Multidimensional Signal Analysis as a Means of Better Understanding Factors Associated with Repetitive Use in Violin Performance

2004 ◽  
Vol 19 (3) ◽  
pp. 129-139 ◽  
Author(s):  
Gongbing Shan ◽  
Peter Visentin ◽  
Arlan Schultz
Keyword(s):  
Motor Control ◽  
Muscle Activity ◽  
Signal Analysis ◽  
Partial Information ◽  
Physical Work ◽  
Inverse Dynamic ◽  
Holistic View ◽  
Overuse Syndrome ◽  
Multidimensional Signal ◽  
Violin Performance

Multidimensional signal analysis (MSA) involves the coordination and correlation of data gathered by multiple analytic techniques. For complex biosystems, MSA provides a means to investigate better aspects of the system that cannot be understood easily using a single method. This is clearly the case for repetitive use injuries, also commonly referred to as overuse syndrome. Injuries from overuse syndrome are the result of deliberate physical behaviors. They typically are investigated through injury-site examinations, statistical or epidemiologic studies, and observation of the behaviors associated with the injury. Diverse methods often must be used to evaluate a patient because individually they provide only partial information relating to the etiology. The use of MSA permits the integration of multiple observational perspectives, generally creating a more holistic view. Using MSA, accurate external description of the movements thought to cause injury can be linked with internal physiologic conditions. Because physical work causes observed damage in overuse syndrome patients, a full examination of internal loading and muscle activity provides one possibility for understanding the evolutionary nature of these pathologies. Kinematic description, internal load analysis, electromyography, and biomechanical modeling are complementary methods used for MSA in this study. In the current study, a nine-camera ViCON v8i system was used to capture three-dimensional body kinematics as input for inverse dynamic modeling. Electromyography (Noraxon; 8-channel, wireless) was measured and synchronized to the model, permitting the correlation of joint moments and selected muscle activity. Results reveal clear relationships between muscle activity and physiologic loading for a variety of bowing speeds, strong interaction among muscles and groups of muscles, and changes in motor control at varying speeds. Additionally, load levels and work patterns are quantitatively established, and evidence is found to support a three-phase division of motor control based on speed: (1) increasing physical effort, (2) optimization, and (3) approaching physiologic limits. Combined with previous kinematic, kinetic, and statistical studies, the current study illuminates the relative risks of static versus dynamic loading, and provides perspective on the working patterns of muscles throughout the kinematic chain of the arms and torso during violin performance. Most importantly, this study begins the process of establishing MSA as a means of gleaning a greater overall view from the separate observational perspectives provided by multiple assessment methods used to examine performing artists’ injuries. This is the first such study for violin performance; an activity highly correlated with overuse syndrome.

Muscle Activity Patterns of Elite Downhill Ski Racers during Landing

1996 ◽  
Vol 12 (2) ◽  
pp. 225-236
Author(s):  
Peter Schaff ◽  
Lars Nordsletten ◽  
Arne Kristian Aune
Keyword(s):  
Motor Control ◽  
Muscle Activity ◽  
Activity Patterns ◽  
Bending Moment ◽  
Acl Injury ◽  
Potential Effect ◽  
Acl Rupture ◽  
Maximum Loading ◽  
Control Pattern ◽  
Downhill Skiing

The purpose of this study was to examine motion and muscle activity in downhill skiing in order to estimate muscular involvement during the landing phase and its potential effect on ACL injury. Specially developed 8-channel portable electromyo-graphy registration was conducted during three jumps on the Russi jump of the 1994 Olympic downhill slope, and six control jumps were carried out in the laboratory. The results reveal that the skier adapts to the expected loading of the knee, possibly by using a learned motor control pattern. It is still not clear, however, how important muscular adaptation to expected forces is. The complex functional EMG pattern that skiers use while landing indicates that ACL rupture caused during a backward fall in downhill skiing might be due to a combination of the boot-top-induced anterior shear, the force generated in the ACL by forceful knee hyperflexion supported by the high bending moment generated by a stiff spoiler, and the possible absence of a significant protecting hamstrings force during maximum loading.

