ERGONOMICS OF MANUAL MATERIALS HANDLING - Environmentally Conscious Materials Handling - page 54

Figure 2.7 Typical gravity-powered conveyors used to move materials from one fixed point
to another fixed point (from Kroemer et al. 2001)

requiring the worker to physically push and/or pull the load from one location to
another. In some situations, loading a hand truck can be done without requiring
the worker to manually lift the load (such as when the lip of a hand truck is
slipped underneath a stack of boxes). However, in many other situations, loads
will have to be lifted onto the hand truck at or very near floor level, resulting in
a hazardous lift (see Section 2.2). Hand trucks replace the carry component of a
task with a push-pull component, but usually require the worker to perform the
lifting and lowering components of the job. Similar to conveyors, they can be
used with hoists or lift tables to address both the lifting and carrying components
of a work task.

3.2 Ergonomic Issues in Device Design, Selection, and Installation

Mechanical materials handling devices may solve one ergonomic issue but at the
same time create new ergonomics concerns for the worker. As a result, workers