The assessment of material-handling strategies in dealing with sudden loading: the effect of uneven ground surface on trunk biomechanical responses

Ergonomics ◽  
2014 ◽  
Vol 58 (2) ◽  
pp. 259-267 ◽  
Author(s):  
Jie Zhou ◽  
Xiaopeng Ning ◽  
Ashish D. Nimbarte ◽  
Fei Dai
Author(s):  
Hossein Motabar ◽  
Saman Madinei ◽  
Xiaopeng Ning

Shoulder disorders have been reported as the most severe musculoskeletal disorders among all body parts. Multiple occupational risk factors such as manual material handling, repetitive motion, overexertion, fatigue, and overhead tasks have been reported to be associated with the development of shoulder disorders. The objective of this study was to investigate the effect of height (low, middle, high) on shoulder muscles during sudden loading. Kinematics and Electromyography (EMG) was recorded from 14 male participants. Effect of height found to be significant on normalized EMG and load travel distance. Bilateral shoulder muscles indicated higher NEMG with the increase of the load’s altitude. This increase of muscle activity could have resulted from the greater potential energy of the load at higher altitudes which required extra muscle activity to maintain the biomechanical stability of the shoulder. Reduced stability of shoulder at higher altitudes caused proprioceptive deficit which resulted in higher load travel distance.


Author(s):  
Zongliang Jiang ◽  
Gwanseob Shin ◽  
Jacklyn Freeman ◽  
Stephanie Reid ◽  
Gary A. Mirka

Many outdoor work environments (e.g. agriculture and construction) require manual material handling activities on variable grade ground surfaces. Quantifying biomechanical responses for lifting under these conditions may provide insight into the etiology of lifting-related injuries. The aim of the current study was to quantify the effect of laterally slanted ground surfaces on biomechanical responses. Ten subjects performed lifting exertions (using a 40% of max load) while standing on a platform that was laterally tilted at 0, 10, 20 and 30 degrees from horizontal. During the lifting tasks the whole body kinematics were collected, which were later used in a dynamic biomechanical model to calculate the time-dependent moment about L5/S1 and the time-dependent lateral forces acting on the body segments. The results showed a consistent reduction in the peak dynamic L5/S1 moment (decreased by 9%) and an increase in the lateral forces (increased by 111%) with increasing slant angle.


Author(s):  
J.N. Ramsey ◽  
D.P. Cameron ◽  
F.W. Schneider

As computer components become smaller the analytical methods used to examine them and the material handling techniques must become more sensitive, and more sophisticated. We have used microbulldozing and microchiseling in conjunction with scanning electron microscopy, replica electron microscopy, and microprobe analysis for studying actual and potential problems with developmental and pilot line devices. Foreign matter, corrosion, etc, in specific locations are mechanically loosened from their substrates and removed by “extraction replication,” and examined in the appropriate instrument. The mechanical loosening is done in a controlled manner by using a microhardness tester—we use the attachment designed for our Reichert metallograph. The working tool is a pyramid shaped diamond (a Knoop indenter) which can be pushed into the specimen with a controlled pressure and in a specific location.


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