Effects of pelvic asymmetry and low back pain on trunk kinematics during sitting: a comparison with standing

How and why do people with chronic low back pain modify their physical activity? A mixed-methods survey

BACKGROUND

This study investigated the impact of Chronic Low Back Pain (CLBP) on individuals' physical activity (PA) behaviours, specifically, how they modify, cease, or continue PA when experiencing CLBP. The primary aim was to explore the relationship between CLBP and PA and how this is influenced in different contexts (e.g., necessity of a task).

METHODS

A mixed-methods survey was administered to 220 participants, including self-reported outcomes, and capturing responses to three distinct questions related to PA and CLBP. The data was analysed via a content analysis.

RESULTS

The findings revealed that individuals with CLBP are most likely to modify PA in work-related contexts and least likely to cease it in the same setting. Housework emerged as the most common domain for cessation of PA, while work/study activities were predominantly continued. Reasons for these trends were typically task-based rather than health or enjoyment based and influenced by the perceived necessity of the task in question.

CONCLUSION

The study highlights the role of occupational and educational settings in individual responses to CLBP. The findings also highlight a gap in public awareness regarding effective CLBP management strategies, emphasising the need for increased education and awareness programs.

Lateral Pelvis and Lumbar Motion in Seated and Standing Office Work and Their Association With Transient Low Back Pain

OBJECTIVE

To assess frontal plane motion of the pelvis and lumbar spine during 2 h of seated and standing office work and evaluate associations with transient low back pain.

BACKGROUND

Although bending and twisting motions are cited as risk factors for low back injuries in occupational tasks, few studies have assessed frontal plane motion during sedentary exposures.

METHODS

Twenty-one participants completed 2 h of seated and standing office work while pelvic obliquity, lumbar lateral bending angles, and ratings of perceived low back pain were recorded. Mean absolute angles were compared across 15-min blocks, amplitude probability distribution functions were calculated, and associations between lateral postures and low back pain were evaluated.

RESULTS

Mean pelvic obliquity (sit = 4.0 ± 2.8°, stand = 3.5 ± 1.7°) and lumbar lateral bending (sit = 4.5 ± 2.5°, stand = 4.1 ± 1.6°) were consistently asymmetrical. Pelvic obliquity range of motion was 4.7° larger in standing (13.6 ± 7.5°) than sitting (8.9 ± 8.7°). In sitting, 52% (pelvis) and 71% (lumbar) of participants, and in standing, 71% (pelvis and lumbar) of participants, were considered asymmetric for >90% of the protocol. Lateral postures displayed weak to low correlations with peak low back pain (R ≤ 0.388).

CONCLUSION

The majority of participants displayed lateral asymmetries for the pelvis and lumbar spine within 5° of their upright standing posture.

APPLICATION

In short-term sedentary exposures, associations between lateral postures and pain indicated that as the range in lateral postures increases there may be an increased possibility of pain.

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.

Exploring 3D Pelvis Orientation: A Cross-Sectional Study in Athletes Engaged in Activities with and without Impact Loading and Non-Athletes

Female athletes subjected to various types of impact loading, especially over a long period of time, may experience changes in their pelvic orientation, which may affect their sport performance and increase the likelihood of injury. The aim of the present study was to determine whether female athletes involved in high-impact loading sports (HILS), odd-impact loading sports (OILS), and repetitive non-impact loading sports (NILS) demonstrate changes in pelvis orientation compared to non-athletes (NATH). Pelvic orientation was determined using Euler/Cardan angles, calculated from the coordinates of the right, and left anterior superior iliac spines and pubic symphysis via a novel method. Two-way ANOVA tests showed significant differences between groups for pelvis position in the frontal plane (p < 0.05), with HILS and OILS demonstrating greater pelvic obliquity compared to NILS athletes and NATH. Significant main effects were also obtained for directions within the sagittal plane (p < 0.001). Significant within-group differences were observed in sagittal pelvic position among female athletes engaged in NILS (p < 0.01) and non-athletes (NATH) (p < 0.05), with a greater anterior pelvic tilt compared to posterior. Our findings suggest that pelvis orientation in female athletes across sports is influenced by sport-specific impact loads, potentially affecting performance and injury occurrence.

EMG Validation of a Subject-Specific Thoracolumbar Spine Musculoskeletal Model During Dynamic Activities in Older Adults

Musculoskeletal models can uniquely estimate in vivo demands and injury risk. In this study, we aimed to compare muscle activations from subject-specific thoracolumbar spine OpenSim models with recorded muscle activity from electromyography (EMG) during five dynamic tasks. Specifically, 11 older adults (mean = 65 years, SD = 9) lifted a crate weighted to 10% of their body mass in axial rotation, 2-handed sagittal lift, 1-handed sagittal lift, and lateral bending, and simulated a window opening task. EMG measurements of back and abdominal muscles were directly compared to equivalent model-predicted activity for temporal similarity via maximum absolute normalized cross-correlation (MANCC) coefficients and for magnitude differences via root-mean-square errors (RMSE), across all combinations of participants, dynamic tasks, and muscle groups. We found that across most of the tasks the model reasonably predicted temporal behavior of back extensor muscles (median MANCC = 0.92 ± 0.07) but moderate temporal similarity was observed for abdominal muscles (median MANCC = 0.60 ± 0.20). Activation magnitude was comparable to previous modeling studies, and median RMSE was 0.18 ± 0.08 for back extensor muscles. Overall, these results indicate that our thoracolumbar spine model can be used to estimate subject-specific in vivo muscular activations for these dynamic lifting tasks.

Static pelvic posture is not related to dynamic pelvic tilt or competition level in dressage riders

Static assessment and grouping of riders by competition level are prevalent in equestrian coaching practice and research. This study explored sagittal pelvic tilt in 35 competitive dressage riders to analyse the relationship between static and dynamic postures and assess the interaction of competition level. Riders were assessed using optical motion capture on a riding simulator at halt and in walk, trot, and left and right canter. Mean, minimum and maximum pelvic tilt, and range of motion (ROM) were measured as the pitch rotation of a rigid body formed by markers placed on the rider's left/right anterior and posterior superior iliac spines and sacrum, averaged over six time-normalised strides. Three key results emerged: (1) there are correlations between the rider's mean pelvic tilt in simulated walk, trot and canter, but not at halt; (2) mean pelvic tilt values are not significantly influenced by competition level (p = 0.233); and (3) the minimum and maximum pelvic tilt values illustrate individual strategies between gaits. Therefore, results from static assessment and grouping of riders by competition level should be interpreted with caution. Riders should be assessed as individuals, during dynamic riding-specific tasks, to understand their postural strategies.

Ankle stiffness asymmetry is associated with balance function in individuals with chronic stroke

Ankle joint is one of important contributors on balance in stroke survivors. This study aimed to investigate the relationships of ankle stiffness symmetry ratios along the talocrural and subtalar axes with clinical balance measures and weight distribution during quiet standing in ambulatory chronic post-stroke survivors. The clinical trials involved 15 ambulatory elderly with chronic post-stroke hemiparesis and 15 healthy controls. Ankle stiffness was evaluated during non-weight-bearing isokinetic passive biaxial ankle movements, and ankle stiffness symmetry ratios between paretic and non-paretic ankle stiffness (SR: Inversion/Eversion SRIE & Dorsi-/Plantarflexion SRDP) were measured. A certified physiotherapist evaluated the Berg Balance Scale (BBS) and weight-distribution ratio (WDR) on bilateral force plates during quiet standing. Correlation coefficients, the factor analysis, and Pearson linear multiple regression were assessed with measured parameters. Correlation coefficients showed significances in-betweens; BBS and SRDP (r = -0.543, p = 0.022), WDR and SRIE (r = -0.667, p = 0.004), SRIE and SRDP (r = -0.604, p = 0.011). The exploratory factor analysis suggested four extracted factors; (1) Balance & Gait, (2) Stroke, (3) Symmetry and (4) Dimension. The first and second factors include general and pathological characteristics in stoke participants respectively. The third factor is associated with symmetrical characteristics explaining up to 99.9% of the variance. Multiple regression analysis showed ankle stiffness ratios predict BBS up to 60% of variance. The biaxial ankle stiffness ratio is a useful clinical variable that assesses balance function, in ambulatory chronic stroke survivors.

