The effects of pelvic movement on lumbar lordosis in the standing position

Adaptation of the Lumbar Spine From Orthostasis to Supine

STUDY DESIGN

Observational-ecologic study.

INTRODUCTION

Spine and pelvis undergo modifications in alignment so that the individual can maintain an orthostatic position, but to date there is no evidence as to the contribution of each lumbar segment and the change that occurs in them when moving from orthostasis to supine position.

OBJECTIVE

To identify the difference in the contribution of the lumbar segments and pelvis to the formation of lumbar lordosis in both positions (orthostasis and supine) and how each one alters in this change.

SUMMARY OF BACKGROUND DATA

lumbar lordosis adapts to the individual's body position and can be physiological or pathologic.

MATERIALS AND METHODS

Retrospective cohort study that included 174 patients: the segments total lumbar lordosis (LL), L1-L4, L4-S1, L4-L5, L5-S1, and sacral slope were measured on x-rays (orthostasis) and MRI (supine). We obtained the mean values, correlations and models proposed for the relationship between the values found.

RESULTS

The SS, LL, L1-L4, L4-S1, and L4-L5 had their angular value reduced, and L5-S1 had its contribution to lordosis significantly increased when lying down. Moderate and strong correlations were obtained between SS × LL, L1-L4 and L4-S1, and between LL versus L1-L4 and L4-S1 in both positions. When using linear regression, proposed models were obtained with a high coefficient of determination between LL versus SS, L1-L4 and L4-S1 in orthostasis, for the same measurements and SS versus L4-S1 in supine, as well as for lordosis when comparing the 2 positions.

CONCLUSIONS

The L5-S1 segment has no change in angular value when lying in supine and is thus the largest contributor to lordosis in supine. L1-L4 increases its angular value when standing in orthostasis, the position in which it is the greatest contributor to lordosis.

Postural asymmetry in low back pain - a systematic review and meta-analysis of observational studies

PURPOSE

Systematic review and meta-analysis to examine common static postural parameters between participants with and without low back pain (LBP).

METHODS

Systematic search on the PubMed, CINAHL, Embase and SCOPUS databases using keywords 'posture' and 'low back pain'. Observational studies comparing static postural outcomes (e.g. lumbar lordosis) between participants with and without LBP were included. Two independent reviewers conducted screening, data extraction and quality assessment. Methodological quality was assessed using Joanna Briggs Institute's critical appraisal tools.

RESULTS

Studies included in review = 46 (5,097 LBP; 6,974 controls); meta-analysis = 36 (3,617 LBP; 4,323 controls). Quality of included studies was mixed. Pelvic tilt was statistically significantly higher in participants with LBP compared to controls (n = 23; 2,540 LBP; 3,090 controls; SMD:0.23, 95%CI:0.10,0.35, p < 0.01, I2=72%). Lumbar lordosis and sacral slope may be lower in participants with LBP; pelvic incidence may be higher in this group; both were not statistically significant and the between study heterogeneity was high. Thoracic kyphosis and leg length discrepancy showed no difference between groups.

CONCLUSIONS

Lumbopelvic mechanisms may be altered in people with LBP, but no firm conclusions could be made. Pelvic tilt appeared to be increased in participants with LBP. Postural variable measurement needs standardisation. Better reporting of study characteristics is warranted.

Do floating toes relate with the ability to perform the deep squat test among baseball players with throwing injury?

Relationship between ability to perform the deep squat test (DST) and floating toes among baseball players with disabled throwing shoulder/elbow was retrospectively investigated. Players performed the DST by fully squatting while having their arms crossed in front of their chest without lifting the heel off the floor or falling backwards. Floating toes were evaluated if all the toes were in contact with the mat or not. The relationship between ability to perform the DST and prevalence of floating toes was statistically analysed. Sixty-three players (69.2%) were unable to perform the DST. Floating toes were observed in 74 players (81.3%). Players with inability to perform the DST had significantly higher prevalence of floating toes (58 players, 92.1%), compared with those who were able to perform the test (16 players, 57.1%) (p < 0.001). Floating toes may relate with inability to perform the DST among baseball players with disabled throwing shoulder/elbow.

The spinopelvic alignment in patients with prior knee or hip arthroplasty undergoing elective lumbar surgery

BACKGROUND CONTEXT

Concurrent degeneration of the lumbar spine, hip, and knee can cause significant disability and lower quality of life. Osteoarthritis in the lower extremities can lead to movement limitations, possibly requiring total knee arthroplasty (TKA) or total hip arthroplasty (THA). These procedures often impact spinal posture, causing alterations in spinopelvic alignment and lumbar spine degeneration. It is unclear if patients with a history of prior total joint arthroplasty (TJA) have different spinopelvic alignment compared to patients without.

PURPOSE

To assess the relationship between a history of previous THA or TKA, as well as combined THA and TKA, and the spinopelvic alignment in patients undergoing elective lumbar surgery for degenerative conditions.

STUDY DESIGN

A retrospective analysis was conducted on patients who underwent lumbar surgery for degenerative conditions. The patients were stratified based on a history of TKA, THA, or both TKA and THA.

PATIENT SAMPLE

A total of 632 patients (63% female) with an average age of 64±11 years and an average BMI of 30±6 kg/m2 were included.

OUTCOME MEASURES

Patients were stratified based on a history of THA, TKA, or combined THA and TKA. Spinopelvic parameters (lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI)) were assessed. The relationship between spinopelvic alignment and prior TKA, THA or TKA and THA was analyzed.

METHODS

The data was tested for normal distribution using the Shapiro-Wilk test. We analyzed the relationship between the spinopelvic parameters and the different arthroplasty groups. Differences in scores between groups were examined using ANOVA. Tukey's Honestly Significant Difference test was used for pairwise comparison for significant ANOVA test results. Multivariable linear regression was applied, adjusted for age, sex and BMI.

RESULTS

A total of 632 patients (63% female) were included in the study. Of these patients, 74 (12%) had a history of isolated TKA, 40 (6%) had prior isolated THA, and 15 (2%) had TKA and THA prior to lumbar surgery. Patients with prior arthroplasty were predominantly female (59%) and significantly older (68±7 years vs 63±12 years, p<.001) with a significantly higher BMI (31±6 kg/m2 vs 29±6 kg/m2, p<.001). The LL was significantly lower (45.0°±13 vs 50.9°±14 p=.011) in the arthroplasty group compared to the nonarthroplasty group. A history of isolated TKA was significantly associated with lower LL (Est=-3.8, 95% CI -7.3 to -0.3, p=.031) and SS (Est=-2.6, 95% CI -5.0 to -0.2, p=.012) compared to patients without TJA. Prior combined THA and TKA was found to be significantly associated with a higher PT compared to the nonarthroplasty group (Est=5.1, 95% CI 0.4-9.8, p=.034).

CONCLUSIONS

The spinopelvic alignment differs between patients with and without prior TJA who undergo elective lumbar surgery. The study shows that a history of TKA is significantly associated with a lower LL and SS. The combination of THA and TKA was associated with a significantly higher PT. These findings highlight the complex relationship between the hip, spine, and knee. Moreover, the results could aid in enhancing preoperative planning of lumbar surgery in patients with known TJA.

Addressing Biomechanical Errors in the Back Squat for Older Adults: A Clinical Perspective for Maintaining Neutral Spine and Knee Alignment

Background/Objectives: Falls pose a significant health risk for older adults, often due to balance disorders and decreased mobility. Methods: The ability to perform sit-to-stand transfers, which involve squatting, is crucial for daily independence. Incorporating squats into exercise routines can enhance lower body strength, reduce fall risk, and improve overall quality of life. Results: While the back squat is beneficial, proper form is essential to avoid biomechanical errors, like lumbar hyperlordosis and knee valgus. Conclusions: Health and fitness professionals, such as physical therapists and/or clinical exercise physiologists, should carefully guide older adults in performing the back squat, addressing any functional deficits, and ensuring proper technique to minimize the risk of injury and maximize the benefits.

Effect of Shoulder Flexion Range of Motion and Trunk Muscle Activity on Lumbar Lordosis in the Streamlined Posture in Healthy Young Men

Objective This study aimed to compare the lumbar spine, pelvic alignment, and trunk muscle activity in healthy participants with and without shoulder flexion restriction in a streamlined posture. Methods The lumbar lordosis angle, pelvic anteversion angle, and trunk muscle activity were measured in 31 young, healthy men in the resting standing position. The streamlined (SL) posture and correlation analysis were performed. Multiple regression analysis was performed to analyze variables that affect the lumbar lordosis angle in the SL posture. Results Correlation analysis revealed that the lumbar lordosis angle in the SL posture had a significant negative correlation with the muscle activity of the internal oblique/transversus abdominis muscle (IO/TrA) during the SL posture (r=-0.37, p<0.045). Multiple regression analysis revealed that lumbar lordosis angle in the SL posture was associated with lumbar lordosis angle in the upright position (β=0.46), IO/TrA activity (β=-0.37), shoulder joint flexion range of motion (β=-0.37), and longissimus dorsi muscle activity during the SL posture (β=-0.28), with a Durbin-Watson statistic adjusted coefficient of determination R2 of 0.67 (p<0.001). Conclusion The lumbar lordosis angle in the SL posture was likely to be high when the range of motion of shoulder joint flexion was small, the activity of the longissimus dorsi muscle in the SL posture was high, and the activity of the IO/TrA was low. This suggests that limited shoulder flexion causes excessive lumbar lordosis, which may be a mechanism of low back pain in swimmers.

