Análise cinesiológica e biomecânica de atividades de manuseio de carga
Abstract
Load handling activities impose great overloads on the musculoskeletal system,
increasing the risk of injuries. The fact that these handling activities are considered
risky had led to several studies regarding load lifting, lowering, pulling and pushing.
The results obtained certainly allowed many findings about influence of different
variables on risk factors of these activities. However, other studies are needed,
especially about risks by load carrying activities, since the literature has not dealt
extensively with this topic. Thus, studies have been carried out about load handling,
leading to 4 scientific papers. Study one aimed at comparing two groups of workers,
with and without musculoskeletal symptoms in the upper limbs when they performed
simulated tasks of handling techniques as to trunk movements and load support.
Movements analysis was quantified by a flexible electrogoniometer and contact
between load and trunk, by load cells. Nine asymptomatic and 10 symptomatic
industrial workers were evaluated. An ANOVA was performed to compare results
between symptomatic and asymptomatic workers. Most of the symptomatic workers
supported the load on their trunk, whilst most of the asymptomatic did not. Higher
values of lumbar flexion occurred for the symptomatic workers (p<0,05). The
objective of the second study was ti describe trunk movements in sedentary subjects,
and in workers with and without musculoskeletal symptoms, when carrying loads in
simulated tasks. The 38 subjects who participated in this study were divided into 4
groups, consisting of 9 male students, 10 female students, 10 female symptomatic
industrial workers and 9 asymptomatic industrial workers. The trunk movements of
all subjects were recorded by biaxial back electrogoniometer when carrying loads
between surfaces of different heights. An analysis of variance for repeated measures
were performed, which was followed by the Duncan post hoc test for comparison of
anthropometrical data between subjects, amplitude of movement, and time spent in
each movement per group and per experimental condition. The height of the surfaces
to which the loads were carried to or from, significantly influenced the trunk
positions during handling (p<0,01), as if subjects were anticipating the target position
whilst handling. Also more time was spent in flexion (p<0,01) than in extension.
These aspects increase the risks of possible injury in such activities. The objective of
the third study was to describe the kinds of grip used during handling activities of
5Kgf and 10 Kgf loads between surfaces of different height and to quantify
flexion/extension movements and wrist radial and ulnar deviations quantified by
electrogoniometry. Ten male volunteers participated in this study handled a box
between surfaces of different heights. The activities was performed to evaluate
significant differences between the anthropometry of volunteers´ hands and between
movements used for load handling and different heights. The results showed that the
surface heights to which the objects were handled significantly influenced (p=0,000)
joint amplitudes, nevertheless there wasn t any difference in the movements for
different load masses handled (p=0,43). Time over what is considered advisable was
spent in radial deviation when handling involved high surfaces. The fourth study
aimed at evaluating the anterior-posterior movements of the trunk and the time spent
in task performance by experienced and inexperienced subjects during load handling
activities to different target surfaces. The 36 subjects who participated in this study
were healthy males, divided into groups of 16 and 20, experienced and inexperience
respectively, in the performance of load handling activities. The activities consisted
of carrying the 7Kg and 15Kg boxes from a surface at a fixed height to another at a
variable height. Lumbar thoracic movements were quantified by a flexible
electrogoniometer. Significant differences were found in the time spent to perform
the handling between the groups (p<0,008) and between the loads (p<0,000).
However, there was no significant difference in the trunk movemets between the
groups (p>0,005) and the loads (p>0,005). Surfaces heights to which the box was
transported significantly influenced trunks movements (p<0,000).