scholarly journals Muscle synergies and complexity of neuromuscular control during gait in cerebral palsy

2015 ◽  
Vol 57 (12) ◽  
pp. 1176-1182 ◽  
Author(s):  
Katherine M Steele ◽  
Adam Rozumalski ◽  
Michael H Schwartz
Keyword(s):  
Cerebral Palsy ◽  
Neuromuscular Control ◽  
Muscle Synergies

scholarly journals Gait synergetic neuromuscular control in children with cerebral palsy at different gross motor function classification system levels

2019 ◽  
Vol 121 (5) ◽  
pp. 1680-1691 ◽  
Author(s):  
Yi Yu ◽  
Xiang Chen ◽  
Shuai Cao ◽  
De Wu ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Motor Function ◽  
Lower Limb ◽  
Classification System ◽  
Neuromuscular Control ◽  
Muscle Synergies ◽  
Gross Motor ◽  
Gross Motor Function ◽  
Gait Abnormalities ◽  
Semg Signals

Cerebral palsy (CP) is a neural developmental disease featured with gait abnormalities. CP gait assessment is usually performed with the Gross Motor Function Classification System (GMFCS) in clinics, which does not involve a thorough assessment of neuromuscular control. To understand how the neuromuscular control disorders lead to gait abnormalities, we explored the relationship between GMFCS levels and the gait synergetic control characteristics in this study. In total, 18 children with CP at different GMFCS levels (mean age: 4.41±1.30 yr) and 8 age-matched typically developing (TD) children (mean age: 4.43±1.36 yr) were recruited to perform a straight walking task, and the surface electromyographic (sEMG) signals from eight lower limb muscles on each side and accelerometer data were collected. A nonnegative matrix factorization method was applied to obtain the muscle synergies from the sEMG signals. Next, synergy structures were projected onto the basic gait synergies to test the completeness of those structures. Subsequently, synergy activation parameters, including total activation duration and coactivation index, were compared across the participants. This study showed that children with CP at GMFCS levels I and II and the TD children had similar synergy structures, but the synergy activations of these children with CP were different from those of TD children. In addition, similar to previous research, we also found that children with CP at GMFCS level III could not access all four basic synergies on both sides. Based on the synergy analysis results, a gait assessment paradigm was proposed to facilitate the clinical CP gait evaluation. NEW & NOTEWORTHY Understanding the mechanism of gait abnormality has important clinical significance for the diagnosis, prognosis, and possible treatment of motor dysfunction in children with cerebral palsy (CP). In this study, the comparisons of the lower limb muscle synergies among different groups of children with CP at different Gross Motor Function Classification System levels might provide some new insight into the mechanism underlying the gait disorder. In particular, the discrepancies of gait synergy structure and activation patterns across the study groups may indicate different neurophysiological and pathological attributes in different groups of patients.

scholarly journals Children With Cerebral Palsy Have Greater Stride-to-Stride Variability of Muscle Synergies During Gait Than Typically Developing Children: Implications for Motor Control Complexity

2018 ◽  
Vol 32 (9) ◽  
pp. 834-844 ◽  
Author(s):  
Yushin Kim ◽  
Thomas C. Bulea ◽  
Diane L. Damiano
Keyword(s):  
Cerebral Palsy ◽  
Motor Control ◽  
Clinical Utility ◽  
Neuromuscular Control ◽  
Muscle Synergy ◽  
Neurological Deficits ◽  
Muscle Synergies ◽  
Children With Cerebral Palsy ◽  
The Central Nervous System ◽  
Potential Clinical Utility

Background. There is mounting evidence that the central nervous system utilizes a modular approach for neuromuscular control of walking by activating groups of muscles in units termed muscle synergies. Examination of muscle synergies in clinical populations may provide insights into alteration of neuromuscular control underlying pathological gait patterns. Previous studies utilizing synergy analysis have reported reduced motor control complexity during walking in those with neurological deficits, revealing the potential clinical utility of this approach. Methods. We extracted muscle synergies on a stride-to-stride basis from 20 children with cerebral palsy (CP; Gross Motor Function Classification System levels I-II) and 8 children without CP, allowing the number of synergies to vary for each stride. Similar muscle synergies across all participants and strides were grouped using a k-means clustering and discriminant analysis. Results. In total, 10 clusters representing 10 distinct synergies were found across the 28 individuals. Relative to their total number of synergies deployed during walking, synergies from children with CP were present in a higher number of clusters than in children with typical development (TD), indicating significantly greater stride-to-stride variability. This increased variability was present despite reduced complexity, as measured by the mean number of synergies in each stride. Whereas children with CP demonstrate some novel synergies, they also deploy some of the same muscle synergies as those with TD, although less frequently and with more variability. Conclusion. A stride-by-stride approach to muscle synergy analysis expands its clinical utility and may provide a method to tailor rehabilitation strategies by revealing inconsistent but functional synergies in each child with CP.

