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Abstract"Manual Materials Handling" (M.M.H.), particularly
manual lifting, has beena topic of interest in many fields of
research. Comparing with the investigationof maximum acceptable
weight of lift (MAWL), the various situations of theobjects are
also important factors that affect the safety and balance
ofsubjects while lifting. The lifting tasks are necessary in our
active dailyliving. One potential hazard in lifting is the
related musculo-skeletal injuryof upper extremity, especially
the wrist. It has become a major course intasks design to reduce
injury efficiently.The purpose of this study was to establish
the 3-D kinematic models of upperlimbs. By imaged based motion
analysis system, the movement pattern of theshoulder, elbow,
wrist and hand-dandle joint of eight right-handed malesubjects
during sixteen different types box lifting(3 weight: 20, 30, 35
kg;3 weight offset: left, middle, right; 4 handle angles: 0°,
10°, 20°, 30°from horizontal) were collected and analyzed. By
using the platform forceplate on the ground, the ground reaction
force all over these different typeslifting was also collected
and analyzed.The result completely described the 3-D kinematic
characteristics and realmovements of upper limbs. The
differences in the range of motion of each jointbetween dominant
and non-dominant side of upper limbs exist significantly.
Thecenter of pressure (COP) calculated from force plate and its
locus showeddifferent patterns while different weight offset of
box were lifted (COPshifted to left when the weight left offset,
and COP shifted to right whenthe weight right offset). It is
worth investigating deeply the unbalancephenomenon while lifting
occurs in the mid-sagittal plane .
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