The effect of pregnancy on footprint parameters. A prospective investigation

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.

Pelvic movements during walking throughout gestation - the relationship between morphology and kinematic parameters

BACKGROUND

Many researchers emphasize adaptations following pregnancy. Our purpose was to get more insight into how morphology interacts with the pelvic walking pattern - the segment most prone to the adaptation following altered body demands.

METHODS

Thirty women were enrolled. Three experimental sessions were arranged according to the same protocol in the first, second and third trimesters of pregnancy. First, the anthropometric measures were taken, then walking trials at a self-selected speed were registered. At the end of the experimental session the subjects were asked to fill out a questionnaire on pain.

FINDINGS

The sagittal plane pelvic range of motion (RoM) significantly increased throughout pregnancy. There were significant positive correlations between pelvic anthropometric dimensions and pelvic tilt and rotation primarily in the third trimester of pregnancy. Significant positive correlations were found between pelvic RoM and thigh circumference. Indicators associated with body mass increase were positively correlated with pelvic obliquity in the second trimester and pelvic tilt and rotation in late pregnancy. It is also worth noting that the individual differences were not related to back pain and that the reported correlations were observed in some but not in all trimesters.

INTERPRETATION

Morphological changes following the fetus growth induced increased pelvic tilt and rotation, however, pelvis movements were not associated with back pain. Overall, the results highlight correlations between morphology and pelvis kinematic patterns in some but not in all trimesters.

Perception and Deception: Human Beauty and the Brain

Human physical characteristics and their perception by the brain are under pressure by natural selection to optimize reproductive success. Men and women have different strategies to appear attractive and have different interests in identifying beauty in people. Nevertheless, men and women from all cultures agree on who is and who is not attractive, and throughout the world attractive people show greater acquisition of resources and greater reproductive success than others. The brain employs at least three modules, composed of interconnected brain regions, to judge facial attractiveness: one for identification, one for interpretation and one for valuing. Key elements that go into the judgment are age and health, as well as symmetry, averageness, face and body proportions, facial color and texture. These elements are all Costly Signals of reproductive fitness because they are difficult to fake. However, people deceive others using tricks such as coloring hair, cosmetics and clothing styles, while at the same time they also focus on detecting fakes. People may also deceive themselves, especially about their own attractiveness, and use self-signally actions to demonstrate to themselves their own true value. The neuroscience of beauty is best understood by considering the evolutionary pressures to maximize reproductive fitness.

Estimation of stature and body weight in Slovak adults using static footprints: A preliminary study

The stature and the body weight as part of the biological profile can aid the personal identification. The dimensions of the human foot, as well as the footprint, can be used for the prediction due to the existence of its positive correlation with the stature and body weight. Five diagonal axes and ball breadth of bilateral static footprints of 132 young Slovak adults were obtained. All diameters were larger in a male group than female group. No bilateral differences were found except the first diagonal axis and ball breadth. A positive correlations between the selected footprint diameters with the stature (r = 0.37-0.64) and the body weight (r = 0.29-0.71) were confirmed. The linear and multiple regression prediction equations were developed. A stature prediction equation using the most lateral diameters (the fourth and fifth diagonal axis) exhibited the highest accuracy ranging from 4 to 7.5 cm. Similar results were found for the body weight estimation of the male and mixed group. In the female group, the most medial axis (first and second) exhibited the highest accuracy. The body weight estimation accuracy ranges from 9.09 to 11.09 kg. The real and predicted stature and body weight were compared and found differences were lower than calculated SEEs. Thresholds and prediction trend of under- or overestimation was identified. The results of the present study show that selected measurements of static footprints could be used to predict stature and body weight but should be applied only for Slovaks due to population specificity.