scholarly journals Muscle Synergies During Walking in Children With Cerebral Palsy: A Systematic Review

2020 ◽  
Vol 11 ◽  
Author(s):  
Annike Bekius ◽  
Margit M. Bach ◽  
Marjolein M. van der Krogt ◽  
Ralph de Vries ◽  
Annemieke I. Buizer ◽  
...  
Keyword(s):  
Systematic Review ◽  
Cerebral Palsy ◽  
Muscle Synergies ◽  
Children With Cerebral Palsy

scholarly journals The Dynamic Motor Control Index as a Marker of Age-Related Neuromuscular Impairment

2021 ◽  
Vol 13 ◽  
Author(s):  
Ashley N. Collimore ◽  
Ashlyn J. Aiello ◽  
Ryan T. Pohlig ◽  
Louis N. Awad
Keyword(s):  
Motor Control ◽  
Age Groups ◽  
Neuromuscular Control ◽  
Muscle Synergies ◽  
Age Related ◽  
Index Study ◽  
Two Measures ◽  
Study Participants ◽  
Young Old ◽  
Neuromuscular Impairment

Biomarkers that can identify age-related decline in walking function have potential to promote healthier aging by triggering timely interventions that can mitigate or reverse impairments. Recent evidence suggests that changes in neuromuscular control precede changes in walking function; however, it is unclear which measures are best suited for identifying age-related changes. In this study, non-negative matrix factorization of electromyography data collected during treadmill walking was used to calculate two measures of the complexity of muscle co-activations during walking for 36 adults: (1) the number of muscle synergies and (2) the dynamic motor control index. Study participants were grouped into young (18–35 years old), young-old (65–74 years old), and old–old (75+ years old) subsets. We found that the dynamic motor control index [χ2(2) = 9.41, p = 0.009], and not the number of muscle synergies [χ2(2) = 5.42, p = 0.067], differentiates between age groups [χ2(4) = 10.62, p = 0.031, Nagelkerke R2 = 0.297]. Moreover, an impairment threshold set at a dynamic motor control index of 90 (i.e., one standard deviation below the young adults) was able to differentiate between age groups [χ2(2) = 9.351, p = 0.009]. The dynamic motor control index identifies age-related differences in neuromuscular complexity not measured by the number of muscle synergies and may have clinical utility as a marker of neuromotor impairment.

scholarly journals Physics-based predictive simulations to explore the differential effects of motor control and musculoskeletal deficits on gait dysfunction in cerebral palsy: a retrospective case study

2019 ◽  
Author(s):  
Antoine Falisse ◽  
Lorenzo Pitto ◽  
Hans Kainz ◽  
Hoa Hoang ◽  
Mariska Wesseling ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Muscle Activity ◽  
Clinical Decision Making ◽  
Neuromuscular Control ◽  
Gait Pattern ◽  
Retrospective Case ◽  
Crouch Gait ◽  
Walking Performance ◽  
Tendon Properties ◽  
Predictive Simulations

ABSTRACTModel-based simulations of walking have the theoretical potential to support clinical decision making by predicting the functional outcome of treatments in terms of walking performance. Yet before using such simulations in clinical practice, their ability to identify the main treatment targets in specific patients needs to be demonstrated. In this study, we generated predictive simulations of walking with a medical imaging based neuro-musculoskeletal model of a child with cerebral palsy presenting crouch gait. We explored the influence of altered muscle-tendon properties, reduced neuromuscular control complexity, and spasticity on gait function in terms of joint kinematics, kinetics, muscle activity, and metabolic cost of transport. We modeled altered muscle-tendon properties by personalizing Hill-type muscle-tendon parameters based on data collected during functional movements, simpler neuromuscular control by reducing the number of independent muscle synergies, and spasticity through delayed muscle activity feedback from muscle force and force rate. Our simulations revealed that, in the presence of aberrant musculoskeletal geometries, altered muscle-tendon properties rather than reduced neuromuscular control complexity and spasticity were the primary cause of the crouch gait pattern observed for this child, which is in agreement with the clinical examination. These results suggest that muscle-tendon properties should be the primary target of interventions aiming to restore a more upright gait pattern for this child. This suggestion is in line with the gait analysis following muscle-tendon property and bone deformity corrections. The ability of our simulations to distinguish the contribution of different impairments on walking performance opens the door for identifying targeted treatment strategies with the aim of designing optimized interventions for neuro-musculoskeletal disorders.

