Pelvic Inclination Research Articles

RELATIONSHIP OF PELVIC ALIGNMENT WITH BALANCE AND GAIT IN PATIENTS WITH STROKE: A SYSTEMATIC REVIEW

Background- Pelvis is the key structure that connects the spine and the lower limbs. Altered Pelvic Alignment and asymmetrical weight bearing on affected lower limbs is a common problem leading to pelvic instability which may have an effect on balance and gait in patients with stroke. Hence, it was aimed to investigate the interdependence of these three components in patients with stroke. Methods- Four databases (PubMed, Google Scholar, Cochrane, Science Direct) were searched to identify eligible studies using the keywords Pelvic Alignment, Gait, Balance, Stroke. Only observational studies published in last 10 years (2010-2020) were included in this review. Results- Thirteen studies were included in the review conducted on sub-acute and chronic stage. All studies investigated the affection of pelvic mal-alignment, balance and gait in combination of two variables except 3 studies which investigated the combined effect of pelvic inclination on both balance and gait. The abnormal pelvic tilt results in lateral displacement of the pelvis on affected side, altered Base of Support, reduced balance control, asymmetry in weight bearing leading to altered gait. Conclusion- Pelvic tilt, anterior and lateral has a significant impact on static balance, gait variables, weight bearing symmetry.

Progression of pelvic retroversion is a critical factor for clinical outcome after Opening-wedge high tibial osteotomy among elderly patients

PurposeTo evaluate the clinical outcome after opening-wedge high tibial osteotomy (OWHTO) and to determine the critical factors for a poor clinical outcome after OWHTO in patients aged over 65 years.MethodsOur retrospective analysis was based on the data from 233 patients who underwent OWHTO for medial compartment knee OA at our institution between January 2013 and December 2018, and 88 patients (36 men and 52 women) over 65 years of age were included in this study. Radiographic parameters of weight-bearing line ratio (WBLR) and pelvic inclination (PI); the knee function, range of motion (ROM) and extension; and clinical outcome with Lysholm score were obtained preoperatively and postoperatively at the final follow-up visit. To evaluate the critical factors for the clinical outcome, univariate regression analysis was used to identify the relationship between postoperative and improved Lysholm score and pre-and post-operative essential factors. To reveal the factor having a greater impact on the clinical outcome, a p < 0.05 in univariate factors was entered into a multivariate regression analysis.ResultsThe preoperative WBLR was significantly changed, and Lysholm score improved from 59.5 to 81.5 (p < 0.0001), whereas the PI, knee extension and ROM were not changed after OWHTO. Regarding the essential factors affecting clinical outcome after OWHTO, age and delta PI were negative, whereas preoperative WBLR, postoperative ROM, especially extension, had a positive effect (p < 0.05). Furthermore, only delta PI had affected the improvement of clinical outcome with OWHTO (p < 0.01), and postoperative knee extension was negatively correlated with the progression of pelvic retroversion (p < 0.01).ConclusionAge at surgery and progression of pelvic retroversion were the critical factors for poor postoperative clinical outcomes after OWHTO. Care should be taken for the progression of pelvic retroversion after OWHTO because it deteriorates the clinical outcome by inducing the knee flexion contracture as the compensatory mechanism for the balance of sagittal alignment.

Biomechanical changes in women with chronic pelvic pain: a case-control study

PurposeChronic pelvic pain can influence women’s quality of life and activity levels; it can lead to several adverse side effects, such as changes in posture and biomechanical alignment. The purpose of this study was to determine the biomechanical changes that occur in women experiencing chronic pelvic pain, either cyclic or noncyclic.MethodsA case-control study was conducted among 60 females from the Gynecology Physiotherapy Clinic of El-Hosary Women Health Care in 6th of October city. The participants were assigned into 3 groups: cyclic chronic pelvic pain group (A), noncyclic chronic pelvic pain group (B), and normal women group (C). An inclinometer was used to assess biomechanical changes in the angles of the cervical, thoracic, and lumbar region; furthermore, a pelvic inclinometer served to measure the pelvic inclination angle.ResultsStatistical analysis revealed that there was a significant increase in biomechanical variables at the lumbar, thoracic, and cervical angles in group B compared with groups A and C and in group A compared with group C. Moreover, there was a significant increase in right and left pelvic inclination angles in groups A and B compared with group C, and no significant difference was observed between groups A and B.ConclusionsBiomechanical alignment changes are seen more frequently in women with noncyclic chronic pelvic pain and cyclic chronic pelvic pain than in normal women.