Impact of the quality of life related to foot health in a sample of pregnant women: A case control study

Pregnancy women coincide with numerous anatomical and physiological changes, which are believed to have a harmful effect on the quality of life related to foot health. The goal of this research was to identify and compare the impact foot health and overall health in a sample of pregnancy women and women without pregnancies with normalised reference values.A sample of 159 participants of a mean age of 30.13 ± 6.28 came to the area of midwifery center where self-reported data were registered, informants' with a 1 or various pregnancy was determined and the scores obtained were compared in the foot health status questionnaire (FHSQ). This has 13 questions that assess 4 health domains of the feet, namely pain, function, general health, and footwear.The pregnant women group showed a worse quality of life related to health in general and to foot health specifically at the following domains, foot function, footwear, general foot, health, physical activity, social capacity, and vigor (P < 0.05) and there were no differences at foot pain and general health (P > 0.05).Pregnant women present a negative impact on the quality of life related to foot health, which appears to be associated with the pregnancy period.

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.

Plantar Pressure During Gait in Pregnant Women

BACKGROUND

During pregnancy, physical and hormonal modifications occur. Morphologic alterations of the feet are found. These observations can induce alterations in plantar pressure. This study sought to investigate plantar pressures during gait in the last 4 months of pregnancy and in the postpartum period. A comparison with nulliparous women was conducted to investigate plantar pressure modifications during pregnancy.

METHODS

Fifty-eight women in the last 4 months of pregnancy, nine postpartum women, and 23 healthy nonpregnant women (control group) performed gait trials on an electronic walkway at preferred speeds. The results for the three groups were compared using analysis of variance.

RESULTS

During pregnancy, peak pressure and contact area decreased for the forefoot and rearfoot. These parameters increased significantly for the midfoot. The gait strategy seemed to be lateralization of gait with an increased contact area of the lateral midfoot and both reduced pressure and a later peak time on the medial forefoot. In the postpartum group, footprint parameters were modified compared with the pregnant group, indicating a trend toward partial return to control values, although differences persisted between the postpartum and control groups.

CONCLUSIONS

Pregnant women had altered plantar pressures during gait. These findings could define a specific pattern of gait footprints in late pregnancy because plantar pressures had characteristics that could maintain a stable and safe gait.

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

The assessment of biomechanical loading in the musculoskeletal system of the pregnant women is particularly interesting since they are subject to morphological, physiological and hormonal changes, which may lead to adaptations in gait. The purpose of this study was to analyze the effect of the increased mass in the trunk associated to pregnancy on the lower limb and pelvis, during walking, on temporal-distance parameters, joint range of motion and moments of force, by comparing a pregnant women group to a non-pregnant group, and to this group while carrying a 5 kg additional load located in the abdomen and breasts during walking, to understand which gait adaptations may be more related with the increased trunk mass, or if may be more associated with other factors such as the girth of the thigh. The subjects performed a previous 12 min training adaption to the added load. To calculate ankle, knee and hip joint angles and moments of force, a three-dimensional biomechanical model was developed. The inverse dynamics method was used to estimate net joint moments of force. The increased mass of the anterior trunk associated with second trimester of pregnancy may influence some gait variables such as the left step time, left and right stance times, double limb support time, maximum hip extension, maximum pelvic right obliquity, pelvic obliquity range of motion, maximum transversal left rotation and peak hip flexion moments of force.

Changes in the spinal curvature, degree of pain, balance ability, and gait ability according to pregnancy period in pregnant and nonpregnant women

[Purpose] The aim of this study was to investigate the changes in pain intensity, spinal curvature, and balance and gait ability according to the pregnancy period. [Subjects] Nineteen pregnant women and fifteen nonpregnant women were recruited in this study. [Methods] The pain intensity, spinal curvature, gait, and balance of pregnant women were measured according to the pregnant period (2nd and 3rd trimester). The changes in the pregnant women were also compared with those in the nonpregnant women. [Results] The pain intensity and spinal curvature in the third trimester of pregnancy were significantly increased compared with the second trimester. Only the lumbar spine curvature in the third trimester pregnancy was significantly greater in the pregnant women than in non-pregnant women. The gait velocity and cadence in the third trimester of pregnancy showed a significant decrease compared with the second trimester. The gait speed in the second and third trimester of pregnancy showed a significant decrease in the pregnant women compared with nonpregnant women. Balance in the third trimester of pregnancy showed significant improvement compared with the second trimester. The balance of the pregnant women showed a significant decrease compare with that nonpregnant women only on unstable surfaces. [Conclusion] These research findings can be used as basic data for health promotion programs for sound daily activities in pregnant women.