The effect of low back pain on spine kinematics: A systematic review and meta-analysis

BACKGROUND

Although impairments in dorso-lumbar spine mobility have been previously reported in patients with low back pain, its exact mechanism is not yet clear. Therefore, the purpose of this systematic review and meta-analysis is to investigate and compare spinal kinematics between subjects with and without low back pain and identify appropriate tools to evaluate it.

METHODS

The PubMed, Scopus and Web of Science databases were searched for relevant literature. The search strategy was mainly focused on studies investigating lumbar kinematics in subjects with and without low back pain during clinical functional tests, gait, sports and daily functional activities. Papers were selected if at least one of these outputs was reported: lumbar range of motion, lumbar velocity, lumbar acceleration and deceleration, lordosis angle or lumbar excursion.

FINDINGS

Among 804 papers, 48 met the review eligibility criteria and 29 were eligible to perform a meta-analysis. Lumbar range of motion was the primary outcome measured. A statistically significant limitation of the lumbar mobility was found in low back pain group in all planes, and in the frontal and transverse planes for thoracic range of motion, but there is no significant limitation for pelvic mobility. The amount of limitation was found to be more important in the lumbar sagittal plane and during challenging functional activities in comparison with simple activities.

INTERPRETATION

The findings of this review provide insight into the impact of low back pain on spinal kinematics during specific movements, contributing to our understanding of this relationship and suggesting potential clinical implications.

Effects of Pelvic-Tilt Imbalance on Disability, Muscle Performance, and Range of Motion in Office Workers with Non-Specific Low-Back Pain

Imbalance in the pelvic tilt is considered to be a major variable in low back pain. The purpose of this study was to investigate the effects of pelvic-tilt imbalance on trunk- and hip-muscle performance, range of motion, low-back pain, and the degree of disability in office workers. This was a cross-sectional study conducted in a physical therapy clinic on forty-one office workers diagnosed with non-specific low-back pain. Among the office workers with non-specific low-back pain, 25 were assigned to the pelvic-tilt-imbalance group and 16 to the normal group without pelvic-tilt imbalance. In order to determine the differences according to the imbalance in pelvic tilt, the pain intensity and disability indices were compared between the groups. In addition, the muscle performance and range of motion of the trunk and hip joints and foot pressure were measured and compared. There were differences between the groups in the disability indices and the ratio of internal and external rotation of the hip joint. However, there were no differences in the other variables. Pelvic-tilt imbalance in office workers with non-specific chronic low-back pain may exacerbate the degree of disability and be related to hip-joint rotational range of motion.

Asymmetry of the pelvis in Polish young adults

Introduction

Symmetry is one of the criteria of correct body posture in upright position. The spatial positioning of the pelvic girdle is crucial to it. Functional and structural asymmetries within the lumbo-pelvic-hip complex can have a significant influence on the structure and functions of many human body organs and systems. The aim of the study was to present the results of inclinometer measurements of selected landmarks of the pelvic girdle in young adults aged 19-29.

Methods

The analysis of occurrence of spatial pelvic asymmetry was based on the authors' original, clinical classification and the significance of the body mass and height for the analyzed asymmetries. The inclinometer measurements of the selected landmarks of the pelvic girdle were performed in a sample consisting of 300 young individuals. Then, the occurrences of the spatial asymmetry of the pelvis were analyzed based on the authors' own clinical classification using alignment symmetry of the iliac crests, the anterior superior iliac spines and the trochanters major as a criterion. All study subjects with asymmetry <1 degree were treated as those with a symmetrical pelvis.

Results

The significance of gender, body mass and height for the analyzed asymmetries was assessed. Symmetric positioning of the iliac crests was observed in only 32% of the respondents. The iliac crest depression on the left side was more frequently observed - in 41% of the respondents. This occurred more often in women (44%) than in men (38%). In the group of women, the rotated pelvis was the most often observed (39.4%) asymmetry, while for men, it was the oblique pelvis (40%). More detailed analysis by pelvic asymmetry subtypes showed their statistical differentiation between women and men (p    <     0.0001). Analysis of moderate rotation of the pelvis for men, were reported slightly higher values but these differences were not statistically significant (p = 0.253). Women, in turn, showed slightly higher mean values but here too, the differences were not statistically significant (p = 0.245).

Discussion

Asymmetries in the pelvis area are common; they were observed in less than three-quarters of the examined population. Oblique pelvis was found in less than a quarter of women and in more than one-third men with the predominant structural asymmetries. Rotated pelvis was observed in more than one-third of women and men with dominating functional asymmetries. There were no linear correlations between the body mass and height, and the angle of asymmetries.

Core stability status classification based on mediolateral head motion during rhythmic movements and functional movement tests

Objective

Core stability assessment is paramount for the prevention of low back pain, with core stability being considered as the most critical factor in such pain. The objective of this study was to develop a simple model for the automated assessment of core stability status.

Methods

To assess core stability-defined as the ability to control trunk position relative to the pelvic position - we used an inertial measurement unit sensor embedded within a wireless earbud to estimate the mediolateral head angle during rhythmic movements (RMs) such as cycling, walking, and running. The activities of muscles around the trunk were analyzed by an experienced, highly trained individual. Functional movement tests (FMTs) were performed, including single-leg squat, lunge, and side lunge. Data was collected from 77 participants, who were then classified into good and poor core stability groups based on their Sahrmann core stability test scores.

Results

From the head angle data, we extrapolated the symmetry index (SI) and amplitude of mediolateral head motion (Amp). Support vector machine and neural network models were trained and validated using these features. In both models, the accuracy was similar across three feature sets for RMs, FMTs, and full, and support vector machine accuracy (∼87%) is greater than neural network (∼75%).

Conclusion

The use of this model, trained with head motion-related features obtained during RMs or FMTs, can help to accurately classify core stability status during activities.

Stereophotogrammetric approaches to multi-segmental kinematics of the thoracolumbar spine: a systematic review

BACKGROUND

Spine disorders are becoming more prevalent in today's ageing society. Motion abnormalities have been linked to the prevalence and recurrence of these disorders. Various protocols exist to measure thoracolumbar spine motion, but a standard multi-segmental approach is still missing. This study aims to systematically evaluate the literature on stereophotogrammetric motion analysis approaches to quantify thoracolumbar spine kinematics in terms of measurement reliability, suitability of protocols for clinical application and clinical significance of the resulting functional assessment.

METHODS

Electronic databases (PubMed, Scopus and ScienceDirect) were searched until February 2022. Studies published in English, investigating the intersegmental kinematics of the thoracolumbar spine using stereophotogrammetric motion analysis were identified. All information relating to measurement reliability; measurement suitability and clinical significance was extracted from the studies identified.

RESULTS

Seventy-four studies met the inclusion criteria. 33% of the studies reported on the repeatability of their measurement. In terms of suitability, only 35% of protocols were deemed suitable for clinical application. The spinous processes of C7, T3, T6, T12, L1, L3 and L5 were the most widely used landmarks. The spine segment definitions were, however, found to be inconsistent among studies. Activities of daily living were the main tasks performed. Comparable results between protocols are however still missing.

CONCLUSION

The literature to date offers various stereophotogrammetric protocols to quantify the multi-segmental motion of the thoracolumbar spine, without a standard guideline being followed. From a clinical point of view, the approaches are still limited. Further research is needed to define a precise motion analysis protocol in terms of segment definition and clinical relevance.

