Comparison between overweight due to pregnancy and due to added weight to simulate body mass distribution in pregnancy

Effect of pregnancy on female gait characteristics: a pilot study based on portable gait analyzer and induced acceleration analysis

Introduction: The changes in physical shape and center of mass during pregnancy may increase the risk of falls. However, there were few studies on the effects of maternal muscles on gait characteristics and no studies have attempted to investigate changes in induced acceleration during pregnancy. Further research in this area may help to reveal the causes of gait changes in women during pregnancy and provide ideas for the design of footwear and clothing for pregnant women. The purpose of this study is to compare gait characteristics and induced accelerations between non-pregnant and pregnant women using OpenSim musculoskeletal modeling techniques, and to analyze their impact on pregnancy gait. Methods: Forty healthy participants participated in this study, including 20 healthy non-pregnant and 20 pregnant women (32.25 ± 5.36 weeks). The portable gait analyzer was used to collect participants' conventional gait parameters. The adjusted OpenSim personalized musculoskeletal model analyzed the participants' kinematics, kinetics, and induced acceleration. Independent sample T-test and one-dimensional parameter statistical mapping analysis were used to compare the differences in gait characteristics between pregnant and non-pregnant women. Results: Compared to the control group, pregnancy had a 0.34 m reduction in mean walking speed (p < 0.01), a decrease in mean stride length of 0.19 m (p < 0.01), a decrease in mean stride frequency of 19.06 step/min (p < 0.01), a decrease in mean thigh acceleration of 0.14 m/s² (p < 0.01), a decrease in mean swing work of 0.23 g (p < 0.01), and a decrease in mean leg falling strength of 0.84 g (p < 0.01). Induced acceleration analysis showed that pregnancy muscle-induced acceleration decreased in late pregnancy (p < 0.01), and the contribution of the gastrocnemius muscle to the hip and joint increased (p < 0.01). Discussion: Compared with non-pregnant women, the gait characteristics, movement amplitude, and joint moment of pregnant women changed significantly. This study observed for the first time that the pregnant women relied more on gluteus than quadriceps to extend their knee joints during walking compared with the control group. This change may be due to an adaptive change in body shape and mass during pregnancy.

Assessment of postural sway with a pendant-mounted wearable sensor

BACKGROUND

Body-worn inertial measurement unit (IMU) sensors have been widely used in postural stability and balance studies because of their low cost and convenience. In most of these studies, a single IMU sensor is attached to a waist belt near the body's center of mass. Some populations such as pregnant women, however, may find a waist belt challenging in terms of fit and comfort. For this reason it may be useful to identify an alternative location for placement of an IMU and a more comfortable means for attaching the sensor to the body. Research question Does placing an IMU sensor in a pendant worn around the neck permit discrimination between conditions with varying postural stability?

METHODS

Twenty-six healthy participants performed three standing tasks (double-leg, tandem, and single-leg standing) under eyes-open and eyes-closed vision conditions to preliminarily assess the ability of the pendant sensor to discriminate between balance conditions. Discrimination based upon data from a belt-mounted IMU was assessed in the same trials. Differences in standard deviation of acceleration components, sway area, and jerkiness due to trial condition and sensor were evaluated using analysis of variance followed by post hoc comparisons. These data were also incorporated into receiver-operator characteristic (ROC) curve analysis to assess the effectiveness of each sensor at discriminating between conditions.

RESULTS

Stability was found to vary across conditions, but there was no interaction between stability and sensor location (all p ≥ 0.323). ROC curve analysis showed that sensors in both locations were good discriminators between conditions. Significance Placing an IMU in a pendant may be feasible for studying and monitoring postural instability. This approach may be especially valuable when considering populations for which wearing a belt is uncomfortable.

Lower extremity kinetics and muscle activation during gait are significantly different during and after pregnancy compared to nulliparous females

BACKGROUND

Low back, pelvic, and lower extremity pain are common during and after pregnancy. Understanding differences in mechanics between pregnant and non-pregnant females is a first step toward identifying potential pathological mechanisms. The primary purpose of this study was to compare joint kinetics and muscle activation during gait between females during and after pregnancy to nulliparous females.

METHODS

Twenty pregnant females completed testing on three occasions (second trimester, third trimester, and post-partum), while 20 matched, nulliparous controls were tested once. Motion capture, force data, and surface electromyography were averaged across seven trials during gait. Lower extremity kinematics, lower extremity moments and work normalized to pre-pregnancy body mass, work distribution, and peak and average muscle activation amplitude were calculated. Independent t-tests were conducted between pregnant and nulliparous females at each time point.

