Tilt In Healthy Subjects Research Articles

The relationship between pelvic tilt, frontal, and axial leg alignment in healthy subjects

IntroductionThe relationship between anterior pelvic tilt and overall sagittal alignment has been well-described previously. However, the relationship between pelvic tilt, frontal, and axial leg alignment remains unclear. The aim of the study was to analyze the relationship between pelvic tilt and frontal and axial leg alignment in healthy subjects. Material and methodsThirty healthy subjects (60 legs) without prior surgery underwent standing biplanar long leg radiograph. Pelvic parameters (pelvic tilt, pelvic incidence, sacral slope), hip-knee-ankle angle (HKA), femoral antetorsion and tibial torsion were measured using SterEOS (EOS Imaging) software. EOS was acquired with the feet directing straight anteriorly, which corresponds to a neutral foot progression angle (FPA). The influence of HKA, femoral antetorsion, tibial torsion and gender on pelvic tilt was analyzed in a univariate correlation and multiple regression model. ResultsSixteen female subjects and 14 male subjects with a mean age of 27.1 years ± 10 (range 20–67) were included. HKA, femoral antetorsion, and tibial torsion correlated with anterior pelvic tilt in univariate analysis (all p < 0.05). Anterior pelvic tilt increased 1.1° (95% CI: 0.7 to 1.5) per 1° of knee valgus (p < 0.001) and 0.5° (95% CI: 0.3 to 0.7) per 1° of external tibial torsion (p < 0.001). Overall, linear regression model fit explained 39% of variance in pelvic tilt by the HKA, femoral antetorsion and tibial torsion (R2 = 0.385; p < 0.001). ConclusionValgus alignment and increasing tibial torsion demonstrated a weak correlation with an increase in anterior pelvic tilt in healthy subjects when placing their feet anteriorly. The relationship between frontal, axial leg alignment and pelvic tilt needs to be considered in patients with multiple joint disorders at the hip, knee and spine. Alteration of the frontal, or rotational profile after realignment surgery or by implant positioning might influence the pelvic tilt when the FPA is kept constant.

Relation of body mass index (BMI) with cardiovascular response to head up tilt in healthy subjects

Background: Tilt table test is used for the last few decades to detect cause in unexplained syncope. The response to tilting may vary physiologically with obesity.&#x0D; Objective: To assess the relationship of BMI to cardiovascular response to tilting.&#x0D; Methods: This experimental study was conducted from March 2019 to Feb 2020 on 90 healthy subjects with different BMI. Fifty one subjects of both gender with BMI 18.5-24.9 kg/m2 were included in the non-obese group and 39 subjects of both gender with BMI of 25-29.9 kg/m2 were included in overweight group and they were further subdivided into male and female. Head up tilting was done for 10 minutes at 600 by using a motorized tilt table. Systolic blood pressure (SBP), diastolic blood pressure (DBP) were recorded by an automatic sphygmomanometer. Heart rate (HR) and peripheral capillary oxygen saturation (SpO2) were measured by a pulse oximeter. For statistical analysis, Independent sample ‘t’ test, Pearson’s correlation test and Chi square tests were applied.&#x0D; Results: Significantly smaller rise of heart rate was observed in overweight males and greater fall of systolic blood pressure was observed in overweight females.&#x0D; Conclusion: This study concluded that over weight is associated with reduced orthostatic tolerance to head up tilt test in both genders.&#x0D; J Bangladesh Soc Physiol. 2020, June; 15(1): 6-10

Validity of quantitative assessment of posterior pelvic tilt and contralateral vaulting in hemiplegia using 3D treadmill gait analysis

ABSTRACT Background Assessing abnormal gait patterns could indicate compensatory movements, which could be an index for recovery and a process of motor learning. To quantify the degree of posterior pelvic tilt, contralateral vaulting is necessary. Objectives This study aimed to develop and evaluate the validity of quantitative indices for posterior pelvic tilt and contralateral vaulting in hemiplegic patients. Methods Forty-six healthy control subjects and 112 hemiplegic patients participated in this study. Of the 112 patients, 50 were selected into each abnormal gait pattern group, with some overlap. Three experienced physical therapists observed their walking and graded the severity of the two abnormalities in five levels. An index to quantify each of the two abnormal gait patterns was calculated from the three-dimensional treadmill gait analysis. The index values of patients were compared with those of healthy subjects and with the results of observational gait assessment done by three physical therapists with expertise in gait analysis. Results The index values were significantly higher in hemiplegic patients than in healthy subjects (28.0% and 44.7% for the posterior pelvic tilt in healthy subjects and patients, respectively and 0.9 and 4.7 for the contralateral vaulting, respectively). A strong correlation was observed between the index value and the median observational rating for two abnormal gait patterns (r = −0.68 and −0.72). Conclusions The proposed indices for posterior pelvic tilt and contralateral vaulting are useful for clinical gait analysis, and thus encouraging a more detailed analysis of hemiplegic gait using a motion analysis system.

