A fourth limitation includes our study design: our study did not
include a control group and we should therefore be careful in
attributing changes in behavior and MSDs to the campaign. Other
factors might have played a role as well. For example, in some of the
occupations, a high proportion of workers (e.g., 60% of the pavers)
indicated that the use of ergonomic measures was legally obliged.
In addition, an increase in the availability or decrease in the selling
price of ergonomic equipment is likely to have an effect on the use
of the measures anyhow. Furthermore, a substantial number of
workers reported having decreased their use of ergonomic measures
over the 2-year period. It is likely that the main barrier
mentioned by the workers, that is, the unavailability of the ergonomic
equipment, possibly as a result of constraints due to varying
working sites, plays an important role in this phenomenon.
Last, our study did not include the employers and it remains
unknown if and to what extent they were reached by the campaign
and how they facilitated the use of ergonomic measures. It is likely
that due to difficult economic circumstances, the purchase of ergonomic
equipment by the employer was restricted, consequently
limiting the availability of the related ergonomic equipment for the
workers.
4.4. Summary and recommendation
Over a 2-year period in which a national campaign was carried
out, we did not find an increase in the use of ergonomic measures,
except for vertical transport. Furthermore, in particular, the bricklayers,
reinforcing iron and rebar workers, and drywall and ceiling
tile installers increased their use of ergonomic measures. We found
no relationship between an increase in the use of ergonomic
measures and a decrease of complaints of the lower back, knees, or
shoulders.
Because sufficient awareness of ergonomic measures is a prerequisite
for using them, the national campaign added positively to
the steps needed to improve physical working conditions for construction
workers. Strategies aimed at improving the availability of
ergonomic equipment complemented with individualized advice
and training in using them might be the required next steps to
increase the use of ergonomic measures.