greater symmetry in the temporalis muscle. Additionally, group 3 displayed the highest mean deviation in both left and right-sided synergic activity of the muscles. The total deviation for the right and left sides was 64.34% and 65.67%, respectively. The findings suggest that sugar-free chewing gums elicit increased muscle activity compared to sugar-containing chewing gums. Furthermore, the utilization of calorie-free chewing gums with a firm texture was associated with better-coordinated muscle activity. These results provide valuable insights into the effects of different chewing gums on masticatory muscle function and coordination, which may have implications for therapeutic interventions and oral health management.

An analysis of the effect of motor experience on muscle synergy in the badminton jump smash

The jump smash is badminton's most aggressive technical manoeuvre, which is often the key to winning a match. This paper aims to explore the neuromuscular control strategies of advanced and beginner players when jumping smash in different ways. Collecting sEMG and kinematic data from 18 subjects with different motor experiences when jumping smash. Nonnegative Matrix Factorization and K-Means clustering were used to extract muscle synergies and exclude irrelevant combined synergies. Uncontrolled manifold analysis was then used to explore the association between synergies and shoulder stability. In addition, motor output at the spinal cord level was assessed by mapping sEMG to each spinal cord segment. The study found that advanced subjects could respond to different jump smash styles by adjusting the coordinated activation strategies of the upper-limb and postural muscles. Long-term training can induce a rapid decrease in the degree of co-variation of the synergies before contact with a shuttlecock to better cope with an upcoming collision. It is recommended that beginners should focus more on training the coordination of upper-limb muscles and postural muscles.

Muscle synergy-informed neuromusculoskeletal modelling to estimate knee contact forces in children with cerebral palsy

Cerebral palsy (CP) includes a group of neurological conditions caused by damage to the developing brain, resulting in maladaptive alterations of muscle coordination and movement. Estimates of joint moments and contact forces during locomotion are important to establish the trajectory of disease progression and plan appropriate surgical interventions in children with CP. Joint moments and contact forces can be estimated using electromyogram (EMG)-informed neuromusculoskeletal models, but a reduced number of EMG sensors would facilitate translation of these computational methods to clinics. This study developed and evaluated a muscle synergy-informed neuromusculoskeletal modelling approach using EMG recordings from three to four muscles to estimate joint moments and knee contact forces of children with CP and typically developing (TD) children during walking. Using only three to four experimental EMG sensors attached to a single leg and leveraging an EMG database of walking data of TD children, the synergy-informed approach estimated total knee contact forces comparable to those estimated by EMG-assisted approaches that used 13 EMG sensors (children with CP, n = 3, R2 = 0.95 ± 0.01, RMSE = 0.40 ± 0.14 BW; TD controls, n = 3, R2 = 0.93 ± 0.07, RMSE = 0.19 ± 0.05 BW). The proposed synergy-informed neuromusculoskeletal modelling approach could enable rapid evaluation of joint biomechanics in children with unimpaired and impaired motor control within a clinical environment.

Variability of Muscle Coordination Patterns in Human Movement

Variability of Muscle Coordination Patterns in Human Movement

Effects of the powerball® system on muscle strength, coordination, fatigue, functionality and quality of life in people with multiple sclerosis. A randomized clinical trial

IntroductionAlthough clinical and functional impairments in the lower limbs have been extensively studied in patients with MS, the upper limb (UL) are also frequently affected. Clinical impairment of the UL in patients with MS is very common with muscle strength and hand dexterity as critical factors in maintaining functional activities that are the basis for independence and quality of life in people with MS.ObjectiveTo investigate the effects of a training protocol using the Powerball® system in combination with conventional physiotherapy on muscle strength, coordination, fatigue, functionality, and quality of life in persons with MS over an 8-week period.Materials and methodsA double-blind randomized controlled trial was conducted. The control group received conventional treatment, while the experimental group received additional UL training using the Powerball® system. Both groups received the same number of sessions and weeks of intervention. The following outcome measures were used: isometric grip and pinch strength, Box and Block Test (BBT), Nine Hole Peg Test (NHPT), Abilhand scale, Fatigue Severity Scale (FSS), Multiple Sclerosis Impact Scale (MSIS-29), and Likert satisfaction questionnaire for the experimental group. All measures were administered at baseline, after the treatment, and during a 3-week follow-up period.Results25 patients completed the study (12 in the experimental and 13 in the control group). The experimental group showed significant improvements in coordination and manual dexterity of the more affected UL as measured by the BBT comparing pre- to post-treatment (p = 0.048) and pre-treatment to follow-up (p = 0.001), and on the less affected UP comparing pre-treatment to follow-up (p < 0.001) and post-treatment to follow-up (p = 0.034). The Likert-type satisfaction questionnaire obtained a mean score of 89.10 (± 8.54) out of 100 points.ConclusionsUpper limb treatment protocol using the Powerball® system, in combination with conventional physiotherapy for 8 weeks resulted in significant improvements in the intra-group analysis for UL coordination and manual dexterity in favor of the experimental group. The experimental group showed excellent satisfaction to the treatment.