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.

Intrinsic Factors Associated with Pregnancy Falls

Approximately 25% to 27% of women sustain a fall during pregnancy, and falls are associated with serious injuries and can affect pregnancy outcomes. The objective of the current study was to identify intrinsic factors associated with pregnancy that may contribute to women's increased risk of falls. A literature search (Medline and Pubmed) identified articles published between January 1980 and June 2013 that measured associations between pregnancy and fall risks, using an existing fall accident investigation framework. The results indicated that physiological, biomechanical, and psychological changes associated with pregnancy may influence the initiation, detection, and recovery phases of falls and increase the risk of falls in this population. Considering the logistic difficulties and ethnic concerns in recruiting pregnant women to participate in this investigation of fall risk factors, identification of these factors could establish effective fall prevention and intervention programs for pregnant women and improve birth outcomes.

Gut estimates: Pregnant women adapt to changing possibilities for squeezing through doorways

Possibilities for action depend on the fit between the body and the environment. Perceiving what actions are possible is challenging, because the body and the environment are always changing. How do people adapt to changes in body size and compression? In Experiment 1, we tested pregnant women monthly over the course of pregnancy to determine whether they adapted to changing possibilities for squeezing through doorways. As women gained belly girth and weight, previously passable doorways were no longer passable, but women's decisions to attempt passage tracked their changing abilities. Moreover, their accuracy was equivalent to that of nonpregnant adults. In Experiment 2, nonpregnant adults wore a "pregnancy pack" that instantly increased the size of their bellies, and they judged whether doorways were passable. Accuracy in the "pregnant" participants was only marginally worse than that of actual pregnant women, suggesting that participants adapted to the prosthesis during the test session. In Experiment 3, participants wore the pregnancy pack and gauged passability before and after attempting passage. The judgments were grossly inaccurate prior to receiving feedback. These findings indicate that experience facilitates perceptual-motor recalibration for certain types of actions.

Anthropometric foot changes during pregnancy: a pilot study

BACKGROUND

Women's feet change during pregnancy owing to hormonal and anatomical changes, thus having a strong influence on the decrease in their quality of life during pregnancy. This preliminary study aimed to value the anthropometric and positional changes that affect their feet.

METHODS

Ten pregnant women were measured during their gestational period to analyze the anthropometric changes in their feet from the 12th week of pregnancy. We examined the changes that occured in foot length, forefoot width, arch of the foot height, and the fixed position of the foot by using the Foot Posture Index, and we analyzed three intervals corresponding to pregnancy weeks 12, 24, and 34.

RESULTS

The most significant finding, with a reliability rate of 95%, is the decrease in internal arch height, which descends 0.65 mm (0.0394 inches) on average at the final stage of the pregnancy period. This change happened in 18 of the feet analyzed, tending toward pronation according to the measure provided by the Foot Posture Index, with a change of 3.78 points on this scale.

CONCLUSIONS

The foot of the pregnant woman tends to flatten during gestational weeks 12 to 34, taking a more pronated posture, and the anthropometric changes in late pregnancy result in increases in foot length and forefoot width, changes that seem to be moderate.

BIOMECHANICAL MODEL FOR KINETIC AND KINEMATIC DESCRIPTION OF GAIT DURING SECOND TRIMESTER OF PREGNANCY TO STUDY THE EFFECTS OF BIOMECHANICAL LOAD ON THE MUSCULOSKELETAL SYSTEM

Walking is daily physical activity and a common way of exercise during pregnancy, but morphological changes can modify the gait pattern. Biomechanical models can help in evaluating joint mechanical loads and kinetics and kinematics during gait, and provide patterns. This study aimed to describe the gait pattern during the second trimester of pregnancy and give an orientation for biomechanical modeling for pregnant women. The ankle and hip joints seem to be more overloaded, mainly in the sagittal and frontal planes, respectively. Results show that pregnant women have a similar walking pattern to the normal gait. This model construction was revealed to be appropriate for describing gait during the second trimester of pregnancy.

