Intramuscular pressure and electromyography in four shoulder muscles

Järvholm, U; Palmerud, Gunnar; Karlsson, Dan; Herberts, Peter; Kadefors, Roland

doi:10.1002/jor.1100090418

Cited by 113 publications

(51 citation statements)

References 39 publications

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“…There is an approximately linear relationship between EMG and active isometric muscle force production (2,5,7,26,31), at least when the correct electromechanical delay is considered (8). Good correlations have been shown between EMG, intramuscular force and isometric force, for arm (33) and shoulder (31) muscles, but the EMG/force relationship is only linear for isometric contractions and depends on velocity, position, and on whether the contraction is eccentric or concentric (26).…”

Section: Introductionmentioning

confidence: 99%

Correspondence between laryngeal vocal fold movement and muscle activity during speech and nonspeech gestures

Poletto

Verdun

Strominger

et al. 2004

Journal of Applied Physiology

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To better understand the role of each of the laryngeal muscles in producing vocal fold movement, activation of these muscles was correlated with laryngeal movement during different tasks such as sniff, cough or throat clear, and speech syllable production. Four muscles (the posterior cricoarytenoid-PCA, lateral cricoarytenoid-LCA, cricothyroid-CT and thyroarytenoid-TA) were recorded with bipolar hooked wire electrodes placed bilaterally in four normal subjects. A nasoendoscope was used to record vocal fold movement while simultaneously recording muscle activity. Muscle activation level was correlated with ipsilateral vocal fold angle for vocal fold opening and closing. Pearson correlation coefficients and their statistical significance were computed for each trial. Significant effects of muscle (p≤0.0005) and task (p=0.034) were found on the r (transformed to Fisher's Z') values. All the PCA recordings related significantly with vocal opening while CT activity was significantly correlated with opening only during sniff. The TA and LCA activities were significantly correlated with vocal fold closing during cough. During speech, the CT and TA activity correlated with both opening and closing. Laryngeal muscle patterning to produce vocal fold movement differed across tasks; reciprocal muscle activity only occurred on cough while speech and sniff often involved simultaneous contraction of muscle antagonists. In conclusion, different combinations of muscle activation are used for biomechanical control of vocal fold opening and closing movements during respiratory, airway protection and speech tasks.

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Section: Introductionmentioning

confidence: 99%

Correspondence between laryngeal vocal fold movement and muscle activity during speech and nonspeech gestures

Poletto

Verdun

Strominger

et al. 2004

Journal of Applied Physiology

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“…6) Flexão dianteira de 30º do ombro ou abdução maior que 30º podem gerar uma diminuição do fluxo sanguíneo no músculo supra espinhal [21].…”

Section: Resultsunclassified

“…[24]. Portanto, de acordo com a literatura [7,9,[17][18][19][20][21][22][23][24][25][26][27][28][29], os resultados obtidos neste estudo apontam que a atividade realizada pelos cortadores de cana tem potencial para causar dores no ombro e no pescoço [17], fadiga muscular rápida [18,19] e gerar uma diminuição do fluxo sanguíneo no músculo supraespinhal [21]. Quanto ao movimento de abdução do ombro, a simulação mostrou que a amplitude permanece acima de 90 graus por mais da metade do tempo total do movimento e, de acordo com Hagberg [22,23], isso pode causar fadiga muscular local em menos de um minuto, com sintomas no pescoço e nos ombros,como dores e desconforto [24,26,27].…”

Section: Discussionunclassified

“…Os resultados obtidos foram avaliados tendo como referência o documento publicado pelo Ministério da Saúde [7], sintetizado no Quadro 1, que descreve vários estudos [9,[17][18][19][20][21][22][23][24][25][26][27][28][29] com objetivo de orientar profissionais que atendem trabalhadores com suspeita de doenças relacionadas ao trabalho. Como se pode observar na Tabela 2, os ângulos de flexão e abdução na simulação do movimento ficam acima do descrito como ideal na literatura [7] em quase 100% do tempo das coletas realizadas.…”

Section: Métodosunclassified

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Risco de lesões de ombro em cortadores de cana-de-açúcar: análise baseada na simulação dos movimentos