Analysis of the quadratus lumborum muscle activity on leg length discrepancy: A randomized controlled trial

BACKGROUND

Quadratus lumborum (QL) discrete region extensions might change depending on whether leg length discrepancy (LLD) individually has any extra erector spinae action in the lumbar spine, which can result in serious injury to the lower extremities and lumbar vertebrae.

OBJECTIVE

This study aims to investigate the effect of QL muscle activity on LLD by using electromyography (EMG) signals.

METHODS

The study employed a randomized controlled design. A total of 100 right-handed volunteers were included in this study. All participants were assessed manually by tape measurement for LLD. EMG signals were recorded during the resting and maximal isometric contraction positions to determine QL muscle activity. The power spectral density (PSD) methods were applied to compute EMG signals.

RESULTS

In maximal isometric contraction position, comparing the short right LLD (Right side = 0.00064 ± 0.00001, Left side = 0.00033 ± 0.0006) and short left LLD (Right side = 0.00001 ± 0.00008, Left side = 0.00017 ± 0.0001), it was found that the short right LLD group had significantly increased PSD of EMG values. In resting position, the short right LLD (Right side = 0.0002 ± 0.0073, Left side = 0.00016 ± 0.0065) had significantly increased PSD of EMG compared to the short left LLD (Right side = 0.00004 ± 0.0003, Left side = 0.0001 ± 0.0008) values of the QL muscle activity. The results of both groups were also statistically significant (p< 0.05).

CONCLUSIONS

The present study showed that it is possible to determine effective experimental interventions for functional LLD using EMG signal analysis of QL muscle activity on an asymptomatic normal population.

The Validity of Wireless Earbud-Type Wearable Sensors for Head Angle Estimation and the Relationships of Head with Trunk, Pelvis, Hip, and Knee during Workouts

The present study was performed to investigate the validity of a wireless earbud-type inertial measurement unit (Ear-IMU) sensor used to estimate head angle during four workouts. In addition, relationships between head angle obtained from the Ear-IMU sensor and the angles of other joints determined with a 3D motion analysis system were investigated. The study population consisted of 20 active volunteers. The Ear-IMU sensor measured the head angle, while a 3D motion analysis system simultaneously measured the angles of the head, trunk, pelvis, hips, and knees during workouts. Comparison with the head angle measured using the 3D motion analysis system indicated that the validity of the Ear-IMU sensor was very strong or moderate in the sagittal and frontal planes. In addition, the trunk angle in the frontal plane showed a fair correlation with the head angle determined with the Ear-IMU sensor during a single-leg squat, reverse lunge, and standing hip abduction; the correlation was poor in the sagittal plane. Our results indicated that the Ear-IMU sensor can be used to directly estimate head motion and indirectly estimate trunk motion.

An anthropometric-based method for the assessment of pelvis position in three-dimensional space

Determining the pelvis position remains a challenge for clinical therapists and researchers mainly due to the difficulty in assessing its potential triaxial rotations in the upright standing posture. The method described in this study aims to determine the position of the pelvis in the upright standing posture by calculating the Euler/Cardan angles of pelvic rotations based on the triaxial coordinates of the anterior superior iliac spines and the pubic symphysis. The coordinates of these bony landmarks were determined with two laser distance meters and a standard metric ruler, all mounted on a custom-made structure. The calculations of all Euler/Cardan angle rotation sequences for both the internal and external rotations of the pelvis were performed by developing an algorithm that executed via a computer program specifically designed for the purpose of this study. The validity of the algorithm was tested by comparing the actual angles of known positions at which an anatomical model of the pelvis was placed with the calculated angles. Our findings revealed <1° differences between the actual and the calculated angles of pelvis rotations regardless of the axis around which it was rotated suggesting that the proposed method can be used for clinical and research purposes.•

The triaxial coordinates of pelvis bony landmarks can be measured anthropometrically using simple measuring instruments

•

Pelvis posture can be determined in 3D space with great accuracy by means of the Euler/Cardan angles

Evaluation of a Chair-Mounted Passive Trunk Orthosis: A Pilot Study on Able-Bodied Subjects

Trunk stability is important for adequate arm function due to their kinematic linkage. People with Duchenne muscular dystrophy (DMD) can benefit from trunk-assistive devices for seated daily activities, but existing devices limit trunk movement to forward bending. We developed a new trunk orthosis that has spring and pulley design. This study evaluated orthosis performance with 40 able-bodied subjects under with and without orthosis condition in 20 seated tasks for trunk rotation, forward bending, and side bending movements. Subjects adopted static posture in specific trunk orientation while their muscle activity was recorded. They also rated the subjective scales of perceived exertion and usability. A percent change in muscle activity for each task, due to orthosis use, is reported. Significant muscle activity reductions up to 31% and 65% were observed in lumbar and thoracic erector spinae muscles, respectively. Using three-way ANOVA, we found these reductions to be specific to the task direction and the choice of upper limb that is used to perform the asymmetric tasks. A total of 70% participants reported acceptable usability and ~1-point increase in exertion was found for maximum voluntary reaching with the orthosis. The outcomes of this study are promising, though tested on able-bodied subjects. Hence, orthosis mounted on wheelchairs should be further evaluated on DMD patients.

Evaluation of the relationship between history of lower back pain and asymmetrical trunk range of motion

BACKGROUND

Low back pain (LBP) is a common complaint and preventive measures should be considered immediately. In addition, asymmetrical trunk motion, which occurs due to repetitive motion upon performing daily activities, may be one of the biomechanical factors to cause LBP.

OBJECTIVE

To investigate the characteristics of asymmetrical trunk motion in women with a history of LBP.

METHODS

Thirty-four women were dichotomously categorized into either the LBP or non-LBP group. Trunk active range of motion (RoM) upon sitting and standing were measured via a three-dimensional motion analysis system. Each RoM and rotation and side-flexion asymmetries were calculated and an unpaired t-tests were used to identify differences between each group.

RESULTS

Trunk rotation asymmetry upon sitting and standing position in LBP group was significantly greater than that in non-LBP group. Furthermore, trunk rotation angle upon sitting in LBP group was significantly larger than that in non-LBP group.

CONCLUSIONS

The limited RoM and asymmetry of trunk rotation may be due to imposed repetitive mechanical stress on habitual excessive motion, including most asymmetrical movements. Our findings indicated that a small trunk rotation angle and asymmetrical trunk rotation may be useful parameters to predict LBP onset or other musculoskeletal conditions of the trunk.

Spinal and Pelvic Alignment of Sitting Posture Associated with Smartphone Use in Adolescents with Low Back Pain

This study aimed to assess the association between smartphone use in the sitting posture and changes in thoracolumbar kyphosis, lumbar lordosis, and pelvic asymmetry in adolescents with low back pain (LBP). Twenty-five adolescents with LBP and 25 healthy adolescents participated in this study. They were instructed to sit on a height-adjustable chair with their hips and knees bent at 90° for 30 min in their usual sitting postures. Thoracolumbar kyphosis, lumbar lordosis, and pelvic asymmetry were measured using a three-dimensional motion capture system. Thoracolumbar kyphosis and lumbar lordosis increased after 30 min of sitting compared to the baseline. In both groups, thoracic kyphosis and lumbar lordosis angle increased with increasing sitting time. Compared to healthy adolescents, adolescents with LBP presented greater thoracolumbar kyphosis and lumbar lordosis after prolonged sitting. Pelvic asymmetry showed no significant difference between the sitting time and groups. Using a smartphone during prolonged sitting may lead to a slumped posture; these associations were more pronounced in adolescents with LBP.

