Ground reaction forces during gait in pregnant fallers and non-fallers

Abstract

Pregnant women are at a high risk of experiencing a fall. To our knowledge, ground reaction forces (GRFs) in pregnant fallers and non-fallers have not been reported. Purpose The purpose of this study was to examine the effects of pregnancy and fall history on GRFs during walking. Methods Forty one pregnant subjects in the mid 2nd and 3rd trimesters (pregnant fallers: n = 15, pregnant non-fallers: n = 14), and 40 control women walked at a freely chosen walking speed along an 8 m walkway. A force plate, hidden in the walkway, was used to collect GRFs (1080 Hz). Kinematic data (120 Hz) were collected from a marker placed on the lumbar spine to estimate walking velocity. GRF variables included mediolateral Center of Pressure (COP) excursion, and GRFs normalized to body mass. A two factor ANOVA (trimester x fall group) was used to compare subject demographics, and walking velocity ( α = 0.05). A two factor ANCOVA (trimester × fall group, covariate: velocity) was performed to examine other GRF variables (Bonferroni corrected α = 0.006) and the mediolateral COP excursion ( α = 0.05). Results Walking velocity was greater in the control group ( p < 0.05). No differences were seen in the GRFs or COP movement between trimesters or between pregnant fallers and non-fallers. Conclusions When walking velocity was considered in the statistical model, ground reaction forces are essentially unchanged by pregnancy.