Dynamic Balance Indices in women with and without Pelvic Organ Prolapse

Introduction: Pelvic Organ Prolapse (POP) is one of the dysfunctions of the Pelvic Floor Muscles (PFM), with descending of pelvic viscera, vaginal wall, uterus, bladder and rectum. Regarding the role of PFM as part of the core muscles in body balance, it has been suggested that women with PFM dysfunctions may have a lower level of balance. Therefore, this study was performed with aim to compare the level of dynamic balance in non-postmenopausal women with and without POP in two positions of full and empty bladder. Methods: This cross-sectional comparative study was performed in 2018 on 30 non-pregnant married women in the Rehabilitation School of Shahid Beheshti University of Medical Sciences. The subjects were divided in to three groups (n=10 in each group): with symptomatic POP, asymptomatic POP and without POP. After collecting demographic information, the pelvic inclination angle, and the dynamic balance in Antero-Posterior, Medio-Lateral planes as well as total balance index were assessed. Data were analyzed using SPSS statistical software (version 22) and Kolmogorov-Smirnov, one-way ANCOVA and Fisher's exact test. P<0.05 was considered statistically significant. Results: No significant differences were not found among three groups in terms of dynamic balance index with both full and empty bladder (p<0.05). Moreover, there were no significant differences among three groups regarding the pelvic inclination angle (p<0.05). Conclusion: The association of POP as one of the dysfunctions of pelvic floor muscle is not confirmed by postural stability. Further studies using the motion analysis system and simultaneous recording of electrical muscle activity are recommended.

Position and orientation of vaginal pessaries in situ on magnetic resonance imaging.

We hypothesize that there are differences in the position and orientation of ring and Gellhorn pessaries in situ on magnetic resonance imaging (MRI). This was a retrospective cohort study comparing MRI findings in 25 women with pessaries in situ at the time of imaging. Scanner coordinates for anatomic and pessary landmarks were obtained and transformed to 3D Pelvic Inclination Correction System coordinates using MATLAB software. The normal vector to the pessary disc was computed and compared to the positive y-axis in the sagittal and coronal planes to determine XY and YZ disc angles, respectively. Comparisons between groups were made using Wilcoxon rank, Fisher's exact, and Brown-Forsythe tests. Twenty-one women with ring pessaries and four women with Gellhorn pessaries met inclusion criteria for the study. Women with ring pessaries were younger (68.4 vs. 80.7years, p= 0.003) but had similar BMI, vaginal parity, history of hysterectomy, and anatomic characteristics. Ring pessaries had a smaller diameter (59.5 vs. 79.3mm, p= 0.004) and were positioned further posterior with respect to the inferior pubic point (midpoint X position 42.6 vs. 29.5mm, p= 0.004). There were significant differences in the magnitude and variance of the XY disc angle (57.0 ± 14.0 vs. -1.2 ± 2.8 degrees, p= 0.002 for magnitude, p= 0.012 for variance) but not the YZ disc angle (3.3 ± 30.6 vs. 1.5 ± 7.7 degrees, p> 0.05 for both) between groups. We found differences in the position and orientation between ring and Gellhorn pessaries in situ using an anatomic 3D reference system. These findings provide insight into the mechanism of action of vaginal pessaries.

Effect of Posterior Pelvic Tilt Taping on Pelvic Inclination, Muscle Strength, and Gait Ability in Stroke Patients: A Randomized Controlled Study.

