Present day manufacturing assembly relies extensively on a variety of fasteners for the
assembly of sub-systems, components and trim. Speed Fastening (SF) is one commonly used
non-structural assembly fastening method. The primary limitation of SF is the lack of
continuously fed rivets. One path to productivity improvement for SF is the development of a
continuously feed tool that would eliminate the non-value added time currently scheduled for
reloading in the work cycle. In preparation for the design of a new tool, a proactive ergonomic
investigation was carried out to examine differences in muscular effort, upper-body posture, as
well as subjective ratings of perceived exertion and discomfort across three different work rates
for a simulated SF task conducted in a laboratory setting. The purpose of this investigation was
to characterize the ergonomic consequences that an increase in work rate would have on SF
operators.
Twelve healthy female subjects participated in simulated SF work over four test-sessions.
The first test session familiarized subjects with the SF tasks as well as the data collection
protocol. Subsequent test days, which were scheduled 24 hours apart, were block randomized to
one of three work rates (7, 14 and 21 fasteners/min.) with subjects required to complete 120
minutes of a simulated SF task at both waist and shoulder height using a 50% work to rest duty
cycle.