Discussion
One goal of the occupationally oriented medical rehabilitation
courses was to teach the female farmers
work techniques that optimized the load on the
musculoskeletal system, especially the back. This goal
was achieved, as the bent and twisted back postures
decreased from 34 to 4% of studied postures. The
change of work postures and movements is difficult, because the old movement techniques have usually
been automatic for many years. Adoption of ergonomic
work techniques requires motor learning, and the
frequency of training is important. During the rehabilitation
course the female farmers trained with the
new work techniques in a classroom, then in a farm
situation and after that on their own farms. The
subjects all suffered from musculoskeletal symptoms,
which may have increased their motivation to change
their traditional work habits.
The video recordings were made during the rehabilitation
course and not in the farmers’ own barns in
normal work situations. Thus it is not possible to say
how much they used the new work techniques daily at
home. At the beginning of the course and in the followup
the subjects were asked to work with their normal
daily work technique. It seems probable that the new
techniques had been in active use during the 6 months,
because the subjects used them in the follow-up very
naturally and in the same manner as at the end of the
course. It would have been difficult to change the
techniques only for video recordings. In particular, the
use of a milking chair when milking at normal speed
would have been very difficult to do only for the
camera.
The computerized OWAS method allowed efficient
data collection and rapid analysis. The method was
suitable for analysing postural load at agricultural
work, because the work included mainly large wholebody
movements. However, the estimation of weight of
loads or force needed was difficult. The main principle
in teaching the new way of working was to transfer the
load from the back to the legs. According to the
classification into OWAS categories, the new postures
with bent back and both knees bent caused higher
musculoskeletal load than the earlier postures with
bent back and straight legs. It is for this reason that the
posture combinations belonging to action category 3
were increased during the course in silage handling and
cow brushing.
Improving work techniques is a long process; it
demands much training and also very high personal
motivation if the subject is to change old habits. It may
be easier to learn improved ways of working during
vocational education rather than to change old work
habits. This change of work postures is one way to
decrease the daily postural load and to increase the
ability to work in spite of prior symptoms due to
musculoskeletal disorders. Further, by developing the
work tools and work environment the physical work
load can be decreased in agricultural work.