Association between lower limb alignment and low back pain: A systematic review with meta-analysis

Low back pain (LBP) is a prevalent and costly condition globally, prompting the need to identify risk factors for effective management. Lower extremity misalignment plays a crucial role in the incidence of LBP. Therefore, we aimed to investigate the current evidence on a link between lower limb alignment and LBP, enhancing the understanding of this relationship. We searched four databases, including PubMed, Embase, Web of Science, and Scopus, up to September 2024. Inclusion criteria encompassed studies related to LBP and lower limb alignment, with eligible study types including case-control, cohort, and cross-sectional studies, all written in English. Two authors independently screened and assessed the methodological quality of the retrieved papers using the Downs and Black quality assessment checklist. Data of interest including study design, age, sample size, cases, association, and P-value were extracted from the included studies. Mean differences and 95% confidence intervals (CI) were calculated with random effects model in RevMan version 5.4. Thirteen articles evaluating lower limb alignment in individuals with LBP were included (102,359 participants in total). The meta-analysis results demonstrated that increased pronation with strong evidence(p = 0.02), increased hip internal rotation with moderate evidence, and increased knee internal rotation with limited evidence are associated with an increased risk of LBP. Overall, while some studies supported a relationship between lower limb alignment and LBP, the heterogeneity of study designs and methodological limitations hindered drawing a definitive conclusion. Future research should emphasize prospective cohort studies, incorporating objective measures of lower extremity alignment and standardized outcome measures.

Immediate Effects of Two Different Methods of Trunk Elastic Taping on Pelvic Inclination, Trunk Impairment, Balance, and Gait in Stroke Patients

Background and Objectives: Stroke patients often experience changes in their pelvic tilt, trunk impairments and decreased gait and balance. While various therapeutic interventions have been attempted to improve these symptoms, there is a need for interventions that are easy to apply and reduce the physical labor of physical and occupational therapists. We aimed to investigate the immediate effects of two different methods of trunk elastic taping on the pelvic inclination, trunk impairment, balance, and gait in chronic stroke patients. Materials and Methods: We performed a single-blind randomized controlled trial involving 45 patients with chronic stroke. Participants were randomly assigned to one of three groups: forward rotation with posterior pelvic tilt taping (FRPPT, n = 14), backward rotation with posterior pelvic tilt taping (BRPPT, n = 14), or placebo taping (PT = 14). This study was conducted from December 2023 to January 2024. All the measurements were performed twice: before the intervention and immediately after the intervention. The pelvic inclination was assessed using the anterior pelvic tilt angle. The trunk impairment scale (TIS) was used to measure the trunk impairment. The balance and gait were evaluated using a force plate and walkway system. Results: The pelvic inclination was significantly different in the FRPPT and BRPPT groups compared to the PT group (p < 0.05, p < 0.001). The TIS and gait were significantly increased in the FRPPT group compared to the PT group (p < 0.05). The balance significantly improved in the FRPPT and BRPPT within groups (p < 0.05). Conclusions: Two different methods of posterior pelvic tilt taping improved the anterior pelvic tilt in chronic hemiplegic stroke patients compared with PT, and the FRPPT method also improved the trunk impairment and gait. Therefore, posterior pelvic tilt taping can be used as an intervention with immediate effect.

Unveiling the influence of hip isokinetic strength on lower extremity running kinematics in male national middle-distance runners: a correlational analysis

BACKGROUND

The relationship between hip strength deficiency in various planes and musculoskeletal injuries within the movement system has been well-established in numerous studies. The present study sought to explore the relationships between hip strength and specific aspects of lower extremity running kinematics.

METHODOLOGY

To achieve this objective, the three-dimensional running kinematics of 21 male elite middle-distance runners (mean age: 19.7 ± 1.2 years; mean experience 6.5 ± 1.0 years) were assessed using nine high-speed cameras on a treadmill at a speed of 16 km·h⁻¹. Concurrently, isokinetic hip strength was measured at a speed of 60 deg·s⁻¹ in both the dominant and non-dominant legs. The Pearson correlation coefficient and Paired Samples t-test were utilized.

RESULTS

While no significant differences were found in several isokinetic strength measurements, notable differences in running kinematics were observed. Specifically, pelvic drop at midstance (MS) was significantly lower in the DL (5.79 ± 3.00°) compared to the NDL (8.71 ± 1.39°) with a large effect size (t=-4.04, p < 0.001, Cohen's d = 1.25). Additionally, knee adduction at maximum showed a moderate effect size difference, with the DL at 2.99 ± 1.13° and the NDL at 3.81 ± 1.76° (t=-2.74, p = 0.03, Cohen's d = 0.55). Results indicated a moderate to highly positive association between running knee adduction in the dominant leg and hip external rotation (r = 0.67, p < 0.05), concentric extension (r = 0.77, p < 0.05), and concentric abduction (r = 0.78, p < 0.05). Additionally, the running tibial external rotation angle in the dominant leg exhibited an inverse relationship with all strength measurements, with statistical significance observed only for concentric extension force (r=-0.68, p < 0.05). Furthermore, hip internal rotation force demonstrated a highly inverse correlation with foot pronation in the dominant leg (r=-0.70, p < 0.05) and anterior pelvic tilt in the non-dominant leg (r=-0.76, p < 0.05).

CONCLUSIONS

These findings underscore the interrelation between hip strength and running kinematics, particularly on the dominant side. In light of these observations, it is imperative to consider hip strength exercises as integral components for correcting running kinematics. Coaches should also be mindful that kinematic deviations contributing to running injuries may manifest unilaterally or specifically in the dominant leg.

Functional analysis of postural spinal and pelvic parameters using static and dynamic spinometry

Background

Spinometry is a radiation-free method to three-dimensional spine imaging that provides additional information about the functional gait patterns related to the pelvis and lower extremities. This radiation-free technology uses the surface topography of the trunk to analyze surface asymmetry and identify bony landmarks, thereby aiding the assessment of spinal deformity and supporting long-term treatment regimes. Especially reliable dynamic spinometric data for spine and pelvis are necessary to evaluate the management of non-specific back pain.

Research aim

This study aims to generate reliable dynamic spinometric data for spine and pelvis parameters that can serve as reference data for future studies and clinical practice.

Methods

This study assessed 366 subjects (185 females) under static and 360 subjects (181 females) under dynamic (walking on a treadmill at 3 km/h and 5 km/h) conditions. The DIERS Formetric 4Dmotion® system uses stripes of light to detect the surface topography of the spine and pelvis and identifies specific landmarks to analyze the spine during standing and walking.

Results

Relevant gender effects were calculated for lordotic angle (ηp2 = 0.22) and pelvic inclination (ηp2 = 0.26). Under static conditions, female subjects showed larger values for both parameters (lordotic angle: 41.6 ± 8.60°; pelvic inclination: 25.5 ± 7.49°). Regarding speed effects, three relevant changes were observed (sagittal imbalance: ηp2 = 0.74, kyphotic angle: ηp2 = 0.13, apical deviation: ηp2 = 0.11). The most considerable changes were observed between static condition and 3 km/h, especially for sagittal imbalance and lordotic angle. For these parameters, relevant effect sizes (d > 0.8) were calculated between static and 3 km/h for males and females. Concerning clinical vertebral parameters, only lordotic angle and pelvic inclination were correlated with each other (r = 0.722).

Conclusion

This study generated a gender-specific reference database of asymptomatic individuals for static and dynamic spinometry. It demonstrated that the DIERS Formetric 4Dmotion® system could capture natural changes in static and dynamic situations and catalogue functional adaptations of spino-pelvic statics at different speeds. The lordotic angle is an indirect marker of pelvic inclination, allowing spinometry to identify individuals at risk even under dynamic conditions.

Correlation between the sacral tilt measured with an inclinometer and the pelvic tilt as a tool for assessing the pelvic position

[Purpose] The aim of this study was to examine whether the forward tilt of the sacrum, which can be measured using an inclinometer, correlates with pelvic tilt and is therefore suitable for therapeutic use as part of a postural assessment for treatment planning or for preventive screening. [Participants and Methods] In 121 athletes (22 females, 99 males), we measured the forward tilt of the sacrum in habitual stance using a digital inclinometer attached to the skin at the level of the posterior superior spinae. At the same time, the forward tilt of the pelvis was determined using videography. For this purpose, we determined the angle between two marker spheres placed on the posterior and anterior superior spinae and the horizontal using sagittal posture photographs. [Results] Taking age as a control variable, we found a significant correlation of moderate strength between pelvic tilt and sacral tilt in men. In women, there was a significant correlation with a strong effect. [Conclusion] The measurement of sacral tilt using an inclinometer positioned on the skin between the posterior superior spinae correlates statistically significantly with pelvic tilt and is therefore suitable as an easy-to-use diagnostic tool for therapeutic use in treatment planning and evaluation.

