On Study of Driver’s Shoulder Fatigue in Manual and Automatic on Grassland Highway

On the grassland highway, the driver is prone to muscle fatigue because of the particularity of its landscape and the linear structure. And vehicle operating system leads to different degree of muscle fatigue. In order to explore the pilot fatigue characteristics in grassland under different operation conversion highway, put forward the fatigue improve measures and improving the quality of driving, I use the real driving test. In this paper, we study the manual and automatic driver’s shoulder muscle fatigue with method of frequency domain analysis through testing the driver, obtaining MF of trapezius muscle in static measurement and the surface electronical signal of the trapezius muscle after 110 minutes’ driving. We devide the drivers into 2 groups (5 drivers in manual group, 5 drivers in automatic group). The results show that the automatic driver’s MF has significantly negative correlation (P =- 0.521) before and after the static test, which suggests automatic driver will be afflicted with shoulder muscle fatigue; The manual drive’s MF before and after the test tends to decrease with time (SlopeMS =- 0.0076, SlopeMD =- 0.0582), which suggests that after test, drivers in manual group are in the right shoulder fatigue, and before test, the decline of MF shows the drivers’ fatigue accumulation. After test, MF of manual and automatic group increases (SlopeAD =- 0.01, SlopeMD =- 0.058), which shows that driving on grassland highway can lead to the driver’s muscle fatigue with the extension of time; and vehicle operating system leads to different degree of muscle fatigue.

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The Effect of Shoulder Muscle Fatigue on Acromiohumeral Distance and Scapular Dyskinesis in Women With Generalized Joint Hypermobility

Journal of Applied Biomechanics ◽

10.1123/jab.2016-0056 ◽

2017 ◽

Vol 33 (6) ◽

pp. 424-430 ◽

Cited By ~ 5

Author(s):

Razie J. Alibazi ◽

Afsun Nodehi Moghadam ◽

Ann M. Cools ◽

Enayatollah Bakhshi ◽

Alireza Aziz Ahari

Keyword(s):

Muscle Fatigue ◽

Shoulder Pain ◽

Joint Hypermobility ◽

Control Group ◽

Scapular Dyskinesis ◽

Generalized Joint Hypermobility ◽

Shoulder Muscle ◽

Before And After ◽

History Of ◽

Acromiohumeral Distance

Muscle fatigue is considered to be one cause of shoulder pain, and subjects with generalized joint hypermobility (GJH) are affected more by shoulder pain. The purpose of this study was to examine the effects of muscle fatigue on acromiohumeral distance (AHD) and scapular dyskinesis in women with GJH. Thirty-six asymptomatic participants were assigned to either a GJH (n = 20) or control group (n = 16) using the Beighton scale. Before and after elevation fatigue trials, AHD was measured with ultrasonography at rest and when the arm was in 90° active elevation. A scapular dyskinesis test was used to visually observe alterations in scapular movement. Our results showed that in both groups, the fatigue reduced AHD in the 90° elevation position and increased the presence of scapular dyskinesis; however, no differences were found between the two groups. Although GJH has been identified as a factor for developing musculoskeletal disorders, generalized joint hypermobility did not result in changes to scapular dyskinesis or AHD, even after an elevation fatigue task. More studies are needed to evaluate the effects of muscle fatigue in subjects with GJH and a history of shoulder instability.

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Normalization to Maximal Voluntary Contraction is Influenced by Subacromial Pain

Journal of Applied Biomechanics ◽

10.1123/jab.2015-0185 ◽

2016 ◽

Vol 32 (5) ◽

pp. 433-440 ◽

Cited By ~ 8

Author(s):

Lucas Ettinger ◽

Jason Weiss ◽

Matthew Shapiro ◽

Andrew Karduna

Keyword(s):

