Read by QxMD icon Read

Muscle synergies

Takahito Suzuki, Ryuta Kinugasa, Senshi Fukashiro
Behavioral evidence has suggested that a small number of muscle synergies may be responsible for activating a variety of muscles. Nevertheless, such dimensionality reduction may also be explained using the perspective of alternative hypotheses, such as predictions based on linear combinations of joint torques multiplied by corresponding coefficients. To compare the explanatory capacity of these hypotheses for describing muscle activation, we enrolled 12 male volunteers who performed isometric plantar flexor contractions at 10-100% of maximum effort...
2017: PloS One
Philippe Dedieu, Rima Chamoun, Guilhaume Lacaud, Thibault Moulinat, Maxime Queron, Pier-Giorgio Zanone
BACKGROUND: Ankle sprains are common joint injuries in daily and sports activities, whose underlying mechanisms have been amply studied. If joint structures are directly damaged, neuromuscular activity can be affected, particularly in the time domain. This study aims to establish whether previous ankle injury correlates with changes in the inter-joint synergy of the entire lower limb and in the muscle activity pattern during walking. METHODS: Three-dimensional walking-gait analysis was conducted on twenty-four adults...
October 18, 2017: Clinical Biomechanics
Alessandro Scano, Andrea Chiavenna, Matteo Malosio, Lorenzo Molinari Tosatti, Franco Molteni
BACKGROUND: A deep characterization of neurological patients is a crucial step for a detailed knowledge of the pathology and maximal exploitation and customization of the rehabilitation therapy. The muscle synergies analysis was designed to investigate how muscles coactivate and how their eliciting commands change in time during movement production. Few studies investigated the value of muscle synergies for the characterization of neurological patients before rehabilitation therapies...
2017: Frontiers in Bioengineering and Biotechnology
Bao Nguyen Tran, Shiro Yano, Toshiyuki Kondo
This study aims to analyze muscle synergies in darts throwing movement to clarify how the central nervous system (CNS) controls muscle activation to produce complicated motion. Activities of 10 different muscles on upper limb were recorded through surface electromyography (EMG) electrodes from four participants with less experience of dart throwing. Subsequently, non-negative matrix factorization (NNMF) was applied to the collected EMG signals for muscle synergy analysis. Results showed that three muscle synergies could explain sufficiently the observed EMG data, with determination coefficient r(2) = 0...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
A Costa, M Itkonen, H Yamasaki, F S Alnajjar, S Shimoda
Current work highlights the importance of muscle selection to evaluate paralysis and recovery level of stroke patients when comparing synergies of affected and non-affected side of the body. The proposed method allows the selection of important muscles that highly contribute to the specific movements according to the power and frequency distribution of the electromyographic signals.. Users participating performed steering-wheel-based therapy focused on upper limb rehabilitation. Final results show that with the appropriate muscles selection, it is possible to compute a Similarity Index between right and left arms (during symmetric motion) associated to the level of paralysis and potential recovery of a given subject...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
D Rimini, V Agostini, S Rosati, C Castagneri, G Balestra, M Knaflitz
The extraction of muscle synergies in human locomotion may be biased by the kind of pre-processing applied to electromyographic (EMG) data. The aim of this contribution is to analyze the differences in the muscle synergies extracted using a standard pre-processing procedure and a new procedure. The new procedure is based on the selection of the muscle's principal activations (necessary actuations of the muscle to accomplish its specific biomechanical task during gait), discarding secondary activations (with an auxiliary function in motor control)...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Ahmed Ebied, Loukianos Spyrou, Eli Kinney-Lang, Javier Escudero
The muscle synergy concept provides the best framework to understand motor control and it has been recently utilised in many applications such as prosthesis control. The current muscle synergy model relies on decomposing multi-channel surface Electromyography (EMG) signals into a synergy matrix (spatial mode) and its weighting function (temporal mode). This is done using several matrix factorisation techniques, with Non-negative matrix factorisation (NMF) being the most prominent method. Here, we introduce a 4(th)-order tensor muscle synergy model that extends the current state of the art by taking spectral information and repetitions (movements) into account...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Carlos Rodrigues, Miguel Correia, Joao M C S Abrantes, Jurandir Nadal, Marco A Benedetti Rodrigues
Given the difficulty of invasive methods to assess muscle action during natural human movement, surface electromyography (sEMG) has been increasingly used to capture muscle activity in relation to kinesiological analysis of specific tasks. Isolated isometric, concentric and eccentric forms of muscle action have been receiving the most attention for research purposes. Nevertheless natural muscle action frequently involves the use of a preceding eccentric muscle action as a form of potentiation of immediate muscle concentric action, in what is designated as muscle stretch-shortening cycle (SSC)...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Nicholas A Bianco, Carolynn Patten, Benjamin J Fregly
Accurate prediction of muscle and joint contact forces during human movement could improve treatment planning for disorders such as osteoarthritis, stroke, Parkinson's disease, and cerebral palsy. Recent studies suggest that muscle synergies, a low-dimensional representation of a large set of muscle electromyographic (EMG) signals (henceforth called "muscle excitations"), may increase the uniqueness of muscle excitations predicted by optimization methods. This study explores the feasibility of using muscle synergy information extracted from eight muscle EMG signals (henceforth called "included" muscle excitations) to accurately construct muscle excitations from up to 16 additional EMG signals (henceforth called "excluded" muscle excitations)...