Muscular Strategies for Correcting the Pelvic Position to Improve Posture-An Exploratory Study

The correction of postural weaknesses through the better positioning of the pelvis is an important approach in sports therapy and physiotherapy. The pelvic position in the sagittal plane is largely dependent on the muscular balance of the ventral and dorsal muscle groups. The aim of this exploratory study was to examine whether healthy persons use similar muscular activation patterns to correct their pelvic position or whether there are different motor strategies. The following muscles were recorded in 41 persons using surface electromyography (EMG): M. trapezius pars ascendens, M. erector spinae pars lumbalis, M. gluteus maximus, M. biceps femoris, M. rectus abdominis, and M. obliquus externus. The participants performed 10 voluntary pelvic movements (retroversion of the pelvis). The anterior pelvic tilt was measured videographically via marker points on the anterior and posterior superior iliac spine. The EMG data were further processed and normalized to the maximum voluntary contraction. A linear regression analysis was conducted to assess the relationship between changes in the pelvic tilt and muscle activities. Subsequently, a Ward clustering analysis was applied to detect potential muscle activation patterns. The differences between the clusters and the pelvic tilt were examined using ANOVA. Cluster analysis revealed the presence of four clusters with different muscle activation patterns in which the abdominal muscles and dorsal muscle groups were differently involved. However, the gluteus maximus muscle was involved in every activation pattern. It also had the strongest correlation with the changes in pelvic tilt. Different individual muscle patterns are used by different persons to correct pelvic posture, with the gluteus maximus muscle apparently playing the most important role. This can be important for therapy, as different muscle strategies should be trained depending on the individually preferred motor patterns.

Concurrent Validity of the Ergotex Device for Measuring Low Back Posture

Highlighting the crucial role of monitoring and quantifying lumbopelvic rhythm for spinal curvature, the Ergotex IMU, a portable, lightweight, cost-effective, and energy-efficient technology, has been specifically designed for the pelvic and lumbar area. This study investigates the concurrent validity of the Ergotex device in measuring sagittal pelvic tilt angle. We utilized an observational, repeated measures design with healthy adult males (mean age: 39.3 ± 7.6 y, body mass: 82.2 ± 13.0 kg, body height: 179 ± 8 cm), comparing Ergotex with a 3D optical tracking system. Participants performed pelvic tilt movements in anterior, neutral, and posterior conditions. Statistical analysis included paired samples t-tests, Bland-Altman plots, and regression analysis. The findings show minimal systematic error (0.08° overall) and high agreement between the Ergotex and optical tracking, with most data points falling within limits of agreement of Bland-Altman plots (around ±2°). Significant differences were observed only in the anterior condition (0.35°, p < 0.05), with trivial effect sizes (ES = 0.08), indicating that these differences may not be clinically meaningful. The high Pearson's correlation coefficients across conditions underscore a robust linear relationship between devices (r > 0.9 for all conditions). Regression analysis showed a standard error of estimate (SEE) of 1.1° with small effect (standardized SEE < 0.26 for all conditions), meaning that the expected average deviation from the true value is around 1°. These findings validate the Ergotex as an effective, portable, and cost-efficient tool for assessing sagittal pelvic tilt, with practical implications in clinical and sports settings where traditional methods might be impractical or costly.

The relationship between low back pain, pelvic tilt, and lumbar lordosis with urinary incontinence using the DIERS formetric 4D motion imaging system

INTRODUCTION AND HYPOTHESIS

Urinary incontinence (UI) is a common public health problem and postural changes may be crucial in women presenting with UI. This study was aimed at evaluating the relationship between low back pain (LBP), pelvic tilt (PT), and lumbar lordosis (LL) in women with and without UI using the DIERS formetric 4D motion imaging system. To date no study has to our knowledge compared postural changes and LBP in women with UI using the DIERS 4D formetric system.

METHODS

This was a case-control study. We included 33 women with UI and 33 without incontinence. The severity of urogenital symptoms was assessed by the IIQ-7 (Incontinence Impact Score) and UDI-6 (Urogenital Distress Inventory), and disability owing to LBP was evaluated using the Oswestry Disability Index (ODI). Posture and movement assessment, LL angle, thoracic kyphosis, and PT assessment were performed with the DIERS Formetric 4D motion imaging system.

RESULTS

The LL angle and pelvic torsion degree were higher in the incontinence group than in the control group (53.9 ± 9.5° vs 48.18 ± 8.3°; p = 0.012, 3.9 ± 4.1 vs 2.03 ± 1.8 mm; p = 0.018 respectively). The LBP visual analog scale value was also significantly higher in the incontinence group (5.09 ± 2.3 vs 1.7 ± 1.8 respectively, p < 0.0001). The LL angle showed a positive correlation with pelvic obliquity, (r = 0.321, p < 0.01) and fleche lombaire (r = 0.472, p < 0.01) and a negative correlation with lumbar range of motion measurements. Pelvic obliquity correlated positively with pelvic torsion (r = 0.649, p < 0.01), LBP (r = 0.369, p < 0.01), and fleche lombaire (r = 0.269, p < 0.01).

CONCLUSIONS

Women with UI were more likely to have lumbopelvic sagittal alignment changes and a higher visual analog scale for LBP. These findings show the need for assessment of lumbopelvic posture in women with UI.

Posterior chain and core training improves pelvic posture, hamstrings-to-quadriceps ratio, and vertical jump performance

BACKGROUND

Poor pelvic posture demonstrated through anterior pelvic tilt (APT) have been known to produce musculoskeletal imbalances involving weakness of the abdominal and pelvic musculature. While stretching and massage techniques have been reported to be effective in alleviating APT, it remains unclear if similar improvements can be elicited by posterior chain and core strength training. Therefore, the aim of this study was to examine the effect of an 8-week posterior and core strengthening program on APT, hamstrings-to-quadriceps (H:Q) strength ratio, and vertical jump performance in healthy individuals.

METHODS

Ten healthy males (age = 26±12 years; mass = 87±14 kg; height = 1.8±0.1 m) and nine healthy females (age = 22±4 years; mass = 70±14 kg; heigh t = 1.7±0.1 m) performed resistance training (2×/week; 40-45 mins) involving a combination of hip extensors and abdominal strengthening exercises for 8 weeks. APT (°), vertical jump power (W), vertical jump height (m), and H:Q ratio at 60, 180, and 300°/s were assessed prior to and following the resistance training program.

RESULTS

APT, vertical jump power, vertical jump height, and H:Q ratio at 60 and 180°/s, were significantly improved following 8 weeks of resistance training (all Ps<0.05).

CONCLUSIONS

Our main finding was that 8 weeks of resistance training emphasizing posterior chain and core strengthening was effective in reducing APT, improving vertical jump performance and H:Q ratio in healthy individuals. Our findings have potential implications for clinicians prescribing resistance training exercises to improve pelvic posture in healthy asymptomatic individuals at risk of developing chronic low back pain and lumbar-spinal pathologies due to excessive anterior pelvic tilt.

The Influence of Multiple Pregnancies on Gait Asymmetry: A Case Study

Gait asymmetry is a predictor of fall risk and may contribute to increased falls during pregnancy. Previous work indicates that pregnant women experience asymmetric joint laxity and pelvic tilt during standing and asymmetric joint moments and angles during walking. How these changes translate to other measures of gait asymmetry remains unclear. Thus, the purpose of this case study was to determine the relationships between pregnancy progression, subsequent pregnancies, and gait asymmetry. Walking data were collected from an individual during 2 consecutive pregnancies during the second and third trimesters and 6 months postpartum of her first pregnancy and the first, second, and third trimesters and 6 months postpartum of her second pregnancy. Existing asymmetries in step length, anterior-posterior (AP) impulses, AP peak ground reaction forces, lateral impulses, and joint work systematically increased as her pregnancy progressed. These changes in asymmetry may be attributed to pelvic asymmetry, leading to asymmetric hip flexor and extensor length, or due to asymmetric plantar flexor strength, as suggested by her ankle work asymmetry. Relative to her first pregnancy, she had greater asymmetry in step length, step width, braking AP impulse, propulsive AP impulse, and peak braking AP ground reaction force during her second pregnancy, which may have resulted from increased joint laxity.

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

INTRODUCTION

The 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 METHODS

Thirty 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.

RESULTS

Sixteen 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).

CONCLUSION

Valgus 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.