The Influence of Kinematic Constraints on Model Performance During Inverse Kinematics Analysis of the Thoracolumbar Spine

Motion analysis is increasingly applied to spine musculoskeletal models using kinematic constraints to estimate individual intervertebral joint movements, which cannot be directly measured from the skin surface markers. Traditionally, kinematic constraints have allowed a single spinal degree of freedom (DOF) in each direction, and there has been little examination of how different kinematic constraints affect evaluations of spine motion. Thus, the objective of this study was to evaluate the performance of different kinematic constraints for inverse kinematics analysis. We collected motion analysis marker data in seven healthy participants (4F, 3M, aged 27–67) during flexion–extension, lateral bending, and axial rotation tasks. Inverse kinematics analyses were performed on subject-specific models with 17 thoracolumbar joints allowing 51 rotational DOF (51DOF) and corresponding models including seven sets of kinematic constraints that limited spine motion from 3 to 9DOF. Outcomes included: (1) root mean square (RMS) error of spine markers (measured vs. model); (2) lag-one autocorrelation coefficients to assess smoothness of angular motions; (3) maximum range of motion (ROM) of intervertebral joints in three directions of motion (FE, LB, AR) to assess whether they are physiologically reasonable; and (4) segmental spine angles in static ROM trials. We found that RMS error of spine markers was higher with constraints than without (p < 0.0001) but did not notably improve kinematic constraints above 6DOF. Compared to segmental angles calculated directly from spine markers, models with kinematic constraints had moderate to good intraclass correlation coefficients (ICCs) for flexion–extension and lateral bending, though weak to moderate ICCs for axial rotation. Adding more DOF to kinematic constraints did not improve performance in matching segmental angles. Kinematic constraints with 4–6DOF produced similar levels of smoothness across all tasks and generally improved smoothness compared to 9DOF or unconstrained (51DOF) models. Our results also revealed that the maximum joint ROMs predicted using 4–6DOF constraints were largely within physiologically acceptable ranges throughout the spine and in all directions of motions. We conclude that a kinematic constraint with 5DOF can produce smooth spine motions with physiologically reasonable joint ROMs and relatively low marker error.

Comparison of pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between people with and without nonspecific low back pain

BACKGROUND

Faults in postural alignment and movement of the pelvis are associated with non-specific low back pain. However, limited studies have investigated the differences in pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between subjects with and without non-specific low back pain.

METHODS

Thirty-one subjects with non-specific low back pain and 31 subjects without non-specific low back pain were examined. Angular measures of the pelvic rotation angle in the transverse plane were obtained in the supine position and during active straight leg raise using a Smart KEMA measurement system.

FINDING

The pelvic rotation angle in the transverse plane during active straight leg raise was significantly greater in subjects with non-specific low back pain than in healthy subjects (p < 0.05). However, the pelvic rotation angle in the transverse plane in the supine position and asymmetry index of the pelvic rotation angle during active straight leg raise were not significantly different between subjects with and those without non-specific low back pain.

INTERPRETATION

This indicates that a greater pelvic rotation angle in the transverse plane during active straight leg raise could be contributing factors to the development of a non-specific low back pain related to lumbopelvic instability.

Monitoring of Sitting Postures With Sensor Networks in Controlled and Free-living Environments: Systematic Review

BACKGROUND

A majority of employees in the industrial world spend most of their working time in a seated position. Monitoring sitting postures can provide insights into the underlying causes of occupational discomforts such as low back pain.

OBJECTIVE

This study focuses on the technologies and algorithms used to classify sitting postures on a chair with respect to spine and limb movements, using sensors and wearables such as inertial measurement units, pressure or piezoresistive sensors, accelerometers or gyroscopes, combined with machine learning approaches.

METHODS

A total of three electronic literature databases were surveyed to identify studies classifying sitting postures in adults. Quality appraisal was performed to extract critical details and assess biases in the shortlisted papers.

RESULTS

A total of 14 papers were shortlisted from 952 papers obtained after a systematic search. The majority of the studies used pressure sensors to measure sitting postures, whereas neural networks were the most frequently used approaches for classification tasks in this context. Only 2 studies were performed in a free-living environment. Most studies presented ethical and methodological shortcomings. Moreover, the findings indicate that the strategic placement of sensors can lead to better performance and lower costs.

CONCLUSIONS

The included studies differed in various aspects of design and analysis. The majority of studies were rated as medium quality according to our assessment. Our study suggests that future work for posture classification can benefit from using inertial measurement unit sensors, since they make it possible to differentiate among spine movements and similar postures, considering transitional movements between postures, and using three-dimensional cameras to annotate the data for ground truth. Finally, comparing such studies is challenging, as there are no standard definitions of sitting postures that could be used for classification. In addition, this study identifies five basic sitting postures along with different combinations of limb and spine movements to help guide future research efforts.

Validity and reliability of smartphone-based pelvic rotation evaluations of children with cerebral palsy while sitting, standing, and standing on one leg

PURPOSE

We explored the test-retest reliability of pelvic rotation measured using a smartphone and established criterion-related validity by analyzing simple linear regression between pelvic rotation data obtained using the smartphone and those measured by a palpation meter.

METHODS

We recruited 12 children with cerebral palsy (CP) (7 boys and 5 girls) and measured pelvic rotation using a smartphone application and a palpation meter in the sitting, standing, and one-leg standing positions. Test-retest reliability was evaluated by calculating intraclass correlation coefficients (ICCs); simple linear regression was analyzed to explore the relationships between smartphone and palpation meter data.

RESULTS

In terms of the test-retest reliability of pelvic rotation measured by the smartphone, the ICCs ranged from 0.85 to 0.95. A positive linear correlation was found between smartphone and palpation meter data.

CONCLUSIONS

We confirmed that measurement of pelvic rotation using a smartphone was reliable when children with CP were in the sitting, standing, and one-leg standing positions. In addition, pelvic rotation measured using the smartphone correlated significantly with that measured using a palpation meter.

The association between pelvic asymmetry and non-specific chronic low back pain as assessed by the global postural system

BACKGROUND

Empirical evidence that demonstrates the relationship between pelvic asymmetry and non-specific chronic low back pain (NCLBP) is currently lacking.

OBJECTIVE

To establish the reliability of the Global Postural System (GPS) in assessing pelvic asymmetry and identify the association between pelvic asymmetry parameters and the occurrence of NCLBP in young adults.

DESIGN

A cross-sectional, regression study.

METHODS

People who were aged between 18 and 30 and were diagnosed with NCLBP were recruited. Healthy individuals who were matched for age, sex, and education level were recruited as controls. Global Postural System (GPS) was employed to assess pelvic asymmetry. Prior to exploring the association, the reliability of GPS was assessed by the ICC (2, k) for interrater reliability, ICC (3, k) for intra-rater reliability, standard error and minimal detectable difference. Bivariate correlation analysis and logistic regression analysis were used to determine the relationship between pelvic asymmetry and the occurrence of NCLBP.

RESULTS

Twenty-eight healthy participants and 28 people with NCLBP were recruited. Moderate to excellent ICCs were observed for the inter-rater and intra-rater reliability of most postural parameters. The bivariate correlation analysis indicated that age, body mass index and pelvic asymmetry parameters were related to the occurrence of NCLBP. Pelvic angle asymmetry (odds ratio = 1.17), and asymmetry of the distance between the posterior superior iliac spine and the floor (odds ratio = 1.21) were associated with NCLBP.

LIMITATIONS

This study did not explore the causal relationship between pelvic asymmetry in the sagittal plane/pelvic asymmetry in the transverse plane and the occurrence of NCLBP. The interpretation of the results may not be generalized beyond the sample population.

CONCLUSIONS

The GPS is a reliable method to assess pelvic asymmetry in a clinical setting. Two pelvic parameters were associated with the presence of NLBP. Measurement of pelvic asymmetry may assist in the early identification of potential occurrence of NCLBP but further work is required.

The Intertester Reliability of a Modified Movement System Impairment Classification System Used to Evaluate Individuals With Prolonged Sitting: A Preliminary Study

OBJECTIVE

Prolonged sitting while working at a computer leads to poor sitting postures, which can aggravate low back pain in many individuals. We examined the intertester reliability of using the modified musculoskeletal impairment schema for classifying participants sitting at computers for prolonged times.

METHODS

Fifty participants were examined independently by each therapist using a test-retest design. Each therapist assigned an musculoskeletal impairment classification upon completion of the examination. The agreement percentages and the kappa coefficient were used to evaluate intertester reliability in classifying participants with prolonged sitting.

