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International Journal of Environmental... Nov 2022Manual materials handling (MMH) contributes to musculoskeletal disorders (MSDs) in the workplace. The development and recovery of muscle fatigue are essential in...
Manual materials handling (MMH) contributes to musculoskeletal disorders (MSDs) in the workplace. The development and recovery of muscle fatigue are essential in work/rest arrangements for MMH tasks. A pulling experiment, including a muscle fatigue test and a muscle fatigue recovery test, was conducted. In the muscle fatigue test, the participant performed a pulling task on a treadmill with a walking velocity of 1 km/h until they could no longer do so. The load was either 30 or 45 kg. The maximum endurance time () was recorded. The pull strength () of the participant both before and after the pulling task was measured. The subjective ratings of muscle fatigue after the pulling task were recorded. In the muscle fatigue recovery test, the participant took a rest after performing the pulling task. The participants reported their subjective ratings of muscle fatigue on the scale after taking a rest for a time period where = 1, 2,…, 6 min. The of the participant was then measured again. It was found that the load significantly affected the for pulling tasks. The load was insignificant to the decrease of the , but was significant to the decrease rate ( decrease per min) of the . The decrease rate for the 45 kg condition (30.8 ± 16.5 N/min) was significantly higher ( < 0.05) than that of the 30 kg condition (15.4 ± 5.5 N/min). The recovery time significantly affected the and . Two models were established to explore the development of muscle fatigue in pulling tasks. A model was constructed to describe the recovery of muscle force. A model was proposed to show the subjective ratings of recovery. These models are beneficial for determining the work/rest allowance for pulling tasks.
Topics: Humans; Muscle Fatigue; Muscle, Skeletal; Walking; Exercise Test; Workplace
PubMed: 36429882
DOI: 10.3390/ijerph192215159 -
Sensors (Basel, Switzerland) Dec 2023Muscle fatigue has proven to be a main factor in developing work-related musculoskeletal disorders. Taking small breaks or performing stretching routines during a work...
Muscle fatigue has proven to be a main factor in developing work-related musculoskeletal disorders. Taking small breaks or performing stretching routines during a work shift might reduce workers' fatigue. Therefore, our objective was to explore how breaks and/or a stretching routine during a work shift could impact muscle fatigue and body kinematics that might subsequently impact the risk of work-related musculoskeletal disorder (WMSD) risk during material handling jobs. We investigated muscle fatigue during a repetitive task performed without breaks, with breaks, and with a stretching routine during breaks. Muscle fatigue was detected using muscle activity (electromyography) and a validated kinematic score measured by wearable sensors. We observed a significant reduction in muscle fatigue between the different work-rest schedules ( < 0.01). Also, no significant difference was observed between the productivity of the three schedules. Based on these objective kinematic assessments, we concluded that taking small breaks during a work shift can significantly reduce muscle fatigue and potentially reduce its consequent risk of work-related musculoskeletal disorders without negatively affecting productivity.
Topics: Humans; Muscle Fatigue; Musculoskeletal Diseases; Electromyography; Rest
PubMed: 38139516
DOI: 10.3390/s23249670 -
Exercise and Sport Sciences Reviews Jan 2002The muscular wisdom hypothesis proposed that the slowing of the motor unit discharge rate during sustained maximal isometric contractions serves to minimize fatigue. The... (Review)
Review
The muscular wisdom hypothesis proposed that the slowing of the motor unit discharge rate during sustained maximal isometric contractions serves to minimize fatigue. The purpose of this review is to examine the applicability of the muscular wisdom hypothesis during other forms of contraction, i.e., prolonged submaximal isometric or dynamic contractions.
Topics: Humans; Models, Biological; Motor Neurons; Muscle Contraction; Muscle Fatigue
PubMed: 11800500
DOI: 10.1097/00003677-200201000-00009 -
Gait & Posture Jan 2016The aim of this study was to investigate the effect of recovery time after quadriceps muscle fatigue on gait in young adults. Forty young adults (20-40 years old)...
The aim of this study was to investigate the effect of recovery time after quadriceps muscle fatigue on gait in young adults. Forty young adults (20-40 years old) performed three 8-m gait trials at preferred velocity before and after muscle fatigue, and after 5, 10 and 20min of passive rest. In addition, at each time point, two maximal isometric voluntary contractions were preformed. Muscle fatigue was induced by repeated sit-to-stand transfers until task failure. Spatio-temporal, kinetic and muscle activity parameters, measured in the central stride of each trial, were analyzed. Data were compared between before and after the muscle fatigue protocol and after the recovery periods by one-way repeated measures ANOVA. The voluntary force was decreased after the fatigue protocol (p<0.001) and after 5, 10 and 20min of recovery compared to before the fatigue protocol. Step width (p<0.001) and RMS of biceps femoris (p<0.05) were increased immediately after the fatigue protocol and remained increased after the recovery periods. In addition, stride duration was decreased immediately after the fatigue protocol compared to before and to after 10 and 20min of rest (p<0.001). The anterior-posterior propulsive impulse was also decreased after the fatigue protocol (p<0.001) and remained low after 5, 10 and 20min of rest. We conclude that 20min is not enough to see full recovery of gait after exhaustive quadriceps muscle fatigue.