Predicting female pelvic tilt and lumbar angle using machine learning in case of urinary incontinence and sexual dysfunction

Urinary incontinence (UI) is defined as any uncontrolled urine leakage. Pelvic floor muscles (PFM) appear to be a crucial aspect of trunk and lumbo-pelvic stability, and UI is one indication of pelvic floor dysfunction. The evaluation of pelvic tilt and lumbar angle is critical in assessing the alignment and posture of the spine in the lower back region and pelvis, and both of these variables are directly related to female dysfunction in the pelvic floor. UI affects a significant number of women worldwide and can have a major impact on their quality of life. However, traditional methods of assessing these parameters involve manual measurements, which are time-consuming and prone to variability. The rehabilitation programs for pelvic floor dysfunction (FSD) in physical therapy often focus on pelvic floor muscles (PFMs), while other core muscles are overlooked. Therefore, this study aimed to predict the activity of various core muscles in multiparous women with FSD using multiple scales instead of relying on Ultrasound imaging. Decision tree, SVM, random forest, and AdaBoost models were applied to predict pelvic tilt and lumbar angle using the train set. Performance was evaluated on the test set using MSE, RMSE, MAE, and R2. Pelvic tilt prediction achieved R2 values > 0.9, with AdaBoost (R2 = 0.944) performing best. Lumbar angle prediction performed slightly lower with decision tree achieving the highest R2 of 0.976. Developing a machine learning model to predict pelvic tilt and lumbar angle has the potential to revolutionize the assessment and management of this condition, providing faster, more accurate, and more objective assessments than traditional methods.

Overhead squat assessment reflects treadmill running kinematics

PURPOSE

Overhead squat assessment (OHSA) is a pre-activity dynamic movement analysis tool used to define deviations from an ideal motion pattern which known as compensation. Compensatory movements may result from abnormality in myofascial activity, length-tension relationships, neuro-motor control strategies, osteokinematics and arthrokinematics. The aim of this study is to identify the association between selected biomechanical variables of the ankle, knee, hip, pelvis, torso during OHSA and 16 km/h treadmill running tasks.

METHODS

Thirteen national long distance male runners (17.3 ± 0.5 age (years); 5.89 ± 1.95 experience (years), 57.9 ± 3.7 body mass (kg); 175.4 ± 5.7 height (cm)) participated in this 2controlled laboratory study. Three-dimensional kinematics were collected at 250 Hz using a 9-camera Qualisys motion analysis system (Qualisys AB, Goteborg, Sweden) while participants performed 16 km/h treadmill running and OHSA tasks.

RESULTS

Correlation coefficients demonstrated that OHSA pelvic anterior tilt angle was in a positive association with foot strike (FS), mid-stance (MS), and toe-off (TO) pelvic anterior tilt angles and MS tibial internal rotation on talus, MS ankle pronation, MS hip internal rotation. OHSA pelvic anterior tilt angle was in a negative association with TO hip extension. OHSA maximal hip adduction was positively correlated with MS and stance maximal knee adduction. FS, MS, stance maximal angular dorsiflexion values were positively correlated with OHSA dorsiflexion. Increased OHSA dorsiflexion angle was negatively associated with TO plantar flexion. OHSA pronation was positively associated with MS and stance pronation. MS hip internal rotation, MS hip adduction angles were increased, and MS ankle dorsiflexion was significantly decreased with the increase of trunk forward lean relative to tibia during OHSA.

CONCLUSIONS

OHSA was associated with some important and dysfunction-related hip, knee and ankle kinematics. Running coaches, may use OHSA as an assessment tool before the corrective training plan to detect injury-related compensation patterns to reduce the risk of injury and improve running technique.

Tilt and mobility of the hip girdle in the sagittal and frontal planes in healthy subjects aged 19-30 years

BACKGROUND

Disturbances in pelvic girdle tilt can cause compensatory changes affecting postural dysfunctions, and can lead to hip and groin strain changes and back pain. However, we still have no clear information on the normative values of pelvic girdle tilt and mobility.

OBJECTIVE

The study aimed to (1) evaluate the position and mobility of the pelvic girdle in the sagittal and frontal planes in asymptomatic adults aged 19-30, (2) evaluate the possible variation of results according to gender and to develop a proposal for normative values, and (3) evaluate whether body mass, height and BMI are related to the magnitude of hip girdle position and mobility.

METHODS

The research was conducted in a sample group consisting of 346 men and women using the scaled form of the anthropometric level of the Duometr® The values of position and mobility of the pelvic girdle in the sagittal and frontal planes were analyzed.

RESULTS

Differences were noted in the values of the pelvic tilt (p= 0.033) between the men and women. The women showed slightly higher values of posterior range of motion (p= 0.0002) and total range of motion (p= 0.002). The other parameters did not show any significant variation. There was no clear association between body weight, height and BMI and the study variables, except for a small, significant correlation between BMI and posterior pelvic tilt in women (r= 0.175, p= 0.005). In the frontal plane there were no differences in the analyzed variables in terms of gender or side of the body measured.

CONCLUSIONS

There was no association between the anthropometric variables and the pelvic girdle tilt and mobility. No size variation by gender was observed in the frontal plane. Slight differences were observed in the sagittal plane. Normative values are proposed.

Differences in lumbar paraspinal muscle morphology in patients with sagittal malalignment undergoing posterior lumbar fusion surgery

PURPOSE

To investigate whether (1) there is a difference between patients with normal or sagittal spinal and spinopelvic malalignment in terms of their paraspinal muscle composition and (2) if sagittal malalignment can be predicted using muscle parameters.

METHODS

A retrospective review of patients undergoing posterior lumbar fusion surgery was conducted. A MRI-based muscle measurement technique was used to assess the cross-sectional area, the functional cross-sectional area, the intramuscular fat and fat infiltration (FI) for the psoas and the posterior paraspinal muscles (PPM). Intervertebral disc degeneration was graded for levels L1 to S1. Sagittal vertical axis (SVA; ≥ 50 mm defined as spinal malalignment), pelvic incidence (PI) and lumbar lordosis (LL) were measured, and PI-LL mismatch (PI-LL; ≥ 10° defined as spinopelvic malalignment) was calculated. A receiver operating characteristic (ROC) analysis was conducted to determine the specificity and sensitivity of the FIPPM for predicting sagittal malalignment.

RESULTS

One hundred and fifty patients were analysed. The PI-LL and SVA malalignment groups were found to have a significantly higher FIPPM (PI-LL:47.0 vs. 42.1%; p = 0.019; SVA: 47.7 vs. 41.8%; p = 0.040). ROC analysis predicted sagittal spinal malalignment using FIPPM (cut-off value 42.69%) with a sensitivity of 73.4% and a specificity of 54.1% with an area under the curve of 0.662.

CONCLUSION

Significant differences in the muscle composition between normal and malalignment groups with respect to FIPPM in both sagittal spinal and spinopelvic alignment were found. This work underlines the imminent impact of the paraspinal musculature on the sagittal alignment.

Exercise in patients with acetabular retroversion and excessive anterior pelvic tilt: A feasibility and intervention study

BACKGROUND

Acetabular retroversion is associated with femoroacetabular impingement syndrome (FAIS). Anterior pelvic tilt enhances risk of FAIS.

OBJECTIVES

To investigate feasibility and change in patient-reported symptoms of a home-based exercise intervention in patients with acetabular retroversion and excessive anterior pelvic tilt, in comparison with a prior control period.

DESIGN

Prospective intervention study.

METHODS

Patients (18-40 years) not eligible for surgery, with radiographic signs of acetabular retroversion and excessive anterior pelvic tilt were recruited. An 8-week control period was followed by an 8-week training period. The home-based intervention consisted of education and exercises for core stability, muscle strengthening and stretching for reducing anterior pelvic tilt. Feasibility assessments were dropout (≤10%), adherence (≥75% of sessions), exercise-related pain, and adverse events. Primary outcome was change in the Copenhagen Hip and Groin Outcome Score (HAGOS) pain-subscale. Pelvic tilt was measured by EOS scanning.

RESULTS

Forty-two patients (93% female, mean age 22.2 ± 4.2 years) were included. Dropout rate was 7% and satisfactory adherence was demonstrated by 85%. Exercise-related pain and adverse events were acceptable. Between-period mean change score for HAGOS-PAIN was 5.2 points (95% CI: -0.3-10.6) and -1.6° (95% CI: -3.9-0.7) of anterior pelvic tilt. Patients responding positively (≥10 points) (n = 10, 26%), had pre-exercise moderate pain (HAGOS-PAIN 47.5-70 points).

CONCLUSIONS

Current exercise intervention was feasible. However, we found no clinically relevant changes in self-reported hip-related pain or anterior pelvic tilt. Post hoc responder analysis revealed that patients with moderate pain at baseline might benefit from this exercise.

Foot Deformity in Patients With Ankylosing Spondylitis: Is It Associated With Functionality and Disease Activity?

Foot involvement affects mobility and functionality in patients with ankylosing spondylitis but it remains unknown if foot deformities in ankylosing spondylitis patients affect functionality, disease activity, and quality of life. The aim of this study was to evaluate in detail the presence of a relationship between radiologically detected foot deformities in ankylosing spondylitis patients and both clinical and electrophysiological findings. The cross-sectional study included 110 patients with ankylosing spondylitis who were diagnosed according to the Assessment in Spondyloarthritis International Society criteria and were followed in our hospital. Demographic and clinical data of all patients were recorded. Bilateral lateral foot x-rays and electrophysiology examinations were evaluated in all subjects. The arch in the dominant foot of the patients was classified in 3 groups as pes cavus, pes planus, or normal. The clinical outcomes, physical examination and electrophysiological findings were compared between the groups, and correlations were examined of the foot deformities with these parameters. Foot deformities were determined at a high rate (74.5%). These deformities affected foot pain, disability and quality of life. Pes cavus deformity was found to be associated with hip pain and enthesopathy. In the electrophysiological studies, the presence of pes planus was found to be associated with the findings of the tibial and sural nerve conduction studies, and the presence of pes cavus with the findings of the peroneal nerve conduction study. In conclusion, foot deformities may have an effect on the quality of life and functionality in ankylosing spondylitis patients.