Objective: Pelvic alignment asymmetry in stroke patients negatively affects postural control ability. This study aimed to investigate the effect of posterior pelvic tilt taping on pelvic inclination, muscle strength, and gait ability in stroke patients. Methods: Forty stroke patients were recruited and randomly divided into the following two groups: the posterior pelvic tilt taping (PPTT) group (n = 20) and the control group (n = 20). All participants underwent sitting-to-standing, indoor walking, and stair walking training (30 min per day, 5 days per week, for 6 weeks). The PPTT group applied posterior pelvic tilt taping during the training period, while the control group did not receive a tape intervention. Pelvic inclination was measured using a palpation meter (PALM). A hand-held dynamometer and the 10-meter walk test were used to measure muscle strength and gait ability. Results: Significantly greater improvements in the pelvic anterior tilt were observed in the PPTT group than in the control group (p < 0.05). Muscle strength in the PPTT group was significantly increased compared to the control group (p < 0.05). Significantly greater improvements in gait speed were observed in the PPTT group than the control group. Conclusions: According to our results, posterior pelvic tilt taping may be used to improve the anterior pelvic inclination, muscle strength, and gait ability in stroke patients.

Cobb angle measurement and pelvic inclination in children with spastic cerebral palsy: A cross-sectional study

Cobb angle measurement and pelvic inclination in children with spastic cerebral palsy: A cross-sectional study

Rear drop: a new radiographic landmark for estimation of pelvic tilt on pelvis AP radiographs.

Estimation of pelvic tilt on anteroposterior (AP) pelvis radiograph is often done by indirect methods based on the midline pelvic landmarks. The purpose of this cadaveric study is to describe a new radiographic landmark and reference measurements to estimate the coronal tilt of the pelvis, independent of the midline references. The new radiologic reference is called ‘rear drop’, and its anatomic location is described with the cadaveric pelvis AP radiographs in various pelvic inclination. The parameters derived from the new reference were used to assess the pelvic tilt, and the results were compared with the previously established method using ‘sacrococcygeal joint to symphysis distance’ (SCSD). The shape of the new figure is used to determine the position of the pelvis, and its relationship with the previously described acetabular retroversion indicators was statistically analyzed. The new reference figure corresponds to the posteroinferior edge of the horseshoe shape of the acetabular margin. The newly derived reference parameters, rear to tear distance and rear to tear angle, changes with pelvic tilt and are strongly correlated with SCSD. The shape of the rear drop changes with the changing pelvic tilt and correlates statistically with the previously described acetabular retroversion indicators. Rear drop and its derivative measurements can be used as a reliable and reproducible indicator to estimate the coronal pelvic tilt, free of midline reference points. This new reference will be a base for future clinical studies on pelvic tilt, rotation and their application in intraoperative hip fluoroscopy.

The impact of sagittal imbalance on walking in patients with lumbar spinal canal stenosis.

Gait and posture disorder severely impedes the quality of life of affected patients with lumbar spinal canal stenosis (LSCS). Despite the major health concern, there is a paucity of literature about the relationships among spatiotemporal gait parameters and spinal sagittal parameters. This is a cross sectional study performed in a single tertiary referral center to determine the relationships among spatiotemporal gait parameters and spinal sagittal parameters in patients with LSCS. A total of 164 consecutive patients with LSCS, 87 men and 77 women with mean age of 70.7 years, were enrolled. Spatiotemporal gait parameters were studied using a gait analysis system. Spinal sagittal parameters were studied including sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic inclination (PI), and pelvic tilt (PT) both in the neutral and stepped positions. SVA was significantly larger in the stepped position than in the neutral position (neutral position, 72.5 mm; stepped position, 96.8 mm; p = 0.003). Parameters regarding the pelvis exhibited significant differences, which could represent pelvic anteversion in the stepped position. By stepwise multiple regression analysis, the prediction models, containing SVA (neutral) and PT (stepped) for double supporting phase, exhibited statistical significance, and accounted for approximately 50% of the variance. The present study provides statistically established evidence of correlation among spatiotemporal gait parameters and spinal sagittal parameters. Differences between sagittal parameters in neutral and stepped position may stand for the postural control during gait cycle, and increased SVA in neutral position and increased PT in stepped position may correlate with prolonged double supporting phase.

