Muscle Coordination Research Articles

Multi-channel EMG manifestations of upper-extremity muscle coordination imbalance among community-dwelling sarcopenic seniors

Multi-channel EMG manifestations of upper-extremity muscle coordination imbalance among community-dwelling sarcopenic seniors

Formulation and optimization of xanthohumol loaded solid dispersion for effective treatment of Parkinson's disease in rats: In vitro and in vivo assessment

Xanthohumol (XH) is a prenylated flavonoid that possesses neuroprotective effects by increasing the levels of dopamine (DA), reducing oxidative stress, and neuroinflammation against Parkinson's disease (PD). However, the neuroprotective efficacy of XH in managing PD is limited by its low solubility, poor bioavailability, and less blood-brain barrier (BBB) permeability leading to decreased therapeutic activity. To overcome these limitations, XH-loaded solid dispersion (SD) has been formulated using the Central Composite Design (CCD) approach. The optimized formulation was evaluated by determining the angle of repose, drug loading, percentage drug release, PXRD, DSC, FTIR, and SEM. The results of PXRD, DSC, and SEM demonstrated the formation of SD. The XH-SD showed a 6.45-fold enhancement in dissolution rate, a 12.7-fold increase in Cmax, and 26.11-fold increase in XH's area under curve (AUC) as compared to the naïve XH. In the pharmacokinetic studies, XH-SD showed a 42.20 folds increase in relative bioavailability(0-∞) compared to naïve XH. To assess pharmacodynamic effects, PD was induced using rotenone. The motor and non-motor functions were evaluated by assessing various behavioral parameters such as catalepsy, spontaneous locomotor activity and muscle coordination test. The formulation exhibited dose-dependent effects, with both low and high doses of XH-SD resulting in significant enhancements (P < 0.001) in motor functions in rats induced with PD. Furthermore, biochemical estimations showed that XH-SD at both doses increased the levels of dopamine (DA), and reduced oxidative stress and neuroinflammation.

Reducing electrocardiographic interference in the multichannel electromyogram to help muscle fatigue assessment in low-intensity contractions.

Surface electromyography (EMG) can be used in the rehabilitation of musculoskeletal disorders, for evaluating the coordination of muscles that stabilize a joint, or as an objective tool in assessing muscle fatigue. This latter may be achieved by evaluating the low-frequency content of the EMG. However, the electrocardiogram (ECG) interference is also recorded when EMG is acquired close to the heart. It may mask or even modify the information of interest in the EMG. Different signal processing techniques have been proposed to eliminate ECG artifacts from the EMG signals, the high-pass filter being the most used one. Nevertheless, this classic filtering approach would also attenuate EMG activities below 30 Hz, which contain information from low-intensity muscle contractions. This work addresses the automatic ECG attenuation when multichannel EMG is collected on the left pectoralis major muscle during a muscle fatigue test. The proposed ECG artifact mitigation extends a successful automatic template subtraction (TS) approach, which does not require an extra reference channel and is now applied to independent EMG source signal components extracted using a blind source separation technique (ICA, Independent Component Analysis). The automatic detection of ECG components was performed through two alternative measures: entropy and Kullback-Leibler divergence. While the ECG interference seems to hamper the detection of muscle fatigue in the low-contraction regime, the association ICA+TS preserved better the EMG low-frequency content, and the entropy-based automatic detection was found to be more suitable, avoiding possible errors that might arise from manual detection procedures.

Changes in lower extremity muscle coordination over a 30-minute walk do not differ by muscle fatigability

Changes in lower extremity muscle coordination over a 30-minute walk do not differ by muscle fatigability

Upper and Lower Limb Training Evaluation System Based on Virtual Reality Technology.