Effects of Pelvic Stabilization Training with Lateral and Posterior Tilt Taping on Pelvic Inclination, Muscle Strength, and Gait Function in Patients with Stroke: A Randomized Controlled Study

Background

This study was aimed at investigating the effect of pelvic tilt taping on muscle strength, pelvic inclination, and gait function in patients with stroke.

Methods

A total of 60 patients with stroke were included in our study and randomly divided into three groups: the posterior pelvic tilt taping (PPTT, n = 20), the lateral pelvic tilt taping (LPPP) with PPTT (LPPP+PPTT, n = 20), and the control (n = 20) groups. All participants performed pelvic stabilization exercises consisting of 6 movements: supine, side lying, quadruped, sitting, squatting, and standing (30 min/day, five days/week, for six weeks). PPTT to correct anterior pelvic tilt was applied to the LPTT+PPTT and PPTT groups, and lateral pelvic tilt taping was additionally applied to the LPTT+PPTT group. LPTT was performed to correct the pelvis tilted to the affected side, and PPTT was performed to correct the anterior pelvic tilt. The control group did not undergo taping. A hand-held dynamometer was used to measure the hip abductor muscle strength. In addition, a palpation meter and 10-meter walk test were used to assess pelvic inclination and gait function.

Results

Muscle strength was significantly stronger in the LPTT+PPTT group than in the other two groups (p = 0.01). The anterior pelvic tilt was significantly improved in the taping group compared to the control group (p < 0.001), and the lateral pelvic tilt was significantly improved in the LPTT+PPTT group compared to the other two groups (p < 0.001). Significantly greater improvements in gait speed were observed in the LPTT+PPTT group than in the other two groups (p = 0.02).

Conclusions

PPPT can significantly affect pelvic alignment and walking speed in patients with stroke, and the additional application of LPTT can further strengthen these effects. Therefore, we suggest using taping as an auxiliary therapeutic-intervention method in postural control training.

Lower-Limb Kinematic Change during Pelvis Anterior and Posterior Tilt in Double-Limb Support in Healthy Subjects with Knee Malalignment

This study aimed to investigate lower-limb kinematic changes during pelvic tilting in participants with knee malalignment. To define participants with lower-limb malalignment, the quadriceps angle (Q-angle) was used in this study. The sample population was divided into two groups in accordance with the Q-angle: the experimental group (ABQ) consisted of participants with an abnormal Q-angle greater than the normal range, and the control group (CON) consisted of participants with a normal Q-angle. All participants performed anterior and posterior pelvic tilts in double-limb support. Kinematic change in the lower limb was evaluated using a three-dimensional motion analysis system (Motion Analysis, Santa Rosa, CA, USA). The horizontal plane hip angle in the ABQ was significantly different compared with that in the CON in all positions (p < 0.05), and no significant difference was observed in the other lower-limb kinematic variables (p > 0.05). A significant correlation was identified only between the Q-angle and horizontal plane hip angle in all positions. Based on the results, the Q-angle was strongly related to the thigh, although it may not be related to malalignment with other segments during double-limb support.

How Does the Lumbopelvic Complex Cope with the Obstetrical Load during Standing? Ergonomic Aspects of Body Posture in Pregnant Women

Pregnancy induces numerous modifications in the musculoskeletal system of the female body. Since one of the essential roles of the lumbopelvic structure is to support mechanical loads in the upright position, this study was designed to simulate the response of this complex to the growing foetus in pregnant women. The authors hypothesized that posture (i.e., lordosis and muscle involvement) under pregnancy conditions might be adjusted to minimize the demands of the obstetrical load. The analysis of the load on the musculoskeletal system during gestation was made based on numerical simulations carried out in the AnyBody Modeling System. The pregnancy-related adjustments such as increased pelvic anteversion and increased lumbar lordosis enhance the reduction of muscle activation (e.g., erector spinae, transversus abdominis or iliopsoas), muscle fatigue and spinal load (reaction force). The results may help develop antenatal exercise programs targeting core strength and pelvic stability.

Lumbopelvic postural differences in adolescent idiopathic scoliosis: A pilot study

BACKGROUND

A primary etiology of adolescent idiopathic scoliosis (AIS) is currently unknown, but poor postural control of the spinal extensor musculature has been identified as an AIS risk factor. Identifiable postural differences would aid in advancing the precise postural behaviors that should be modified during Physiotherapy Scoliosis Specific Exercise (PSSE) to help limit the progression of AIS.

RESEARCH QUESTION

Are there any determinable differences in lumbopelvic posture or range of motion between subjects with AIS and controls?

METHODS

This prospective cohort pilot study consisted of 53 subjects (27 AIS and 26 control) aged 11-17 years. Subjects had their lumbopelvic posture assessed and monitored using the ViMove DorsaVi sensor package. All subjects underwent a live assessment to obtain initial lumbopelvic (LP) range of motion (ROM) measurements. Subjects were then monitored while continuing with normal activities of daily living (ADLs) for 12 h. With an alpha level of 0.05, nonparametric analyses were performed for each variable via a Mann-Whitney U-test.

RESULTS

During the live assessment, controls exhibited a significantly greater anterior pelvic tilt ROM in the sitting position than the AIS group (p = 0.0433). When compared to female controls, females with AIS had a sitting pelvic tilt ROM that was significantly more retroverted (p = 0.0232) and less anteverted (p = 0.0010). During ADLs, female controls exhibited a higher total number of extension events than their female with AIS (p = 0.0263). These associations did not strengthen with greater spinal deformity.

SIGNIFICANCE

This work demonstrates postural differences between patients with AIS and controls. Further study is necessary to determine why patients with AIS adopt these postures, and if PSSEs can be utilized to limit the progression of AIS.

The Association between Symmetrical or Asymmetrical High-Arched Feet and Muscle Fatigue in Young Women

The foot arches are responsible for proper foot loading, optimal force distribution, and transmission throughout the soft tissues. Since the foot arch is an elastic structure, able to adapt to forces transmitted by the foot, it was reported that low arch is related to excessive foot pronation, while high arched foot is more rigid and inflexible. Therefore, it is also probable, that foot arch alterations may change the force transmission via myofascial chains. The objective of this study was to evaluate the effect of symmetrical and asymmetrical excessive feet arching on muscle fatigue in the distal body parts such as the lower limbs, trunk, and head. Seventy-seven women (25.15 ± 5.97 years old, 62 ± 10 kg, 167 ± 4 cm) were assigned to three groups according to the foot arch index (Group 1—both feet with normal arch, Group 2—one foot with normal arch and the other high-arched, Group 3—both feet with high-arch). The bioelectrical activity of the right and left hamstrings muscles, erector spine, masseter, and temporalis muscle was recorded by sEMG during the isometric contraction lasting for 60 s. The stable intensity of the muscle isometric contraction was kept for all the time during the measurement. Mean frequency difference (%), slope (Hz), and intercept (Hz) values were calculated for muscle fatigue evaluation. No differences were observed in fatigue variables for all evaluated muscles between the right and left side in women with symmetrical foot arches, but in the group with asymmetric foot arches, the higher muscle fatigue on the normal-arched side compared to the high-arched side was noted. Significantly greater values of the semitendinosus—semimembranosus muscle frequency difference was observed on the normal-arched side compared to the high-arched side (p = 0.04; ES = 0.52; −29.5 ± 9.1% vs. −24.9 ± 8.4%). In the group with asymmetric foot arches, a significantly higher value of lumbar erector spinae muscle frequency slope (p = 0.01; ES = 1.32; −0.20 ± 0.04 Hz vs. −0.14 ± 0.05 Hz) and frequency difference (p = 0.04; ES = 0.92; −7.8 ± 3.1% vs. −4.8 ± 3.4%) were observed on the high-arched foot side compared to the side with normal foot arching. The thoracic erector spine muscle frequency slope was significantly larger in women with asymmetrical arches than in those with both feet high-arched (right side: p = 0.01; ES = 1.25; −0.20 ± 0.08 Hz vs. −0.10 ± 0.08 Hz); (left side: p = 0.005; ES = 1,17; −0.19 ± 0.04 Hz vs. −0.13 ± 0.06 Hz) and compared to those with normal feet arches (right side: p = 0.02; ES = 0.58; −0.20 ± 0.08 Hz vs. −0.15 ± 0.09 Hz); (left side: p = 0.005; ES = 0.87; −0.19 ± 0.04 Hz vs. −0.14 ± 0.07 Hz). In the group with asymmetric foot arches, the frequency difference was significantly higher compared to those with both feet high-arched (right side: p = 0.01; ES = 0.87; −15.4 ± 6.8% vs. 10.4 ± 4.3%); (left side: p = 0.01; ES = 0.96; 16.1 ± 6.5% vs. 11.1 ± 3.4%). In the group with asymmetric foot arches, a significantly higher value of the masseter muscle frequency difference was observed on the high-arched side compared to the normal-arched side (p = 0.01; ES = 0.95; 6.91 ± 4.1% vs. 3.62 ± 2.8%). A little increase in the longitudinal arch of the foot, even though such is often not considered as pathological, may cause visible changes in muscle function, demonstrated as elevated signs of muscles fatigue. This study suggests that the consequences of foot high-arching may be present in distal body parts. Any alterations of the foot arch should be considered as a potential foot defect, and due to preventing muscle overloading, some corrective exercises or/and corrective insoles for shoes should be used. It can potentially reduce both foot overload and distant structures overload, which may diminish musculoskeletal system pain and dysfunctions.