Concurrent Validity and Test-retest Reliability of the OPTOGait Photoelectric Cell System for the Assessment of Spatio-temporal Parameters of the Gait of Young Adults

[Purpose] The purpose of this study was to investigate the concurrent validity and test-retest reliability of the recently introduced OPTOGait Photoelectric Cell System for the assessment of spatio-temporal parameters of gait. [Subjects] Twenty healthy young adults (mean age = 27.35, SD = 7.4) were asked to walk 3 times on walkway at a comfortable speed. [Methods] Concurrent validity was assessed by comparing data obtained using the OPTOGait and GAITRite systems, and reliability was assessed by comparing data from the first and third OPTOGait sessions. [Results] Concurrent validity, as identified by intra-class correlation coefficients (ICC (2, 1) = 0.929–0.998), coefficients of variation (CV_ME = 0.32–11.30%), and 95% limits of agreement, showed high levels of correlation. In addition, the test-retest reliability of the OPTOGait Photoelectric Cell System was demonstrated as showing a high level of correlation with all spatio-temporal parameters by intra-class correlation coefficients (ICC (3, 1) = 0.785–0.952), coefficients of variation (CV_ME = 1.66–4.06%), 95% limits of agreement, standard error of measurement (SEM = 2.17–5.96%), and minimum detectable change (MDC₉₅% = 6.01–16.52%). [Conclusion] The OPTOGait Photoelectric Cell System has strong concurrent validity along with relative and absolute test-retest reliabilities. This portable system with easy-to-use features can be used for clinical assessments or research purposes as an objective means of assessing gait.

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.

Trunk motion and gait characteristics of pregnant women when walking: report of a longitudinal study with a control group

Background

A longitudinal repeated measures design over pregnancy and post-birth, with a control group would provide insight into the mechanical adaptations of the body under conditions of changing load during a common female human lifespan condition, while minimizing the influences of inter human differences. The objective was to investigate systematic changes in the range of motion for the pelvic and thoracic segments of the spine, the motion between these segments (thoracolumbar spine) and temporospatial characteristics of step width, stride length and velocity during walking as pregnancy progresses and post-birth.

Methods

Nine pregnant women were investigated when walking along a walkway at a self-selected velocity using an 8 camera motion analysis system on four occasions throughout pregnancy and once post birth. A control group of twelve non-pregnant nulliparous women were tested on three occasions over the same time period. The existence of linear trends for change was investigated.

Results

As pregnancy progresses there was a significant linear trend for increase in step width (p = 0.05) and a significant linear trend for decrease in stride length (p = 0.05). Concurrently there was a significant linear trend for decrease in the range of motion of the pelvic segment (p = 0.03) and thoracolumbar spine (p = 0.01) about a vertical axis (side to side rotation), and the pelvic segment (p = 0.04) range of motion around an anterio-posterior axis (side tilt). Post-birth, step width readapted whereas pelvic (p = 0.02) and thoracic (p < 0.001) segment flexion-extension range of motion decreased and increased respectively. The magnitude of all changes was greater than that accounted for with natural variability with re testing.

Conclusions

As pregnancy progressed and post-birth there were significant linear trends seen in biomechanical changes when walking at a self-determined natural speed that were greater than that accounted for by natural variability with repeated testing. Not all adaptations were resolved by eight weeks post birth.

Changes in the plantar pressure distribution during gait throughout gestation

BACKGROUND

The intention of this investigation was to longitudinally describe and compare the plantar pressure distribution in orthostatic posture and gait throughout pregnancy.

METHODS

A prospective longitudinal observational study was conducted with six pregnant women (mean ± SD age, 32 ± 3 years) with a mean ± SD weight gain of 10.0 ± 1.4 kg. Peak pressure, contact time, contact area, and maximum force in five plantar areas were evaluated using capacitive insoles during gait and orthostatic posture. For 1 year, the plantar pressures of pregnant women were evaluated the last month of each trimester. Comparisons among plantar areas and trimesters were made by analysis of variance.