RESULTS

The percentage agreement between the 2 examiners for participants who maintained the sitting posture for prolonged times was 84%. The calculated kappa coefficient was 0.73, reflecting a substantial level of agreement.

CONCLUSIONS

The present findings provide some evidence to support the classification of individuals who sit at computers for prolonged times and participants with rotation with flexion pattern would need to manage asymmetry pattern in a subclinical group.

Using a Motion Sensor to Categorize Nonspecific Low Back Pain Patients: A Machine Learning Approach

Nonspecific low back pain (NSLBP) constitutes a critical health challenge that impacts millions of people worldwide with devastating health and socioeconomic consequences. In today’s clinical settings, practitioners continue to follow conventional guidelines to categorize NSLBP patients based on subjective approaches, such as the STarT Back Screening Tool (SBST). This study aimed to develop a sensor-based machine learning model to classify NSLBP patients into different subgroups according to quantitative kinematic data, i.e., trunk motion and balance-related measures, in conjunction with STarT output. Specifically, inertial measurement units (IMU) were attached to the trunks of ninety-four patients while they performed repetitive trunk flexion/extension movements on a balance board at self-selected pace. Machine learning algorithms (support vector machine (SVM) and multi-layer perceptron (MLP)) were implemented for model development, and SBST results were used as ground truth. The results demonstrated that kinematic data could successfully be used to categorize patients into two main groups: high vs. low-medium risk. Accuracy levels of ~75% and 60% were achieved for SVM and MLP, respectively. Additionally, among a range of variables detailed herein, time-scaled IMU signals yielded the highest accuracy levels (i.e., ~75%). Our findings support the improvement and use of wearable systems in developing diagnostic and prognostic tools for various healthcare applications. This can facilitate development of an improved, cost-effective quantitative NSLBP assessment tool in clinical and home settings towards effective personalized rehabilitation.

It is Time to Have Rest: How do Break Types Affect Muscular Activity and Perceived Discomfort During Prolonged Sitting Work

Background

Prolonged sitting at work can lead to adverse health outcomes. The health risk of office workers is an increasing concern for the society and industry, with prolonged sitting work becoming more prevalent.

Objective

This study aimed to explore the variation in muscle activities during prolonged sitting work and found out when and how to take a break to mitigate the risk of muscle symptoms.

Methods

A preliminary survey was conducted to find out the prevalence of muscle discomfort in sedentary work. Firstly, a 2-h sedentary computer work was designed based on the preliminary study to investigate the variation in muscle activities. Twenty-four participants took part in the electromyography (EMG) measurement study. The EMG variations in the trapezius muscle and latissimus dorsi were investigated. Then the intervention time was determined based on the EMG measurement study. Secondly, 48 participants were divided into six groups to compare the effectiveness of every break type (passive break, active break of changing their posture, and stand and stretch their body with 5 or 10 mins). Finally, data consisting of EMG amplitudes and spectra and subjective assessment of discomfort were analyzed.

Results

In the EMG experiment, results from the joint analysis of the spectral and amplitude method showed muscle fatigue after about 40 mins of sedentary work. In the intervention experiment, the results showed that standing and stretching for 5 mins was the most effective break type, and this type of break could keep the muscles' state at a recovery level for about 30−45 mins.

Conclusions

This study offers the possibility of being applied to office workers and provides preliminary data support and theoretical exploration for a follow-up early muscle fatigue detection system.

Workplace interventions for increasing standing or walking for decreasing musculoskeletal symptoms in sedentary workers

BACKGROUND

The prevalence of musculoskeletal symptoms among sedentary workers is high. Interventions that promote occupational standing or walking have been found to reduce occupational sedentary time, but it is unclear whether these interventions ameliorate musculoskeletal symptoms in sedentary workers.

OBJECTIVES

To investigate the effectiveness of workplace interventions to increase standing or walking for decreasing musculoskeletal symptoms in sedentary workers.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, OSH UPDATE, PEDro, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) search portal up to January 2019. We also screened reference lists of primary studies and contacted experts to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-randomised controlled trials (cluster-RCTs), quasi RCTs, and controlled before-and-after (CBA) studies of interventions to reduce or break up workplace sitting by encouraging standing or walking in the workplace among workers with musculoskeletal symptoms. The primary outcome was self-reported intensity or presence of musculoskeletal symptoms by body region and the impact of musculoskeletal symptoms such as pain-related disability. We considered work performance and productivity, sickness absenteeism, and adverse events such as venous disorders or perinatal complications as secondary outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts, and full-text articles for study eligibility. These review authors independently extracted data and assessed risk of bias. We contacted study authors to request additional data when required. We used GRADE considerations to assess the quality of evidence provided by studies that contributed to the meta-analyses.

MAIN RESULTS

We found ten studies including three RCTs, five cluster RCTs, and two CBA studies with a total of 955 participants, all from high-income countries. Interventions targeted changes to the physical work environment such as provision of sit-stand or treadmill workstations (four studies), an activity tracker (two studies) for use in individual approaches, and multi-component interventions (five studies). We did not find any studies that specifically targeted only the organisational level components. Two studies assessed pain-related disability. Physical work environment There was no significant difference in the intensity of low back symptoms (standardised mean difference (SMD) -0.35, 95% confidence interval (CI) -0.80 to 0.10; 2 RCTs; low-quality evidence) nor in the intensity of upper back symptoms (SMD -0.48, 95% CI -.096 to 0.00; 2 RCTs; low-quality evidence) in the short term (less than six months) for interventions using sit-stand workstations compared to no intervention. No studies examined discomfort outcomes at medium (six to less than 12 months) or long term (12 months and more). No significant reduction in pain-related disability was noted when a sit-stand workstation was used compared to when no intervention was provided in the medium term (mean difference (MD) -0.4, 95% CI -2.70 to 1.90; 1 RCT; low-quality evidence). Individual approach There was no significant difference in the intensity or presence of low back symptoms (SMD -0.05, 95% CI -0.87 to 0.77; 2 RCTs; low-quality evidence), upper back symptoms (SMD -0.04, 95% CI -0.92 to 0.84; 2 RCTs; low-quality evidence), neck symptoms (SMD -0.05, 95% CI -0.68 to 0.78; 2 RCTs; low-quality evidence), shoulder symptoms (SMD -0.14, 95% CI -0.63 to 0.90; 2 RCTs; low-quality evidence), or elbow/wrist and hand symptoms (SMD -0.30, 95% CI -0.63 to 0.90; 2 RCTs; low-quality evidence) for interventions involving an activity tracker compared to an alternative intervention or no intervention in the short term. No studies provided outcomes at medium term, and only one study examined outcomes at long term. Organisational level No studies evaluated the effects of interventions solely targeted at the organisational level. Multi-component approach There was no significant difference in the proportion of participants reporting low back symptoms (risk ratio (RR) 0.93, 95% CI 0.69 to 1.27; 3 RCTs; low-quality evidence), neck symptoms (RR 1.00, 95% CI 0.76 to 1.32; 3 RCTs; low-quality evidence), shoulder symptoms (RR 0.83, 95% CI 0.12 to 5.80; 2 RCTs; very low-quality evidence), and upper back symptoms (RR 0.88, 95% CI 0.76 to 1.32; 3 RCTs; low-quality evidence) for interventions using a multi-component approach compared to no intervention in the short term. Only one RCT examined outcomes at medium term and found no significant difference in low back symptoms (MD -0.40, 95% CI -1.95 to 1.15; 1 RCT; low-quality evidence), upper back symptoms (MD -0.70, 95% CI -2.12 to 0.72; low-quality evidence), and leg symptoms (MD -0.80, 95% CI -2.49 to 0.89; low-quality evidence). There was no significant difference in the proportion of participants reporting low back symptoms (RR 0.89, 95% CI 0.57 to 1.40; 2 RCTs; low-quality evidence), neck symptoms (RR 0.67, 95% CI 0.41 to 1.08; two RCTs; low-quality evidence), and upper back symptoms (RR 0.52, 95% CI 0.08 to 3.29; 2 RCTs; low-quality evidence) for interventions using a multi-component approach compared to no intervention in the long term. There was a statistically significant reduction in pain-related disability following a multi-component intervention compared to no intervention in the medium term (MD -8.80, 95% CI -17.46 to -0.14; 1 RCT; low-quality evidence).