Upper and lower limb rehabilitation training is essential for restoring patients' physical movement ability and enhancing muscle strength and coordination. However, traditional rehabilitation training methods have limitations, such as high costs, low patient participation, and lack of real-time feedback. The purpose of this study is to design and implement a rehabilitation training evaluation system based on virtual reality to improve the quality of patients' rehabilitation training. This paper proposes an upper and lower limb rehabilitation training evaluation system based on virtual reality technology, aiming to solve the problems existing in traditional rehabilitation training. The system provides patients with an immersive and interactive rehabilitation training environment through virtual reality technology, aiming to improve patients' participation and rehabilitation effects. This study used Kinect 2.0 and Leap Motion sensors to capture patients' motion data and transmit them to virtual training scenes. The system designed multiple virtual scenes specifically for different upper and lower limbs, with a focus on hand function training. Through these scenes, patients can perform various movement training, and the system will provide real-time feedback based on the accuracy of the patient's movements. The experimental results show that patients using the system show higher participation and better rehabilitation training effects. Compared with patients receiving traditional rehabilitation training, patients using the virtual reality system have significantly improved movement accuracy and training participation. The virtual reality rehabilitation training evaluation system developed in this study improves the quality of patients' rehabilitation and provides personalized treatment information to medical personnel through data collection and analysis, promoting the systematization and personalization of rehabilitation training. This system is innovative and has broad application potential in the field of rehabilitation medicine.

Impact of spilanthol supplementation with balance training on neuromuscular performance

Abstract Background Age-related reductions in muscle mass, muscle contraction power, force, and coordination contribute to an elevated risk of falls and associated consequences. Research suggests that the enhancement of neuromuscular function is attainable through a regimen of targeted exercises and the strategic inclusion of certain supplements like spilanthol. This randomized controlled trial investigated the effect of resistance exercise with either spilanthol plus coordination/ balance training (BAL) or BAL-alone on neuromuscular function (countermovement jump, multiple one-leg hopping, and sit-to-stand test). Materials and methods In the course of this study, a cohort of 68 healthy male participants, aged 40 to 50 years, completed a rigorous 6-month intervention, from the initial 75 recruits. In the spilanthol-plus-BAL group, participants engaged in 30 minutes of resistance exercise sessions four times a week, complemented by daily supplementation of 17.5 mg of spilanthol. Results The analysis of the results showed significant improvements in the spilanthol-plus-BAL group, particularly evident in the peak countermovement power (p &amp;lt; 0.01). The mean effect size for this parameter was a + 1.5[0.9 to 2.1] W/kg greater change in spilanthol-plus-BAL group than BAL-alone group after six months. Moreover, multiple one-leg hopping performance showed significant enhancement in the spilanthol-plus-BAL group post-intervention. The parameters of sit-to-stand duration (1.04 s vs. 1.95 s; p = 0.03) and average acceleration (1.54 g vs. 1.06 g; p = 0.04) both exhibited substantial improvements in the spilanthol-plus-BAL group compared to the BAL-alone group. Conclusions The findings of this investigation contribute empirical evidence supporting the proposition that spilanthol supplementation, when integrated with BAL training, can exert a more pronounced impact on select facets of neuromuscular function. Key messages • Spilanthol supplementation with balance training can exert a pronounced impact on neuromuscular function. • Spilanthol supplementation with balance training demonstrates potential in mitigating sarcopenia and other degenerative conditions.

Dynamical network-based evaluation for neuromuscular dysfunction in stroke-induced hemiplegia during standing

BackgroundA given movement requires precise coordination of multiple muscles under the control of center nervous system. However, detailed knowledge about the changing characteristics of neuromuscular control for multi-muscle coordination in post-stroke hemiplegic patients during standing is still lacking. This study aimed to investigate the hemiplegia-linked neuromuscular dysfunction during standing from the perspective of multi-muscle dynamical coordination by utilizing a novel network approach – weighted recurrence network (WRN).MethodsTen male hemiplegic patients with first-ever stroke and 10 age-matched healthy male adults were instructed to stand on a platform quietly for 30 s with eyes opened and eyes closed, respectively. The WRN was constructed based on the surface electromyography signals of 16 muscles from trunk, hips, thighs and calves. Relevant topological parameters, including clustering coefficient (C) and average shortest path length (L), were extracted to evaluate the dynamical coordination of multiple muscles. A measure of node centrality in network theory, degree of centrality (DC), was innovatively introduced to assess the contribution of single muscle in the multi-muscle dynamical coordination. The standing-related assessment metric, center of pressure (COP), was provided by the platform directly.ResultsResults showed that the post-stroke hemiplegic patients stood with remarkably higher similarity of muscle activation and more coupled intermuscular dynamics, characterized by higher C and lower L than the healthy subjects (p < 0.05). The DC values and rankings of back, hip and calf muscles on the affected side were significantly decreased, whereas those on the unaffected side were significantly increased in hemiplegia group compared with the healthy group (p < 0.05). Without visual feedback, subjects exhibited enhanced muscle coordination and increased muscle involvement (p < 0.05). A decrease in C and an increase in L of WRN were observed with decreased COP areas (p < 0.05).ConclusionsThese findings revealed that stroke-induced hemiplegia could significantly influence the neuromuscular control, which was manifested as more coupled intermuscular dynamics, abnormal deactivation of muscles on affected side and compensation of muscles on unaffected side from the perspective of multi-muscle coordination. Enhanced multi-muscle dynamical coordination was strongly associated with impaired postural control. This study provides a novel analytical tool for evaluation of neuromuscular dysfunction and specification of responsible muscles for impaired postural control in stroke-induced hemiplegic patients, and could be potentially applied in clinical practice.