Messias

Andrade

Artero

et al. 2017

Sci Med

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Este artigo está licenciado sob forma de uma licença Creative Commons Atribuição 4.0 Internacional, que permite uso irrestrito, distribuição e reprodução em qualquer meio, desde que a publicação original seja corretamente citada. ABSTRACT AIMS:To evaluate whether the amplitude angles of shoulder flexion and abduction, in the movements performed during a simulation of the sugarcane cutting task, exceed the limits considered safe. METHODS: Non-randomized controlled simulations of the movement of sugarcane cutting were performed in volunteers recruited among university students. Inclusion criteria were (a) male sex; (b) age between 21 and 40 years; (c) right handed; (d) without orthopedic and/or neurological impairment; (e) physical characteristics and a history of work activities similar to that of sugarcane cutters; (f) performing aerobic physical activity at least three times a week in the last six months. The exclusion criteria were (a) presence of pain during the tests; and (b) inability to perform the movement. The study was carried out in the laboratory of occupational biomechanics of the Center for Study and Research in Ergonomics of the School of Science and Technology of the State University of São Paulo. The kinematic data were collected by the Vicon ® Three-Dimensional Movement Analysis System. The movements of flexion and abduction of the right shoulder were measured and classified. The parameters used as reference to evaluate the results were those published by the Ministry of Health of Brazil, which synthesizes the safe limits of amplitude of these movements. RESULTS: Ten subjects were evaluated, with a mean age of 24.5±4.78 years. A total of 39 samples obtained with the movement repetitions were analyzed during an average period of 30 seconds. The angle of shoulder in flexion remained above 30 degrees during 98.18% of the task execution time, above 45 degrees during 88.84%, above 60 degrees during 42.19% and above 90 degrees during 7.72% of the time. The abduction angle remained above 60 degrees throughout all the time and above 90 degrees during 57.59% of the time. In the amplitude of movement spikes, abduction apertures with angles greater than 100 degrees were observed. CONCLUSIONS: During most of the time of the experiments that simulated the movement of sugarcane cutting, the flexion and abduction angles of the shoulder were above those considered safe, indicating that the activity performed by sugarcane cutters has a strong potential to cause damage to the shoulder joint.

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“…Increasing hours of overhead work is strongly associated with shoulder pain and disorders (Holmstrom et al, 1992;Welch et al, 1995). The mechanism of injury was explained by decreased blood supply due to increased gravity and intramuscular pressure (Hagberg and Wegman, 1987;Jarvholm et al, 1991) and mechanical impingement under the acromion (Flatow et al, 1994).…”

Section: Introductionmentioning

confidence: 99%

Effect of Working Posture on the Productivity and Perceived Discomfort while Drilling on the Ceiling

Yoon

Yoon²

2013

Journal of the Ergonomics Society of Korea

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Objective: The purpose of this study was to compare the performance of drilling on the ceiling in three different postures (standing, standing on the ladder and supine on the height adjusted board) and the subjective responses of perceived discomfort after the drilling. Background: Overhead work has been identified as a major occupational risk factor and has been a main research subject. Method: Ten young participants drilled 20 holes at the pre-marked places on the ceiling in three different postures. The drilling duration, resting and drilling heart rate were measured. The levels of perceived discomfort at neck, shoulder, elbow, hand and overall body were asked at the end of each task. Results: The working posture affected the heart rate after the drilling. Perceived discomfort in the neck decreased significantly in supine compared to drilling on the ladder. Conclusion: The results of this study suggest that drilling in supine can be an alternative way to reduce the drilling heart rate and the level of perceived discomfort in the neck without sacrificing the productivity. Application: The results of this study would be considered when drilling on the ceiling is required in construction workers.

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Intramuscular pressure and electromyography in four shoulder muscles

Cited by 113 publications

References 39 publications

Correspondence between laryngeal vocal fold movement and muscle activity during speech and nonspeech gestures

Correspondence between laryngeal vocal fold movement and muscle activity during speech and nonspeech gestures

Risco de lesões de ombro em cortadores de cana-de-açúcar: análise baseada na simulação dos movimentos

Effect of Working Posture on the Productivity and Perceived Discomfort while Drilling on the Ceiling

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