RESULTS

Compared to controls, peak hip abductor moments were greater throughout and after pregnancy. Females in second trimester also demonstrated greater sagittal negative ankle work and greater percent contribution of the ankle and smaller percent contribution of the hip to negative work. Compared to controls, during third trimester there were greater knee abductor, ankle plantarflexor, and ankle dorsiflexor moments and greater work at the ankle and total work. Several moment and work variables continued to be elevated post-partum compared to controls. Gluteus maximus muscle activation amplitude was smaller in second trimester and post-partum compared to controls.

SIGNIFICANCE

While overall joint demands were greater during and after pregnancy, there was a smaller relative sagittal utilization of the hip early in pregnancy and smaller gluteus maximus muscle amplitude during second trimester and post-partum. Because the gluteus maximus muscle contributes to force closure and dynamic stability of the low back and pelvis, relative gluteus maximus disuse, concurrent with increased joint loads, could potentially contribute to pain during and after pregnancy.

Mechanisms of Gait Adaptation in Overweight Pregnant Women

BACKGROUND

Pregnancy is a period when a woman's body undergoes changes. The purpose of this study was to analyze the mechanisms of gait adaptation in overweight pregnant women regarding spatiotemporal gait parameters, ground reaction forces, and plantar pressure distribution.

METHODS

The tests were performed in 29 normal-weight pregnant women and 26 pregnant women who were overweight before pregnancy. The measurements included spatiotemporal gait parameters, in-shoe plantar pressure distribution, and ground reaction forces during gestation.

RESULTS

The results indicate that both normal-weight and overweight pregnant women make use of the same spatiotemporal gait parameters to increase body stability and safety of movement during pregnancy. The double-step duration in the third trimester of pregnancy was higher in normal-weight and overweight pregnant women compared with in the first trimester (P < .05). A significant change in pressure amplitude was found under all anatomical parts of the foot in the third trimester (P < .05). The results also suggest a higher increase in the maximum amplitude of force in overweight pregnant women in the third trimester compared with the normal-weight group.

CONCLUSIONS

This study suggests that both normal-weight and overweight pregnant women use different mechanisms of gait adaptation during pregnancy. In practice, understanding the biomechanical changes in women's gait can protect the musculoskeletal system during gestation.

Special footwear designed for pregnant women and its effect on kinematic gait parameters during pregnancy and postpartum period

During pregnancy, an array of changes occurs in women body to enable the growth and development of the future baby and the consequent delivery. These changes are reflected in the range of motion of trunk, pelvis, lower limbs and other body segments, affect the locomotion and some of these changes may persist to the postpartum period. The aim of this study was to describe the changes affecting the gait during pregnancy and to determine the effect of tested footwear on kinematic gait characteristics during pregnancy as previous studies indicate that special orthopaedic insoles and footwear might be useful in prevention of the common musculoskeletal pain and discomfort related to pregnancy. Participants from the control group (n = 18), without any intervention, and the experimental group (n = 23), which was wearing the tested shoes, were measured at their 14, 28 and 37 gestational weeks and 28 weeks postpartum to capture the complete pregnancy-related changes in gait. The gait 3D kinematic data were obtained using Simi Motion System. The differences between the control and experimental group at the first data collection session in most of the analysed variables, as well as relatively high standard deviations of analysed variables indicate large individual differences in the gait pattern. The effect of tested footwear on kinematic gait pattern changes may be explained by its preventive effect against the foot arches falling. In the control group, changes associated previously with the foot arches falling and hindfoot hyperpronation were observed during advanced phases of pregnancy and postpartum, e.g. increase in knee flexion or increase in spinal curvature. For the comprehensive evaluation of the tested footwear on pregnancy gait pattern, future studies combining the kinematic and dynamic plantographic methods are needed.

Examination of the effects of coordination and balance problems on gait in ataxic multiple sclerosis patients

OBJECTIVE

To investigate the effects of coordination and balance problems on gait and plantar pressure distribution in multiple sclerosis patients.

METHODS

This was an observational, cross-sectional study. It was conducted at Necmettin Erbakan University between March and December 2017. Twenty-four individuals with coordination problems, 36 individuals with balance problems and 32 healthy individuals were included in the study. The EDSS, Functional Reach Test, Dynamic Gait Index, baropodometry and stabilometry evaluations were performed.