Trapezius Muscle ◽

Pain Scale ◽

Voluntary Contraction ◽

Subacromial Impingement Syndrome ◽

Serratus Anterior ◽

Upper Trapezius ◽

Subacromial Injection ◽

Shoulder Muscle ◽

Before And After ◽

Lower Trapezius

In this study, we aimed to determine if electromyography (EMG) normalization to maximal voluntary isometric contractions (MVIC) was influenced by subacromial pain in patients with subacromial impingement syndrome. Patients performed MVICs in unique testing positions for each shoulder muscle tested before and after subacromial injection of local anesthetic. In addition to collection of MVIC data, EMG data during an arm elevation task were recorded before and after injection. From a visual analog pain scale, patients had a 64% decrease in pain following the injection. Significant increases in MVICs were noted in 4 of the 7 shoulder muscles tested: anterior, middle and posterior deltoid, and lower trapezius. No significant differences were noticed for the upper trapezius, latissimus dorsi, or serratus anterior. MVIC condition (pre and post injection) had a significant influence on EMG normalization for the anterior deltoid and lower trapezius muscle. Results indicate that subacromial pain can influence shoulder muscle activity, especially for the deltoid muscles and lower trapezius. In addition, normalization to MVIC in the presence of pain can have unpredictable results. Caution should be taken when normalizing EMG data to MVIC in the presence of pain.

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Errors in Force Generation and Changes in Controlling Patterns Following Agonist Muscle Fatigue

Journal of Applied Biomechanics ◽

10.1123/jab.25.4.293 ◽

2009 ◽

Vol 25 (4) ◽

pp. 293-303 ◽

Cited By ~ 4

Author(s):

Yi-Ming Huang ◽

Ya-Ju Chang ◽

Miao-Ju Hsu ◽

Chia-Ling Chen ◽

Chia-Ying Fang ◽

...

Keyword(s):

Muscle Fatigue ◽

Constant Error ◽

Antagonist Muscle ◽

Activation Level ◽

Before And After ◽

Agonist And Antagonist ◽

Common Drive ◽

The Common ◽

Possible Cause ◽

Related Increase

The purpose of this study was to evaluate whether agonist muscle fatigue changed the coactivation time and the co-contraction magnitude of the agonist and antagonist muscle, and if the agonist muscle fatigue produced bias (constant error: CE) and inconsistency (variable error: VE) of the force. Subjects are 10 healthy people and one person with impaired proprioception. EMG and force for fast (0.19 ± 0.06 s) and slow (1.20 ± 0.44 s) targeted isometric dorsiflexions were recorded before and after fatigue of the dorsiflexors. The results revealed that the coactivation time increased after fatigue only in the slow contractions but the co-contraction magnitude did not change. The postfatigue increment of the CE was greater in the fast contractions than in the slow ones. We conclude that the postfatigue compensatory strategy can reduce the fatigue-induced bias. The change of muscles activation level after fatigue might be under the influence of the common drive. Impaired proprioception is a possible cause of the fatigue-related increase in bias and inconsistency.

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Neck muscle fatigue and spatial orientation during stepping in place in humans

Journal of Applied Physiology ◽

10.1152/japplphysiol.00494.2004 ◽

2005 ◽

Vol 99 (1) ◽

pp. 141-153 ◽

Cited By ~ 28

Author(s):

Micaela Schmid ◽

Marco Schieppati

Keyword(s):

Muscle Fatigue ◽

Afferent Input ◽

Neck Muscle ◽

Median Frequency ◽

Optoelectronic System ◽

Neck Proprioception ◽

Before And After ◽

Spatial Reference Frame ◽

Stepping In Place ◽

Neck Muscle Fatigue

Neck proprioceptive input, as elicited by muscle vibration, can produce destabilizing effects on stance and locomotion. Neck muscle fatigue produces destabilizing effects on stance, too. Our aim was to assess whether neck muscle fatigue can also perturb the orientation in space during a walking task. Direction and amplitude of the path covered during stepping in place were measured in 10 blindfolded subjects, who performed five 30-s stepping trials before and after a 5-min period of isometric dorsal neck muscle contraction against a load. Neck muscle electromyogram amplitude and median frequency during the head extensor effort were used to compute a fatigue index. Head and body kinematics were recorded by an optoelectronic system, and stepping cadence was measured by sensorized insoles. Before the contraction period, subjects normally stepped on the spot or drifted forward. After contraction, some subjects reproduced the same behavior, whereas others reduced their forward progression or even stepped backward. The former subjects showed minimal signs of fatigue and the latter ones marked signs of fatigue, as quantified by the dorsal neck electromyogram index. Head position and cadence were unaffected in either group of subjects. We argue that the abnormal fatigue-induced afferent input originating in the receptors transducing the neck muscle metabolic state can modulate the egocentric spatial reference frame. Notably, the effects of neck muscle fatigue on orientation are opposite to those produced by neck proprioception. The neck represents a complex source of inputs capable of modifying our orientation in space during a locomotor task.