Tonic-to-phasic shift of lumbo-pelvic muscle activity during 8 weeks of bed rest and 6-months follow up

2007 ◽  
Vol 103 (1) ◽  
pp. 48-54 ◽  
Author(s):  
Daniel L. Belavý ◽  
Carolyn A. Richardson ◽  
Stephen J. Wilson ◽  
Dieter Felsenberg ◽  
Jörn Rittweger
Keyword(s):  
Motor Control ◽  
Skill Acquisition ◽  
Muscle Activity ◽  
Muscle Activation ◽  
Weight Bearing ◽  
Young Male ◽  
Bed Rest ◽  
Movement Model ◽  
Musculoskeletal Function

Prior motor control studies in unloading have shown a tonic-to-phasic shift in muscle activation, particularly in the short extensors. Tonic muscle activity is considered critical for normal musculoskeletal function. The shift from tonic-to-phasic muscle activity has not been systematically studied in humans in unloading nor at the lumbo-pelvic (LP) region. Ten healthy young male subjects underwent 8 wk of bed rest with 6-mo follow up as part of the “Berlin Bed-Rest Study.” A repetitive knee movement model performed in the prone position is used to stimulate tonic holding LP muscle activity, as measured by superficial EMG. Tonic and phasic activation patterns were quantified by relative height of burst vs. baseline electromyographic linear-envelope signal components. Statistical analysis shows a shift toward greater phasic activity during bed rest and follow up ( P < 0.001) with a significant interaction across muscles ( P < 0.001) specifically affecting the short lumbar extensors. These changes appear unrelated to skill acquisition over time ( P all ≥0.196). This change of a shift from tonic LP muscle activation to phasic is in line with prior research on the effects of reduced weight bearing on motor control.

Signal Denoising Method Based on KICA by Noise Components

2013 ◽  
Vol 329 ◽  
pp. 269-273
Author(s):  
Ling Li Jiang ◽  
Ping Li ◽  
Bo Zeng
Keyword(s):  
Independent Component Analysis ◽  
Signal Analysis ◽  
Vibration Signal ◽  
Independent Component ◽  
Signal Denoising ◽  
Denoising Method ◽  
One Dimensional ◽  
Kernel Independent Component Analysis ◽  
Multidimensional Signal

Denoising is an essential part of fault signal analysis. This paper proposes a kernel independent component analysis (KICA)-based denoising method for removing the noise from vibration signal. By introducing noise components of the observed signal, one-dimensional observed signal is extended to multi-dimensional signal. Then performing KICA on multidimensional signal, the noise in the observed signal consistent with the introduced noise will be removed that achieve the purpose of denosing. The effectiveness of the proposed method is demonstrated by the case study.

scholarly journals Biomechanical demands of percussive techniques in the context of early stone toolmaking

2021 ◽  
Vol 18 (178) ◽  
pp. 20201044
Author(s):  
R. Macchi ◽  
G. Daver ◽  
M. Brenet ◽  
S. Prat ◽  
L. Hugheville ◽  
...  
Keyword(s):  
Motor Control ◽  
Muscle Activity ◽  
Joint Angle ◽  
Biceps Brachii ◽  
Stone Tool ◽  
Muscle Coordination ◽  
Physical Demands ◽  
Kinematic Pattern ◽  
Evolutionary Advantage ◽  
Behavioural Repertoire