AUTHORS' CONCLUSIONS

Currently available limited evidence does not show that interventions to increase standing or walking in the workplace reduced musculoskeletal symptoms among sedentary workers at short-, medium-, or long-term follow up. The quality of evidence is low or very low, largely due to study design and small sample sizes. Although the results of this review are not statistically significant, some interventions targeting the physical work environment are suggestive of an intervention effect. Therefore, in the future, larger cluster-RCTs recruiting participants with baseline musculoskeletal symptoms and long-term outcomes are needed to determine whether interventions to increase standing or walking can reduce musculoskeletal symptoms among sedentary workers and can be sustained over time.

A preliminary study investigating functional movement screen test scores in female collegiate age horse-riders

The functional movement screen (FMS) is an easily administered and non-invasive tool to identify areas of weakness and asymmetry during specific exercises. FMS is a common method of athlete screening in many sports and is used to ascertain injury risk, but has to be used within an equestrian population. The aim of this study was to establish FMS scores for female collegiate age (18-26 years) riders, to inform a normative data set of FMS scores in horse riders in the future. Thirteen female collegiate horse riders (mean ± standard deviation (sd); age 21.5±1.4 years, height 167.2±5.76 cm, mass 60.69±5.3 kg) and 13 female collegiate non-riders (mean ± sd; age 22.5±2.1 years, height 166.5±5.7 cm, mass 61.5±4.9 kg) were assessed based on their performance on a 7-point FMS (deep squat, hurdle step, in-line lunge, shoulder mobility, active straight leg raise, trunk stability and rotary stability). The mean composite FMS scores (± sd) for the rider group was 14.15±1.9 and for the non-riders was 13.15±1.77. There was no statistically significant difference in median FMS composite scores between the rider and non-rider groups (Mann-Whitney U test, z=-1.249, P=0.223). However, 46% of riders and 69% of non-riders scored ≤14, indicating that a non-rider is 1.5 times (odds ratio) more likely to be at increased risk of injury compared to riders. Collegiate female riders scored higher than the non-rider population, but lower than seen in other sports suggesting some riders may be at risk of injury. Riders’ FMS scores demonstrated asymmetric movement patterns potentially limiting left lateral movement. Asymmetry has a potential impact on equestrian performance, limiting riders’ ability to apply the correct cues to the horse. The findings of such screening could inform the development of axillary training programmes to correct asymmetry pattern and target injury prevention.

Visual and instrumental diagnostics using chromokinegraphics: Reliability and validity for low back pain stratification

BACKGROUND

Low back pain patients have been suggested to exhibit dysfunctional spinal movement patterns. However, there is a lack of clinically applicable but valid and reliable assessment tools, helping to discriminate normal and pathologically altered movement.

OBJECTIVE

We aimed to examine whether kinematic parameters determined with an ultrasound-based motion analysis and thereof derived chromokinegraphical angle-time matrices (CATMAs) are able to discriminate between non-symptomatic and symptomatic movement behaviour in individuals with non-specific chronic (CLBP), specific low back pain (SLBP), and controls.

METHODS

Thoracic and lumbar spine range of motion (ROM [∘]); angular velocity (V [∘/sec]) and side-to-side differences [%] during a lateral flexion movement were assessed in 17 healthy participants, 16 individuals with CLBP and 11 SLBP patients. CATMAs ratings of two investigators (6-item Likert scale) were dichotomised, classifying the observed movement as physiological or non-physiological. Intrarater and interrater reliability were estimated using kappa statistics and Cronbach's Alpha. T-tests and a ROC analysis to determine optimal cut-offs for the separation of the collectives as well as contingency tables for selectivity of the cut-offs (motor outcomes) were calculated.

RESULTS

CATMA ratings displayed partly moderate to good (rater B; i.e. CLBP vs. controls) and partly insufficient discriminant validity (rater A). Due to this, inter-rater reliability was poor (k= 0.061 to 0.135), while intra-rater-reliability was moderate to good for both raters (k= 0.329 to 0.625) except for SLBP vs. controls (rater A; k=-0.18). Regarding kinematics, group differences occurred neither in ROM nor in V (p> 0.05), but in terms of the relative side comparison between CLBP and controls (p<0.05). ROC analysis (CLBP vs. controls) revealed an optimal cut-off at side asymmetries of 16.9% (ROM) and 28.9% (V). Between SLBP patients and controls, no significant differences were observed neither in terms of the absolute values nor the relative side differences of both kinematic variables.

CONCLUSIONS

Side asymmetries of V and ROM may be used to differentiate between controls and individuals with CLBP. CATMAs appear to be of limited diagnostic value for the identification of pathological spine movement.

Multi-segment spine kinematics: Relationship with dance training and low back pain

BACKGROUND

Spine posture, range of motion (ROM) and movement asymmetry can contribute to low back pain (LBP). These variables may have greater impact in populations required to perform repetitive spine movements, such as dancers; however, there is limited evidence to support this.

RESEARCH QUESTION

What is the influence of dance and LBP on spinal kinematics?

METHODS

In this cross-sectional study, multi-segment spinal kinematics were examined in 60 female participants, including dancers (n = 21) and non-dancers (n = 39) with LBP (n = 33) and without LBP (n = 27). A nine-camera motion analysis system sampling at 100 Hz was used to assess standing posture, as well as ROM and movement asymmetry for side bend and trunk rotation tasks. A two-way ANOVA was performed for each of the outcome variables to detect any differences between dancers and non-dancers, or individuals with and without LBP.

RESULTS

Compared to non-dancers, dancers displayed a flatter upper lumbar angle when standing (p < 0.01, ηp² = 0.15), and achieved greater frontal plane ROM for the upper lumbar (p = 0.04, ηp² = 0.08) and lower thoracic (p = 0.02, ηp² = 0.09) segments. There were no differences between dancers and non-dancers for transverse plane ROM (p > 0.05) or movement asymmetry (p > 0.05). There was no main effect for LBP symptoms on any kinematic measures, and no interaction effect for dance group and LBP on spinal kinematics (p > 0.05).

SIGNIFICANCE

Female dancers displayed a flatter spine posture and increased spine ROM compared to non-dancers for a select number of spine segments and movement tasks. However, the overall number of differences was small, and no relationship was observed between LBP and spinal kinematics. This suggests that these simple, static posture, ROM, and asymmetry measures often used in clinical practice can provide only limited generalisable information about the impact of dance or LBP on spinal kinematics.

Associations of office workers' objectively assessed occupational sitting, standing and stepping time with musculoskeletal symptoms

We examined the association of musculoskeletal symptoms (MSS) with workplace sitting, standing and stepping time, as well as sitting and standing time accumulation (i.e. usual bout duration of these activities), measured objectively with the activPAL3 monitor. Using baseline data from the Stand Up Victoria trial (216 office workers, 14 workplaces), cross-sectional associations of occupational activities with self-reported MSS (low-back, upper and lower extremity symptoms in the last three months) were examined using probit regression, correcting for clustering and adjusting for confounders. Sitting bout duration was significantly (p < 0.05) associated, non-linearly, with MSS, such that those in the middle tertile displayed the highest prevalence of upper extremity symptoms. Other associations were non-significant but sometimes involved large differences in symptom prevalence (e.g. 38%) by activity. Though causation is unclear, these non-linear associations suggest that sitting and its alternatives (i.e. standing and stepping) interact with MSS and this should be considered when designing safe work systems. Practitioner summary: We studied associations of objectively assessed occupational activities with musculoskeletal symptoms in office workers. Workers who accumulated longer sitting bouts reported fewer upper extremity symptoms. Total activity duration was not significantly associated with musculoskeletal symptoms. We underline the importance of considering total volumes and patterns of activity time in musculoskeletal research.

