scholarly journals How Do Violinists Adapt to Dynamic Assistive Support? A Study Focusing on Kinematics, Muscle Activity, and Musical Performance

2021 ◽  
pp. 001872082110334
Author(s):  
Clara Ziane ◽  
Benjamin Michaud ◽  
Mickaël Begon ◽  
Fabien Dal Maso
Keyword(s):  
Muscle Fatigue ◽  
Injury Risk ◽  
Muscle Activation ◽  
Musical Performance ◽  
Experimental Conditions ◽  
Muscle Activation Patterns ◽  
Left Elbow ◽  
Repetitive Nature ◽  
Injury Risk Factor ◽  
Muscle Activations

Objective Assessing violinists’ motor and musical performance adaptations to dynamic assistive support (DAS) provided by a passive device, using a force-field adaptation paradigm. Background Up to 93% of instrumentalists are affected by musculoskeletal injuries and particularly violinists. The repetitive nature of their work may lead to muscle fatigue, an injury risk factor. DAS has been used in occupational settings to minimize muscle activations and limit fatigue accumulation. DAS may however affect motor and musical performance. Method Fifteen expert violinists were equipped with reflective markers and surface and intramuscular electromyography (EMG) sensors. Movements, muscle activations, and sound were recorded while participants completed three experimental conditions for which they continuously played a 13-s musical excerpt: Control (no DAS), Adaptation (DAS), and Washout (no DAS). DAS was applied at the left elbow (violin-holding side). Conditions were repeated 1 week later. Participants later listened to their own audio recordings playing with and without DAS and blindly assessed their performances. Linear mixed models were used to compare DAS and no-DAS conditions’ kinematic, EMG, and musical performance data. Results DAS perturbed user kinematics but reduced mean activations of left medial deltoid and superior trapezius. Joint kinematic and muscle activation patterns between DAS and no DAS conditions however remained similar. Musical performance was unchanged with DAS. Conclusion Though DAS modified violinists’ upper-limb configurations, resulting kinematics were not detrimental to musical performance. Reduced muscle activations with DAS could contribute to lessening muscle fatigue. Application Although its effect on muscle fatigue should be further investigated, DAS might be useful in preventing violinists’ injuries.

scholarly journals Lower complexity of motor primitives ensures robust control of high-speed human locomotion

2020 ◽  
Author(s):  
Alessandro Santuz ◽  
Antonis Ekizos ◽  
Yoko Kunimasa ◽  
Kota Kijima ◽  
Masaki Ishikawa ◽  
...  
Keyword(s):  
High Speed ◽  
Muscle Activation ◽  
Human Locomotion ◽  
Muscle Synergies ◽  
Activation Patterns ◽  
Motor Primitives ◽  
Muscle Activation Patterns ◽  
Relative Contribution ◽  
Muscle Activations ◽  
Low Dimensional

AbstractWalking and running are mechanically and energetically different locomotion modes. For selecting one or another, speed is a parameter of paramount importance. Yet, both are likely controlled by similar low-dimensional neuronal networks that reflect in patterned muscle activations called muscle synergies. Here, we investigated how humans synergistically activate muscles during locomotion at different submaximal and maximal speeds. We analysed the duration and complexity (or irregularity) over time of motor primitives, the temporal components of muscle synergies. We found that the challenge imposed by controlling high-speed locomotion forces the central nervous system to produce muscle activation patterns that are wider and less complex relative to the duration of the gait cycle. The motor modules, or time-independent coefficients, were redistributed as locomotion speed changed. These outcomes show that robust locomotion control at challenging speeds is achieved by modulating the relative contribution of muscle activations and producing less complex and wider control signals, whereas slow speeds allow for more irregular control.

The Human Central Pattern Generator for Locomotion: Does It Exist and Contribute to Walking?

