Changes in the plantar pressure distribution during gait throughout gestation

Changes in Foot Biomechanics during Pregnancy and Postpartum: Scoping Review

(1) Background: During pregnancy, changes in foot biomechanics affect structural stability and gait. (2) Objective: To map the available evidence for changes in foot biomechanics during pregnancy and the postpartum period. (3) Methods: Scoping review according to the methodology of the Joanna Briggs Institute through the relevant databases via EBSCO, MEDLINE with full text, BioOne Complete, CINAHL Plus with full text, Academic Search Complete, and SPORT Discus with full text. The search was conducted in SCOPUS and PubMed. (4) Results: Eight studies were included in the scoping review. Two independent reviewers performed data extraction and synthesized data in narrative form. We found that changes in the length and volume of the foot occur during pregnancy and remain in the postpartum period. (5) Conclusions: During pregnancy, anatomical and biomechanical changes occur in the pregnant woman's foot, potentially contributing to the risk of musculoskeletal disorders. However, more research is needed to determine whether these biomechanical changes can lead to the risk of musculoskeletal disorders.

Influence of pregnancy related anthropometric changes on plantar pressure distribution during gait—A follow-up study

Background

As foot constitutes the base of support for the whole body, the pregnancy-related anthropometric changes can result in adaptive plantar pressure alterations. The present study aimed to investigate how pregnancy affects foot loading pattern in gait, and if it is related to body adjustments to growing foetus that occur in the course of pregnancy.

Methods

A prospective longitudinal study included 30 women. Three experimental sessions in accordance with the same procedure were carried out in the first, second and third trimesters of pregnancy. First, the anthropometric measures of the body mass and waist circumference were taken. Then walking trials at a self-selected speed along a ~6-m walkway were registered with the FreeMED force platform (Sensor Medica, Italy). Vertical foot pressure was recorded by the force plate located in the middle of the walkway.

Findings

The correlation of individual foot loading parameters across different trimesters was relatively high. Nevertheless, our results revealed a longitudinal foot arch flattening with the strongest effect in late pregnancy (P = 0.01). The anthropometric characteristics also influenced the foot loading pattern depending on the phase of pregnancy. In particular, arch flattening correlated with the body mass in all trimesters (r≥0.44, P≤0.006) while the medial-lateral loading index correlated only in the first (r = 0.45, P = 0.005) and second (r = 0.36, P = 0.03) trimesters. Waist circumference changes significantly influenced dynamic arch flattening but only in the late pregnancy (r≥0.46, P≤0.004). In the third trimester, a small though significant increase in the right foot angle was observed (P = 0.01).

Interpretation

The findings provided the characteristics of the relative foot areas loading throughout pregnancy. Growing abdominal size increases the risk of medial arch flattening, which can result in less stable gait. The observed increase in foot angle in late pregnancy may constitute a strategy to enhance gait stability.

Does the first trimester of pregnancy induce alterations in the walking pattern?

Introduction

From among many studies observing the walking pattern throughout pregnancy, only two items monitor the influence of pregnancy on the movement system during gait considering the period before gestation.

Research question

Does the women’s gait pattern at the end of the first trimester undergo changes in comparison to body movement pattern before pregnancy?

Methods

All subjects who met the inclusion criteria gave signed and informed consent before the study. Two experimental sessions were arranged according to the same protocol: (P0) before pregnancy and (P1) at the end of the first trimester of pregnancy (12^th week of gestation). At first the anthropometric measures were taken. Then, walking trials at a self-selected speed along a walkway were registered with Vicon 250 (Oxford Metrics Ltd.; Oxford, UK) and FreeMED force platform (Sensor Medica, Italy).

Results

An analysis of anthropometric parameters in 12^th pregnancy week demonstrated significant changes in mean values of waist circumference and waist to hip ratio as well as waist to height ratio indexes compared to the results before pregnancy. No significant differences were found in the basic kinematic gait parameters between experimental conditions. Significant increase of mean inter—ankle distance during double support phase occurred during the first trimester of pregnancy. Also, the ratio of the ankle separation width to the pelvic width was noticeably higher in gestation. Then, angular changes of the pelvis in coronal and transverse planes throughout gait cycle during pregnancy demonstrated significant differences compared to those measured before pregnancy. At the same time in the first trimester of pregnancy no adaptive changes in the pattern of feet loading take place.