Gait analysis of pregnant patients with lumbopelvic pain using inertial sensor

BACKGROUND

Lumbopelvic pain (LPP) is one of the most common discomforts during pregnancy. However, few studies have evaluated relation between LPP and gait in pregnancy quantitatively.

RESEARCH QUESTION

This study aimed to investigate the relation between the LPP and gait characteristics such as symmetry, stability, and the degree of motion during pregnancy.

METHODS

Gait data were collected for fifty-two pregnant women between the third and tenth month of pregnancy on smooth, horizontal walkway by using inertial measurement sensor units attached to the participants' lumbar. The degrees of trunk movement, movement symmetry, gait variability, and symmetry of rotation were expressed as the root mean square (RMS), autocorrelation peak (AC), coefficient of variance (CV), and the degree of asymmetry at the approximate amount of angular variation (DA) respectively, which were calculated from measured acceleration data and angular velocity data. An independent t-test was performed to investigate differences in these gait parameters between LPP group and pain free group classified according to the presence or absence of the pain, which is evaluated by using a questionnaire. In addition, LPP group was divided into 5 subgroups based on the types of pain, and the differences between the groups were also investigated by using a one way ANOVA.

RESULTS

Rotational asymmetry was observed in movement of the roll direction of the LPP patients. The DA of the roll angle of the LPP group was significantly greater than that in the pain free group (0.140 ± 0.093 vs. 0.077 ± 0.053, respectively; p =  0.004). In the analysis of pain complications, the significant difference in DA of roll angle, and CV of yaw angle were observed.

SIGNIFICANCE

The results indicated that motion asymmetry of both rotation and translation increased significantly in LPP patients' gait.

A Brief Self-Directed Intervention to Reduce Office Employees' Sedentary Behavior in a Flexible Workplace

OBJECTIVE

The aim of the study was to assess changes in employees' sedentary behavior after a brief self-directed intervention in a flexible workplace.

METHODS

A total of 30 employees (69% female; 39.5 ± 9 years) completed an online questionnaire before and after a 6-week intervention. The intervention comprised one group-based action planning session, using a smart activity tracker for self-monitoring, weekly email reminders, and a healthy living seminar.

RESULTS

Total self-reported sitting time (including occupational and nonoccupational sitting) decreased nonsignificantly on days when working at the office (MΔ = -56 min/d, 95% confidence interval [CI], -128.5 to 17.0) and increased nonsignificantly when working at home (MΔ = 20.5 min/d, 95% CI, -64.5 to 105.5). The program had high acceptability in this participant group.

CONCLUSIONS

Brief self-directed interventions using activity tracker devices show promise and may be highly acceptable in a flexible workplace. Additional strategies may be needed to create change in sedentary behavior.

Is there evidence to use kinematic/kinetic measures clinically in low back pain patients? A systematic review

BACKGROUND

Currently, there is a widespread reliance on self-reported questionnaires to assess low back pain patients. However, it has been suggested that objective measures of low back pain patients' functional status should be used to aid clinical assessment. The aim of this study is to systematically review which kinematic /kinetic parameters have been used to assess low back pain patients against healthy controls and to propose clinical kinematic/kinetic measures.

METHODS

PubMed, Embase and Scopus databases were searched for relevant studies. Reference lists of selected studies and hand searches were performed. Studies had to compare people with and without non-specific low back pain while performing functional tasks and report body segment/joint kinematic and/or kinetic data. Two reviewers independently identified relevant papers.

FINDINGS

Sixty-two studies were included. Common biases identified were lack of assessor blinding and sample size calculation, use of samples of convenience, and poor experimental protocol standardization. Studies had small sample sizes. Range of motion maneuvers were the main task performed (33/62). Kinematic/kinetic data of different individual or combination of body segments/joints were reported among the studies, commonest was to assess the hip joint and lumbar segment motion (13/62). Only one study described full body movement. The most commonly reported outcome was range of motion. Statistically significant differences between controls and low back pain groups were reported for different outcomes among the studies. Moreover, when the same outcome was reported disagreements were noted.

INTERPRETATION

The literature to date offers limited and inconsistent evidence of kinematic/kinetic measures in low back pain patients that could be used clinically.

Relative mobility of the pelvis and spine during trunk axial rotation in chronic low back pain patients: A case-control study

Background

Trunk axial rotation is a risk factor for chronic low back pain (CLBP). The characteristics of rotational mobility in the pelvis and spine among CLBP patients are not fully understood.

Purpose

The purpose of this study was to examine three-dimensional kinematic changes, and to compare the differences of rotational mobility and coupled motion, in patients with and without CLBP.

Methods

Fifteen patients with CLBP and 15 age and sex matched healthy subjects participated in this study. Each subject performed trunk rotation to maximum range of motion (ROM) in a standing position. The kinematics data was collected using a three-dimensional motion analysis system. The outcomes measured were the rotational ROM and the spine/pelvis ratio (SPR) in transvers plane at both maximum and 50% rotation position. The coupled angles in sagittal and frontal planes were also measured.

Results

No significant differences in rotational ROM of the thorax, pelvis, and spine were observed between two groups at maximum rotation position. However, there was a significant interaction between groups and rotational ROM of pelvis and spine (F = 4.57, p = 0.04), and the SPR in CLBP patients was significantly greater than that of the healthy subjects (CLBP; 0.50 ± 0.10 Control; 0.41 ± 0.12, p = 0.04). The results at 50% rotation position were similar to that at maximum rotation. This indicates a relative increase in spinal rotation in the CLBP patients during trunk rotation. Moreover, the CLBP patients exhibited a significantly higher anterior tilt of the pelvis and extension of the spine in the sagittal plane coupled with rotation.

Conclusions

CLBP patients had relative hyper rotational mobility of the spine as well as excessive spinal extension coupled with trunk rotation. These results suggest that uncoordinated trunk rotation might be a functional failure associated with CLBP.

Seat Pressure Distribution Characteristics During 1 Hour Sitting in Office Workers With and Without Chronic Low Back Pain

Background

Low back pain (LBP) is a major problem for office workers. Individuals adopting poor postures during prolonged sitting have a considerably increased risk of experiencing LBP. This study aimed to investigate seat pressure distribution characteristics, i.e., average pressure, peak pressure ratio, frequency of postural shift, and body perceived discomfort (BPD), during 1 hour of sitting among office workers with and without chronic LBP.

Methods

Forty-six participants (chronic LBP = 23, control = 23) typed a standardized text passage at a computer work station for an hour. A seat pressure mat device was used to collect the seat pressure distribution data. Body discomfort was assessed using the Body Perceived Discomfort scale.

Results

Office workers with chronic LBP sat significantly more asymmetrically than their healthy counterparts. During 1-hour sitting, all workers appeared to assume slumped sitting postures after 20 minutes of sitting. Healthy workers had significantly more frequent postural shifts than chronic LBP workers during prolonged sitting.

Conclusion

Different sitting characteristics between healthy and chronic LBP participants during 1 hour of sitting were found, including symmetry of sitting posture and frequency of postural shift. Further research should examine the roles of these sitting characteristics on the development of LBP.

Patterns of directional asymmetry in the pelvis and pelvic canal

OBJECTIVES

The human pelvis is unique among modern taxa for supporting both parturition of large brained young and obligate bipedalism. Though much work has focused on pelvic development and variation, little work has explored the presence or absence of asymmetry in the pelvis despite well-known patterns of asymmetry in other skeletal regions. This study investigated whether patterns of directional asymmetry (DA) could be observed in the pelvis or pelvic canal.