2017 ◽  
Vol 23 (6) ◽  
pp. 649-663 ◽  
Author(s):  
Karen Minassian ◽  
Ursula S. Hofstoetter ◽  
Florin Dzeladini ◽  
Pierre A. Guertin ◽  
Auke Ijspeert
Keyword(s):  
Spinal Cord ◽  
Neural Control ◽  
Muscle Activation ◽  
Central Pattern Generators ◽  
Lumbar Spinal Cord ◽  
Step Cycle ◽  
Experimental Conditions ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Cord Injury

The ability of dedicated spinal circuits, referred to as central pattern generators (CPGs), to produce the basic rhythm and neural activation patterns underlying locomotion can be demonstrated under specific experimental conditions in reduced animal preparations. The existence of CPGs in humans is a matter of debate. Equally elusive is the contribution of CPGs to normal bipedal locomotion. To address these points, we focus on human studies that utilized spinal cord stimulation or pharmacological neuromodulation to generate rhythmic activity in individuals with spinal cord injury, and on neuromechanical modeling of human locomotion. In the absence of volitional motor control and step-specific sensory feedback, the human lumbar spinal cord can produce rhythmic muscle activation patterns that closely resemble CPG-induced neural activity of the isolated animal spinal cord. In this sense, CPGs in humans can be defined by the activity they produce. During normal locomotion, CPGs could contribute to the activation patterns during specific phases of the step cycle and simplify supraspinal control of step cycle frequency as a feedforward component to achieve a targeted speed. Determining how the human CPGs operate will be essential to advance the theory of neural control of locomotion and develop new locomotor neurorehabilitation paradigms.

scholarly journals Prediction of Muscle Fatigue during Minimally Invasive Surgery Using Recurrence Quantification Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Keshavarz Panahi ◽  
Sohyung Cho
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Muscle Fatigue ◽  
Invasive Surgery ◽  
Muscle Activation ◽  
Recurrence Quantification Analysis ◽  
Recurrence Quantification ◽  
Quantification Analysis ◽  
Muscle Groups ◽  
Muscle Activations

Due to its inherent complexity such as limited work volume and degree of freedom, minimally invasive surgery (MIS) is ergonomically challenging to surgeons compared to traditional open surgery. Specifically, MIS can expose performing surgeons to excessive ergonomic risks including muscle fatigue that may lead to critical errors in surgical procedures. Therefore, detecting the vulnerable muscles and time-to-fatigue during MIS is of great importance in order to prevent these errors. The main goal of this study is to propose and test a novel measure that can be efficiently used to detect muscle fatigue. In this study, surface electromyography was used to record muscle activations of five subjects while they performed fifteen various laparoscopic operations. The muscle activation data was then reconstructed using recurrence quantification analysis (RQA) to detect possible signs of muscle fatigue on eight muscle groups (bicep, triceps, deltoid, and trapezius). The results showed that RQA detects the fatigue sign on bilateral trapezius at 47.5 minutes (average) and bilateral deltoid at 57.5 minutes after the start of operations. No sign of fatigue was detected for bicep and triceps muscles of any subject. According to the results, the proposed novel measure can be efficiently used to detect muscle fatigue and eventually improve the quality of MIS procedures with reducing errors that may result from overlooked muscle fatigue.

Effect of Fatigue on Single-Leg Hop Landing Biomechanics

2006 ◽  
Vol 22 (4) ◽  
pp. 245-254 ◽  
Author(s):  
Karl F. Orishimo ◽  
Ian J. Kremenic
Keyword(s):  
Muscle Fatigue ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Plantar Flexion ◽  
Thigh Muscle ◽  
Functional Improvement ◽  
Compensatory Mechanisms ◽  
Knee Motion ◽  
Muscle Activation Patterns ◽  
Knee Pathology