Significance

Since our study is of longitudinal character, in the course of pregnancy we expect compensatory mechanisms more clearly demonstrated. Therefore, we hope to identify a strategy of the gravid body progression in space.

Gait assessment of the expectant mothers - Systematic review

INTRODUCTION

Since pregnant women may have potentially greater difficulty maintaining balance, their stability has been investigated by some researchers. However, there is no consensus considering the results. The purpose of our investigation was to compare all the experimental studies focusing on the analysis of gait that have been conducted over the last years to assess their methodological issues and changes induced by pregnancy.

METHODS

The PRISMA Guidelines incorporating a risk of bias and strength of recommendations were used as a methodological template for this review. Literature searches were conducted using the following databases: PubMed, Embase, SPORTDiscus, Scopus. After limiting the search to meet the inclusion criteria, 25 articles remained in the final analysis.

RESULTS

Some authors emphasised that adaptations due to pregnancy are recognised to provide safety and stability. Thus, they consistently reported reduced walking velocity as a result of lower frequency and smaller length of the steps. Longer contact times were reflected by the shortened peak forces. Plantar loads were redistributed from the rearfoot (decrease) to the midfoot and forefoot (increase) throughout pregnancy. Another adjustment was an increase of base of support to improve lateral gait stability which allows to compensate increased medio-lateral ground reaction force. During the course of pregnancy the increase of anterior body mass and hormonal changes enhance some realignments of the pelvis and lumbar spine. Methodological approaches varied across the included studies. The critical appraisal identified some areas of weaknesses that should be considered for designing the future investigations.

CONCLUSIONS

Since many gait parameters are interrelated, in order to understand the cause-and-effect relationships an integrative and complete analysis of multiple factors is required.

Do Structural Changes of the Foot Influence Plantar Pressure Patterns During Various Stages of Pregnancy and Postpartum?

BACKGROUND

The foot of a pregnant woman undergoes morphological changes with the advancement of pregnancy. It is important to understand the structural changes of the foot during pregnancy and postpartum because any such change may alter the plantar pressure pattern and the entire foot biomechanics.

METHOD

Primigravidae with a gestational age of 12 weeks or less, aged between 18 and 35 years were included in the study. They were prospectively studied across 5 time periods during pregnancy and postpartum. The measures recorded were length, width, navicular height, truncated foot length and normalized navicular height, truncated ratio of the foot, and the static plantar pressure pattern. Repeated-measures ANOVA was done to analyze the changes across various time periods.

RESULTS

All the foot parameters, except foot length and truncated foot length, showed significant differences across various time periods of pregnancy and postpartum (P < .001). It was found that the static plantar pressures also varied significantly (P ≤ .001).The maximum pressure was recorded at the hindfoot of the dominant leg.

CONCLUSION

The feet of pregnant women tend to get pronated as pregnancy advances but do not reach baseline values even at 6 weeks postpartum. Pregnant women tend to bear more weight on the dominant foot with an increased static hindfoot pressure as pregnancy progresses.

LEVELS OF EVIDENCE

Prognostic study, Level I: Prospective.

Relation between foot pain and plantar pressure in pregnancy

Background/aim: Hormonal and structural changes that occur during pregnancy cause alterations in body biomechanics. These alterations reach their peak in the last trimester. Adaptive changes that appear in the foot result in pain in the foot and ankle. Pedobarography is a noninvasive measurement method that can be used to understand the origin of such pain. Materials and methods: One hundred and thirty-one pregnant women who did not have a foot or ankle problem prior to pregnancy volunteered to take part in the study. Pain was quantified by a visual analog scale (VAS). A cut-off value of 2.95 was taken to divide the subjects into two groups: Group 1 (n = 70) with VAS scores of <2.95 and Group 2 (n = 61) with VAS scores of ?2.95. Plantar pressure measurements were taken by Tekscan HR Mat using midgait protocol. Results: Forces experienced by the total right foot area, right forefoot, and the midfoot for both feet were significantly higher in Group 2 (P < 0.05). Contact area was significantly larger in Group 2 (P < 0.05). Conclusion: Results indicate that presence and severity of foot pain during pregnancy are related to the force distribution along the foot, especially at midfoot and the contact area.