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Reversal of muscle fatigue during 16 h of heavy intermittent cycle exercise

Journal of Applied Physiology ◽

10.1152/japplphysiol.00565.2004 ◽

2004 ◽

Vol 97 (6) ◽

pp. 2166-2175 ◽

Cited By ~ 11

Author(s):

H. J. Green ◽

T. A. Duhamel ◽

S. Ferth ◽

G. P. Holloway ◽

M. M. Thomas ◽

...

Keyword(s):

Oxygen Consumption ◽

Muscle Fatigue ◽

Intermittent Exercise ◽

Low Frequency ◽

Quadriceps Muscle ◽

Stimulation Frequency ◽

Peak Oxygen Consumption ◽

Force Frequency ◽

Reduction In Force ◽

Before And After

This study examined the effects of extended sessions of heavy intermittent exercise on quadriceps muscle fatigue and weakness. Twelve untrained volunteers (10 men and 2 women), with a peak oxygen consumption of 44.3 ± 2.3 ml·kg−1·min−1, exercised at ∼91% peak oxygen consumption for 6 min once per hour for 16 h. Muscle isometric properties assessed before and after selected repetitions (R1, R2, R4, R7, R12, and R15) were used to quantitate fatigue (before vs. after repetitions) and weakness (before vs. before repetitions). Muscle fatigue at R1 was indicated by reductions ( P < 0.05) in peak twitch force (135 ± 13 vs. 106 ± 11 N) and by a reduction ( P < 0.05) in the force-frequency response, which ranged between ∼53% at 10 Hz (113 ± 12 vs. 52.6 ± 7.4 N) and ∼17% at 50 Hz (324 ± 27 vs. 270 ± 30 N). No recovery of force, regardless of stimulation frequency, was observed during the 54 min between R1 and R2. At R2 and for all subsequent repetitions, no reduction in force, regardless of stimulation frequency, was generally found after the exercise. The only exception was for R2, where, at 20 Hz, force was reduced ( P < 0.05) by 18%. At R15, force before repetitions for high frequencies (i.e., 100 Hz) returned to R1 (333 ± 29 vs. 324 ± 27 N), whereas force at low frequency (i.e., 10 Hz) was only partially ( P < 0.05) recovered (113 ± 12 vs. 70 ± 6.6 N). It is concluded that multiple sessions of heavy exercise can reverse the fatigue noted early and reduce or eliminate weakness depending on the frequency of stimulation.

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Navicular Drop Before and After Fatigue of the Ankle Invertor Muscles

International Journal of Athletic Therapy & Training ◽

10.1123/ijatt.18.6.36 ◽

2013 ◽

Vol 18 (6) ◽

pp. 36-39 ◽

Cited By ~ 2

Author(s):

Fredrick Anthony Gardin ◽

David Middlemas ◽

Jennifer L. Williams ◽

Steven Leigh ◽

Rob R. Horn

Keyword(s):

Muscle Fatigue ◽

Correlation Coefficients ◽

Standing Position ◽

Medial Longitudinal Arch ◽

Intra Class Correlation ◽

College Age ◽

Navicular Drop ◽

Main Effect ◽

Before And After ◽

Good Internal Consistency

Context:Navicular drop is widely believed to be an indicator of elevated susceptibility to pronation-related injuries, which may be increased by fatigue in the muscles that dynamically support the medial longitudinal arch.Objective:The purpose of this study was to evaluate navicular drop before and after fatigue of the ankle invertor muscles among individuals with different foot types.Participants:20 male and 16 female recreationally active, college-age volunteers (20.03 ± 1.48 years of age).Methods:Navicular drop was measured before and after inducing fatigue in the ankle invertor muscles. Participants’ foot types were classified as high-arch, neutral, or low-arch.Results:There was no interaction between foot type and trial, and no main effect for trial. A main effect for foot type was significant (p = .001). Intra-class correlation coefficients for prefatigue and postfatigue measurements indicated good internal consistency.Conclusion:Our fndings failed to provide any evidence to support the existence of a relationship between ankle invertor muscle fatigue and static measurements of change in navicular height from a sitting to standing position.