The objective of this study was to measure adaptations in landing strategy during single-leg hops following thigh muscle fatigue. Kinetic, kinematic, and electromyographic data were recorded as thirteen healthy male subjects performed a single-leg hop in both the unfatigued and fatigued states. To sufficiently fatigue the thigh muscles, subjects performed at least two sets of 50 step-ups. Fatigue was assessed by measuring horizontal hopping ability following the protocol. Joint motion and loading, as well as muscle activation patterns, were compared between fatigued and unfatigued conditions. Fatigue significantly increased knee motion (p = 0.012) and shifted the ankle into a more dorsiflexed position (p = 0.029). Hip flexion was also reduced following fatigue (p = 0.042). Peak extension moment tended to decrease at the knee and increase at the ankle and hip (p = 0.014). Ankle plantar flexion moment at the time of peak total support moment increased from 0.8 (N⋅m)/kg (SD, 0.6 [N⋅m]/kg) to 1.5 (N⋅m)/kg (SD, 0.8 [N⋅m]/kg) (p = 0.006). Decreased knee moment and increased knee flexion during landings following fatigue indicated that the control of knee motion was compromised despite increased activation of the vastus medialis, vastus lateralis, and rectus femoris (p = 0.014, p = 0.014, and p = 0.017, respectively). Performance at the ankle increased to compensate for weakness in the knee musculature and to maintain lower extremity stability during landing. Investigating the biomechanical adaptations that occur in healthy subjects as a result of muscle fatigue may give insight into the compensatory mechanisms and loading patterns occurring in patients with knee pathology. Changes in single-leg hop landing performance could be used to demonstrate functional improvement in patients due to training or physical therapy.

scholarly journals Surfboard Paddling Technique and Neuromechanical Control: A Narrative Review

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Wynand Volschenk ◽  
Zachary Crowley-McHattan ◽  
John Whitting ◽  
Rudi Meir ◽  
Alec McKenzie
Keyword(s):  
Injury Risk ◽  
Muscle Activation ◽  
Narrative Review ◽  
Future Research ◽  
Research Directions ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Future Research Directions ◽  
Neuromechanical Control ◽  
And Training

Surfboard paddling is an essential activity when surfing. Research investigating surfboard paddling, especially as it pertains to neuromechanical control and techniques used, is limited. Previous research made use of swim ergometers to examine surfboard paddling demands. The validity of using swim ergometers in surfboard paddling research and training deserves further analysis. To establish ecologically valid findings, researchers have begun to use swim flumes and still-water paddling environments to investigate paddling efficiency and technique. This emerging body of research has reported that muscle activation patterns, intensities, and timings differ as surfers move through different paddle stroke phases. A deeper understanding of paddling's neuromechanical control may help enhance the understanding of how to improve paddle performance and perhaps reduce injury risk. Therefore, the purpose of this review was to identify the gaps in the existing literature to help identify future research directions in relation to surfboard paddling techniques and neuromechanical control.

EMG-Assisted Neuromusculoskeletal Models Can Estimate Physiological Muscle Activations and Joint Moments Across the Neck Before Impacts

2021 ◽  
Author(s):  
Pavlos Silvestros ◽  
Claudio Pizzolato ◽  
David G. Lloyd ◽  
Ezio Preatoni ◽  
Harinderjit S. Gill ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Muscle Activation ◽  
Inverse Dynamics ◽  
A Priori ◽  
Neck Muscle ◽  
Joint Moments ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Flexion Extension ◽  
Muscle Activations

Abstract Knowledge of neck muscle activation strategies prior to sporting impacts is crucial for investigating mechanisms of severe spinal injuries. However, measurement of muscle activations during impacts is experimentally challenging and computational estimations are not often guided by experimental measurements. We investigated neck muscle activations prior to impacts with the use of electromyography (EMG)-assisted neuromusculoskeletal models. Kinematics and EMG recordings from four major neck muscles of a rugby player were experimentally measured during rugby activities. A subject-specific musculoskeletal model was created with muscle parameters informed from MRI measurements. The model was used in the Calibrated EMG-Informed Neuromusculoskeletal Modelling toolbox and three neural solutions were compared: i) static optimisation (SO), ii) EMG-assisted (EMGa) and iii) MRI-informed EMG-assisted (EMGaMRI). EMGaMRI and EMGa significantly (p¡0.01) outperformed SO when tracking cervical spine net joint moments from inverse dynamics in flexion/extension (RMSE = 0.95, 1.14 and 2.32 Nm) but not in lateral bending (RMSE = 1.07, 2.07 and 0.84 Nm). EMG-assisted solutions generated physiological muscle activation patterns and maintained experimental co-contractions significantly (p¡0.01) outperforming SO, which was characterised by saturation and non-physiological "on-off" patterns. This study showed for the first time that physiological neck muscle activations and cervical spine net joint moments can be estimated without assumed a priori objective criteria prior to impacts. Future studies could use this technique to provide detailed initial loading conditions for theoretical simulations of neck injury during impacts.