The Influence of a Multistage Mountain-Bike Race on Neuromuscular Activation and Synergies: A Case Study.

This case study aimed to describe potential changes in neuromuscular activation and synergies after an 8-day cross-country mountain-bike stage race. A peak power output test was performed 5days before the race. Two days before the start and after 7days of racing, the athlete performed a power-based Lamberts Submaximal Cycling Test, including surface electromyography, and completed a Daily Analysis of Life Demands of Athletes questionnaire. Neuromuscular activation, in terms of root mean square, timing (onset-offset) of muscle activation, and synergies, was obtained from electromyography recordings. The athlete reported an increase in symptoms of experienced stress after the stage race on the Daily Analysis of Life Demands of Athletes questionnaire. Both biceps femoris and tibialis anterior muscles showed a reduction in normalized amplitude after the stage race. In addition, the number of synergies that was necessary to describe neuromuscular activation increased from 2 to 3. In this case study, the increase in synergies suggests that, after the stage race, the athlete showed a more complex muscle-recruitment pattern. This may indicate that muscle coordination can change when muscle fatigue occurs; however, further research is needed to confirm these results in a larger sample.

Direction-Specific Changes in Trunk Muscle Synergies in Individuals With Extension-Related Low Back Pain.

Background Identifying altered trunk control is critical for treating extension-related low back pain (ERLBP), a common subgroup classified by clinical manifestations. The changed coordination of trunk muscles within this group during particular trunk tasks is still not clearly understood. Objectives The objective of this study is to investigate trunk muscle coordination during 11 trunk movement and stability tasks in individuals with ERLBP compared to non-low back pain (LBP) participants. Methods Thirteen individuals with ERLBP and non-LBP performed 11 trunk movement and stability tasks. We recorded the electromyographic activities of six back and abdominal muscles bilaterally. Trunk muscle coordination was assessed using the non-negative matrix factorization (NMF) method to identify trunk muscle synergies. Results The number of synergies in the ERLBP group during the cross-extension and backward bend tasks was significantly higher than in the non-LBP group (p<0.05). The cluster analysis identified the two trunk synergies for each task with strikingly similar muscle activation patterns between groups. In contrast, the ERLBP group exhibited additional trunk muscle synergies that were not identified in the non-LBP group. The number of synergies in the other tasks did not differ between groups (p>0.05). Conclusion Individuals with ERLBP presented directionally specific alterations in trunk muscle synergies that were considered as increased coactivations of multiple trunk muscles. These altered patterns may contribute to the excessive stabilization of and the high frequency of hyperextension in the spine associated with the development and persistence of ERLBP.

Changes in muscle coordination patterns during 400‐m sprint: Impact of fatigue and performance decline

AbstractThe purpose of this study was to compare the muscle synergies extracted from 14 unilateral lower‐limb and trunk muscles between the first and final parts of a 400‐m sprint in experienced sprinters to understand neuromuscular coordination of multiple muscles in the fatigued condition sprint. Nine male 400‐m sprinters (400‐m personal record: 48.11 ± 1.6 s) performed 400‐m sprints as with the real competition strategy. We defined the first part (100–150 m section) and the final part (350–400 m section), and obtained mean spatiotemporal variables (e.g., running speed, step frequency, and step length) for both parts. Electromyography (EMG) signals were obtained using wireless EMG sensors (2000 Hz) from 14 lower‐limb and trunk muscles. Non‐negative matrix factorization was performed to extract the muscle synergies for both parts. We observed significantly declined spatiotemporal variables in the final part induced by fatigue. The extracted number of synergies was 7.0 ± 0.7 (mean ± SD) for the first part and 7.2 ± 0.4 for the final part with no significant differences between parts. However, we identified specific muscle synergy, and alterations in the individual muscle weightings of several hip muscles (rectus femoris: RF, tensor fasciae latae: TFL, and glutes maximus: Gmax muscles) while there was no change in the muscle weighting of shank muscles and the temporal patterns of all muscles even following fatigue in the 400‐m sprint. Fatigue‐induced performance decline in a 400‐m sprint corresponds to alterations in muscle synergies, particularly in hip muscles, with notable shifts in RF, TFL, and Gmax activation.