Topics: Adult; Female; Gait; Humans; Isometric Contraction; Male; Muscle Fatigue; Quadriceps Muscle; Recovery of Function; Young Adult
PubMed: 26531768
DOI: 10.1016/j.gaitpost.2015.10.015 -
Clinical Neurophysiology : Official... Aug 2015
Topics: Humans; Isometric Contraction; Male; Movement; Muscle Fatigue; Posture
PubMed: 25488401
DOI: 10.1016/j.clinph.2014.11.011 -
Advances in Experimental Medicine and... 1995In daily life, muscle fatigue often becomes noticeable as an apparent decline in the efficiency of force production by central commands, making it necessary to increase... (Review)
Review
In daily life, muscle fatigue often becomes noticeable as an apparent decline in the efficiency of force production by central commands, making it necessary to increase drive (or "effort") to produce a constant motor output. Such aspects of fatigue may be caused by changes in the way in which synaptic messages arriving at the motoneurons are translated into forces by the muscle fibers. Therefore, an understanding of these neuromuscular gradation mechanisms is essential for any analysis of motor fatigue. A brief general review is given of 1) how muscle fibers transduce motoneuronal discharge rates into force; 2) how synaptic currents are transduced into motoneuronal discharge rates; 3) how activity-dependent changes in the neuromuscular transduction mechanisms contribute to neuromuscular fatigue; and 4) how the matching between the transduction mechanisms of motoneurons and those of their muscle fibers may help to optimize neuromuscular gradation efficiency and decrease the severity of fatigue.
Topics: Animals; Motor Neurons; Muscle Fatigue; Muscle Fibers, Skeletal; Neuromuscular Junction
PubMed: 8585446
DOI: 10.1007/978-1-4899-1016-5_11 -
Photomedicine and Laser Surgery Jul 2016
Topics: Humans; Laser Therapy; Muscle Fatigue; Muscle, Skeletal
PubMed: 27258805
DOI: 10.1089/pho.2016.4130 -
Medicine Oct 2022Fatigue is a common phenomenon encountered by athletes in ordinary life and sports. Fatigue results in decreased muscle strength, balance, agility, and an increased risk... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Fatigue is a common phenomenon encountered by athletes in ordinary life and sports. Fatigue results in decreased muscle strength, balance, agility, and an increased risk of injury, which together results in hampered sports performance. Several studies have examined the effects of Kinesio Tape (KT) application on muscle fatigue however, contradictory findings are reported. This study aimed to examine the effects of the application of KT on calf muscle fatigability.
METHODS
A three-arm parallel pretest-post-test experimental design was used. Forty-five collegiate female athletes (mean age of 20.57 years) were randomly assigned to three groups. For the experimental group, KT with 50% tension; for the sham group, KT without any tension; and for the placebo group, rigid tape without any tension was applied. The number of heel rises (HRn) was measured before and after taping in the three groups, using Haberometer and Metronome. The tapes were applied in the Y shape to the calf muscle region.
RESULTS
In the experimental group: The HRn significantly increased by 18.76 % (P = .000) after applying KT. In the sham and placebo groups: There was no change in HRn before and after Taping (P > .05).
CONCLUSION
Y-shaped application of KT with 50% tension over the calf muscle region is effective in reducing its fatigability.
Topics: Adult; Female; Humans; Young Adult; Athletes; Athletic Tape; Muscle Fatigue; Muscle, Skeletal
PubMed: 36316875
DOI: 10.1097/MD.0000000000031004 -
Journal of the Peripheral Nervous... 1996Evidence is reviewed that a reflex increase in fusimotor activity develops during fatiguing muscle contraction in decerebrate and/or spinal cats. This phenomenon is... (Review)
Review
Evidence is reviewed that a reflex increase in fusimotor activity develops during fatiguing muscle contraction in decerebrate and/or spinal cats. This phenomenon is apparently due to an increased inflow from small-diameter afferents that is elicited by metabolic products liberated and/or accumulated in the muscle tissue. It occurs in fusimotor neurones to the contracting muscle as well as in those to its close synergists, inactive remote muscle groups, and in a smaller number of those to antagonist muscles. It is finely modulated by afferent inflow of other origin and results in changes of muscle spindle outflow and responsiveness. According to the magnitude and time course of the responses, the fusimotor-spindle system might contribute to: (1) optimization of skeletomotor activity directed to the contracting muscle so as to relieve the fatigue-induced changes in its contractile properties; (2) spreading of activity to initially inactive muscle groups when the agonist gets fatigued; (3) providing more information to skeletomotor neurones and higher motor centres both during and after the fatiguing contraction until the muscle recovers. However, it remains to be assessed whether such a reflex increase plays a role in muscle fatigue in intact animals and/or humans.
Topics: Animals; Humans; Muscle Fatigue; Muscle Spindles; Muscle, Skeletal
PubMed: 10975717
DOI: No ID Found -
Advances in Experimental Medicine and... 1995This chapter reviews several mechanisms that the CNS may use to mitigate muscle fatigue, including intrinsic motoneuron properties and feedback systems. The emphasis is... (Review)
Review
This chapter reviews several mechanisms that the CNS may use to mitigate muscle fatigue, including intrinsic motoneuron properties and feedback systems. The emphasis is on the effects of sensory inputs on spinal cord interneurons including: Renshaw cells; Ib inhibitory interneurons; interneurons mediating presynaptic inhibition; Ia inhibitory interneurons; and interneuronal networks constituting central pattern generators for locomotion. This exercise brings out how little is known about the operation of these circuits in dealing with muscle fatigue.
Topics: Animals; Interneurons; Motor Neurons; Muscle Fatigue; Spinal Cord
PubMed: 8585454
DOI: 10.1007/978-1-4899-1016-5_19