scholarly journals The Capacity of Generic Musculoskeletal Simulations to Predict Knee Joint Loading Using the CAMS-Knee Datasets

2020 ◽  
Vol 48 (4) ◽  
pp. 1430-1440 ◽  
Author(s):  
Zohreh Imani Nejad ◽  
Khalil Khalili ◽  
Seyyed Hamed Hosseini Nasab ◽  
Pascal Schütz ◽  
Philipp Damm ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Biceps Femoris ◽  
Contact Forces ◽  
Generic Model ◽  
Model Parameters ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Level Walking ◽  
Muscle Activations

Abstract Musculoskeletal models enable non-invasive estimation of knee contact forces (KCFs) during functional movements. However, the redundant nature of the musculoskeletal system and uncertainty in model parameters necessitates that model predictions are critically evaluated. This study compared KCF and muscle activation patterns predicted using a scaled generic model and OpenSim static optimization tool against in vivo measurements from six patients in the CAMS-knee datasets during level walking and squatting. Generally, the total KCFs were under-predicted (RMS: 47.55%BW, R 2: 0.92) throughout the gait cycle, but substiantially over-predicted (RMS: 105.7%BW, R 2: 0.81) during squatting. To understand the underlying etiology of the errors, muscle activations were compared to electromyography (EMG) signals, and showed good agreement during level walking. For squatting, however, the muscle activations showed large descrepancies especially for the biceps femoris long head. Errors in the predicted KCF and muscle activation patterns were greatest during deep squat. Hence suggesting that the errors mainly originate from muscle represented at the hip and an associated muscle co-contraction at the knee. Furthermore, there were substaintial differences in the ranking of subjects and activities based on peak KCFs in the simulations versus measurements. Thus, future simulation study designs must account for subject-specific uncertainties in musculoskeletal predictions.

scholarly journals Modulation of finger muscle activation patterns across postures is coordinated across all muscle groups

2020 ◽  
Vol 124 (2) ◽  
pp. 330-341
Author(s):  
Sang Wook Lee ◽  
Dan Qiu ◽  
Heidi C. Fischer ◽  
Megan O. Conrad ◽  
Derek G. Kamper
Keyword(s):  
Muscle Activation ◽  
Solution Space ◽  
Force Output ◽  
Activation Patterns ◽  
Hand Muscles ◽  
Muscle Activation Patterns ◽  
Postural Changes ◽  
Force Direction ◽  
Muscle Groups ◽  
Muscle Activations

We examined how hand muscles adapt to changing external (force direction) and internal (posture) conditions. Muscle activations, particularly of the extrinsic extensors, were significantly affected by postural changes of the interphalangeal, but not metacarpophalangeal, joints. Joint impedance was modulated so that the effects of the signal-dependent motor noise on the force output were reduced. Comparisons with theoretical solutions showed that the chosen activation patterns occupied a small portion of the possible solution space, minimizing the maximum activation of any one muscle.

scholarly journals Daily physical function and frailty in persons with Parkinson's disease: a focus on females

2013 ◽  
Vol 38 (3) ◽  
pp. 358-358
Author(s):  
Kaitlyn P. Roland
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Physical Function ◽  
Muscle Fatigue ◽  
Muscle Activation ◽  
Functional Independence ◽  
Extensive Literature ◽  
Physically Active ◽  
Muscle Activation Patterns ◽  
Physiological Capacity