Postural Variabilities Associated with the Most Comfortable Sitting Postures: A Preliminary Study

This study examined postural variabilities based on the self-perceived most comfortable postures of 12 participants (six men and six women) when sitting on three commonly used types of chairs (a stool, computer chair, and gaming chair). Participants’ global joint angles were recorded and analyzed. Of the chairs studied, the stool was not adjustable, but the computer and gaming chairs were moderately and highly adjustable, respectively. During the test, participants were encouraged to adjust the chairs until they perceived that the most comfortable posture had been reached. The results demonstrated that in a sitting position perceived to be comfortable, the participants’ postural variabilities with respect to global joint angle, calculated from five repetitions, were unexpectedly high for all three chair types, at approximately 9.4, 10.2, and 11.1° for head inclination, trunk angle, and knee angle, respectively. The average differences in range for each joint angle among the three chair types were relatively low, with all values within 3°. The result also showed that gender (p < 0.01) and chair type (p < 0.001) significantly affected trunk angle, whereas these variables did not affect head inclination or knee angle (p > 0.05). The preliminary results observed unexpectedly high variabilities in sitting posture when the participants sat at a posture that they perceived to be the most comfortable. The findings also indicated an inherent difference in comfortable sitting posture between genders; women tend to extend their trunk backward more than men. For permanent use with only an initial adjustment and memory-aided seat design, designers should minimize the loads that are borne by body parts over a prolonged period due to an unchanging sitting posture.

Determining the interactions between postural variability structure and discomfort development using nonlinear analysis techniques during prolonged standing work

PURPOSE

Nonlinear analysis techniques provide a powerful approach to explore dynamics of posture-related time-varying signals. The aim of this study was to investigate the fundamental interactions between postural variability structure and discomfort development during prolonged standing.

METHODS

Twenty participants, with equal distribution for gender and standing work experience (SWE), completed a simulated long-term standing test. Low back and legs discomfort, center of pressure, lumbar curvature, and EMG activity of trunk and leg muscles were monitored. Nonlinear measures including largest lyapunov exponent, multi-scale entropy, and detrended fluctuation analysis were applied to characterize the variability structure (i.e., complexity) in each signal. The size (i.e., amount) of variability was also computed using traditional linear metrics.

RESULTS

With progress of low back and legs discomfort over standing periods, significant lower levels were perceived by the participants having SWE. The amount of variability in all signals (except external oblique EMG activity) were significantly increased with the time progress for all participants. The structure of variability in most signals demonstrated a lower complexity (more regularity) with fractal properties that deviated from 1/f noise. The SWE group showed a higher complexity levels.

CONCLUSIONS

Overall, the findings verified variations in structure and amount of the postural variability. However, nonlinear analysis identified postural strategies according to the perceived discomfort in a different way. These results provide supports for future application of nonlinear tools in evaluating standing tasks and related ergonomics interventions as it allows further insight into how discomfort development impact the structure of postural changes.

Clinical Measures of Pelvic Tilt in Physical Therapy

Pelvic tilt refers to the spatial position or motion of the pelvis about a frontal horizontal axis on the rest of the body in the sagittal plane. It is relevant for several musculoskeletal conditions commonly seen in physical therapist practice, particularly conditions affecting the hip and groin. Despite the relevance of pelvic tilt identified in biomechanical studies, and the historical precedence for assessing pelvic tilt, there is a lack of clarity regarding the utility of clinical measures that are practical in a rehabilitation setting. There are several options available to assess pelvic tilt which are discussed in detail in this commentary. All of these options come with potential benefits and considerable limitations. The purpose of this commentary is to provide an overview of the relevance of understanding pelvic tilt in the pathology and rehabilitation of conditions affecting the hip joint, with a focus applying evidence towards identifying clinical measures that may be useful in the rehabilitation setting and considerations that are needed with these measures.

LEVEL OF EVIDENCE

5.

The association of reactive balance control and spinal curvature under lumbar muscle fatigue

Background

Although low back fatigue is an important intervening factor for physical functioning among sedentary people, little is known about its possible significance in relation to the spinal posture and compensatory postural responses to unpredictable stimuli. This study investigates the effect of lumbar muscle fatigue on spinal curvature and reactive balance control in response to externally induced perturbations.

Methods

A group of 38 young sedentary individuals underwent a perturbation-based balance test by applying a 2 kg load release. Sagittal spinal curvature and pelvic tilt was measured in both a normal and Matthiass standing posture both with and without a hand-held 2 kg load, and before and after the Sørensen fatigue test.

Results

Both the peak anterior and peak posterior center of pressure (CoP) displacements and the corresponding time to peak anterior and peak posterior CoP displacements significantly increased after the Sørensen fatigue test (all at p < 0.001). A lumbar muscle fatigue led to a decrease of the lumbar lordosis in the Matthiass posture while holding a 2 kg load in front of the body when compared to pre-fatigue conditions both without a load (p = 0.011, d = 0.35) and with a 2 kg load (p = 0.000, d = 0.51). Also the sacral inclination in the Matthiass posture with a 2 kg additional load significantly decreased under fatigue when compared to all postures in pre-fatigue conditions (p = 0.01, d = 0.48). Contrary to pre-fatigue conditions, variables of the perturbation-based balance test were closely associated with those of lumbar curvature while standing in the Matthiass posture with a 2 kg additional load after the Sørensen fatigue test (r values in range from −0.520 to −0.631, all at p < 0.05).

Conclusion

These findings indicate that lumbar muscle fatigue causes changes in the lumbar spinal curvature and this is functionally relevant in explaining the impaired ability to maintain balance after externally induced perturbations. This emphasizes the importance for assessing both spinal posture and reactive balance control under fatigue in order to reveal their interrelations in young sedentary adults and predict any significant deterioration in later years.

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.

Changes in Low Back Muscle Activity and Spine Kinematics in Response to Smartphone Use During Walking

STUDY DESIGN

Within-subject design of an experimental study.

OBJECTIVE

The aim of this study was to determine the effects of smartphone use on the activity level of the lumbar erector spinae muscles and spine kinematics during walking.

SUMMARY OF BACKGROUND DATA

Using a smartphone while walking makes the user hold the phone steady and look downward to interact with the phone. Walking with this non-natural posture of the head and the arms may alter the spine kinematics and increase the muscular load on the low back extensor muscles.

METHODS

Twenty healthy young individuals participated in the laboratory experiment. Each participant walked on a treadmill in five different conditions: normal walking without using a phone, conducting one-handed browsing while walking, two-handed texting while walking, walking with one arm bound, and walking with both arms bound. Spine kinematics variables and the myoelectric activity levels of the lumbar erector spinae muscles were quantified and compared between the five walking conditions.

RESULTS

Participants walked with significantly (P < 0.05) more thoracic kyphosis and lumbar lordosis when using a phone compared to when walking without using the phone. The median level of muscle activity was also 16.5% (browsing) to 31.8% (texting) greater for the two smartphone use conditions than for the normal walking condition, and the differences were significant (P < .05). Between the normal walking and the two bound arm walking conditions, no significant difference in the muscle activity was found.

CONCLUSION

Study results show that the concurrent use of a smartphone while walking could pose a larger muscular load to the lumbar erector spinae muscles than that of normal walking. Habitual use of a smartphone while walking could be a risk factor for low back musculoskeletal problems.Level of Evidence: N/A.

Effects of the posterior pelvic tilt sitting posture on thoracic morphology and respiratory function

[Purpose] We investigated how differences in pelvic angle in the posterior pelvic tilt sitting posture simultaneously affect the thoracic morphology and the respiratory function. [Participants and Methods] The participants were 18 healthy young males. We positioned the pelvis at 0°, 10°, 20°, and 30° of posterior tilt, following which the thoracic expansion volume ratio, thoracic spine tilt angle, and respiratory function were measured. We calculated the thoracic volume and thoracic spine tilt angle by measuring the amount of displacement of reflective markers attached to the thoracic area using the Vicon MX 3D-analysis system. Respiratory function was measured by spirometry. [Results] The expansion volume ratio decreased significantly in response to 10-30° posterior pelvic tilt sitting at the mid-thorax and 30° posterior pelvic tilt sitting at the lowest thorax. The upper thoracic spine level showed a change in anterior tilt at 10-30° posterior pelvic tilt sitting, whereas the lower thoracic spine level showed a change in posterior tilt at 30° posterior pelvic tilt sitting. Respiratory function was significantly lower at 30° posterior pelvic tilt sitting than at 0° posterior pelvic tilt sitting. A positive correlation between thoracic expansion volume ratio and respiratory function was found at 30° posterior pelvic tilt sitting. [Conclusion] Changes in thoracic spine tilt angle due to posterior pelvic tilt sitting may restrict the expansion of thoracic motion during respiration, thereby affecting respiratory function.