October 16, 2017: Journal of Biomechanical Engineering
Elvira Pirondini, Martina Coscia, Jesus Minguillon, José Del R Millán, Dimitri Van De Ville, Silvestro Micera
Electroencephalography (EEG) of brain activity can be represented in terms of dynamically changing topographies (microstates). Notably, spontaneous brain activity recorded at rest can be characterized by four distinctive topographies. Despite their well-established role during resting state, their implication in the generation of motor behavior is debated. Evidence of such a functional role of spontaneous brain activity would provide support for the design of novel and sensitive biomarkers in neurological disorders...
October 16, 2017: Scientific Reports
Akira Saito, Aya Tomita, Ryosuke Ando, Kohei Watanabe, Hiroshi Akima
This study aimed to examine muscle synergies involving the deeper muscles of the lower limb during level and uphill treadmill walking. Seven men and five women walked on a treadmill at three speeds (60, 80, and 100m/min) and two grades (level and 10% grade). Surface electromyographic (EMG) signals were recorded from 10 muscles of the lower limb, including vastus intermedius, adductor magnus, and adductor longus. Muscle synergies were extracted applying non-negative matrix factorization, and the relative co-activation across muscles and the temporal information of synergy recruitment were identified by the muscle synergy vector and synergy activation coefficient, respectively...
October 8, 2017: Gait & Posture
Gennaro Boccia, Chiara Zoppirolli, Lorenzo Bortolan, Federico Schena, Barbara Pellegrini
Nordic walking is a form of walking that includes a poling action, and therefore an additional subtask, with respect to conventional walking. The aim of this study was to assess whether Nordic walking required a task-specific muscle coordination with respect to conventional walking. We compared the electromyographic (EMG) activity of 15 upper and lower limb muscles of nine Nordic walking instructors, while executing Nordic walking and conventional walking at 1.3 ms(-1) on a treadmill. Non-negative matrix factorization method was applied to identify muscle synergies, representing the spatial and temporal organization of muscle coordination...
October 13, 2017: Scandinavian Journal of Medicine & Science in Sports
Marzieh M Ardestani, Philip Malloy, Denis Nam, Aaron G Rosenberg, Markus A Wimmer
Nearly 20% of patients who have undergone total knee arthroplasty (TKA) report persistent poor knee function. This study explores the idea that, despite similar knee joint biomechanics, the neuro-motor synergies may be different between high-functional and low-functional TKA patients. We hypothesized that (1) high-functional TKA recruit a more complex neuro-motor synergy pattern compared to low-functional TKA and (2) high-functional TKA patients demonstrate more stride-to-stride variability (flexibility) in their synergies...
September 28, 2017: Journal of Electromyography and Kinesiology
Ji Won Han, Young Mi Kim
BACKGROUND: The abdominal muscles, upper extremities, and diaphragm work in synergy to maintain trunk stability during breathing. OBJECTIVE: This study aimed to investigate the effects of a breathing technique combined with dynamic upper extremity exercise on the pulmonary function of healthy adults. METHOD: Forty male participants in their 20s were recruited and randomly divided into two groups of 20 participants each: the experimental group performed a dynamic upper extremity exercise with breathing, and the control group only performed the breathing exercise...