METHODS

Seventeen bilaterally paired osteometric measurements of the os coxae (34 measures in total) were taken from 128 skeletons (female n = 65, male n = 63) from recent human populations in five geographic regions. Paired sample t-tests and Mann-Whitney U-tests were used to investigate DA.

RESULTS

Results from a pooled sample of all individuals showed that the pelvis exhibited a left-bias in DA. In contrast, the pelvic canal exhibited a pattern in which the anterior canal exhibited a right-bias and the posterior canal exhibited a left-bias. Neither sex nor populational differences in DA were observed in the pelvis or pelvic canal.

CONCLUSIONS

The varying patterns of asymmetry uncovered here accord with prior work and may indicate that loading from the trunk and legs place differing stresses on the pelvis and canal, yielding these unequal asymmetries. However, this is speculative and the possible influence of genetics, biomechanics, and nutritional status on the development of pelvic and canal asymmetries presents a rich area for future study. Additionally, the potential influence of pelvic canal asymmetry on obstetric measures of pelvic capacity merits future research. Am. J. Hum. Biol. 28:804-810, 2016. © 2016Wiley Periodicals, Inc.

Inequality in leg length is important for the understanding of the pathophysiology of lumbar disc herniation

Objective:

Inequality in leg length may lead to to abnormal transmission of load across the endplates and degeneration lumbar spine and the disc space. There has been no study focusing on lumbar disc herniation (LDH) and leg length discrepancy. This subject was investigated in this study.

Materials and Methods:

Consecutive adult patients with leg length discrepancy and low back pain (LBP) admitted to our department were respectivelly studied.

Results:

A total number of 39 subjects (31 women and eight men) with leg length discrepancy and LBP and 43 (25 females and 18 males) patients with LBP as a control group were tested. Occurrence of disc herniation is statistically different between patients with hip dysplasia and control groups (P < 0.05).

Conclusion:

The results of this study showed a statistically significant association between leg length discrepancy and occurrence of LDH. The changes of spine anatomy with leg length discrepancy in hip dysplastic patients are of importance in understanding the nature of LDH.

Effects of a good posture belt on buttock pressure during cross-legged sitting

[Purpose] The purpose of the present study was to examine the effects of wearing a good posture belt on buttock pressure during cross-legged sitting. [Subjects] The study subjects were 34 adults who were divided into a good posture belt group (7 men, and 10 women) and a control group (7 men, and 10 women), with 17 subjects each. [Methods] Sensor mats were used to measure buttock pressure and changes in the total travel distance of the center of pressure, maximum pressure, and mean pressure. [Results] The good posture belt group showed smaller increments in center of pressure, maximum pressure, and mean pressure than the control group. [Conclusion] The use of the good posture belt during cross-legged sitting is considered to control the increment of buttock pressure, thereby greatly helping the maintenance of efficient postures.

Spinal, pelvic, and hip movement asymmetries in people with lower-limb amputation: Systematic review

Following amputation, people with transfemoral amputation (TFA) and transtibial amputation (TTA) adapt with asymmetrical movements in the spinal and lower-limb joints. The aim of this review is to describe the trunk, lumbopelvic, and hip joint movement asymmetries of the amputated limb of people with TFA and TTA during functional tasks as compared with the intact leg and/or referent leg of nondisabled controls. Electronic databases were searched from inception to February 2014. Studies with kinematic data comparing (1) amputated and intact leg and (2) amputated and referent leg of nondisabled controls were included (26 articles). Considerable heterogeneity in the studies precluded data pooling. During stance phase of walking in participants with TFA, there is moderate evidence for increased trunk lateral flexion toward the amputated limb as compared with the intact leg and increased anterior pelvic tilt as compared with nondisabled controls. None of the studies investigated spinal kinematics during other functional tasks such as running, ramp walking, stair climbing, or obstacle crossing in participants with TFA or TTA. Overall, persons with TFA adapt with trunk and pelvic movement asymmetries at the amputated limb to facilitate weight transfer during walking. Among participants with TTA, there is limited evidence of spinal and pelvic asymmetries during walking.

A preliminary study to evaluate postural improvement in subjects with scoliosis: active therapeutic movement version 2 device and home exercises using the Mulligan's mobilization-with-movement concept

OBJECTIVE

The purpose of this preliminary study was to determine if the use of Active Therapeutic Movement Version 2 (ATM2) device and home exercises using the Mulligan's mobilization-with-movement concept by subjects with scoliosis would result in postural improvement and to document any changes in trunk range of motion and quality of life.

METHODS

Forty-three subjects between the ages of 12 to 75 years were recruited for the study. Each subject underwent a low back evaluation along with specific measurements for their scoliosis. Subjects participated in a 4-week intervention, 2 times a week consisting of treatment utilizing the ATM2 and were also given a home exercise program to mimic the specific movement(s) they performed on the ATM2. Photographic assessment of posture was taken before and after the intervention. Subjects were surveyed during the initial assessment and again at the final intervention using the following outcome measures: Fear Avoidance Belief Questionnaire, Short-Form Health Survey-36, Oswestry Disability Index, and a Numeric Pain Rating Scale.

RESULTS

Results were significant for most of the variables measured. Subjects gained improvement in spinal ranges of motion for all directions except for flexion and extension (most subjects had reference range of flexion and extension at the beginning of the study). Most subjects had improved pelvic alignment after the intervention. Before and after photographs demonstrated improved posture. Subjective measurements of pain, disability, and quality of life improved.

CONCLUSIONS

Results of this preliminary study showed improvement for selected variables. The use of ATM2 and home exercises using the Mulligan's mobilization-with-movement concept by subjects with scoliosis appears to be a potentially viable conservative treatment alternative to address various findings associated with scoliosis, including posture improvement.

Biomechanical determinants of elite rowing technique and performance

In rowing, the parameters of injury, performance, and technique are all interrelated and in dynamic equilibrium. Whilst rowing requires extreme physical strength and endurance, a high level of skill and technique is essential to enable an effective transfer of power through the rowing sequence. This study aimed to determine discrete aspects of rowing technique, which strongly influence foot force production and asymmetries at the foot-stretchers, as these are biomechanical parameters often associated with performance and injury risk. Twenty elite female rowers performed an incremental rowing test on an instrumented rowing ergometer, which measured force at the handle and foot-stretchers, while three-dimensional kinematic recordings of the ankle, knee, hip, and lumbar-pelvic joints were made. Multiple regression analyses identified hip kinematics as a key predictor of foot force output (R(2)  = 0.48), whereas knee and lumbar-pelvic kinematics were the main determinants in optimizing the horizontal foot force component (R(2)  = .41). Bilateral asymmetries of the foot-stretchers were also seen to significantly influence lumbar-pelvic kinematics (R(2)  = 0.43) and pelvic twisting (R(2)  = 0.32) during the rowing stroke. These results provide biomechanical evidence toward aspects of technique that can be modified to optimize force output and performance, which can be of direct benefit to coaches and athletes.

Foot posture, leg length discrepancy and low back pain--their relationship and clinical management using foot orthoses--an overview

Mechanical low back pain (LBP) is a very common, expensive, and significant health issue in the western world. Functional musculoskeletal conditions are widely thought to cause mechanical low back pain. The role of foot posture and leg length discrepancy in contributing to abnormal biomechanics of the lumbopelvic region and low back pain is not sufficiently investigated. This critical review examines the evidence for the association between foot function, particularly pronation, and mechanical LBP. It also explores the evidence for a role for foot orthoses in the treatment of this condition. There is a body of evidence to support the notion that foot posture, particularly hyperpronation, is associated with mechanical low back pain. Mechanisms that have been put forward to account for this finding are based on either mechanical postural changes or alterations in muscular activity in the lumbar and pelvic muscles. More research is needed to explore and quantify the effects of foot orthoses on chronic low back pain, especially their effects on lumbopelvic muscle function and posture. The clinical implications of this work are significant since foot orthoses represent a simple and potentially effective therapeutic measure for a clinical condition of high personal and social burden.