Neuromuscular synergy characteristics of Tai Chi leg stirrup movements: optimal coordination patterns throughout various phases.

To investigate the neuromuscular activity characteristics of Tai Chi athletes and identify optimal muscle synergy patterns. Data were collected from 12 elite Tai Chi athletes using a Vicon motion capture system, a Kistler 3D force plate, and a Noraxon surface electromyography system. Muscle synergy patterns were extracted using Non-negative Matrix Factorization. Four muscle synergy patterns were identified in each of the three phases of the leg stirrup movement, with the optimal synergy pattern for each phase determined as follows: knee lift phase: rectus femoris and vastus lateralis of the right leg; extension phase: rectus femoris, vastus lateralis, biceps femoris, and medial gastrocnemius of the right leg; recovery phase: rectus femoris, vastus lateralis, and medial gastrocnemius of the right leg. These patterns explain the muscle coordination activities for each phase. This study identified the optimal muscle synergy patterns for each phase, supporting the fluidity and force generation of the leg stirrup movement. This provides Tai Chi athletes with a more efficient way to exert strength and maintain balance.

The impact of anterior knee displacement on knee joint load during the forward bow step in Tai Chi.

While the forward bow step is a crucial component of Tai Chi (TC) practice, little research has been conducted on its impact on knee joint load and muscle coordination. This study aims to investigate the effects of three different knee forward positions during the TC forward bow step on knee joint loading. Twenty TC practitioners were recruited, and motion capture systems, force platforms, and surface electromyography were utilized to synchronously collect biomechanical parameters of three types of forward bow steps: knee joint not exceeding the tip of the foot (NETT), knee joint forward movement level with the tip of the foot (LTT), and knee joint forward movement exceeding the tip of the foot (ETT). Ligament and muscle forces were calculated using OpenSim software for musculoskeletal modeling and simulation. One-way ANOVA was used to analyze the variations of the indicators during the peak anterior displacement of the knee joint in three movements. Additionally, spm1d one-way ANOVA was employed to examine the variations in the one-dimensional curve of the indicators throughout the entire movement process. Compared with LTT and ETT, the NETT posture was associated with significantly decreased knee flexion angle (F = 27.445, p = 0.001), knee anterior-posterior translation (F = 36.07, p < 0.001), flexion-extension torque (F = 22.232, p = 0.001), ligament force (F = 9.055, p = 0.011). Additionally, there was also a significant reduction in muscle strength, including quadriceps (F = 62.9, p < 0.001), long biceps femoris (F = 18.631, p = 0.002), lateral gastrocnemius (F = 24.933, p = 0.001) and soleus (F = 7.637, p = 0.017). This study further confirms that in the forward lunge movement of Tai Chi, the knee joint load is mainly concentrated during the forward movement phase. Compared to the knee joint load at the NETT position, the load is greater at the LTT position; and compared to the LTT position, the load is even greater at the ETT position.

De novo sensorimotor learning through reuse of movement components.

From tying one's shoelaces to driving a car, complex skills involving the coordination of multiple muscles are common in everyday life; yet relatively little is known about how these skills are learned. Recent studies have shown that new sensorimotor skills involving re-mapping familiar body movements to unfamiliar outputs cannot be learned by adjusting pre-existing controllers, and that new task-specific controllers must instead be learned "de novo". To date, however, few studies have investigated de novo learning in scenarios requiring continuous and coordinated control of relatively unpractised body movements. In this study, we used a myoelectric interface to investigate how a novel controller is learned when the task involves an unpractised combination of relatively untrained continuous muscle contractions. Over five sessions on five consecutive days, participants learned to trace a series of trajectories using a computer cursor controlled by the activation of two muscles. The timing of the generated cursor trajectory and its shape relative to the target improved for conditions trained with post-trial visual feedback. Improvements in timing transferred to all untrained conditions, but improvements in shape transferred less robustly to untrained conditions requiring the trained order of muscle activation. All muscle outputs in the final session could already be generated during the first session, suggesting that participants learned the new task by improving the selection of existing motor commands. These results suggest that the novel controllers acquired during de novo learning can, in some circumstances, be constructed from components of existing controllers.