Recent discoveries in archaeology and palaeoanthropology highlight that stone tool knapping could have emerged first within the genera Australopithecus or Kenyanthropus rather than Homo . To explore the implications of this hypothesis determining the physical demands and motor control needed for performing the percussive movements during the oldest stone toolmaking technology (i.e. Lomekwian) would help. We analysed the joint angle patterns and muscle activity of a knapping expert using three stone tool replication techniques: unipolar flaking on the passive hammer (PH), bipolar (BP) flaking on the anvil, and multidirectional and multifacial flaking with free hand (FH). PH presents high levels of activity for Biceps brachii and wrist extensors and flexors. By contrast, BP and FH are characterized by high solicitation of forearm pronation. The synergy analyses depict a high muscular and kinematic coordination. Whereas the muscle pattern is very close between the techniques, the kinematic pattern is more variable, especially for PH. FH displays better muscle coordination and conversely lesser joint angle coordination. These observations suggest that the transition from anvil and hammer to freehand knapping techniques in early hominins would have been made possible by the acquisition of a behavioural repertoire producing an evolutionary advantage that gradually would have been beneficial for stone tool production.

scholarly journals When 90% of the variance is not enough: residual EMG from muscle synergy extraction influences task performance

2019 ◽  
Author(s):  
Victor R. Barradas ◽  
Jason J. Kutch ◽  
Toshihiro Kawase ◽  
Yasuharu Koike ◽  
Nicolas Schweighofer
Keyword(s):  
Motor Control ◽  
Dimensionality Reduction ◽  
Muscle Activity ◽  
Muscle Force ◽  
Muscle Synergy ◽  
Muscle Synergies ◽  
Systematic Effect ◽  
Extraction Techniques ◽  
Force Mapping ◽  
Variance Explained

AbstractMuscle synergies are usually identified via dimensionality reduction techniques, such that the identified synergies reconstruct the muscle activity to a level of accuracy defined heuristically, such as 90% of the variance explained. Here, we question the assumption that the residual muscle activity not explained by the synergies is due to noise. We hypothesize instead that the residual activity is structured and can therefore influence the execution of a motor task. Young healthy subjects performed an isometric reaching task in which surface electromyography of 10 arm muscles was mapped onto estimated two-dimensional forces used to control a cursor. Three to five synergies were extracted to account for 90% of the variance explained. We then altered the muscle-force mapping via “hard” and “easy” virtual surgeries. Whereas in both surgeries the forces associated with synergies spanned the same single dimension of the virtual environment, the muscle-force mapping was as close as possible to the initial mapping in the easy surgery and as far as possible in the hard surgery. This design therefore maximized potential differences in reaching errors attributable to the residual muscle activity. Results show that the easy surgery produced much smaller directional errors than the hard task. In addition, systematic estimations of the errors for easy and hard surgeries constructed with 1 to 10 synergies show that the errors differ significantly for up to 8 synergies, which account for 98% of the variance on average. Our study therefore indicates the need for cautious interpretations of results derived from synergy extraction techniques based on heuristics with lenient levels of accuracy.Author summaryThe muscle synergy hypothesis states that the central nervous system simplifies motor control by grouping muscles that share common functions into modules called muscle synergies. Current techniques use unsupervised dimensionality reduction algorithms to identify these synergies. However, these techniques rely on arbitrary criteria to determine the number of synergies, which is actually unknown. An example of such criteria is that the identified synergies must be able to reconstruct the measured muscle activity to at least a 90% level of accuracy. Thus, the residual muscle activity, the remaining 10% of the muscle activity, is often disregarded as noise. We show that residual muscle activity following muscle synergy identification has a large systematic effect on movements even when the number of synergies approaches the number of muscles. This suggests that current synergy extraction techniques may discard a component of muscle activity that is important for motor control. Therefore, current synergy extraction techniques must be updated to identify true physiological synergies.

scholarly journals Myofascial trigger points alter the modular control during the execution of a reaching task: a pilot study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tommaso Geri ◽  
Leonardo Gizzi ◽  
Anna Di Marco ◽  
Marco Testa
Keyword(s):  
Motor Control ◽  
Muscle Activity ◽  
Shoulder Girdle ◽  
Reciprocal Inhibition ◽  
Trigger Points ◽  
Preliminary Evidence ◽  
Myofascial Trigger Points ◽  
Reaching Task ◽  
Weighting Coefficients ◽  
Dominant Condition