Relationship between Gait, Static Balance, and Pelvic Inclination in Patients with Chronic Stroke

Relationship between Gait, Static Balance, and Pelvic Inclination in Patients with Chronic Stroke

Sacral incidence to pubis: a novel and alternative morphologic radiological parameter to pelvic incidence in assessing spinopelvic sagittal alignment

BackgroundAlthough pelvic incidence (PI) is a key morphologic parameter in assessing spinopelvic sagittal alignment, accurate measurements of PI become difficult in patients with severe hip dislocation or femoral head deformities. This study aimed to investigate the reliability of our novel morphologic parameters and the correlations with established sagittal spinopelvic parameters.MethodsOne hundred healthy volunteers (25 male and 75 female), with an average age of 38.9 years, were analysed. Whole-body alignment in the standing position was measured using a slot-scanning X-ray imager. We measured the established spinopelvic sagittal parameters and a novel parameter: the sacral incidence to pubis (SIP). The correlation coefficient of each parameter, regression equation of PI using SIP, and regression equation of lumbar lordosis (LL) using PI or SIP were obtained. The intraclass correlation coefficient (ICC) was calculated as an evaluation of the measurement reliability.ResultsReliability analysis showed high intra- and inter-rater agreements in all the spinopelvic parameters, with ICCs > 0.9. The SIP and pelvic inclination angle (PIA) demonstrated strong correlation with PI (R = 0.96) and pelvic tilt (PT) (R = 0.92). PI could be predicted according to the regression equation: PI = − 9.92 + 0.905 * SIP (R = 0.9596, p < 0.0001). The ideal LL could be predicted using the following equation using PI and age: ideal LL = 32.33 + 0.623 * PI – 0.280 * age (R = 0.6033, p < 0.001) and using SIP and age: ideal LL = 24.29 + 0.609 * SIP – 0.309 * age (R = 0.6177, p < 0.001).ConclusionsBoth SIP and PIA were reliable parameters for determining the morphology and orientation of the pelvis, respectively. Ideal LL was accurately predicted using the SIP with equal accuracy as the PI. Our findings will assist clinicians in the assessment of spinopelvic sagittal alignment.Trial registrationThis study was retrospectively registered with the UMIN Clinical Trials Registry (UMIN000042979; January 13, 2021).

A sitting or standing position – which one exerts more loads on the musculoskeletal system of the lumbar spine? Comparative tests based on the methods of mathematical modelling

The work aimed to assess the functioning of the musculoskeletal system within the lumbar spine in relation to everyday postures of sitting and standing. The comparative analysis was based both on experimental tests and computer simulations performed in the AnyBody Modeling System environment. Input data used to prepare models were based on the information obtained in experimental tests. The test participants were tasked with adopting two postures: 1) standing position and 2) sitting position. Kinematics measurements were performed using the Zebris ultrasonic system. During sitting position, the tests additionally involved the use of a dynamometric platform measuring reaction forces occurring between buttocks and the seat. The comparative analysis included measurements of the trunk inclination angle and the pelvic inclination angle as well as results of computer simulations. The sitting posture is responsible for increased trunk inclination and a change in the position of the pelvis. In terms of the sitting position, it was possible to observe an increase in the loads affecting individual intervertebral joints of the lumbar spine by 155-184% in comparison with the standing posture (100%). Simulations revealed an increased muscle activity of the erector spinae, abdominal internal oblique muscles and abdominal external oblique muscles. Adopting a sitting position increases the loads on the lumbar spine and increases the activity of the erector spinae and abdominal muscles compared to the standing position, which is caused by change in the position of the pelvis and the curvature of the lumbar region.