scholarly journals Greater Reliance on Cerebral Palsy-Specific Muscle Synergies During Gait Relates to Poorer Temporal-Spatial Performance Measures

2021 ◽  
Vol 12 ◽  
Author(s):  
Yushin Kim ◽  
Thomas C. Bulea ◽  
Diane L. Damiano
Keyword(s):  
Cerebral Palsy ◽  
Muscle Activation ◽  
Step Length ◽  
Motor Dysfunction ◽  
Muscle Synergies ◽  
Muscle Coordination ◽  
Specific Level ◽  
Z Scores ◽  
Gait Abnormalities ◽  
Coordination Patterns

Children with cerebral palsy typically exhibit reduced complexity of muscle coordination patterns during walking; however, the specific patterns that characterize their gait abnormalities are still not well documented. This study aimed to identify the specific repertoire of muscle coordination patterns in children with CP during walking compared to same-aged peers without CP and their relationships to gait performance. To identify muscle coordination patterns, we extracted muscle synergies from 10 children with CP and 10 age-matched typically developing children (TD). K-mean clustering and discriminant analyses of all extracted synergies were used to group similar synergies. Then, weight-averaged z-scores were quantified for each cluster to determine their group-specific level. In this cohort, 10 of the 17 distinct clusters were largely CP-specific while six clusters were seen mainly in TD, and one was non-specific. CP-specific clusters generally showed merging of two TD synergies, excessive antagonist co-activation, decreased muscle activation compared to TD, and complex or atypical pattern. Significant correlations were found between weight-averaged z-scores and step length asymmetry, cadence asymmetry, self-selected treadmill speed and AP-COM displacement of the pelvis such that greater CP-specificity of muscle synergies was related to poorer performance, thus indicating that CP-specific synergies can influence motor dysfunction.

The effect of prolonged walking on muscle fatigue and neuromuscular control in children with cerebral palsy

2022 ◽  
Author(s):  
Sanne Ettema ◽  
Laura M. Oudenhoven ◽  
Karin Roeleveld ◽  
Annemieke I. Buizer ◽  
Marjolein M. van der Krogt
Keyword(s):  
Cerebral Palsy ◽  
Muscle Fatigue ◽  
Neuromuscular Control ◽  
Children With Cerebral Palsy

scholarly journals Modularity speeds up motor learning by overcoming mechanical bias in musculoskeletal geometry

2018 ◽  
Vol 15 (147) ◽  
pp. 20180249 ◽  
Author(s):  
Shota Hagio ◽  
Motoki Kouzaki
Keyword(s):  
Cortical Neurons ◽  
Muscle Activation ◽  
Primary Motor Cortex ◽  
Neuromuscular Control ◽  
Muscle Synergies ◽  
Model Learning ◽  
Joint Torques ◽  
Muscle Activation Patterns ◽  
Wide Range ◽  
Simple Neural Network

We can easily learn and perform a variety of movements that fundamentally require complex neuromuscular control. Many empirical findings have demonstrated that a wide range of complex muscle activation patterns could be well captured by the combination of a few functional modules, the so-called muscle synergies. Modularity represented by muscle synergies would simplify the control of a redundant neuromuscular system. However, how the reduction of neuromuscular redundancy through a modular controller contributes to sensorimotor learning remains unclear. To clarify such roles, we constructed a simple neural network model of the motor control system that included three intermediate layers representing neurons in the primary motor cortex, spinal interneurons organized into modules and motoneurons controlling upper-arm muscles. After a model learning period to generate the desired shoulder and/or elbow joint torques, we compared the adaptation to a novel rotational perturbation between modular and non-modular models. A series of simulations demonstrated that the modules reduced the effect of the bias in the distribution of muscle pulling directions, as well as in the distribution of torques associated with individual cortical neurons, which led to a more rapid adaptation to multi-directional force generation. These results suggest that modularity is crucial not only for reducing musculoskeletal redundancy but also for overcoming mechanical bias due to the musculoskeletal geometry allowing for faster adaptation to certain external environments.

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