Static Postural Stability in Women during and after Pregnancy: A Prospective Longitudinal Study.

This longitudinal study aimed to compare static postural stability in women between early pregnancy, advanced pregnancy, and at 2 and 6 months postpartum. Forty-five pregnant women were enrolled and 31 completed the protocol. Data were collected at 7-16 and 34-39 weeks gestation, and at 6-10 and 26-30 weeks postpartum. For each subject, the center of foot pressure path length and mean velocity (with directional subcomponents) were computed from 30-s long quiet-standing trials on a stationary force plate with eyes open or closed. The body mass, stance width, and sleep duration within 24 h before testing were also recorded. Static postural stability was not different between pregnancy and postpartum, except for the anterior posterior sway tested in the eyes-closed condition, which was significantly increased in late pregnancy compared to that at 2 and 6 months postpartum. Pregnant/postpartum women's body mass weakly positively correlated with anterior-posterior sway in the eyes-closed condition and their stance width weakly positively correlated with the anterior-posterior sway in the eyes-open condition. No effect of sleep duration on postural sway was found. Our findings indicate that under visual deprivation conditions women in advanced pregnancy may have decreased static stability compared to their non-pregnant state.

Comparison of static postural stability in exercising and non-exercising women during the perinatal period.

BACKGROUND: The purpose of the study was to determine whether women who exercised during and after pregnancy had better static postural stability compared to those who did not exercise. MATERIAL AND METHODS: Posturographic tests were performed in 31 women at 34-39 weeks gestation, and again at 6-10 weeks postpartum. The center of pressure mean velocity (with directional subcomponents) and sway area were computed from 30-s quiet standing trials on a stationary force plate with eyes open or closed. The women were surveyed about their lifestyle and physical activity in the perinatal period. Based on the survey, 12 of the women were assigned as regular exercisers and 19 as non-exercisers. A Mann-Whitney U test was used to compare data of the exercisers and the non-exercisers in their advanced pregnancy and again at 2 months postpartum. RESULTS: Postural sway measures were not significantly different between the exercisers and the non-exercisers in advanced pregnancy and at 2 months postpartum (p>0.05). CONCLUSIONS: Individually performed physical activity during the perinatal period did not affect pregnant/postpartum women's postural stability characteristics of quiet standing.

Impact of excess body weight on walking at the preferred speed.

The implications of a long-lasting mechanical load on the locomotor activity are poorly understood. The objective of the present studies was to determine an impact of excess body weight on basic spatiotemporal gait measures and to test the hypothesis that leg swing phase may account for a load-related adaptation of the stride characteristics. To this end the basic spatial and temporal stride measures were assessed in 100 obese and 36 lean women (age range between 18 and 67 years) walking with their self-selected pace on a 10-meter long and 1 meter wide instrumented pathway. Among the subjects there were: 44 with class I obesity, 27 with class II obesity, and 29 with class III. Subjects' stance and swing times as well as the stride lengths were recorded by means of contact copper-film electrodes attached to a sole of subject' footwear. The acquired gait measures were used then to compute: a mean velocity of walking, double support times and a mean velocity of a foot during swing phase. Data analysis showed that subjects from every experimental groups walked with a very similar speed (1.08 +/- 0.2 m/s) and cadence (106 +/- 10 steps/min). Their stance time was not affected by body weight and it remained at the mean level of 746 +/- 90 ms for all groups. The temporal stride characteristics and the stance-to-swing ratio were, however, substantially modified in obese individuals due to attenuation of the swing time. As a consequence, the remaining normalized (i.e., expressed as percentage of gait cycle time) phases of stride: the stance and the double support were relatively longer. While the swing time negatively correlated with the body mass index (BMI), the normalized stance and the double support exhibited strong positive correlation (r=0.46) with the BMI. The increase of leg swing velocity seems the main and unique adaptation mechanism that is utilized in the preferred walking gait in obese women.

Paffenbarger Physical Activity Questionnaire as an additional tool in clinical assessment of patients with coronary artery disease treated with angioplasty.

BACKGROUND: The association between frequency, intensity and duration of physical activity and the risk of cardiovascular disease has been investigated in several studies. Out of many methods used for assessment of physical activity, a questionnaire seems to be a simple and affordable method of assessing the risk of coronary artery disease (CAD). However, the number of clinical studies investigating the usefulness of physical activity questionnaires is limited. AIM: To analyse the usefulness of Paffenbarger Physical Activity Questionnaire (PPAQ) in assessment of the correlation between the magnitude of physical activity-related energy expenditure and physical capacity assessed with treadmill exercise test (ET), risk of early onset of major adverse cardiovascular events (MACE) and selected haemodynamic parameters in patients with CAD. METHODS: The study group consisted of 211 patients aged 34-79 years (mean 59) with CAD, with or without previous myocardial infarction (MI). All patients were surveyed using PPAQ at the time of PCI and then 6 months later together with ET and echocardiography. RESULTS: There was a significant correlation between the value of activity-related weekly energy expenditure assessed with the PPAQ and selected parameters of ET (duration: r = 0.2966, p < 0.0001; METs: r = 0.2221, p < 0.001; VO(2)max: r = 0.3075, p < 0.0001; resting HR: r = 0.1615, p < 0.01 and maximal HR: r = -0.1475, p < 0.01) and echocardiography (LVESD r = 0.2346, p < 0.0001). After the PCI procedure, there was a considerable increase in physical capacity (ET duration: 5.82 vs. 7.48 min, p < 0.0001; MET: 7.57 vs. 9.18, p < 0.0001; VO(2)max: 29.23 vs. 34.79 ml, p < 0.0001; HRmax: 123 vs. 132 beats/min, p < 0.0001) and LV function (EF% 51.64 vs. 52.45%, p < 0.01). There was an insignificant change in total physical activity-related energy expenditure of low intensity (< 4 MET), not exceeding 2000 kcal/week (from 3120.13 to 3139.18 kcal/week, p > 0.05). Thirty-seven patients with MACE had a trend towards a lower value of average weekly energy expenditure than the remaining 174 patients (2690.71 vs. 3206.06 kcal/week, NS). CONCLUSIONS: High values of correlation coefficients between the questionnaire results and some variables of ET and echocardiography examination make the PPAQ a useful tool in clinical studies.

Effects of excessive body weight on postural control.

Research that evaluated both static and dynamic stability was performed, to clarify the impact of excessive body weight on postural control. The spontaneous center of foot pressure (CP) motion during quiet stance and a range of forward voluntary CP displacements were studied in 100 obese, and 33 lean women. Characteristics of postural sway were acquired while the subjects were standing quiet on a force plate with eyes open (EO) and with eyes closed (EC). Their anterior range of CP voluntary displacements was assessed upon a range of maximal whole body leanings which were directed forward. A substantial reduction of postural sway was observed in all patients which had increased body weight. Main postural sway parameters i.e., the total path length as well as its directional components were negatively correlated with the body mass and body mass index (BMI). The range of a whole body voluntary forward leaning, did not exhibit any significant change in patients with an obesity grade of I and II. Such a deficit was, however, found in subjects with a body mass index above 40. In conclusion, the increased body weight imposed new biomechanical constraints, that resulted in functional adaptation of the control of the erect posture. This functional adaptation was characterized by a reduced postural sway associated with a substantial reduction of the dynamic stability range in subjects with BMI>40.