BACKGROUND: Lifting objects without knowing its weight may result in postural imbalances
and be a risk factor for falls.
OBJECTIVE: The aim of this study was to examine the influence of the load knowledge in
postural balance when lifting different weight loads.
METHODS: Thirteen male subjects (23.8 ± 3.1 years; 73.5 ± 7.8 kg; 179.1 ± 7.5 cm; foot length, 25.7 ± 1.2 cm) participated in the study. The effect of
the weight overestimation on the postural stability was measured by the
Index of Proximity to Stability Boundary (IPSB) and through the
anterior-posterior and medio-lateral lengths displacements of the Center of
Pressure (CoP).
RESULTS: The results showed an increase in the IPSB when the 5 kg lifting task was
performed with load knowledge. Moreover, the length of the antero-posterior
and medio-lateral CoP displacement was reduced in the 5 kg lift with
knowledge.
CONCLUSIONS: Results showed that the lack of the loads' knowledge may lead to balance
loss. Thus, when the preparation processes are not adequate, picking up
similar objects with different loads may increase the risk of fall, mainly
when a light weight is suddenly lifted up after a heavy one.