Grapho-plastic program to improve fine motor skills

The development of fine motor skills commences in infancy and progresses as the child gains muscle control and coordination throughout their growth. These skills are essential for a wide range of tasks required throughout life. This study focuses on enhancing fine motor skills in 4-year-old children through a specialized plastic graph program. Thirty children participated, and their progress was assessed using an observation sheet. Adequate fine motor development is crucial not only for academic success and daily activities but also for cognitive and social growth. The results indicate significant progress in fine motor skills development, along with enthusiastic participation in group activities and subsequent improvement in manual dexterity.

A framework based on subject-specific musculoskeletal models and Monte Carlo simulations to personalize muscle coordination retraining

Excessive loads at lower limb joints can lead to pain and degenerative diseases. Altering joint loads with muscle coordination retraining might help to treat or prevent clinical symptoms in a non-invasive way. Knowing how much muscle coordination retraining can reduce joint loads and which muscles have the biggest impact on joint loads is crucial for personalized gait retraining. We introduced a simulation framework to quantify the potential of muscle coordination retraining to reduce joint loads for an individuum. Furthermore, the proposed framework enables to pinpoint muscles, which alterations have the highest likelihood to reduce joint loads. Simulations were performed based on three-dimensional motion capture data of five healthy adolescents (femoral torsion 10°–29°, tibial torsion 19°–38°) and five patients with idiopathic torsional deformities at the femur and/or tibia (femoral torsion 18°–52°, tibial torsion 3°–50°). For each participant, a musculoskeletal model was modified to match the femoral and tibial geometry obtained from magnetic resonance images. Each participant’s model and the corresponding motion capture data were used as input for a Monte Carlo analysis to investigate how different muscle coordination strategies influence joint loads. OpenSim was used to run 10,000 simulations for each participant. Root-mean-square of muscle forces and peak joint contact forces were compared between simulations. Depending on the participant, altering muscle coordination led to a maximum reduction in hip, knee, patellofemoral and ankle joint loads between 5 and 18%, 4% and 45%, 16% and 36%, and 2% and 6%, respectively. In some but not all participants reducing joint loads at one joint increased joint loads at other joints. The required alteration in muscle forces to achieve a reduction in joint loads showed a large variability between participants. The potential of muscle coordination retraining to reduce joint loads depends on the person’s musculoskeletal geometry and gait pattern and therefore showed a large variability between participants, which highlights the usefulness and importance of the proposed framework to personalize gait retraining.

Towards Human-like Walking with Biomechanical and Neuromuscular Control Features: Personalized Attachment Point Optimization Method of Cable-Driven Exoskeleton.

The cable-driven exoskeleton can avoid joint misalignment, and is substantial alterations in the pattern of muscle synergy coordination, which arouse more attention in recent years to facilitate exercise for older adults and improve their overall quality of life. This study leverages principles from neuroscience and biomechanical analysis to select attachment points for cable-driven soft exoskeletons. By extracting key features of human movement, the objective is to develop a subject-specific design methodology that provides precise and personalized support in the attachment points optimization of cable-driven exoskeleton to achieve natural gait, energy efficiency, and muscle coordination controllable in the domain of human mobility and rehabilitation. To achieve this, the study first analyzes human walking experimental data and extracts biomechanical features. These features are then used to generate trajectories, allowing better natural movement under complete cable-driven exoskeleton control. Next, a genetic algorithm-based method is employed to minimize energy consumption and optimize the attachment points of the cable-driven system. This process identifies connections that are better suited for the human model, leading to improved efficiency and natural movement. By comparing the calculated elderly human model driven by exoskeleton with experimental subject in terms of joint angles, joint torques and muscle forces, the human model can successfully replicate subject movement and the cable output forces can mimic human muscle coordination. The optimized cable attachment points facilitate more natural and efficient collaboration between humans and the exoskeleton, making significant contributions to the field of assisting the elderly in rehabilitation.

