assessment of isometric muscle exertion in short-term considering task-rest schedule

Numerous workers experience occupational diseases, especially musculoskeletal disorders, due to various physical, psychological, and individual factors. among known risk factors for musculoskeletal disorders, work-rest patterns, and muscle fatigue are to be named. assessment of muscle fatigue plays an important role, leading to a proper design for a work-rest program. this study was aimed to investigate isometric muscle strength in iranian workers during repetitive activities based on gender and rest time. it has been attempted to present a model for isometric muscle strength. in a laboratory experiment, 31 students comprised of 19 males and 12 females participated, and muscle strength was recorded by a dynamometer. minitab software results analysis proved that females’ upper body muscles showed a higher level of resistance to fatigue rather than males. furthermore, tests’ results for each individual were more in line with cubic regression so that four models with a high r-sq index (at least 94.4%) and high r-sq (adj) index (at least 77.8%) were presented to predict isometric muscle strength in short-run. finally, it has been suggested to use male workers for repetitive activities with a high workload and enough rest time and use female workers for repetitive activities with low workload and high frequency.