RESULTS

There were significant differences between the groups (velocity p=0.000, cadence p=0.000, step width p=0.018, step length p=0.000, foot angle p=0.000). Multiple comparisons demonstrated that the velocities and cadences of the coordination group were lower, while their step widths were found to be higher, compared to the balance group (p=0.012, p=0.004, p=0.017, respectively). In static plantar pressure distribution, lateral forefoot pressure, lateral hindfoot pressure and medial hindfoot pressure were significantly different between the groups (p=0.002, p=0.000, respectively) Multiple comparisons showed that the pressure on the lateral part of the hindfoot in the coordination group was found to be significantly higher compared to the balance group (p=0.002). According to the dynamic plantar pressure distribution, lateral forefoot, medial forefoot, lateral hindfoot and medial hindfoot pressures were significantly different between the groups (p<0.05).

CONCLUSION

Coordination and balance problems affect gait and plantar pressure distribution. The identification of these changes will help physiotherapists determine specific therapeutic targets.

Changes in segmental mass and inertia during pregnancy: A musculoskeletal model of the pregnant woman

BACKGROUND

One in four pregnant women falls at least once during her pregnancy. During pregnancy, the body undergoes tremendous vascular, hormonal, physiological, and psychological changes to accommodate the growing fetus. The pregnancy-induced mass gain of 10 to 25 kg is not evenly distributed and results in a large change in mass distribution and shift in segmental centers of mass. To accurately understand how the change in mass distribution leads to an increase in fall events, a musculoskeletal model of the pregnant body is necessary. Generic musculoskeletal models cannot accurately represent the morphology of pregnant women and the study of postural stability of pregnant women is limited by the lack of adapted musculoskeletal models.

RESEARCH QUESTION

Could a model reflecting the change in segmental inertia during pregnancy explain the pregnancy-related risk of falling?

METHODS

We built a musculoskeletal model of the pregnant women, combining literature anthropomorphic measurements with generic models. We optimized the dimensions of the anthropomorphic model shapes to fit the average measurements of 25 pregnant women. The mass, center of mass, and inertia of each segment are then computed throughout pregnancy. Finally, the stance phase of a gait cycle was modeled using the pregnancy-specific and the generic models. The ankle, knee, hip and lumbar joint moments during gait were compared between the two models.

RESULTS

The built musculoskeletal model of the pregnant woman includes changes in mass and geometry of the thorax, pelvis, thighs, and legs. The model reproduces the change in lumbar curvature during pregnancy. Gait simulation results show a limited impact of pregnancy on the ankle, knee, and hip moment, but a large impact on the lumbar moment.

SIGNIFICANCE

Such a musculoskeletal model will help elucidate the mechanisms leading to falls or low back pain during pregnancy.

The Biomechanics of Pregnancy: A Systematic Review

During pregnancy, a number of biomechanical and hormonal changes occur that can alter spinal curvature, balance, and gait patterns by affecting key areas of the human body. This can greatly impact quality of life (QOL) by increasing back pain and the risk of falls. These effects are likely to be the ultimate result of a number of hormonal and biomechanical changes that occur during pregnancy. Research Question and Methodology: Using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, this systematic review sets out to analyse all available literature relating to the biomechanics factors caused by pregnancy and assess how this might reduce QOL. Fifty papers were deemed eligible for inclusion in this review based on the PUBMED and SCOPUS databases. Results: Angles of lordosis and kyphosis of the spine are significantly increased by pregnancy, but not consistently across all studies. Back pain is significantly increased in pregnant women, although this is not significantly correlated with spinal changes. Increased movements of centre of pressure (COP) and increased stability indexes indicate postural control is reduced in pregnancy. Trunk range of motion, hip flexion, and extension are reduced, as well as decreased stride length, decreased gait velocity, and increased step width; again, not consistently. It is likely that each woman adopts unique techniques to minimise the effects, for example increasing step width to improve balance. Further research should focus on how altered limb kinematics during gait might affect QOL by influencing the human body, as well as assessing parameters in all planes to develop a wider understanding of pregnant biomechanical alterations.

Kinematic and spatiotemporal gait characteristics in pregnant women with pelvic girdle pain, asymptomatic pregnant and non-pregnant women

BACKGROUND

Walking difficulties are common among pregnant women with pelvic girdle pain. This cross-sectional study investigated the influence of pelvic girdle pain, pregnancy and speed on spatiotemporal and trunk, pelvic and hip kinematics during gait in the 2nd trimester of pregnancy.

METHODS

Three-dimensional gait analysis at self-selected speed was performed in 25 pregnant women with pelvic girdle pain, 24 asymptomatic pregnant and 24 non-pregnant women. Linear mixed models were used to investigate between-group differences in gait variables. Adjustment for gait speed was included in the analysis. Correlations between speed and fear of movement, disability and pain were examined using Spearman correlation coefficient (r_s).