September 8, 2017: Journal of Back and Musculoskeletal Rehabilitation
Adam Rozumalski, Katherine M Steele, Michael H Schwartz
BACKGROUND: The aim of this study was to determine whether changes in synergies relate to changes in gait while walking on a treadmill at multiple speeds and slopes. The hypothesis was that significant changes in movement pattern would not be accompanied by significant changes in synergies, suggesting that synergies are not dependent on the mechanical constraints but are instead neurological in origin. METHODS: Sixteen typically developing children walked on a treadmill for nine combinations (stages) of different speeds and slopes while simultaneously collecting kinematics, kinetics, and surface electromyography (EMG) data...
September 14, 2017: Journal of Biomechanics
Camille Charissou, David Amarantini, Robin Baurès, Eric Berton, Laurent Vigouroux
PURPOSE: The mechanisms governing the control of musculoskeletal redundancy remain to be fully understood. The hand is highly redundant, and shows different functional role of extensors according to its configuration for a same functional task of finger flexion. Through intermuscular coherence analysis combined with hand musculoskeletal modelling during maximal isometric hand contractions, our aim was to better understand the neural mechanisms underlying the control of muscle force coordination and agonist-antagonist co-contraction...
November 2017: European Journal of Applied Physiology
Shunta Togo, Hiroshi Imamizu
The muscle synergy hypothesis assumes that individual muscle synergies are independent of each other and voluntarily controllable. However, this assumption has not been empirically tested. This study tested if human subjects can voluntarily activate individual muscle synergies extracted by non-negative matrix factorization (NMF), the standard mathematical method for synergy extraction. We defined the activation of a single muscle synergy as the generation of a muscle activity pattern vector parallel to the single muscle synergy vector...
2017: Frontiers in Computational Neuroscience
Mariusz P Furmanek, Stanisław Solnik, Daniele Piscitelli, Omid Rasouli, Ali Falaki, Mark L Latash
The authors used two analyses developed within the framework of the uncontrolled manifold hypothesis to quantify multimuscle synergies during voluntary body sway: analysis of intertrial variance and analysis of motor equivalence with respect to the center of pressure (COP) trajectory. Participants performed voluntary sway tasks in the anteroposterior direction at 0.33 and 0.66 Hz. Muscle groups were identified in the space of muscle activations and used as elemental variables in the synergy analyses. Changing mechanical and vision feedback-based constraints led to significant changes in indices of sway performance such as COP deviations in the uninstructed, mediolateral direction and indices of spontaneous postural sway...
September 15, 2017: Journal of Motor Behavior
M Mendel, M Chłopecka, N Dziekan, W Karlik
Continued ingestion of plant secondary metabolites by ruminants can provoke pharmacological interactions with pharmaceutical agents used in animals. As some drugs and phytocompounds affect smooth muscle activity, the aim of this study was to verify the possible interaction between selected pharmaceutical agents and plant secondary metabolites towards bovine gastrointestinal motility. The interactions between phytocompounds-apigenin, quercetin, hederagenin, medicagenic acid-and medicines-erythromycin, flunixin meglumine and levamisole-were evaluated on bovine isolated abomasal and duodenal specimens obtained from routinely slaughtered cows...
September 14, 2017: Journal of Veterinary Pharmacology and Therapeutics
Caitlin L Banks, Mihir M Pai, Theresa E McGuirk, Benjamin J Fregly, Carolynn Patten
Muscle synergy analysis (MSA) is a mathematical technique that reduces the dimensionality of electromyographic (EMG) data. Used increasingly in biomechanics research, MSA requires methodological choices at each stage of the analysis. Differences in methodological steps affect the overall outcome, making it difficult to compare results across studies. We applied MSA to EMG data collected from individuals post-stroke identified as either responders (RES) or non-responders (nRES) on the basis of a critical post-treatment increase in walking speed...
2017: Frontiers in Computational Neuroscience
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"