Measurement of Localized Muscle Fatigue in Biceps Brachii Using Objective and Subjective Measures

Objective The purpose of this study was to evaluate localized muscle fatigue responses at three upper-extremity ergonomics threshold limit value (TLV) duty cycles. Background Recently, a TLV equation was published to help mitigate excessive development of localized muscle fatigue in repetitive upper limb tasks. This equation predicts acceptable levels of maximal voluntary contraction (% MVC) for a given duty cycle (DC). Experimental validation of this TLV curve has not yet been reported, which can help guide utilization by practitioners. Method Eighteen participants performed intermittent isometric elbow flexion efforts, in three separate counter-balanced sessions, at workloads defined by the American Conference of Governmental Industrial Hygenists’ (ACGIH) TLV equation: low DC (20% DC, 29.6% MVC), medium DC (40% DC, 19.7% MVC), and high DC (60% DC, 13.9% MVC). Targeted localized muscle fatigue (LMF) of the biceps brachii was tracked across numerous response variables, including decline in strength (MVC), electromyography (EMG) amplitude and mean power frequency (MnPF), and several psychophysical ratings. Results At task completion, biceps MnPF and MVC (strength) were significantly different between each TLV workload, with the high DC condition eliciting the largest declines in MnPF and MVC. Conclusion Findings demonstrate that working at different DCs along the ACGIH TLV curve may not be equivalent in preventing excessive LMF. Higher DC workloads elicited a greater LMF response across several response variables. Application High DC work of the upper extremity should be avoided to mitigate excess LMF development. Current TLVs for repetitive upper-extremity work may overestimate acceptable relative contraction thresholds, particularly at higher duty cycles.

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Effect of localized muscle fatigue induced at different joints on postural control

PsycEXTRA Dataset ◽

10.1037/e577432012-010 ◽

2005 ◽

Author(s):

Navrag B. Singh ◽

Maury A. Nussbaum ◽

Dingding Lin ◽

Michael L. Madigan

Keyword(s):

Postural Control ◽

Muscle Fatigue ◽

Localized Muscle Fatigue

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Intramuscular and surface electromyogram changes during muscle fatigue

Journal of Applied Physiology ◽

10.1152/jappl.1986.60.4.1179 ◽

1986 ◽

Vol 60 (4) ◽

pp. 1179-1185 ◽

Cited By ~ 258

Author(s):

T. Moritani ◽

M. Muro ◽

A. Nagata

Keyword(s):

Muscle Fatigue ◽

Biceps Brachii ◽

Surface Emg ◽

Firing Frequency ◽

Voluntary Contraction ◽

Mean Power ◽

Mean Power Frequency ◽

Surface Electromyogram ◽

Spike Amplitude ◽

Frequency Power

Twelve male subjects were tested to determine the effects of motor unit (MU) recruitment and firing frequency on the surface electromyogram (EMG) frequency power spectra during sustained maximal voluntary contraction (MVC) and 50% MVC of the biceps brachii muscle. Both the intramuscular MU spikes and surface EMG were recorded simultaneously and analyzed by means of a computer-aided intramuscular spike amplitude-frequency histogram and frequency power spectral analysis, respectively. Results indicated that both mean power frequency (MPF) and amplitude (rmsEMG) of the surface EMG fell significantly (P less than 0.001) together with a progressive reduction in MU spike amplitude and firing frequency during sustained MVC. During 50% MVC there was a significant decline in MPF (P less than 0.001), but this decline was accompanied by a significant increase in rmsEMG (P less than 0.001) and a progressive MU recruitment as evidenced by an increased number of MUs with relatively large spike amplitude. Our data suggest that the surface EMG amplitude could better represent the underlying MU activity during muscle fatigue and the frequency powers spectral shift may or may not reflect changes in MU recruitment and rate-coding patterns.

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Early development of EMG localized muscle fatigue in hand muscles of patients with chronic heart failure

Archives of Physical Medicine and Rehabilitation ◽

10.1016/s0003-9993(98)90206-4 ◽

1998 ◽

Vol 79 (1) ◽

pp. 41-45 ◽

Cited By ~ 11

Author(s):

Michelangelo Buonocore ◽

Cristina Opasich ◽

Roberto Casale

Keyword(s):

Heart Failure ◽

Chronic Heart Failure ◽

Muscle Fatigue ◽

Early Development ◽

Hand Muscles ◽

Localized Muscle Fatigue

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Effects of Muscle Fatigue and Recovery on Complexity of Surface Electromyography of Biceps Brachii

Entropy ◽

10.3390/e23081036 ◽

2021 ◽

Vol 23 (8) ◽

pp. 1036

Author(s):

Fuyuan Liao ◽

Xueyan Zhang ◽

Chunmei Cao ◽

Isabella Yu-Ju Hung ◽

Yanni Chen ◽

...