Musculoskeletal Effects of Pregnancy on the Lower ExtremityA Literature Review

Pregnant women are often burdened with musculoskeletal symptoms of the lower extremity due to the physical, hormonal, and anatomical changes that occur throughout pregnancy. These symptoms are associated with musculoskeletal dysfunctions, modified gait, joint laxity, muscle imbalance, and increased body mass. This article reviews the literature involving the lower-extremity changes experienced by women during pregnancy and their respective pathophysiologic causes.

The influence of body mass on foot dimensions during pregnancy

In this study, a time-series approach was used to measure women's feet to accurately analyze changes in foot size and body mass during pregnancy. One-hundred women who were pregnant for the first time were asked to respond to questions on subjective complaints of foot discomfort listed in a questionnaire. Among these 100 women, a sample of 30 was obtained and used to measure the women's feet from the twentieth week of the gestation period until labor. The data (from 5 of the 30 women) were used to establish a prediction model for the influence of body mass on changes in foot size during pregnancy. The results indicate that the women subjectively complained that their shoes were too tight, resulting in foot discomfort. From the twentieth to the thirty-eighth week of pregnancy, the average increase in foot length, width, and back foot surface was 0.86 cm (3.6%), 0.25 cm (2.6%), and 18.36 cm(2) (11.9%), respectively. The height of the arch decreased by an average of 0.52 cm (-24.2%). Body mass accounted for more than 90% of the variation (R(2)) in foot dimensions during pregnancy and, thus indicated satisfactory predictive ability. The prediction model developed in this study can serve as a reference for clinical applications and shoe design to prevent women from experiencing extreme discomfort in their feet during pregnancy.

Static and dynamic biomechanical adaptations of the lower limbs and gait pattern changes during pregnancy

The purpose of this literature review is to evaluate the studies that have investigated static and dynamic biomechanical changes of the lower limbs and gait patterns during pregnancy. Original articles on this subject, published between 1934 and 2012, were considered. In general, pregnant women demonstrated greater hip flexion, more extended knees and less plantar flexion ankles. These changes could explain the gait patterns of pregnant women characterized by increased hip angles, decreased propulsion forces associated with increased durations of stance phase and changes in distributions of the plantar loads with increased loads in the forefoot and decreased ones in the rearfoot. This can lead to arthrokinematic deviations that, with time, contribute to the development of musculoskeletal discomfort. In summary, these findings showed the importance of further longitudinal studies to investigate the relationships between musculoskeletal discomfort in pregnant women in the lower limbs and gait changes observed throughout this period.

Ultrasound assessment of bilateral symmetry in dorsal Lisfranc ligament

Bilateral symmetry of the ligaments is a common assumption used as an intrasubject control for clinical diagnosis. The present study investigated the bilateral symmetry of the dorsal Lisfranc ligament (dLL) using ultrasound. Data were acquired from 50 asymptomatic subjects in a seated position at a loaded calf raise machine equipped with a force plate. The testing conditions included low, medium, and high stress at 0° and 15° abducted foot positions. Images of the dLL were captured and measured using a 10.0-MHz ultrasound transducer and custom written MATLAB software, respectively. The data were analyzed using paired t tests to compare the bilateral measurements of the dLL length under all test conditions. The bilateral pooled dLL length was 7.01 ± 1.38 mm and showed a moderate correlation with the foot length and width. No bilateral differences were found in the dLL length under any of the stress loads in the abducted position or under the medium and high stress load in the rectus position. However, the low stress load rectus position demonstrated a significant bilateral difference in the dLL length (p = .005). The smallest bilateral difference was observed at the 15° abducted position under medium stress (measurement error mean -0.062 mm). Our data suggest that the contralateral dLL length can be used as an intrasubject control for clinical purposes. However, we recommend that the dLL length measurements should be taken in weightbearing position with the foot in the abducted position under medium stress (bilateral stance), reducing potential strain-induced asymmetry.