RESULTS

For orthostatic posture, no differences in contact time, contact area, peak pressure, and maximum force throughout the trimesters were found. During gait, peak pressure and maximum force of the medial rearfoot were reduced from the first to third and second to third trimesters. Maximum force increased at the medial forefoot from the first to second trimester. Contact area increased at the lateral rearfoot from the second to third trimester and at the midfoot from the first to third trimester. Contact time increased at the midfoot and medial and lateral forefoot from the first to third trimester.

CONCLUSIONS

Pregnant women do not alter plantar pressure during orthostatic posture, but, during gait, the plantar loads were redistributed from the rearfoot (decrease) to the midfoot and forefoot (increase) throughout pregnancy. These adjustments help maintain the dynamic stability of the pregnant woman during locomotion.

Lower extremity changes experienced during pregnancy

The anatomic and physiologic changes occurring with pregnancy result in a variety of symptoms affecting the lower extremity. The purpose of this investigation is to provide a comprehensive look at the lower extremity changes experienced during pregnancy and correlate symptoms with underlying etiology in a literature review. In this retrospective study, 100 postpartum women were interviewed regarding the lower extremity changes experienced in pregnancy. The interview included dermatologic, vascular, neurologic, and musculoskeletal portions. Results demonstrate more than 50% of women reported faster toenail growth, roughened toenail texture, increased dryness of the skin, swelling of the foot, ankle, and leg, unsteady gait, increased foot width, and hip pain. Though a majority of patients did not experience the remaining symptoms represented in the interview, all results are pertinent and deserve understanding to provide better insight and care for the pregnant woman. Therefore, a thorough literature review is presented to correlate the outcomes of the present study with previously published research.

Plantar pressure and foot pain in the last trimester of pregnancy

BACKGROUND

Back and foot pain are common complaints during pregnancy. Progression of symptoms is seen especially in the third trimester as the center of gravity (COP) is altered due to weight gain. The aim of the study was to evaluate plantar pressure changes and postural balance differences of pregnant women.

MATERIAL AND METHODS

Thirty-five last trimester pregnant women with complaints of foot pain were included. The control group consisted of 35 non-pregnant women who were age and body mass index (BMI) matched volunteers. All selected cases were overweight. Foot pain in pregnancy was measured by Visual analogue scale (VAS). Percentages of pressure on forefoot and hindfoot were measured using static pedobarography and peak pressures at forefoot, midfoot and hindfoot were measured using dynamic pedobarography. As a measurement of balance, COP sway length and width were also analyzed.

RESULTS

Compared to overweight individuals, pregnant patients had higher forefoot pressure on the right side with standing and walking. Also, significant increases in contact times under the forefoot and longer floor contact times were found. VAS scores were correlated with forefoot contact times during walking. Although the sway length from COP was higher than controls, no significant correlation was found in sway length and weight gain.

CONCLUSION

These data suggest that forefoot pressures increase in the last trimester of pregnancy during standing and walking. There is prominent increased postural sway in anterior-posterior direction in this period.

CLINICAL RELEVANCE

We believe that based on the observed pressure changes, foot pain in pregnancy due to changes in body mass and distribution may be relieved by exercise and shoewear modifications.

Midfoot plantar pressure significantly increases during late gestation

BACKGROUND

A rise in plantar pressure has been observed in pregnant women with foot pain. The current literature on plantar pressure in pregnancy is sparse. It has been postulated that changes in plantar pressure result from the physiological effects of pregnancy. In this study we aim to quantify the plantar pressure of women in late pregnancy.

METHODS

Twenty-two pregnant women undergoing a caesarean section and twenty non-pregnant women were recruited from University Hospital Coventry and Warwickshire between May to June 2007. Plantar pressure measurements were performed using an in-shoe measurement system. The control group was compared with the pregnant group at 38 weeks gestation. A selection of the pregnant group had repeat measurements at 4 months post-partum. The pre and post-partum measurements were also compared.

RESULTS

The pregnant group (PG) exerted a significantly higher mean midfoot pressure compared to the non-pregnant control group (CG) (PG=115.5kPa, CG=95.4kPa; p=0.001). Post-partum (PP), there was a significant reduction in the mean and maximum midfoot pressure (mean; PG=111.9kPa, PP=66.2kPa; p<0.001, maximum; PG=184.0kPa, PP=108.3kPa; p<0.001).