Keyword(s):

Muscle Fatigue ◽

Surface Electromyography ◽

Biceps Brachii ◽

Cupping Therapy ◽

Nonlinear Method ◽

Muscle Recovery ◽

Sham Control ◽

Semg Signal ◽

Relative Change ◽

Semg Signals

This study aimed to investigate the degree of regularity of surface electromyography (sEMG) signals during muscle fatigue during dynamic contractions and muscle recovery after cupping therapy. To the best of our knowledge, this is the first study assessing both muscle fatigue and muscle recovery using a nonlinear method. Twelve healthy participants were recruited to perform biceps curls at 75% of the 10 repetitions maximum under four conditions: immediately and 24 h after cupping therapy (−300 mmHg pressure), as well as after sham control (no negative pressure). Cupping therapy or sham control was assigned to each participant according to a pre-determined counter-balanced order and applied to the participant’s biceps brachii for 5 min. The degree of regularity of the sEMG signal during the first, second, and last 10 repetitions (Reps) of biceps curls was quantified using a modified sample entropy (Ems) algorithm. When exercise was performed immediately or 24 h after sham control, Ems of the sEMG signal showed a significant decrease from the first to second 10 Reps; when exercise was performed immediately after cupping therapy, Ems also showed a significant decrease from the first to second 10 Reps but its relative change was significantly smaller compared to the condition of exercise immediately after sham control. When exercise was performed 24 h after cupping therapy, Ems did not show a significant decrease, while its relative change was significantly smaller compared to the condition of exercise 24 h after sham control. These results indicated that the degree of regularity of sEMG signals quantified by Ems is capable of assessing muscle fatigue and the effect of cupping therapy. Moreover, this measure seems to be more sensitive to muscle fatigue and could yield more consistent results compared to the traditional linear measures.

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Sex-specific Effects of Localized Muscle Fatigue on Upper Body Kinematics During a Repetitive Pointing Task

10.21203/rs.3.rs-944845/v1 ◽

2021 ◽

Author(s):

Chen Yang ◽

Julie N. Côté

Keyword(s):

Muscle Fatigue ◽

Musculoskeletal Disorders ◽

Movement Pattern ◽

Upper Body ◽

Lateral Flexion ◽

Joint Angles ◽

Localized Muscle Fatigue ◽

Specific Effects ◽

Spinal Movement ◽

Pointing Task

Abstract BackgroundFemales are reported to have a higher risk of musculoskeletal disorders than males. Among risk factors for musculoskeletal disorders, the mechanism of muscle fatigue remains unclear. Especially how females and males adapt to localized fatigue is poorly understood. The purpose of the study was to examine the sex-specific effects of fatigue location on shoulder, elbow and spinal joint angles, and angular variabilities during a repetitive pointing task.MethodsSeven males and ten females performed a standing repetitive pointing task when they were non-fatigued (NF), elbow-fatigued (EF), shoulder-fatigued (SF) and trunk-fatigued (TF), while trunk and upper body tridimensional kinematic data was recorded. Joint angles and angular variabilities of shoulder, elbow, upper thorax, lower thorax, and lumbar were calculated. ResultsResults showed that shoulder angles changed the most after EF in males, but after SF in females. The similarities between sexes were that SF increased the variabilities at upper (lateral flexion: 0.15° greater than NF, rotation: 0.26° greater than all other conditions) and lower thorax (lateral flexion: 0.13° greater than NF, rotation: averagely 0.1° greater than all other condition) in both sexes. TF altered upper thorax variability (0.36° smaller than SF), lower thorax angle (lateral flexion: 3.00° greater than NF, rotation: 1.68° greater than SF), and lumbar angle (averagely 1.8° smaller than all other conditions) in both sexes. However, females had greater lower thorax angle (lateral flexion: 8.3° greater, p=0.005) as well as greater upper (rotation: 0.53° greater, p=0.006) and lower thorax (rotation: 0.5° greater, p=0.007; flexion: 0.6° greater, p=0.014) angular variabilities.ConclusionsThe overall greater lower and upper thorax angular variabilities suggested a more unstable spinal movement pattern in females. The kinematic differences between sexes highlighted a few sex differences in adapting the localized muscle fatigue.

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