Dynamic testing of volleyball players' body posture using a formetric 3D device

Volleyball activities involve several factors such as asymmetrical movements, muscle imbalance, and continual overloading that damage body posture. This study aimed to determine postural changes of volleyball players in spike overhand front set, overhand pass ball, and mat ball motions, and if there is any postural variation difference between short training and long training volleyball players. Methods: Fifteen long training and short training male volleyball players aged 21–23 years were recruited in this study. The upper-thoracic angle, thoracic-lumbar segment angle, lower lumbar-sacral segment, pelvic inclination, and inclination of the acromion were measured using DIERS formetric 3D device in a dynamic way. During the overhand pass motion, long training participants showed a significant larger peak upper-thoracic and peak thoracic-lumbar angles than short training participants. During the mat ball motion, the long training volleyball players demonstrated a significant higher peak upper-thoracic angle, but a smaller peak inclination of the acromion than short trainers. During the spike overhand front set motion, long trainers showed a significant smaller peak upper-thoracic angle than short trainers. Athletes should consider developing an appropriate dynamic trunk stabilization to reduce posture imbalance during volleyball activities.

Extra-Articular Impingement at the Anterior Inferior Iliac Spine: A Cause of Refractory Periarticular Pain After Total Hip Arthroplasty

BackgroundPeriarticular pain after total hip arthroplasty (THA) can significantly impair the postoperative functionality. Extra-articular impingement between the greater trochanter and the anterior inferior iliac spine is presented as a cause of refractive pain after THA. MethodsTwenty patients were treated for refractive periarticular pain and limited internal rotation between January 2014 and April 2016. All patients underwent a positive chair rise test, pelvic inclination test, and Marcainisation test. Patients were treated with bone resection of the anterior part of the greater trochanter with or without component revision. ResultsAt a mean follow-up of 20 months, all functional outcomes had improved significantly. All patients were willing to undergo the surgery again. Sixteen (80%) indicated the result as very good, 3 (15%) as good, and one (5%) as poor. Two patients developed a postoperative heterotopic ossification that required resection. ConclusionsExtra-articular impingement should be considered as a possible cause of refractive groin pain after THA. Bony resection through the Hueter interval provides immediate pain relief with improved functional outcomes 1 year after surgery.

Automatic Characterization of Pelvic and Sacral Measures from 200 Subjects.

An understanding of pelvic and acetabular morphology and orientation is required for accurate surgical reconstruction of the hip and spine, as well for component placement in a total hip arthroplasty. Our objectives were to develop an automated system for measuring pelvic and sacral orientations utilizing computed tomographic (CT) scans and to characterize these measures across 200 asymptomatic subjects. An automated feature recognition algorithm was created to identify acetabular and pelvic orientation across 200 scans generated for non-musculoskeletal conditions. Three-dimensional models were generated from CT data to serve as inputs to the algorithm. Acetabular orientation was defined by comparing a plane fit to the acetabular rim with the anterior pelvic plane. Pelvic inclination, pelvic tilt, and sacral slope were defined as the angles between landmarks identified across the pelvis: pubic tubercles, acetabular center, left and right anterior superior iliac spines, and sacral plate. The mean sacral slope was 36.49°, the mean pelvic tilt was 15.60°, and the mean pelvic incidence was 52.05°. The mean sacropubic angle was 32.48° and the mean pelvic-Lewinnek angle was 8.93°. Significant differences between male and female subjects were observed in the sacral slope (mean difference, 4.72°; p < 0.05), pelvic tilt α (mean difference, 4.17°; p < 0.05), pelvic tilt γ (mean difference, 3.06°; p < 0.05), and the pelvic-Lewinnek angle (mean difference, 1.76°; p < 0.05). The comparison of acetabular orientation measures with those in a prior study of the same cohort yielded intraclass correlation coefficients (ICCs) all above 0.97. The validation of sacral orientation via manual measurement also yielded ICC values all at or above 0.97. Our algorithm showed a high degree of consistency in acetabular orientation measures with respect to a prior study of the same cohort. The measures of pelvic orientation were found to be accurate and reliable when compared with manual measurements of the same data set. All measurements of pelvic orientation were consistent with the means reported in the literature. An accurate and reproducible, automated technique for determining pelvic and acetabular orientation provides a way to characterize these measures as an aid in clinical diagnosis and preoperative planning.

