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Effects of age, gender, and task parameters on fatigue development during intermittent isokinetic torso extensions
Yassierlia, Nussbaum M.A.b
a Faculty of Industrial Technology, Institut Teknologi Bandung, Indonesia
b Department of Industrial and Systems Engineering, Virginia Tech, United States
[vc_row][vc_column][vc_row_inner][vc_column_inner][vc_separator css=”.vc_custom_1624529070653{padding-top: 30px !important;padding-bottom: 30px !important;}”][/vc_column_inner][/vc_row_inner][vc_row_inner layout=”boxed”][vc_column_inner width=”3/4″ css=”.vc_custom_1624695412187{border-right-width: 1px !important;border-right-color: #dddddd !important;border-right-style: solid !important;border-radius: 1px !important;}”][vc_empty_space][megatron_heading title=”Abstract” size=”size-sm” text_align=”text-left”][vc_column_text]This study investigated the effects of age, gender, and task parameters on muscle fatigue during prolonged isokinetic torso exercises, and assessed the sensitivity of EMG-based measures to fatigue. Two groups of 24 participants (older: 55-65 years, younger: 18-25 years), with gender balanced within each group, performed repetitive intermittent torso extensions until exhaustion. Effort levels were set to 30% and 40% of individual maximum voluntary contraction (MVC) and work-rest cycles had durations of 30 and 60 s with a 50% duty cycle. Electromyographic (EMG) signals were obtained bilaterally from the paraspinal muscles. EMG-based fatigue measures, along with declines in MVC and changes in ratings of perceived discomfort, were used to evaluate fatigue progression. While the older group had 23% less initial strength than the younger counterpart, effects of age and gender on fatigue were marginal. However, significant interactive effects of age and gender with effort level were found. These findings overall suggest the importance of carefully considering individual factors and task parameters in designing jobs requiring repetitive torso efforts. In the dynamic torso efforts investigated, the sensitivity of EMG measures to fatigue was relatively low. Relevance to industry: Manual material handling tasks such as lifting are often characterized by intermittent dynamic torso efforts. This paper provides evidence regarding age-related differences in torso capacity (strength, fatigue, and endurance), and the influences of effort level and cycle duration. These results can be used for task evaluation and design, and to address older workers in particular. © 2008 Elsevier B.V. All rights reserved.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Author keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Aging,Cycle durations,Duty cycles,Electromyographic signals,Individual factors,Interactive effects,Intermittent work,Manual material handlings,Maximum voluntary contractions,Muscle fatigue,Older workers,Paraspinal muscles,Torso,Younger counterparts[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Indexed keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Aging,Dynamic contraction,Electromyography,Intermittent work,Muscle fatigue,Torso[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Funding details” size=”size-sm” text_align=”text-left”][vc_column_text]Support for this work was provided by Cooperative Agreement Number R01 OH04089 from the Centers for Disease Control and Prevention (CDC). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the CDC. The authors thank Dr. Hardianto Iridiastadi for his assistance in designing the experiment.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”DOI” size=”size-sm” text_align=”text-left”][vc_column_text]https://doi.org/10.1016/j.ergon.2008.05.003[/vc_column_text][/vc_column_inner][vc_column_inner width=”1/4″][vc_column_text]Widget Plumx[/vc_column_text][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row][vc_row][vc_column][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][/vc_column][/vc_row]