Notions of "optimal" posture are loaded with meaning. Perceptions of sitting posture among asymptomatic members of the community

BACKGROUND

Notions of "optimal" posture are widespread in modern society and strongly interconnected with preconceived beliefs.

OBJECTIVES

To quantitatively evaluate spinal posture among members of the community during habitual sitting, and when asked to assume an "optimal" posture.

DESIGN

Observational study.

METHODS

Marker-based kinematic analyses of the head, spine, and pelvis were conducted on 100 individuals. Habitual sitting posture and self-perceived "optimal" posture, and whether participants believed that their habitual sitting reflected an "optimal" posture, were evaluated. The Wilcoxon signed-rank test assessed angular differences between the two postures adopted. Exploratory post-hoc analyses were conducted by using the Mann-Whitney U test to assess differences between genders.

RESULTS

None of the participants stated that their habitual sitting was "optimal". Statistically significant differences were observed in most of the measured angles (p < 0.001) between habitual and self-perceived "optimal" posture. In habitual sitting posture, a significant interaction with gender was found only in the thoracolumbar (p < 0.05) and pelvic (p < 0.001) angles, with small effect sizes. In self-perceived "optimal" posture females were more extended in the head, upper thoracic, lower thoracic, lumbar and pelvic (p < 0.01) regions, than the males.

CONCLUSIONS

A group of young, asymptomatic participants, consistently changed their habitual sitting posture to a more upright posture when asked to assume an "optimal" sitting posture, although the amount of change observed varied between spinal regions. These findings also highlight gender differences in not just habitual sitting posture, but also the degree to which habitual sitting posture is modified when trying to assume an "optimal" sitting posture.

Bestimmung einer Beckenasymmetrie – Sinn oder Unsinn

Pathologien des tiefen Rückens, der Becken- sowie Knie- und Hüftgelenke werden immer wieder mit einer Messung der Beinlänge und Feststellung einer Beckenasymmetrie in Verbindung gebracht. Aufgrund dieser Messungen werden therapeutische Wege eingeschlagen. Zu diesem Thema wurden auf der Basis einer systematischen Literatursuche in zwei maßgeblichen Datenbanken 28 Artikel ermittelt. Die inhaltliche Analyse beschäftigt sich v. a. mit der Variationsanatomie des Beckens sowie der Reliabilität palpatorischer und apparativer Bestimmungen von knöchernen Referenzpunkten am Becken. Hieraus ergeben sich maßgebliche Erkenntnisse: Eine Variationsanatomie des Beckens ist häufig und kommt auch bei nichtsymptomatischen Personen vor. Die palpatorische und apparative Bestimmungen der knöchernen Referenzpunkte sind gering bis moderat reliabel. Der Rückschluss von einer festgestellten Beckenasymmetrie auf den Einfluss bestehender oder noch zu erwartender Rücken‑, Hüft- oder Beckengelenkbeschwerden ist nach derzeitiger Studienlage zumindest umstritten und daher nicht empfehlenswert.

Relationship between pelvic tilt control, horse-rider synchronisation, and rider position in sitting trot

Investigation of dressage riders suggests that the performance outcomes of riding can be enhanced by a rider correctly adapting the motion of their pelvis. The pelvis has been identified as an important component of the physical connection of the horse and the rider. This preliminary study aimed to assess whether riders with better control of their pelvic movement, had increased postural stability and horse-rider synchronicity. Twenty-six amateur riders competing in Novice to Grand Prix level dressage rode 35 mixed breed horses in active dressage training which they were used to riding. Riders were divided into two groups according to their ability to perform posterior pelvic tilt whilst sat on a Swiss ball. High-speed motion-capture was captured from the left and right sides and used to assess rider body position, angular measurements and horse-rider synchronicity whilst riding a pre-defined test at collected trot on an artificial surface. Appropriate statistical analyses were used to compare variables between groups. Differences between groups were compared using one-way ANOVA or independent samples t-tests; the significance level was set at P<0.05. No riders in the study were able to perform anterior or posterior pelvic tilt whilst seated on a ball without demonstrating mild or major compensations; the most common of these were inclusion of the lumbar spine or leaning forwards or backwards. The results suggest that riders who could not perform pelvic tilt without major compensations had a more leaning forward posture, were more asymmetrical between the left and right sides and more phase shifted during the swing and stance phases than riders who could perform pelvic tilt with mild compensations.

Using Magneto-Inertial Measurement Units to Pervasively Measure Hip Joint Motion during Sports

The use of wireless sensors to measure motion in non-laboratory settings continues to grow in popularity. Thus far, most validated systems have been applied to measurements in controlled settings and/or for prescribed motions. The aim of this study was to characterize adolescent hip joint motion of elite-level athletes (soccer players) during practice and recreationally active peers (controls) in after-school activities using a magneto-inertial measurement unit (MIMU) system. Opal wireless sensors (APDM Inc., Portland OR, USA) were placed at the sacrum and laterally on each thigh (three sensors total). Hip joint motion was characterized by hip acceleration and hip orientation for one hour of activity on a sports field. Our methods and analysis techniques can be applied to other joints and activities. We also provide recommendations in order to guide future work using MIMUs to pervasively assess joint motions of clinical relevance.

Concurrent validity and within-session reliability of gait kinematics measured using an inertial motion capture system with repeated calibration

INTRODUCTION

Wearable inertial measurement units (IMUs) enable gait analysis in the clinic, but require calibrations that may affect subsequent gait measurements. This study assessed concurrent validity and within-session reliability of gait kinematics measured by a frequently calibrated IMU-based system. Calibration pose accuracy and intra-rater repeatability, and IMU orientation tracking accuracy, were additionally quantified.

METHODS

Calibration poses and gait were recorded in 15 women using IMUs and optical motion capture (OMC) (reference standard) simultaneously. Participants performed six consecutive trials: each comprising a calibration pose and a walk. IMU tracking was assessed separately (once-off) using technical static and dynamic tests. Differences of > 5° constituted clinical significance.

RESULTS

Concurrent validity for gait revealed clinically significant between-system differences for sagittal angles (root-mean-square error [RMSE] 6.7°-15.0°; bias -9.3°-3.0°) and hip rotation (RMSE 7.9°; bias -4.2°). After removing modelling offsets, differences for all angles (except hip rotation) were < 5°. Gait curves correlated highly between systems (r > 0.8), except hip rotation, pelvic tilt and -obliquity. Within-session reliability of IMU-measured gait angles was clinically acceptable (standard error of measurement [SEM] < 5°). Calibration poses were repeatable (SEM 0.3°-2.2°). Pose accuracy revealed mean absolute differences (MAD) < 5° for all angles except sagittal ankle, hip and pelvis. IMU tracking accuracy demonstrated RMSE ≤ 2.0°.

CONCLUSION

A frequently calibrated IMU system provides reliable gait measurements; comparing highly to OMC after removing modelling differences. Calibration poses can be implemented accurately for most angles and consistently. IMU-measured gait data are clinically useful and comparable within participants, but should not be compared to OMC-measured data.

Assessment of Lumbar Lordosis Distribution with a Novel Mathematical Approach and Its Adaptation for Lumbar Intervertebral Disc Degeneration

Introduction

Low back pain and disc degeneration could be linked to global spinal geometry. Our study aimed to develop a reliable new mathematical method to assess the local distribution of total lumbar lordosis with a single numeric parameter and compare it with lumbar intervertebral disc degeneration using routine MRI scans.

Methods

An online, open access, easy-to-use platform for measurements was developed based on a novel mathematical approach using MRIs of 60 patients. Our Spinalyze Software can be used online with uploaded MRIs. Several new parameters were introduced and assessed to describe variation in segmental lordosis distribution with a single numerical value. The Pfirrmann grading system was used for the classification of lumbar intervertebral disc degeneration. Relationships were investigated between the grade categories of L1-S1 lumbar discs and the MRI morphological parameters with correlation analysis.

Results

Results confirm that the determination of measurement points and calculated parameters are reliable (ICCs and Pearson r values > 0.90), and these parameters were independent of gender. The digression percentage (K%), one of our new parameters, did not show a statistical relationship with the Cobb-angle. According to our results, the maximum deflection breaking-point of lumbar lordosis and its location can be different with the same Cobb-angle and the distribution of global lordosis is uneven because the shape of the lumbar lordosis is shifted downward and centered around the L4 lumbar vertebra. The interobserver reliability of the Pfirrmann grades reading was in the excellent agreement category (88.33% agreement percentage, 0.84 kappa), and digression percentage (K%) showed a significant negative correlation with all L1-S1 disc grades with increasing r correlation values. This means that the smaller the value of digression percentage (K%), the more the number of worn discs in the lower lumbar sections.