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Muscle Activity Before and After Subacromial Injection

Journal of Sport Rehabilitation ◽

10.1123/jsr.2020-0524 ◽

2021 ◽

pp. 1-7

Author(s):

Lucas Ettinger ◽

Matthew Shaprio ◽

Andrew Karduna

Keyword(s):

Rotator Cuff ◽

Muscle Activation ◽

Rotator Cuff Tears ◽

Subacromial Impingement ◽

Upper Trapezius ◽

Subacromial Injection ◽

Shoulder Muscle ◽

Shoulder Muscles ◽

Before And After ◽

Arm Elevation

Context: Shoulder muscle activation in patients with subacromial impingement is highly cited and variable in the literature. Differences between studies could be due to artifacts introduced by normalization practices in the presence of pain. Ultimately, this lack of knowledge pertaining to pathogenesis limits the clinical treatment and restoration of muscular function. Design: A total of 21 patients with stage 2 subacromial impingement and 21 matched controls were recruited for EMG testing of their affected shoulder during an arm elevation task. The patients were tested before and after receiving an injection to their subacromial bursa. Methods: The EMG from 7 shoulder muscles were measured before and after treatment during humeral motion in the scapular plane. Results: Our findings indicate an increase in anterior deltoid, middle deltoid, and upper trapezius activity following the injection; further, this trend extended to the controls. The control subjects had a greater activation of the latissimus dorsi at peak arm elevation when compared with the patient group postinjection. Conclusions: Our results indicate that a reduction in subacromial pain is associated with changes in shoulder muscle recruitment, primarily of the deltoid. This change in deltoid activity may lend evidence to rotator cuff function in patients without rotator cuff tears.

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A Real-Time Algorithm to Estimate Shoulder Muscle Fatigue Based on Surface EMG Signal For Static and Dynamic Upper Limb Tasks

10.1109/embc46164.2021.9630702 ◽

2021 ◽

Author(s):

Marianne Boyer ◽

Laurent Bouyer ◽

Jean-Sebastien Roy ◽

Alexandre Campeau-Lecours

Keyword(s):

Muscle Fatigue ◽

Real Time ◽

Upper Limb ◽

Time Algorithm ◽

Surface Emg ◽

Emg Signal ◽

Shoulder Muscle ◽

Surface Emg Signal

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High-density surface electromyography maps after computer-aided training in individual with congenital transverse deficiency: a case study

BMC Musculoskeletal Disorders ◽

10.1186/s12891-020-03694-4 ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Katarzyna Kisiel-Sajewicz ◽

Jarosław Marusiak ◽

Mónica Rojas-Martínez ◽

Damian Janecki ◽

Sławomir Chomiak ◽

...

Keyword(s):

Spatial Distribution ◽

Upper Limb ◽

Trapezius Muscle ◽

High Density ◽

Emg Activity ◽

Average Intensity ◽

Mental Training ◽

Sensory Stimuli ◽

Computer Aided ◽

Before And After

Abstract Background The aim of this study was to determine whether computer-aided training (CAT) of motor tasks would increase muscle activity and change its spatial distribution in a patient with a bilateral upper-limb congenital transverse deficiency. We believe that our study makes a significant contribution to the literature because it demonstrates the usefulness of CAT in promoting the neuromuscular adaptation in people with congenital limb deficiencies and altered body image. Case presentation The patient with bilateral upper-limb congenital transverse deficiency and the healthy control subject performed 12 weeks of the CAT. The subject’s task was to imagine reaching and grasping a book with the hand. Subjects were provided a visual animation of that movement and sensory feedback to facilitate the mental engagement to accomplish the task. High-density electromyography (HD-EMG; 64-electrode) were collected from the trapezius muscle during a shrug isometric contraction before and after 4, 8, 12 weeks of the training. After training, we observed in our patient changes in the spatial distribution of the activation, and the increased average intensity of the EMG maps and maximal force. Conclusions These results, although from only one patient, suggest that mental training supported by computer-generated visual and sensory stimuli leads to beneficial changes in muscle strength and activity. The increased muscle activation and changed spatial distribution of the EMG activity after mental training may indicate the training-induced functional plasticity of the motor activation strategy within the trapezius muscle in individual with bilateral upper-limb congenital transverse deficiency. Marked changes in spatial distribution during the submaximal contraction in the patient after training could be associated with changes of the neural drive to the muscle, which corresponds with specific (unfamiliar for patient) motor task. These findings are relevant to neuromuscular functional rehabilitation in patients with a bilateral upper-limb congenital transverse deficiency especially before and after upper limb transplantation and to development of the EMG based prostheses.

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