Ageing and cardiovascular responses to head-up tilt in healthy subjects

Objective Ageing is associated with increased postural blood pressure changes and attenuated cardiovascular reactivity. As the background of these changes remains uncertain, we examined arterial stiffness, cardiac function and vascular resistance in healthy subjects in supine position and during orthostatic challenge. Methods Haemodynamics of 179 normotensive subjects (109 female and 70 male, 21–59 years) were examined using continuous radial pulse wave analysis, whole-body impedance cardiography, and plethysmographic finger blood pressures. Results Both in supine position and during head-up tilt central and peripheral blood pressure and augmentation index (amplitude of the reflected pressure wave divided by pulse pressure) increased, and time of pulse wave reflection decreased with age. Supine pulse wave velocity progressively increased with age. There were only minor differences in supine and upright systemic vascular resistance, cardiac index, stroke index, and heart rate that were not systematically related to age. In regression analysis, the explanatory factors for a more pronounced decrease in central systolic blood pressure during the head-up tilt were in the age of 50–59 years, higher baseline pulse wave velocity and central systolic BP. None of the changes in other haemodynamic variables during tilt were related to age. Conclusion As no systematic age-related differences were observed in cardiac function or vascular resistance, these results support the view that progressive reduction of large arterial compliance contributes to the exaggerated age-related decrease in central systolic blood pressure in response to head-up tilt.

Reproducibility of sagittal pelvic tilt measurements in normal subjects using digital inclinometry

Standing sagittal pelvic tilt posture is widely assessed qualitatively, yet no efficient non-invasive quantitatively method is available for measuring pelvic tilt position or its amplitude. The main objective of the current study was to assess the intra- and inter-tester reproducibility of digital inclinometry-based (DI) measurements of pelvic tilt in healthy subjects. Pelvic inclination was measured while standing in neutral position (NP), maximal anterior pelvic tilt (APT) and maximal posterior pelvic tilt (PPT) which served for calculating the total pelvic tilt (TPT) range of motion (TPT = PPT–APT). On two separate test occasions two convenience samples of healthy women and men ( N = 15 in each) were each measured by two different testers. In both groups the intra-tester reproducibility indices of NP, APT, PPT and TPT were acceptable as revealed by high and significant ICCs and low standard error of measurements (SEM). In women the inter-tester reproducibility indices, of the same variables, were high as distinguished by no significant differences between testers and high and significant ICCs. In men, significant differences were found in APT and PPT but the between-testers TPT scores were similar. Collectively these findings indicate that pelvic inclinometry yields acceptable reproducibility which in the light of the facility of the method may render it an efficient clinical tool.

Age dependency of cardiovascular autonomic responses to head-up tilt in healthy subjects.

In elderly subjects, heart rate responses to postural change are attenuated, whereas their vascular responses are augmented. Altered strategy in maintaining blood pressure homeostasis during upright position may result from various cardiovascular changes, including age-related cardiovascular autonomic dysfunction. This exploratory study was conducted to evaluate impact of age on cardiovascular autonomic responses to head-up tilt (HUT) in healthy subjects covering a wide age range. The study population consisted of 63 healthy, normal-weight, nonsmoking subjects aged 23-77 yr. Five-minute electrocardiogram and finger blood pressure recordings were performed in the supine position and in the upright position 5 min after 70 degrees HUT. Stroke volume was assessed from noninvasive blood pressure signals by the arterial pulse contour method. Heart rate variability (HRV) and systolic blood pressure variability (SBPV) were analyzed by using spectral analysis, and baroreflex sensitivity (BRS) was assessed by using sequence and cross-spectral methods. Cardiovascular autonomic activation during HUT consisted of decreases in HRV and BRS and an increase in SBPV. These changes became attenuated with aging. Age correlated significantly with amplitude of HUT-stimulated response of the high-frequency component (r = -0.61, P < 0.001) and the ratio of low-frequency to high-frequency power of HRV (r = -0.31, P < 0.05) and indexes of BRS (local BRS: r = -0.62, P < 0.001; cross-spectral baroreflex sensitivity in the low-frequency range: r = -0.38, P < 0.01). Blood pressure in the upright position was maintained well irrespective of age. However, the HUT-induced increase in heart rate was more pronounced in the younger subjects, whereas the increase in peripheral resistance was predominantly observed in the older subjects. Thus it is likely that whereas the dynamic capacity of cardiac autonomic regulation decreases, vascular responses related to vasoactive mechanisms and vascular sympathetic regulation become augmented with increasing age.

Different patterns of cardiovascular autonomic regulation during non‐hypotensive head‐up tilt in healthy subjects – impact of age

Different patterns of cardiovascular autonomic regulation during non‐hypotensive head‐up tilt in healthy subjects – impact of age