Spatiotemporal patterns of throwing muscle synergies in yips-affected baseball players

“Yips” are involuntary movements that interfere with the automatic execution of sports movements. However, how the coordination among the various muscles necessary for sports movements is impaired in athletes with yips remains to be fully understood. This study aimed to assess whether muscle synergy analysis through non-negative matrix factorization (NMF) could identify impaired spatiotemporal muscle coordination in baseball players with throwing yips. Twenty-two college baseball players, including 12 with and 10 without yips symptoms participated in the study. Electromyographic activity was recorded from 13 ipsilateral upper extremity muscles during full-effort throwing. Muscle synergies were extracted through NMF. Cluster analysis was conducted to identify any common spatiotemporal patterns of muscle synergies in players with yips. Whether individual players with yips showed deviations in spatiotemporal patterns of muscle synergies compared with control players was also investigated. Four muscle synergies were extracted for each player, but none were specific to the yips group. However, a more detailed analysis of individual players revealed that two of the three players who presented dystonic symptoms during the experiment exhibited specific patterns that differed from those in control players. By contrast, each player whose symptoms were not reproduced during the experiment presented spatiotemporal patterns of muscle synergies similar to those of the control group. The results of this study indicate no common spatiotemporal pattern of muscle synergies specific to the yips group. Furthermore, these results suggest that the spatiotemporal pattern of muscle synergies in baseball throwing motion is not impaired in situations where symptoms are not reproduced even if the players have yips symptoms. However, muscle synergy analysis can identify the characteristics of muscle coordination of players who exhibit dystonic movements. These findings can be useful in developing personalized therapeutic strategies based on individual characteristics of yips symptoms.

Orientin Modulates Nrf2-ARE, PI3K/Akt, JNK-ERK1/2, and TLR4/NF-kB Pathways to Produce Neuroprotective Benefits in Parkinson's Disease.

Parkinson's disease (PD) is characterized by oxidative stress and neuroinflammation as key pathological features. Emerging evidence suggests that nuclear factor erythroid 2 related factor 2-antioxidant response element (Nrf2-ARE), phosphatidylinositol 3‑kinase-protein kinase B (PI3K-Akt), c-Jun N-terminal kinase-extracellular signal-regulated kinase 1/2 (JNK-ERK1/2), and toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-kB) pathways play pivotal roles in PD pathogenesis. Orientin, a phenolic phytoconstituent, has demonstrated modulatory potential on these pathways in various experimental conditions other than PD. In this study, we aimed to evaluate the neuroprotective effects of Orientin against rotenone-induced neurodegeneration in SH-SY5Y cell lines and the Swiss albino mice model of PD. Orientin was administered at doses 10 and 20µM in cell lines and 10 and 20mg/kg in mice, and its effects on rotenone-induced neurodegeneration were investigated. Oxidative stress markers including mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as inflammatory markers including interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were measured. The expression levels of genes related to Nrf2-ARE (Nrf2), PI3K/Akt (Akt), JNK-ERK1/2 (TNF-α), and TLR4/NF-kB (TNF-α) pathways were measured to understand the modulatory effect of Orientin on these pathways. Additionally, behavioral studies assessing locomotor activity, muscle coordination, and muscle rigidity were conducted with mice. Our results indicate that Orientin dose-dependently attenuated rotenone-induced changes in oxidative stress markers, inflammatory markers, gene expression levels, and behavioral parameters. Therefore, our study concludes that Orientin exhibits significant neuroprotective benefits against rotenone-induced PD by modulating Nrf2-ARE, PI3K-Akt, JNK-ERK1/2, and TLR4/NF-kB pathways.

Effects of workload and saddle height on muscle activation of the lower limb during cycling.

Cycling workload is an essential factor in practical cycling training. Saddle height is the most studied topic in bike fitting, but the results are controversial. This study aims to investigate the effects of workload and saddle height on the activation level and coordination of the lower limb muscles during cycling. Eighteen healthy male participants with recreational cycling experience performed 15 × 2-min constant cadence cycling at five saddle heights of 95%, 97%, 100%, 103%, and 105% of greater trochanter height (GTH) and three cycling workloads of 25%, 50%, and 75% of functional threshold power (FTP). The EMG signals of the rectus femoris (RF), tibialis anterior (TA), biceps femoris (BF), and medial gastrocnemius (MG) of the right lower limb were collected throughout the experiment. Greater muscle activation was observed for the RF and BF at a higher cycling workload, whereas no differences were observed for the TA and MG. The MG showed intensified muscle activation as the saddle height increased. The mean and maximum amplitudes of the EMG signals of the MG increased by 56.24% and 57.24% at the 25% FTP workload, 102.71% and 126.95% at the 50% FTP workload, and 84.27% and 53.81% at the 75% FTP workload, respectively, when the saddle height increased from 95 to 100% of the GTH. The muscle activation level of the RF was minimal at 100% GTH saddle height. The onset and offset timing revealed few significant differences across cycling conditions. Muscle activation of the RF and BF was affected by cycling workload, while that of the MG was affected by saddle height. The 100% GTH is probably the appropriate saddle height for most cyclists. There was little statistical difference in muscle activation duration, which might be related to the small workload.