CONCLUSIONS

The physiological changes in late pregnancy result in an increase in midfoot plantar pressure. This increase resolves post-partum.

Balance (perceived and actual) and preferred stance width during pregnancy

BACKGROUND

Pregnant women often remark that their balance degrades during pregnancy; however, it appears that no studies have documented the gravida's perception of her balance nor measured direction-specific changes in balance throughout pregnancy or after delivery.

METHODS

Thirty women, fifteen pregnant and fifteen non-pregnant controls, were tested monthly and through 6-month postpartum. For each session, perceived degradation in sense of balance, laboratory-based balance measures, stance width, and the number of falls since the previous session were recorded. Laboratory-based balance measures, quantified by direction-specific measures of postural sway, were computed from ten 30s quiet-standing trials on a stationary force platform. Repeated-measures analysis of variance, paired t-tests, and Pearson correlations were use to examine group and time effects.

FINDINGS

For the pregnant group, perceived balance degradation and stance width were highly correlated (r = 0.94). Both increased during pregnancy (P < or = 0.016) and dropped to near-control levels after delivery (P < or = 0.004). Compared to the control group, pregnant subjects displayed increased sway, especially in the anterior-posterior and radial directions (P < or = 0.039). Anterior-posterior sway measures strongly correlated with perceived balance (0.82 > r > 0.72) and also decreased significantly between the third trimester and postpartum (P < or = 0.029). Interestingly, medial-lateral balance measures varied little during pregnancy, but increased after delivery. Contrary to recent work suggesting fall rates of 25%, only 13% of our subjects (n = 2) fell during pregnancy.

INTERPRETATION

Perceived degradation in balance during pregnancy was strongly related to increasing postural sway instability in the anterior-posterior direction. Lateral stability was maintained during pregnancy and likely accomplished by increasing stance width.

[Changes in shape and size of the foot during pregnancy]

Many women report an increase in foot size during their pregnancy. Our objective was to verify this anecdotal evidence. In an initial survey of 21 mothers in 2 Münster nursery schools we found a tendency towards an increase in foot size during pregnancy. We therefore developed a measuring system to measure changes in foot length, width, height and volume. A total of 40 women recruited from the antenatal clinic of the University Hospital of Münster and a participating practice were seen three times during their pregnancy. The results were analysed using the Wilcoxon test. We found a statistically significant increase in foot length, width and volume, whereas foot height decreased slightly. This difference was, however, not significant. Especially in diabetic women with polyneuropathy it is important to pay attention to shoe size to prevent pressure sores.

Spatial parameters of walking gait and footedness

OBJECTIVE

The present study was undertaken to assess whether footedness has effects on selected spatial and angular parameters of able-bodied gait by evaluating footprints of young adults.

SUBJECTS AND METHODS

A total of 112 males and 93 females were selected from among students and staff members of the University of Malawi using a simple random sampling method. Footedness of subjects was assessed by the Waterloo Footedness Questionnaire Revised. Gait at natural speed was recorded using the footprint method. The following spatial parameters of gait were derived from the inked footprint sequences of subjects: step and stride lengths, gait angle and base of gait. The anthropometric measurements taken were weight, height, leg and foot length, foot breadth, shoulder width, and hip and waist circumferences.

RESULTS

The prevalence of right-, left- and mix-footedness in the whole sample of young Malawian adults was 81%, 8.3% and 10.7%, respectively. One-way analysis of variance did not reveal a statistically significant difference between footedness categories in the mean values of anthropometric measurements (p > 0.05 for all variables). Gender differences in step and stride length values were not statistically significant. Correction of these variables for stature did not change the trend. Males had significantly broader steps than females. Normalized values of base of gait had similar gender difference. The group means of step length and normalized step length of the right and left feet were similar, for males and females. There was a significant side difference in the gait angle in both gender groups of volunteers with higher mean values on the left side compared to the right one (t = 2.64, p < 0.05 for males, and t = 2.78, p < 0.05 for females). One-way analysis of variance did not demonstrate significant difference between footedness categories in the mean values of step length, gait angle, bilateral differences in step length and gait angle, stride length, gait base and normalized gait variables of male and female volunteers (p > 0.05 for all variables).