Novel Method of Measuring Pelvic Floor Muscle Motion May Improve Accessibility of Pelvic Floor Muscle Coordination Training.

Pelvic floor muscle ultrasound is an important clinical tool for improving motor coordination and even strength. Although the gold standard approach involves transperineal probe placement, this is not always feasible with sensitive populations, requires privacy owing to probe placement, and additional sonography training. This article introduces a novel transabdominal method for measuring pelvic floor muscle motion that incorporates a reference point within the bladder. The hypothesis is that the novel measurement will correlate positively with transperineal measurements. A total of 55 women (15 nulliparous, 40 parous; 20 continent, 35 incontinent) performed pelvic floor muscle contraction and strain. Transabdominal ultrasound measured bladder diagonal length (BDL) and transperineal ultrasound measured bladder neck height (BNH), levator plate length (LPL), and levator plate angle (LPA). Spearman's test measured the correlation between the measurement outcomes and an independent t test compared outcomes based on parity and stress urinary incontinence symptom status. Spearman's correlation showed moderate positive correlations between the pelvic floor measurements for both tasks, which reduced slightly when grouping by parity and symptom status. Group differences were significant for BDL during the muscle contraction, factoring in SUI symptoms (p = 0.019) and parity status (p = 0.005) and LPL during contraction, factoring in parity status (p = 0.033). BDL correlates with BNH, LPL, and LPA with slightly reduced correlation when factoring in parity and continence status. The advantages of the method include accessibility for sensitive populations, nontraditional positions due to the anatomical reference point, functional locations due to limited privacy needs, and minimal training required for pelvic floor therapists to incorporate into rehabilitation.

Ocular and systemic manifestations of Joubert syndrome: A case report

Joubert syndrome (JS) is a group of rare disorders that stem from defects in sensory organelle, the primary cilia. Affected patients often present with disorders affecting multiple systems, including the brain, eye, and kidneys. Oculomotor apraxia is the most frequent ocular manifestation (80%), followed by strabismus (74%) and nystagmus (72%). A minority of patients also present with ptosis (43%), chorioretinal coloboma (30%), and optic nerve atrophy (22%). Common symptoms include breathing abnormalities, mental developmental delays, loss of voluntary muscle coordination, and abnormal eye movements, with diagnostic “molar tooth” sign observed by magnetic resonance imaging of the midbrain. Hepatic and renal function need to be monitored. Delayed diagnosis is usually related to its variable, nonspecific presentation. Awareness of the characteristic clinical and radiological findings in JS will help in early diagnosis, appropriate counseling, and proper rehabilitation.

Investigating Muscle Coordination during Dynamic Functional Reach Assessment

Investigating Muscle Coordination during Dynamic Functional Reach Assessment

Quantifying toddler exploration in different postures with powered mobility

ABSTRACT Access to powered mobility can support play and development for toddlers with disabilities. Using powered mobility in a standing posture has been theorized to support development of muscle coordination, balance, head and trunk stability, and transition to ambulation. The purpose of this study was to quantify and characterize joystick control, bodyweight support, and muscle activity while using the Permobil Explorer Mini in seated and supported standing postures. Nine children with mobility disabilities participated in four visits where they completed two, 15–20 minute play sessions, one in each posture, with a break between. We found that all toddlers engaged with the joystick in both postures, with individual differences in favored directions and control patterns. Participants had similar loading through their feet in both postures, but had slightly higher muscle activity in standing, especially while driving. These results demonstrate that young children with disabilities quickly engage with joystick-based powered mobility in seated and standing postures, with important individual differences that can inform future design of devices and interventions to support play and development.

Silk Fabric Functionalized by Nanosilver Enabling the Wearable Sensing for Biomechanics and Biomolecules.