Conclusions

Spinalyze Software based on a novel mathematical approach provides a free, easy-to-use, reliable, and online measurement tool using standard MRIs to approximate the curvature of lumbar lordosis. The new reliable K% (digression percentage) is one single quantitative parameter to assess the local distribution of total lumbar lordosis. The results indicate that digression percentage (K%) may possibly be associated with the development of lumbar intervertebral disc degeneration. Further evaluation is needed to assess its behavior and advantage.

The association between high-arched feet, plantar pressure distribution and body posture in young women

The aim of this study was to examine the effect of excessive feet arching (symmetrical and asymmetrical) on plantar pressure distribution and on the alignment of pelvis, spine and shoulder girdle. Eighty-one women (20-40 years old, 61 +/- 12 kg, 165 +/- 5 cm) were divided into 3 groups based on the foot arch index (Group 1 - with normally arched feet, Group 2 with one foot properly arched and the other high-arched, Group 3 with both feet high-arched). Plantar pressure distribution between the right and left foot for the forefoot, midfoot and rearfoot, respectively and body posture were assessed. A slight increase in longitudinal arch of the foot caused changes in the distribution of feet loads both between limbs and between the forefoot and rearfoot and also influenced the whole body. Asymmetrical high-arching of the feet resulted in asymmetry of lower limb load and in the height of the shoulder girdle. We have suggested that any alteration of the foot arch may be harmful to body tissues and should not be considered as correct. Due to the fact that slight increases in longitudinal arch of the foot are very common, they should be considered as a foot defect, and appropriate corrective exercises should be used to prevent forefoot overload and alterations in body posture.

The Influence of the Schoolbag on Standing Posture of First-Year Elementary School Students

The purpose of this study was to determine the influence of the mass of a schoolbag on standing posture in first-year elementary school children. First-year elementary school students (n = 76) participated in this study. The data was digitized and analyzed using SkillSpector and Kinovea. Results have shown a change of Center of Gravity (COG) position in all three anatomical planes (p < 0.01), as well as a change in two out of three measured postural angles-craniovertebral (p < 0.01) and craniocervical (p < 0.01) angle. The most important aspect of changed posture, anterior shift of COG, was measured to be 2.4 cm and was in moderate negative correlation with student body mass (-0.4, p < 0.01) and height (-0.4, p < 0.01) when students were encumbered with a schoolbag weighing 16.11% of their body mass, on the average. Also, this study confirms that when encumbered, students' head posture shifts to a more protracted position.

Foot hyperpronation alters lumbopelvic muscle function during the stance phase of gait

BACKGROUND

Although altered muscular control of the lumbopelvic region is one of the main risk factors for the development of low back pain and dysfunction, the influence of abnormal foot posture on lumbopelvic muscular function has not been investigated.

RESEARCH QUESTION

To determine possible functional changes due to hyperpronation in the main muscles that control the lumbopelvic segment.

METHODS

Kinematic and kinetic data were collected from 15 persons with hyperpronated feet and compared to a control group of 15 persons with normally aligned feet during the stance phase of gait. A generic OpenSim musculoskeletal model was scaled for each participant. A computed muscle control approach was used to produce a forward dynamic simulation of walking to determine muscle function.

RESULTS

In the hyperpronation group significantly greater peak forces were observed in the erector spinae, iliopsoas and abdominals compared to controls. The former group showed peak latencies for abdominal muscles during early stance, and for erector spinae muscles during both early and late stance. No significant between-group differences were found in gluteus maximus muscle activation in the stance phase of gait.

SIGNIFICANCE

Abnormal foot pronation can change the timing and intensity of lumbopelvic muscle activation. These changes may predispose people to develop secondary dysfunctions.

The musculoskeletal and cognitive effects of under-desk cycling compared to sitting for office workers

Alternate work positions are being considered as a way to address sedentary behaviour for office workers. This study evaluated the effect of two hours of just-sitting versus sitting while under-desk cycling on musculoskeletal discomfort and cognitive function (sustained attention and creative problem solving). To consider mechanisms, muscle fatigue, kinematics and mental state were also measured. Discomfort increased significantly across all body areas with knee and ankle discomfort greater (in a clinically meaningful manner) in under-desk cycling. Sustained attention reaction time was the only cognitive measure to show a difference between conditions (slower for under-desk cycling [β-34.82 CI (-62.12 to -7.53)]). There was no evidence of muscle fatigue, while kinematic differences between conditions were identified. Mental state deteriorated over time in both conditions. This study found no clear benefit of under-desk cycling compared to just-sitting for musculoskeletal health and cognitive function measures.

Does proactive cyclic usage of a footrest prevent the development of standing induced low back pain?

Various interventions, such as standing intermittently with one leg on a footrest, have been suggested to prevent low back pain (LBP) development during prolonged standing. To assess this standing intervention twelve participants stood for 80 min while cycling through three minute periods of level-ground standing divided by one minute periods with either the right or left leg elevated onto a platform. All participants had previously participated in a prolonged level standing protocol and were classified as pain (PD) or non-pain developers (NPD). Out of the six known PDs, only one PD developed LBP by the end of the standing intervention. The intervals of elevated leg standing resulted in increased lumbar spine flexion in comparison to level standing. In addition, over time there was an increase in lumbar spine flexion during the level standing intervals. This change in lumbar spine posture in standing pain developers likely contributed to the reduced LBP development during this prolonged standing intervention.

Gait analysis in patients after bilateral versus unilateral total hip arthroplasty

BACKGROUND

Gait abnormalities were reported in patients after total hip arthroplasty (THA). One-stage bilateral THA was introduced for bilateral hip pathologies, showing similar clinical and surgical outcome to unilateral procedure. However, no studies analyze the gait features after bilateral THA surgery compared to unilateral THA.

RESEARCH QUESTION

Are there differences in gait characteristics between bilateral and unilateral THA patients and are there differences between these cases and asymptomatic age-matched healthy subjects?

METHODS

In this prospective observational study, thirty-five patients with bilateral (n = 18) or unilateral THA (n = 17) and twenty asymptomatic age-matched volunteers were studied. Participants underwent three-dimensional gait analysisin order to detect gait spatial-temporal and kinematic (Gait Variable Score - GVS) parameters. Mobility (Timed Up and Go - TUG), fear of movement (Tampa Scale of Kinesiophobia - TSK) and pain during walking (Numeric Rating Scale - NRS) were also assessed. Patients were evaluated the day before surgery and at seven days, whereas healthy subjects underwent a single evaluation. ANOVA was used to assess differences between the three groups at each time-point and within-group differences in bilateral and unilateral groups.

RESULTS

At baseline, no differences between the two groups of patients were found. As expected, their gait spatial-temporal and kinematic parameters and functional variables were impaired with respect to healthy subjects, both before and after surgery. After surgery, GVS Pelvic-TILT closer to normative values, longer stance and shorter swing phases were found in bilateral cases compared to unilateral patients. Moreover, a higher NRS score was found in bilateral patients, whereas TUG and TSK revealed no differences between the two groups of patients.

SIGNIFICANCE

The current findings, focusing on short-term effectiveness of bilateral THA, could assist physiotherapists in selecting the best ambulation training and an appropriate rehabilitation approach immediately after surgery.

Video rasterstereography of the spine and pelvis in eight erect positions: A reliability study

INTRODUCTION

To investigate the reliability and variability of Video Rasterstereography (VR) measurements of the spine and pelvis, for eight proposed standing postures, in order to help define an optimal standing position for erect pelvis radiography.

METHODS

Surface topography data were collected using the formetic 4D dynamic modelling (Diers) system. 61 healthy participants were recruited; each participant performed eight different standing positions. Four positions were performed with the feet shoulder width apart and parallel, and four positions were performed with the feet shoulder width apart and internally rotated. For the upper extremity, each of the (two sets of) four positions were performed with different arm positions (arms by the sides, arms crossed over the chest, arms 30° flexed and touching the medial end of the clavicle, arms 30° flexed with the hands holding a support). Three sets of surface topography were collected in the eight positions (n = 24). The variability was assessed by calculating standard error of the measurement (SEm) and the coefficient of variation (CV). Reliability was assessed using intra-class correlation coefficients (ICC ± 95% CI).

RESULTS

No significant differences in the SEm were found between the three paired measurements for all standing positions (P > 0.05). ICC values demonstrated excellent reliability for all measurements across the eight standing positions (range 0.879-1.00 [95% CI 0.813-1.00]).

CONCLUSION

Evaluating eight standing positions radiographically would be unethical as it would involve repeat radiation exposures. Using the formetic 4D dynamic modelling (Diers) system, provides an alternative and has shown that there was only a minimal, non-statistically significant, differences between the eight different standing positions.

IMPLICATION FOR PRACTICE

Different standing positions were proposed for erect pelvis radiography.