CONCLUSIONS

The present study demonstrated that footedness does not affect spatial and angular parameters of walking gait.

Effects of Botulinum Toxin-A on Gait Velocity, Step Length, and Base of Support of Patients with Dynamic Equinovarus Foot

OBJECTIVE

The aim of this study was to identify if botulinum toxin type A is a drug able to modify walking velocity, step length, and width of the base of support of adult patients with dynamic equinovarus foot deformity resulting from upper motor neuron syndrome.

DESIGN

This retrospective study analyzed data from 20 patients' files selected from 448 consecutive charts. The main inclusion criteria were the presence of dynamic equinovarus foot deformity due to upper motor neuron syndrome, age between 20 and 80 yrs, evaluation of temporospatial parameters of gait by the Gait Mat II before and 4 wks after botulinum toxin type A injection to the calf muscles, and the ability to walk barefoot, unassisted, and without braces. For data analysis, based on walking velocity, we divided the patients into two groups, slow walking velocity (0.18-0.49 m/sec) and medium walking velocity (0.50-0.99 m/sec).

RESULTS

Width of the base of support was significantly reduced after botulinum toxin type A treatment, both for the affected (P < 0.005) and the unaffected limbs (P < 0.002), in the group of subjects walking at medium velocity. Walking velocity or step length of either group of patients was not significantly modified by botulinum toxin type A treatment.

CONCLUSIONS

Based on this study, a significant effect of botulinum toxin type A on width of the base of support is evident and seems to be the result of a better position of the affected foot during the stance phase of locomotion leading to increased body stability and consequent reduction of width of the base of support of the unaffected limb. No change was evident in step length or walking velocity for this patient population.

A cross-cultural investigation of the role of foot size in physical attractiveness

Disparate cultural practices suggest that small foot size may contribute to female attractiveness. Two hypotheses potentially explain such a pattern. Sexual dimorphism in foot size may lead observers to view small feet as feminine and large feet as masculine. Alternately, because small female feet index both youth and nulliparity, evolution may have favored a male preference for this attribute in order to maximize returns on male reproductive investment. Whereas the observational hypothesis predicts symmetrical polarizing preferences, with small feet being preferred in women and large feet being preferred in men, the evolutionary hypothesis predicts asymmetrical preferences, with the average phenotype being preferred in men. Using line drawings that varied only in regard to relative foot size, we examined judgments of attractiveness in nine cultures. Small foot size was generally preferred for females, while average foot size was preferred for males. These results provide preliminary support for the hypothesis that humans possess an evolved preference for small feet in females.

Pregnancy-related pelvic girdle pain (PPP), I: Terminology, clinical presentation, and prevalence

Pregnancy-related lumbopelvic pain has puzzled medicine for a long time. The present systematic review focuses on terminology, clinical presentation, and prevalence. Numerous terms are used, as if they indicated one and the same entity. We propose "pregnancy-related pelvic girdle pain (PPP)", and "pregnancy-related low back pain (PLBP)", present evidence that the two add up to "lumbopelvic pain", and show that they are distinct entities (although underlying mechanisms may be similar). Average pain intensity during pregnancy is 50 mm on a visual analogue scale; postpartum, pain is less. During pregnancy, serious pain occurs in about 25%, and severe disability in about 8% of patients. After pregnancy, problems are serious in about 7%. The mechanisms behind disabilities remain unclear, and constitute an important research priority. Changes in muscle activity, unusual perceptions of the leg when moving it, and altered motor coordination were observed but remain poorly understood. Published prevalence for PPP and/or PLBP varies widely. Quantitative analysis was used to explain the differences. Overall, about 45% of all pregnant women and 25% of all women postpartum suffer from PPP and/or PLBP. These values decrease by about 20% if one excludes mild complaints. Strenuous work, previous low back pain, and previous PPP and/or PLBP are risk factors, and the inclusion/exclusion of high-risk subgroups influences prevalence. Of all patients, about one-half have PPP, one-third PLBP, and one-sixth both conditions combined. Overall, the literature reveals that PPP deserves serious attention from the clinical and research communities, at all times and in all countries.

