Article

Pregnant women experience numerous physical alterations during pregnancy which
may place them at an increased risk of falls. The purpose of this study was to
examine ground reaction forces (GRFs) during staircase locomotion in pregnant and
non-pregnant women. METHODS: Data were collected on 29 pregnant women in their
second and third trimesters, and on 40 control women. Subjects walked at their
freely chosen speeds during stair ascent and descent. A force plate imbedded in
the second stair, but structurally independent of the staircase, was used to
collect GRF data (1080 Hz). A marker placed on the L3/L4 spinal segment was used
to determine ascent and descent velocity from a motion-capture system. In the
statistical analyses, trimester (control, second trimester, third trimester) and
subject were the independent variables. Stance time and ascent/descent velocity
were analyzed with an ANOVA. Mediolateral excursion of the COP during the step
was analyzed with an ANCOVA. The GRFs were categorized into anterioposterior,
mediolateral, and vertical forces. A two factor MANCOVA (subject, trimester) was
performed on each GRF category. Mass and velocity served as covariates in each
analysis (alpha=0.05). RESULTS: The mediolateral excursion of the COP during
ascent was greater in the third trimester (p=0.04). The anterioposterior braking
impulse was greater in both ascent (p=0.01) and descent (p=0.01) during
pregnancy. The vertical GRF loading rate during descent was greater in pregnant
women than in controls (p=0.04). CONCLUSION: These alterations are likely related
to increased instability during stairway walking and could contribute to
increased fall risk during pregnancy.
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Langue : ANGLAIS