Abstract Myofascial trigger points (TP) constitute a conundrum in research and clinical practice as their etiopathogenesis is debated. Several studies investigating one or few muscles have shown that both active and latent TP causes an increased muscle activity, however the influence of TP on modular motor control during a reaching task is still unclear. Electromyographic signals, recorded from the muscles of the shoulder girdle and upper arm during a reaching task, were decomposed with Non-Negative Matrix Factorization algorithm. The extracted matrices of motor modules and activation signals were used to label the muscles condition as dominant or non-dominant. The presence of latent and active TP was detected in each muscle with manual examination. Despite a similar muscle activity was observed, we found that muscles with active TP had increased weighting coefficients when labeled in the dominant condition. No influences were found when muscles were in the non-dominant condition. These findings suggest that TP altered the motor control without co-contraction patterns. As a preliminary evidence, the present results suggest that the increased weighting coefficients in presence of TPs are associated with an alteration of the modular motor control without affecting the dimensionality of motor modules for each individual and reciprocal inhibition.

Lip Muscle Activity Related to Speech Rate and Loudness

2000 ◽  
Vol 43 (5) ◽  
pp. 1229-1239 ◽  
Author(s):  
Amy B. Wohlert ◽  
Vicki L. Hammen
Keyword(s):  
Motor Control ◽  
Muscle Activity ◽  
Speech Rate ◽  
Speech Motor Control ◽  
Connected Speech ◽  
Amplitude Analysis ◽  
Oral Motor ◽  
Emg Amplitude ◽  
Task Effects ◽  
Speech Motor

Changes in suprasegmental speech parameters may require adjustments in oral motor control that are reflected in the activity of perioral musculature. In order to evaluate possible patterns of difference, perioral surface electromyographic (EMG) signals were obtained from 20 adults who read a paragraph aloud at habitual rate and at self-judged proportionately slower and faster rates, at habitual loudness and at proportionately softer and louder levels, and in a "precise" manner. EMG amplitude analysis showed significant task effects, with higher average amplitudes for fast, loud, and precise speech and lower average amplitudes for slow and soft speech. These results are compatible with a model of multidimensional reorganization of speech motor control for suprasegmental changes applied to connected speech.

Incoordination in pianists with overuse syndrome

Neurology ◽  
1998 ◽  
Vol 51 (2) ◽  
pp. 512-519 ◽  
Author(s):  
H.J.H. Fry ◽  
M. Hallett ◽  
T. Mastroianni ◽  
N. Dang ◽  
J. Dambrosia
Keyword(s):  
Motor Control ◽  
Quantitative Analysis ◽  
Outcome Measures ◽  
Classification Tree ◽  
Overuse Syndrome ◽  
Expected Time ◽  
Key Press ◽  
History Of ◽  
Metronome Beat

To investigate claims that painful musculoligamentous overuse in the arms and hands of pianists is accompanied by loss of motor control, we studied 18 pianists with overuse syndrome of one or both arms and hands and 22 skill-matched pianists with no history of overuse. All of the pianists performed continuous repetitions of a five-finger exercise on a piano keyboard at metronome-paced tempos. The main outcome measures were quantitative analysis of four measurements of performance (duration of key presses, interval between key presses, velocity of key presses [loudness], and time off the metronome beat [difference between actual and expected time of key press)]; comparison of the errors in the two groups; and comparison of the performances by a listening panel. The two groups had significant differences in performance, and a classification tree had a sensitivity of 0.886 and a specificity of 0.862 in identifying the affected hands. The pianists with overuse syndrome made more skill-based errors. The listening panel could distinguish between the affected and unaffected hands. We conclude that pianists with overuse syndrome have a coordination disturbance.

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