Reliability of the GAITRite walkway system for the quantification of temporo-spatial parameters of gait in young and older people

The purpose of this study was to evaluate the test-retest reliability of an instrumented walkway system (the GAITRite mat) for the measurement of temporal and spatial parameters of gait in young and older people. Thirty young subjects (12 males, 18 females) aged between 22 and 40 years (mean 28.5, S.D. 4.8) and 31 older subjects (13 males, 18 females) aged between 76 and 87 years (mean 80.8, S.D. 3.1) walked at a self-selected comfortable walking speed across the pressure-sensor mat three times and repeated the process approximately 2 weeks later. Intra-class correlation coefficients (ICC), coefficients of variation (CV) and 95% limits of agreement were then determined. For both groups of subjects, the reliability of walking speed, cadence and step length was excellent (ICCs between 0.82 and 0.92 and CVs between 1.4 and 3.5%). Base of support and toe in/out angles, although exhibiting high ICCs, were associated with higher CVs (8.3-17.7% in young subjects and 14.3-33.0% in older subjects). It is concluded that the GAITRite mat exhibits excellent reliability for most temporo-spatial gait parameters in both young and older subjects, however, base of support and toe in/out angles need to viewed with some caution, particularly in older people.

Gait coordination in pregnancy: transverse pelvic and thoracic rotations and their relative phase

OBJECTIVE

To examine the effects of pregnancy on the coordination of transverse pelvic and thoracic rotations during gait.

DESIGN

Gait of healthy pregnant women and nulligravidae was studied during treadmill walking at predetermined velocities ranging from 0.17 to 1.72 m/s.

BACKGROUND

pelvis-thorax coordination during walking is altered in women with postpartum pregnancy-related pelvic girdle pain. This coordination has not been investigated in a healthy pregnant population.

METHODS

Comfortable walking velocity was established. Amplitudes of pelvic and thoracic rotations were calculated. Their coordination was characterized by relative Fourier phase and its standard deviation.

RESULTS

Comfortable walking velocity was significantly reduced. The amplitudes of pelvic and thoracic rotations were somewhat reduced, with significantly smaller intra-individual standard deviations. Also pelvis-thorax relative Fourier phase was somewhat smaller, its intra-individual standard deviation was negatively correlated with week of pregnancy, and significantly lower at velocities > or = 1.06 m/s.

CONCLUSIONS

The general pattern of gait kinematics in pregnant women is very similar to that of nulligravidae. Still, it appears that pregnant women experience difficulties in realizing the more anti-phase pelvis-thorax coordination that is required at higher walking velocities.

RELEVANCE

The present study shows that gait in healthy pregnancy is remarkably normal, but some differences in pelvis-thorax coordination were detected. In healthy pregnancy, anti-phase pelvis-thorax coordination appears difficult, but less so than in pregnancy-related pelvic girdle pain. Better understanding of gait in healthy pregnancy may provide insight into the gait problems of women with pregnancy-related pelvic girdle pain.

Center of body mass and the evolution of female body shape

Among primates, the genus Homo has a unique sexual dimorphism in general body shape. The stenotypic female "hourglass figure" has often been attributed to sexual selection. Sexual dimorphism both in shape and in position of the center of body mass (CoM) emerges during puberty and is related to hormonal influences. These are only the proximal and not the ultimate causes of this feature. This article explores the hypothesis that the evolutionary (i.e., ultimate) reason for female body shape and male preference for a lower waist-to-hip ratio (WHR) is due to the acquisition of bipedal locomotion and different biomechanical constraints on each sex. The demands of pregnancy and subsequently carrying infants may have more tightly constrained CoM in females than in males. A lower-position of CoM relative to height (RCoM=(CoM/height)*100%) would contribute to better stability during pregnancy and infant carrying. Using body measurements from 119 female students, we show that RCoM correlates negatively with only maximal thigh circumference and positively with only WHR and shoulder width. The relationship between RCoM and traits that best characterize female body shape seems to confirm a hypothesis of biomechanical selection pressure that may have acted on Homo female morphology, thus contributing to sexual dimorphism.