Movement Caused by Electrical Stimulation of the Lumbosacral Region in Standing Horses

Electrical stimulation is commonly used as a modality for physical therapy in human and veterinary medicine. However, studies measuring the movement generated by electrical stimulation in horses are rare. The present study therefore evaluates the range of movement provoked by a commercially available physical therapy unit (FES310) and contrasts it with the movement generated by manually induced pelvic inclination (back rounding). Ten horses were tested on three measurement days over one week. Electrical stimulation was applied via a back treatment pad (belonging to the FES310 system) containing six electrodes (three on either side of the spine) placed over the lumbosacral region. This system produced a pulsed, biphasic electrical stimulation in a rectangular waveform which was gradually increased to a maximum of 10 volts. Before and after electrical stimulation testing, manual pelvic inclination was achieved by pressure on two points lateral to the root of the tail. Muscle tone and lameness were evaluated before and after treatments. Skinfold thickness, body condition score, and body mass were measured to detect possible confounding factors. Using kinematics, the angle ranges during movement of ten three-dimensional angles of the trunk, the pelvis, and the hind limbs were further analyzed. Movement was produced with manual stimulation in every tested individual on all measurement days and with electrical stimulation on at least one measurement day. The electrical stimulation led to significantly (P < .05) smaller angle ranges which were 15 %–57 % of the median of the manually stimulated movement. Strong positive correlations between angle ranges of the electrically generated movement were found for the hind limbs implicating their involvement in the movement created. Correlations between skinfold thickness, body condition score, and body mass with the angle ranges were weak and not significant. Before and after electrical and manual stimulation, muscle tone and lameness were similar. In the present study, both electrical and manual stimulation were proven to produce significant trunk and hind limb movement. Within this study’s electrical stimulation treatment protocol, the movement generated by electrical stimulation was significantly less than the movement caused by manual pelvic inclination. However, electrical stimulation could easily be applied over a longer period and in a higher frequency than it would be possible for manual pelvic inclination. This treatment shows potential for stabilization and or mobilization of the lumbosacral region, although its efficiency as a therapeutic tool and its effect on specific orthopedic problems and is to be evaluated in further research.

12주간의 에어리얼 요가 실시가 성인여성의 체형 및 기능성 움직임에 미치는 영향

The purpose of this study was to examine the effects of aerial yoga on the body shape and functional movement of 12-week antigravity exercise. The subjects were classified into 23 adult women with normal menstruation into 10 aerial yoga groups (23.0±1.2 yr, exercise group) and 13 daily maintenance groups (20.7±0.2 yr, control group). Front and side body alignments were taken. Functional movement screen (FMS) measured the imbalance, mobility, stability and balance of the body by the evaluation method through seven movements. The aerial yoga program performed 23 movements twice a week for 60 minutes for 12 weeks, with 50-60% strength at the maximum heart rate. All items were presented as mean±standard error and two-way ANOVA with repeated measures was performed. Independent t-test was performed to verify the mean difference between dependent variables before and after exercise. As a result, there was a significant decrease in pelvic inclination (4.5±2.5 in 6.2±3.1) and knee flexion (170.9±2.2 in 173.6±3.4) in the exercise group, but there was no difference in the control group. FMS increased significantly in the in-line lunge, active straight leg raise, and FMS total scores (14.7±2.4 to 18.0±0.9) in the exercise group. In conclusion, it was confirmed that long-term aerial yoga is an effective exercise for improving body shape and functional movement in adult women.

Prediction of Pelvic Inclination in the Sitting Position after Corrective Surgery for Adult Spinal Deformity.

