Pregnant women are at a high risk of falling. To our knowledge, ground reaction forces (GRFs) during stair locomotion have not been reported for pregnant women. PURPOSE: To examine the effects of advancing pregnancy on GRFs during stair locomotion. METHODS: Data were collected on 41 pregnant women in the mid 2nd and 3rd trimesters, and on 40 control women. Subjects walked at their freely chosen walking speeds during 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). Three trials were collected from each subject. GRF variables were normalized to body mass. A two-factor ANOVA (trimester x subject) was performed on each of these vertical GRF variables: passive peak, time to passive peak, loading rate, min between peaks, time to min between peaks, active peak, time to active peak, and impulse. A second ANOVA was performed on each of these shear GRF variables: max braking force, time to max braking force, braking impulse, max propulsive force, time to max propulsive force, propulsive impulse, medial impulse and lateral impulse. (Bonferroni-corrected a = 0.006). Tukey post-hoc tests were performed when appropriate. RESULTS: Differences in GRFs between pregnant women in their 2nd and 3rd trimesters and control women were noted for both ascent and descent. CONCLUSIONS: Pregnant women demonstrated GRF alterations that may be related to a slower walking velocity or increased instability. In particular, the increase in the medial impulse during pregnancy may be related to 'waddling' and changes in frontal plane control.
Links with this icon indicate that you are leaving the CDC website.
The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
You will be subject to the destination website's privacy policy when you follow the link.
CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website.
For more information on CDC's web notification policies, see Website Disclaimers.
CDC.gov Privacy Settings
We take your privacy seriously. You can review and change the way we collect information below.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
Cookies used to make website functionality more relevant to you. These cookies perform functions like remembering presentation options or choices and, in some cases, delivery of web content that based on self-identified area of interests.
Cookies used to track the effectiveness of CDC public health campaigns through clickthrough data.
Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. These cookies may also be used for advertising purposes by these third parties.
Thank you for taking the time to confirm your preferences. If you need to go back and make any changes, you can always do so by going to our Privacy Policy page.