FINDINGS

Pregnant women with pelvic girdle pain walked 18% slower (estimated marginal means (95% confidence intervals) 1.18 (1.22, 1.24) meter/s) compared to asymptomatic pregnant women (1.44 (1.38, 1.50) meter/s) (P < 0.001). Moreover, with longer double limb support (5%, P = 0.04), shorter contralateral step length (3%, P = 0.03) and more restricted pelvic and hip kinematics (0.001 ≤ P ≤ 0.01) adjusted for speed. Only stance, double limb support and thoracic rotation (0.001 ≤ P ≤ 0.04) differed between asymptomatic pregnant and non-pregnant women. Speed was negatively correlated with fear of movement (r_s = -0.63, P = 0.01) and disability (r_s = -0.46, P = 0.03) in the pelvic girdle pain group.

INTERPRETATION

Gait is primarily influenced by pelvic girdle pain and less by pregnancy. Pregnant women with pelvic girdle pain walked slower and with a more rigid gait pattern compared to asymptomatic pregnant women, presumably related to altered load transfer. Our results may assist clinical evaluation of pelvic girdle pain, as well as direct future research.

Spinal Curvature and Lower Extremities Kinematics of Simulated Pregnancy during Stair Ascending and Descending

The purpose of this work is to investigate the effect of anteriorly-added mass to simulate pregnancy on lower extremities kinematic and lumbar and thoracic angles during stair ascending and descending. 18 healthy females ascended and descended, with and without a pseudo-pregnancy sac of 12 kg (experimental and control groups, respectively), a costume-made wooden staircase while instrumented with 20 reflective markers placed on the lower extremities and the spine. The movements were captured by 12 infrared cameras surrounding the staircase. Tracked position data were exported to MATLAB to calculate the required joints angles. SPSS was used to compare the ascent and descent phases of control group, and to find if there are any significant differences between control and experimental groups in the ascent phase as well as in the descent phase. When comparing the ascent and descent phases of control group, data revealed a higher hip flexion during ascending and greater ankle planter-flexion and dorsiflexion, lumbar, and thoracic angles during descending; however, no significant difference was shown in the knee flexion angle between ascending and descending. Non-pregnant data showed greater maximum hip flexion and ankle dorsiflexion during stair ascending compared to simulated-pregnant group; while ankle planter-flexion, knee flexion, and lumbar angle were greater for simulated-pregnant status. During stair descending, non-pregnant group had greater minimum hip flexion and ankle dorsiflexion compared to simulated pregnant group; while ankle planter-flexion, knee flexion, and maximum hip flexion were greater for simulated-pregnant group. However, the lumbar and thoracic angles were found to be similar for simulated-pregnant and non-pregnant groups during stair descending. In conclusion, the current study revealed important kinematic modifications pregnant women adopt while ascending and descending stairs at their final stage of pregnancy to increase their stability.

Spatiotemporal gait changes in healthy pregnant women and women with pelvic girdle pain: A systematic review

INTRODUCTION

Gait is affected in women with pelvic girdle pain (PGP), a musculoskeletal condition affecting 20% of pregnant women. Whilst there is evidence of spatiotemporal changes in gait during healthy pregnancy, less is known in relation to women with PGP. Appreciating gait characteristics during healthy pregnancy could inform our understanding of the role of gait in PGP.

PURPOSE

The purpose of this review was to systematically analyse differences in the spatiotemporal parameters of gait in healthy pregnant women and those with PGP, and to make recommendations to improve research methods in investigating gait in PGP women.

METHODS

The review was undertaken following the PRISMA guidelines. Three databases and pre-existing literature were electronically and manually searched. Study selection and data extraction were conducted by two reviewers. Quality assessment was performed using the NHLBI tool for Observational Cohort and Cross-sectional Studies.

RESULTS

The search returned 2925 results. Fourteen studies were selected for data extraction. Twelve studies investigated gait in healthy pregnant women and two in PGP women. Studies employed either a cohort or cross-sectional design and used various methods to assess gait. Three, nine and two studies were high, medium and low in quality, respectively. Direct comparisons between studies were impeded due to incomparable gestational time-points investigated, in addition to variations in gait parameters and definitions used.

CONCLUSION

Evidence from studies on healthy pregnant women could inform future research on PGP women, for which current evidence is scarce. We recommend the standardisation of critical factors to allow inter-study comparisons for a meta-analysis.

