461 research outputs found
The Difference in Gaze Behavior between Expert and Non-Expert Female Team-Handball Players
No full textThe effects of fatigue on scapulothoracic kinematics during total shoulder abduction.
No full textIntroduction: Recently, scapular muscle fatigue during an elevation task wasfound to alter scapular kinematics. Muscle fatigue may be a key factor in thedevelopment of shoulder and neck discomfort and pain. Shoulder girdle musclefatigue has been shown to alter scapulothoracic kinematics. However it is unclearwhether muscle fatigue results in increased or decreased scapular upwardsrotation.Aim: The focus of this study is to examine the effects of shoulder muscle fatigueon the 3-dimensional scapular kinematics during arm elevation, using theQualisys motion capture system. We aim to examine whether an upwardsdisplacement of the humerus, increased anterior tilting of the scapula andncreased upwards rotation will result from fatigue, kinematic changes suspectedto cause a shortening of the subacromial space and leading to the development ofshoulder pain.Methods: Nine healthy subjects took part in the study and data for six subjectscompleting five repetitions of elevation and lowering in the scapular planeabduction was obtained, before and after a fatigue protocol. Maximum voluntarysometric contraction force which served as a measure of local muscle fatigue inthis study was measured with the subjects standing on a force plate performingmaximum voluntary isometric contractions of the shoulder while pushing upagainst a strap attached to the floor besides the force platform. Realtime3-dimensional kinematics was recorded during the repetitons of shoulder elevationusing a Qualisys Motion capture system.Results: There was a significant drop in force between conditions indicating localmuscle fatigue. The results of this study indicate that overall muscular fatigue ofthe shoulder affects scapulothoracic and glenohumeral kinematics. There was asignificant effect of fatigue for Anterior/posterior tilt of the scapula after thefatiguing exercise, with a mean increase of 4.13°and a maximal increase of7.73°anterior tilt however small, this represented a change in rotation of almost45%.Conclusion: This study showed that small but potentially clinically significantchanges in scapular kinematics were found after a shoulder fatigue protocol. Anincrease in scapular anterior tilt, humeral internal rotation, flexion and abductionin the early phases of shoulder elevation was found after fatigue<br/
Characteristics of physical exposure when undocking a half-size trolley from a flight galley
No full textReliabilitet af hånd-holdt dynamometer og overflade EMG ved isometriske kontraktioner i skulderen: Et between-day reliabilitetsstudie
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Smattress:a smart mattress providing an active unobstructive bedding system based on musculoskeletal modeling
No full textFunctional Connectivity Analysis on Resting State Electroencephalography Signals Following Chiropractic Spinal Manipulation in Chronic Stroke Patients
No full textBackground Stroke is a global problem affecting billionsof people. Many of these patients suffers frompost stroke impairments, which can both be presentas cognitive and motor deficits, which results in a declinein life quality. Early and effective rehabilitationare therefore important for these patients, as recoveryand mechanisms, like neuroplasticity, linked to recoveryare maximized at the early stages of stroke.Methods The present study investigated chiropracticspinal manipulation (SM) and its effects on restingstate functional connectivity in chronic stroke patients.Functional connectivity analysis were computedthrough the metrics of Mutual Information (MI)and Phase Lag Index (PLI). Non-parametric clusterbased permutation test were used to asses the statisticalsignificance of the dataset within both SM sessionand a control session and between the two, in order toevaluate the effect of the interventions.Results Significantly increased functional connectivityof PLI were found within the Default Mode Network(DMN), between the posterior cingulate cortexand parahippocampal regions, for the SM session. Nosignificant changes occurred for the control session orfor the MI metric.Conclusion These findings suggests that SM altersfunctional connectivity in the brain of chronic strokepatients. The patients might have experienced a decreasedpain perception, episodic memory and spatialrepresentation and navigation. But it is uncertain, asthese effects were not included in the study. Thereforefurther research regarding the effects of these resultsand SM, taking into account further information, areneeded in order to validate if stroke patients can benefitfrom SM in a rehabilitation program
Functional connectivity of hand-arm muscles during a repetitive dynamic task
No full textThe aim of the study was to investigate the temporal changes in functional connectivity between pairs of selected hand-arm muscles. I recorded the surface bipolar electromyographic (EMG) activity of biceps brachii, triceps brachii, deltoideus anterior, serratus anterior, upper and lower trapezius during a repetitive dynamic task performed until participants’ rating of perceived exertion reached eight on Borg’s CR-10. The functional connectivity was assessed in terms of Wiener-Granger-causality (G-causality) between each pair of EMG time series revealing the contribution of one muscle (e.g. Y) to yield an improved prediction of EMG time series of another muscle (e.g. X) at each time point over and above the prediction which could be achieved from previous values of X itself (Y→X). Only the G-causality from deltoid anterior to biceps brachii (deltoid anterior→biceps brachii) increased with time, suggesting a possible co-contraction effect associated with fatigue development. However, the extent of functional connectivity was not associated with time to task termination suggesting the inability of the subjects in this study to adopt a load sharing pattern among the hand and arm muscles assisting them to prolong the time to task termination. Investigating the functional connectivity between the involved muscles in a task can provide some insights to the mechanics of the movement pattern.</p
An introduction to signal processing for non-engineers
No full textThis book introduces the basic concepts of signal processing for scientists and students with no engineering background. The book presents the concepts with minimum use of mathematical formulations and more emphasis on visual illustrations. The idea is to present an intuitive approach to understanding the basics of signal processing and exemplify some practical applications of the concepts by which the readers achieve basic knowledge and skills in signal processing. Most of illustrations in the book have been created by computer programming in MATLAB®; thus, the reader will learn the basics of using computers in signal processing applications
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