Integrating biomechanical and biomolecular sensing mechanisms into wearable devices is a formidable challenge and key to acquiring personalized health management. To address this, we have developed an innovative multifunctional sensor enabled by plasma functionalized silk fabric, which possesses multimodal sensing capabilities for biomechanics and biomolecules. A seed-mediated in situ growth method was employed to coat silver nanoparticles (AgNPs) onto silk fibers, resulting in silk fibers functionalized with AgNPs (SFs@Ag) that exhibit both piezoresistive response and localized surface plasmon resonance effects. The SFs@Ag membrane enables accurate detection of mechanical pressure and specific biomolecules during wearable sensing, offering a versatile solution for comprehensive personalized health monitoring. Additionally, a machine learning algorithm has been established to specifically recognize muscle strain signals, potentially extending to the diagnosis and monitoring of neuromuscular disorders such as amyotrophic lateral sclerosis (ALS). Unlike electromyography, which detects large muscles in clinical medicine, sensing data for tiny muscles enhance our understanding of muscle coordination using the SFs@Ag sensor. This detection model provides feasibility for the early detection and prevention of neuromuscular diseases. Beyond muscle stress and strain sensing, biomolecular detection is a critical addition to achieving effective health management. In this study, we developed highly sensitive surface-enhanced Raman scattering (SERS) detection for wearable health monitoring. Finite-difference time-domain numerical simulations ware utilized to analyze the efficacy of the SFs@Ag sensor for wearable SERS sensing of biomolecules. Based on the specific SERS spectra, automatic extraction of signals of sweat molecules was also achieved. In summary, the SFs@Ag sensor bridges the gap between biomechanical and biomolecular sensing in wearable applications, providing significant value for personalized health management.

Corticospinal excitability during motor preparation of upper extremity reaches reflects flexor muscle synergies: A novel principal component-based motor evoked potential analyses.

Previous research has shown that noninvasive brain stimulation can be used to study how the central nervous system (CNS) prepares the execution of a motor task. However, these previous studies have been limited to a single muscle or single degree of freedom movements (e.g., wrist flexion). It is currently unclear if the findings of these studies generalize to multi-joint movements involving multiple muscles, which may be influenced by kinematic redundancy and muscle synergies. The objective of this study was to characterize corticospinal excitability during motor preparation in the cortex prior to functional upper extremity reaches. 20 participants without neurological impairments volunteered for this study. During the experiment, the participants reached for a cup in response to a visual "Go Cue". Prior to movement onset, we used transcranial magnetic stimulation (TMS) to stimulate the motor cortex and measured the changes in motor evoked potentials (MEPs) in several upper extremity muscles. We varied each participant's initial arm posture and used a novel synergy-based MEP analysis to examine the effect of muscle coordination on MEPs. Additionally, we varied the timing of the stimulation between the Go Cue and movement onset to examine the time course of motor preparation. We found that synergies with strong proximal muscle (shoulder and elbow) components emerged as the stimulation was delivered closer to movement onset, regardless of arm posture, but MEPs in the distal (wrist and finger) muscles were not facilitated. We also found that synergies varied with arm posture in a manner that reflected the muscle coordination of the reach. We believe that these findings provide useful insight into the way the CNS plans motor skills.

Evaluating the Impact of Collaborative Robots in E-Waste Disassembly Through EMG-EMG Coherence Analysis

With the advance of human-robot collaboration (HRC), collaborative robots (cobots) have emerged as solutions to alleviate the manual tasks involved in electronic waste (e-waste) disassembly. This study employed surface electromyography (EMG) to investigate whether cobots can enhance muscle coordination. EMG-EMG coherence in both beta and gamma bands was calculated from 22 participants to quantify coordination between four muscle groups—biceps brachii (BB), brachioradialis (BR), upper trapezius (UT), and erector spinae (ES). Comparison results showed that after the introduction of the cobot, significant increases in left BR&amp;BB, BR&amp;UT, BR&amp;ES, and BB&amp;UT pairs, right BR&amp;BB, BR&amp;UT, and BB&amp;ES pairs, and bilateral BR pair were observed. Notably, left BR&amp;ES presented the most substantial increase at 18.88% and 26.39% in the beta and gamma bands, respectively ( p &lt; .05). These findings suggest that cobots hold potential to enhance muscle coordination during e-waste disassembly, thereby shedding light on the construction of HRC-based e-waste disassembly systems.

The Importance of Physical Fitness Parameters in Rhythmic Gymnastics: A Scoping Review.