Persons with Parkinson's disease (PD) are often excluded from frailty studies, and thus little is known about how frailty influences decline in physiological capacity in persons with PD. Impaired physiological capacity impacts the ability to remain physically active, which reduces physical function that is necessary for independent living. The overall purpose of this dissertation was to examine physiological capacity (i.e., muscle activation patterns) and physical activity in males and females with PD during routine daily activities to determine whether they influence physical function and frailty. An extensive literature review of sex differences in PD highlighted that greater declines in gait speed, balance, and motor function occur in females compared with males. This dissertation demonstrated persons with PD, especially females with PD, were weaker and have less muscle quiescence, as measured with gaps in the electromyography, compared with controls and males with PD. These results provide insight into mechanisms (i.e., physiological capacity) that determine PD and sex-related declines in functional performance. In addition, greater muscle activity and less quiescence in females with PD may perpetuate frailty through increased muscle fatigue and slowness of movement. Females with PD are more vulnerable to prefrailty than males and factors that are associated with frailty are quality of life (QoL) and self-reported exhaustion. The neuromuscular changes associated with frailty exacerbate PD, which may create greater muscle fatigue that results in self-reported exhaustion. In conclusion, research presented within this dissertation demonstrates that addressing frailty in PD is important, especially in females who are at greater risk for functional decline. This research presents new knowledge by suggesting that frail females with PD remain physically active during daily life and that disease management may better reflect frailty than disease severity or duration. Understanding how frailty concurrently exists with PD and how these conditions progress within the aging adult may enhance identification and implementation of management strategies aimed at improving functional independence and QoL.

scholarly journals Patterns of whole-body muscle activations following vertical perturbations during standing and walking

2020 ◽  
Author(s):  
Desiderio Cano Porras ◽  
Jesse V. Jacobs ◽  
Rivka Inzelberg ◽  
Yotam Bahat ◽  
Gabriel Zeilig ◽  
...  
Keyword(s):  
Tibialis Anterior ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Visual Input ◽  
Whole Body ◽  
Muscle Activation Patterns ◽  
Eyes Closed ◽  
Postural Responses ◽  
Muscle Activations

Abstract Background Falls commonly occur due to losses of balance associated with vertical body movements (e.g. reacting to uneven ground, street curbs). Research, however, has focused on horizontal perturbations, such as forward and backward translations of the standing surface. This study describes and compares muscle activation patterns following vertical and horizontal perturbations during standing and walking, and investigates the role of vision during the standing postural responses. Methods Fourteen healthy participants (ten males; 27±4 years-old) responded to downward, upward, forward, and backward perturbations while standing and walking in a virtual reality (VR) facility containing a moveable platform with an embedded treadmill; participants were also exposed to visual perturbations in which only the virtual scenery moves. We collected bilateral surface electromyography (EMG) signals from 8 muscles (tibialis anterior, rectus femoris, rectus abdominis, external oblique, gastrocnemius, biceps femoris, paraspinals, deltoids). Parameters included onset latency, duration of activation, and activation magnitude. Standing perturbations comprised dynamic-camera (congruent), static-camera (incongruent) and eyes-closed sensory conditions. ANOVAs were used to compare the effects of perturbation direction and sensory condition across muscles. Results Vertical perturbations induced longer onset latencies and durations of activation with lower activation magnitudes in comparison to horizontal perturbations. Downward perturbations while standing generated faster activation of rectus femoris and tibialis anterior, whereas biceps femoris and gastrocnemius were faster to respond to upward perturbations. Initial responses to downward and upward perturbations activated trunk/hip flexors and extensors, respectively. Eyes-closed conditions induced longer durations of activation and larger activation magnitudes, whereas static-camera conditions induced longer onset latencies. During walking, downward perturbations promptly activated contralateral trunk and deltoid muscles, and upward perturbations triggered early activation of trunk flexors. Visual perturbations elicited muscle activation in 67.7% of trials. Conclusion Our results demonstrate that vertical (vs. horizontal) perturbations generate unique balance-correcting muscle activations with prioritized control of trunk/hip configuration for postural control after vertical perturbations. Availability of visual input appears to affect response efficiency, and incongruent visual input can adversely affect response triggering. Our findings have clinical implications for the design of robotic exoskeletons (to ensure user safety in dynamic balance environments) and for perturbation-based balance and gait rehabilitation.

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