Impact of lumbopelvic pain on postural balance during sit-to-stand activity in pregnant women: a cross-sectional study

Abstract Introduction: The emergence of painful pathologies during gestation, such as lumbopelvic pain (LPP), can influence in the achievement of functional activities, such as sit-to-stand, throughout the gestational period. Objective: To compare the variables of static and dynamic postural balance (sit-to-stand activity) among pregnant women with and whitout lumbopelvic pain and the outcome variables between the gestational trimesters. Method: A total of 100 pregnant women participated in this study allocated as follows: 51 in the LPP group and 49 in the group without LPP. All participants were subjected to an evaluation protocol: filling an identification form, Analogic Visual Scale (AVS) and Oswestry Disability Index (ODI). Evaluation of postural balance was subsequently performed using the Balance Master System®. Results: 64.7% of women during the third trimester of pregnancy reported LPP. No statistically significant differences were found between LBP presence or absence in postural balance variables (p>0.05). However, gestational age influenced the VFEC variable (p=0.001). Conclusion: Women during the third gestational trimester presented complaints of lumbopelvic pain. However, the data acquired suggest that women with LPP do not have alterations in postural balance during sit-to-stand movement when compared to pregnant women without pain.

Validation of the Fitbit Zip and Fitbit Flex with pregnant women in free-living conditions

Physical activity (PA) is a part of a healthy pregnancy. To date, no consumer-based activity monitors have been validated with this population. The aim of this study was to validate the Fitbit Zip and Fitbit Flex monitors in free-living conditions with pregnant women using the ActiGraph GT3X as the ?gold standard?. We compared the accuracy of the Fitbit Zip and Fitbit Flex devices in measuring steps, sedentary time and time spent in different activity intensities. Sixteen women in their third trimester of pregnancy wore the ActiGraph GT3X (hip) plus one Fibit Zip (hip) and one Fitbit Flex (wrist) during seven consecutive days. The validity of Fitbit Zip and Fitbit Flex is good, depending on measured parameters. Fitbit Zip is accurate to measure steps whereas Fitbit Flex is precise for MVPA. When choosing between Fitbit Zip and Fitbit Flex monitors, pregnant women should take into account their preferred PA and the parameters they want to measure..

Influence of virtual reality on postural balance and quality of life of pregnant women: controlled clinical trial randomized

Abstract Introduction: During pregnancy women undergo several transformations, which promote changes in their gravity center (GC) and can result in postural and balance changes. Objective: To evaluate the influence of Nintendo WiiFit Plus® on postural balance and quality of life of pregnant women in the third trimester. Methods: 250 pregnant women enrolled through a non-probabilistic sampling process. The sample consisted of 32 women selected according to the eligibility criteria (nulliparity; low-risk pregnancy, absence of musculoskeletal disorders or surgical procedures in the spine, pelvis, hip or knee), musculoskeletal disorders, allocated as follows: 17 pregnant women in the control group (CG) and 15 pregnant women in the experimental group (EG). The intervention was performed in 12 sessions of 30 minutes each, three times a week. Sociodemographic and obstetric data were presented as median and interquartile range (25% - 75%). A comparison of the relative values of variables before and after the exercise program was performed using the 2x2 ANOVA test (5% significance level). Results: There were no significant statistical differences in variables related to postural balance (P > 0.06) and quality of life (P > 0.13). Conclusion: The use of Nintendo WiiFit Plus games was not able to promote improvement in postural balance and quality of life of the pregnant women studied.

Changes in Gait with Anteriorly Added Mass: A Pregnancy Simulation Study

During pregnancy, the female body experiences structural changes, such as weight gain. As pregnancy advances, most of the additional mass is concentrated anteriorly on the lower trunk. The purpose of this study is to analyze kinematic and kinetic changes when load is added anteriorly to the trunk, simulating a physical change experienced during pregnancy. Twenty healthy females walked on a treadmill while wearing a custom made pseudo-pregnancy sac (1 kg) under 3 load conditions: sac-only condition, 10-lb condition (4.535 kg added anteriorly), and 20-lb condition (9.07 kg added anteriorly), used to simulate pregnancy in the second trimester and at full-term pregnancy, respectively. The increase in anterior mass resulted in kinematic changes at the knee, hip, pelvis, and trunk in the sagittal and frontal planes. In addition, ankle, knee, and hip joint moments normalized to baseline mass increased with increased load; however, these moments decreased when normalized to total mass. These kinematic and kinetic changes may suggest that women modify gait biomechanics to reduce the effect of added load. Furthermore, the increase in joint moments increases stress on the musculoskeletal system and may contribute to musculoskeletal pain.