This scoping review presents an overview of physical fitness parameters in rhythmic gymnastics as well as the association of fitness with gymnasts' performance, competitive level, and age. PubMed, Scopus, and Sport Discus databases were searched. Of the 586 records retrieved, 41 studies met the inclusion criteria (n = 1915 participants). The included studies examined flexibility, aerobic capacity, muscle power, muscle endurance, muscle strength, sprint speed, agility, balance, and coordination. Performance was associated with flexibility, aerobic capacity, lower-limb muscle power, agility, muscular endurance, balance, and coordination from a young age. Flexibility, aerobic capacity, and muscle power were, in general, higher in high-level gymnasts than in low-level gymnasts or controls. Older rhythmic gymnasts demonstrated higher scores than the younger ones in flexibility, aerobic capacity, balance, and sport-specific coordination but not in muscle endurance, while some studies reported a decline in muscle power with age. Supplementary physical fitness training improved all physical abilities irrespective of the gymnasts' level. Rhythmic gymnastics training alone improved muscle power, agility, speed, muscular endurance, and balance to a lesser extent than targeted fitness training. Muscular strength, speed, and agility are largely under-researched in rhythmic gymnastics. Emphasis should be given to targeted strength and power training due to the high mechanical loads placed on skeletally immature athletes.

Temporal Dynamics and Physical Priori Multimodal Network for Rehabilitation Physical Training Evaluation.

Sensor-based rehabilitation physical training assessment methods have attracted significant attention in refined evaluation scenarios. A refined rehabilitation evaluation method combines the expertise of clinicians with advanced sensor-based technology to capture and analyze subtle movement variations often unobserved by traditional subjective methods. Current approaches center on either body postures or muscle strength, which lack more sophisticated analysis features of muscle activation and coordination, thereby hindering analysis efficacy in deep rehabilitation feature exploration. To address this issue, we present a multimodal network algorithm that integrates surface electromyography (sEMG) and stress distribution signals. The algorithm considers the physical knowledge a priori to interpret the current rehabilitation stage and efficiently handles temporal dynamics arising from diverse user profiles in an online setting. Besides, we verified the performance of this model using a learned-nonuse phenomenon assessment task in 24 subjects, achieving an accuracy of 94.7%. Our results surpass those of conventional feature-based, distance-based, and ensemble baseline models, highlighting the advantages of incorporating multimodal information rather than relying solely on unimodal data. Moreover, the proposed model presents a network design solution for rehabilitation physical training that requires deep bioinformatic features and can potentially assist real-time and home-based physical training work.

Muscle synergies in upper limb stroke rehabilitation: a scoping review.

Upper limb impairment is a common consequence of stroke, significantly affecting the quality of life and independence of survivors. This scoping review assesses the emerging field of muscle synergy analysis in enhancing upper limb rehabilitation, focusing on the comparison of various methodologies and their outcomes. It aims to standardize these approaches to improve the effectiveness of rehabilitation interventions and drive future research in the domain. Studies included in this scoping review focused on the analysis of muscle synergies during longitudinal rehabilitation of stroke survivors' upper limbs. A systematic literature search was conducted using PubMed, Scopus, and Web of Science databases, until September 2023, and was guided by the PRISMA for scoping review framework. Fourteen studies involving a total of 247 stroke patients were reviewed, featuring varied patient populations and rehabilitative interventions. Protocols differed among studies, with some utilizing robotic assistance and others relying on traditional therapy methods. Muscle synergy extraction was predominantly conducted using Non-Negative Matrix Factorization from electromyography data, focusing on key upper limb muscles essential for shoulder, elbow, and wrist rehabilitation. A notable observation across the studies was the heterogeneity in findings, particularly in the changes observed in the number, weightings, and temporal coefficients of muscle synergies. The studies indicated varied and complex relationships between muscle synergy variations and clinical outcomes. This diversity underscored the complexity involved in interpreting muscle coordination in the stroke population. The variability in results was also influenced by differing methodologies in muscle synergy analysis, highlighting a need for more standardized approaches to improve future research comparability and consistency. The synthesis of evidence presented in this scoping review highlights the promising role of muscle synergy analysis as an indicator of motor control recovery in stroke rehabilitation. By offering a comprehensive overview of the current state of research and advocating for harmonized methodological practices in future longitudinal studies, this scoping review aspires to advance the field of upper limb rehabilitation, ensuring that post-stroke interventions are both scientifically grounded and optimally beneficial for patients.