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Full-Text Articles in Ergonomics
The Effect Of A Knee Support On The Biomechanical Response Of The Low Back, Yu Shu, Zongliang Jiang, Xu Xu, Gary A. Mirka
The Effect Of A Knee Support On The Biomechanical Response Of The Low Back, Yu Shu, Zongliang Jiang, Xu Xu, Gary A. Mirka
Gary A. Mirka
Stooping and squatting postures are seen in a number of industries (e.g., agriculture, construction) where workers must work near ground level for extended periods of time. The focus of the current research was to evaluate a knee support device designed to reduce the biomechanical loading of these postures. Ten participants performed a series of sudden loading tasks while in a semisquat posture under two conditions of knee support (no support and fully supported) and two conditions of torso flexion (45 and 60°). A weight was released into the hands of the participants who then came to steady state while maintaining …
An Adaptive System Identification Model Of The Biomechanical Response Of The Human Trunk During Sudden Loading, Brad M. Lawrence, Gregory D. Buckner, Gary A. Mirka
An Adaptive System Identification Model Of The Biomechanical Response Of The Human Trunk During Sudden Loading, Brad M. Lawrence, Gregory D. Buckner, Gary A. Mirka
Gary A. Mirka
Sudden loading injuries to the low back are a concern. Current models are limited in their ability to quantify the time-varying nature of the sudden loading event. The method of approach used six males who were subjected to sudden loads. Response data (EMG and kinematics) were input into a system identification model to yield time-varying torso stiffness estimates. The results show estimates of system stiffness in good agreement with values in the literature. The average root mean square error of the model’s predictions of sagittal motion was equal to 0.1deg. In conclusion, system identification can be implemented with minimal error …
The Effect Of A Repetitive, Fatiguing Lifting Task On Horizontal Ground Reaction Forces, Yu Shu, Jonathan Drum, Stephanie Southard, Gwanseob Shin, Gary A. Mirka
The Effect Of A Repetitive, Fatiguing Lifting Task On Horizontal Ground Reaction Forces, Yu Shu, Jonathan Drum, Stephanie Southard, Gwanseob Shin, Gary A. Mirka
Gary A. Mirka
There are many outdoor work environments that involve the combination of repetitive, fatiguing lifting tasks and less-than-optimal footing (muddy/slippery ground surfaces). The focus of the current research was to evaluate the effects of lifting-induced fatigue of the low back extensors on lifting kinematics and ground reaction forces. Ten participants performed a repetitive lifting task over a period of 8 minutes. As they performed this task, the ground reaction forces and whole body kinematics were captured using a force platform and magnetic motion tracking system, respectively. Fatigue was verified in this experiment by documenting a decrease in the median frequency of …