Introduction Hip dislocation rates in patients with combined total hip arthroplasty (THA) and spinal deformity fixation are significantly higher than those of THA alone. Nevertheless, there are no treatment recommendations for patients who undergo THA and require a spine deformity correction later. Methods Twenty-eight patients underwent spinal fixation surgery for adult spinal deformity. Sagittal spinopelvic alignment was analyzed on lateral radiographs taken preoperatively and postoperatively in the sitting and standing positions. Univariate linear regression analysis was conducted to identify the factors affecting the pelvic inclination in the sitting position after spinal fixation. Multiple regression analysis was conducted to determine the most efficient combination of radiographic parameters for predicting postoperative pelvic inclination while sitting. Results There were significantly weak associations between postoperative sacral slope (SS) in the sitting position and the following factors: the number of vertebral levels fused (β = 0.30, p = 0.003); the presence of sacral fixation (β = 0.22, p = 0.01); the presence of sacroiliac joint fixation (β = 0.24, p = 0.008); and preoperative SS while standing and sitting (β = 0.21, p = 0.01 and β = 0.34, p = 0.001). Postoperative lumbar lordosis (LL) while standing was strongly associated with postoperative SS in the sitting position (β = 0.67, p <.0001). The combination of postoperative LL in the standing position and preoperative SS in the sitting position was the best fit, and the adjusted R-squared was 0.82. Conclusions We devised a prediction formula for pelvic inclination while sitting after spinal fixation that has high predictability: postoperative SS while sitting = 11.7+ (0.4 × postoperative planned LL while standing) + (0.16 × preoperative SS while sitting). This study could be the basis for treatment recommendations for patients who have undergone THA and require a spine deformity correction later.

Posterior-Anterior Projection of Pelvic Radiographs in Children Meets the Correct Positioning Criteria

Background: There are many studies suggesting that the pelvic radiographs taken in posterior-anterior (PA) projection cause far less radiation exposure than anterior-posterior (AP) projection. However, PA projection is rarely used in daily practice due to the concern that the obtained images will not provide radiological standards. Objectives: The aim of the study was to determine whether PA projections meet the radiological criteria of correct positioning as AP projections. Patients and Methods: In this prospective study, radiographs of 160 patients (80 PA and 80 AP images) were obtained randomly. Pelvic rotation index (PRI), symphysis ischium angle (SIA) and pelvic inclination index (PII) were used to evaluate whether the pelvic radiographs were suitable for radiological assessment. Results: The reliability of AP and PA projections was excellent for PRI (Intraclass correlation coefficient [ICC] = 0.66, 95% confidence interval [CI] = 0.90 - 0.98), SIA (ICC = 0.99, 95% CI = 0.90 - 0.98), and PII (ICC = 0.95, 95% CI = 0.90 - 0.98). Conclusion: PA projection instead of AP projection for pelvic radiography has no drawback in terms of acceptability criteria. Considering PA projection is a dose reducing technique requiring no additional equipment, it may be a safer option for children.

The effect of the pelvis position in the sagittal plane on loads in the human musculoskeletal system

The research work aimed to perform the mathematical modelling-based assessment concerning the effect of the position of the pelvis in the sagittal plane on loads present in the musculoskeletal system in the standing position. The analysis of the effect of various positions of the pelvis was performed using the Free Posture Model in the AnyBody Modeling System software. Simulated positions involving various values of pelvis inclination ranged from the extreme pelvic retroposition (-7°) through normative values (0-23°) to the extreme pelvic anteversion (33°). The lowest resultant reaction forces in the intervertebral joints recorded for an angle of inclination restricted within the range of 9-27° and segment L5-S1 amounted to less than 0.7 BW. A change in the pelvic inclination from the normative values towards retroposition or anteversion resulted in the increased muscular activity of the erector spinae, transverse abdominal muscles as well as internal and external oblique muscles. Regarding the lower limbs, changes in the activity were observed in the biceps femoris muscle, iliac muscle, gluteus minimus, gluteus medius and the gluteus maximus. The results obtained in the research-related tests confirmed that the pelvic inclination affects loads present in the musculoskeletal system. The abovenamed results will be used to develop therapeutic exercises aimed to reduce loads present in the musculoskeletal system. The aforesaid exercises will be used to teach participants how to properly position their pelvis and how to activate individual groups of muscles.