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Background: Recently, the oscillatory bar has been proposed as a new and effective rehabilitation tool in people with nonspecific low back pain (NSLBP), although its effects on muscular control in this population have not been well documented, especially in lower extremity muscles and different support surface conditions.Objective: This study aimed to evaluate and compare the effects of flexi-bar use on stable and unstable surfaces on electromyographic activity of trunk and lower extremity muscles in healthy persons and those with NSLBP.Material and Methods: 18 healthy men and 18 men with NSLBP participated in this cross-sectional study. The root mean square value of electromyographic activity was calculated in the trunk and lower extremity muscles during 4 different task conditions: quiet standing (QS) or flexi-bar use on a rigid or foam support surface. A repeated measures test was used for statistical analysis.Results: The results showed that the amplitude activity of almost all muscles was significantly greater during flexi-bar use than in the QS condition (P

The central nervous system (CNS) dynamically employs a sophisticated weighting strategy of sensory input, including vision, vestibular and proprioception signals, towards attaining optimal postural control during different conditions. Non-specific low back pain (NSLBP) patients frequently demonstrate postural control deficiencies which are generally attributed to challenges in proprioceptive reweighting, where they often rely on an ankle strategy regardless of postural conditions. Such impairment could lead to potential loss of balance, increased risk of falling, and Low back pain recurrence. In this study, linear and non-linear indicators were extracted from center-of-pressure (COP) and trunk sagittal angle data based on 4 conditions of vibration positioning (vibration on the back, ankle, none or both), 2 surface conditions (foam or rigid), and 2 different groups (healthy and non-specific low back pain patients). Linear discriminant analysis (LDA) was performed on linear and non-linear indicators to identify the best sensory condition towards accurate distinction of non-specific low back pain patients from healthy controls. Two indicators: Phase Plane Portrait ML and Entropy ML with foam surface condition and both ankle and back vibration on, were able to completely differentiate the non-specific low back pain groups. The proposed methodology can help clinicians quantitatively assess the sensory status of non-specific low back pain patients at the initial phase of diagnosis and throughout treatment. Although the results demonstrated the potential effectiveness of our approach in Low back pain patient distinction, a larger and more diverse population is required for comprehensive validation.

Background/Purpose: To prevent falling, a common incident with debilitating health consequences among stroke survivors, it is important to identify significant fall risk factors (FRFs) towards developing and implementing predictive and preventive strategies and guidelines. This review provides a systematic approach for identifying the relevant FRFs and shedding light on future directions of research.Methods: A systematic search was conducted in 5 popular research databases. Studies investigating the FRFs in the stroke community were evaluated to identify the commonality and trend of FRFs in the relevant literature.Results: twenty-seven relevant articles were reviewed and analyzed spanning the years 1995–2020. The results confirmed that the most common FRFs were age (21/27, i.e., considered in 21 out of 27 studies), gender (21/27), motion-related measures (19/27), motor function/impairment (17/27), balance-related measures (16/27), and cognitive impairment (11/27). Among these factors, motion-related measures had the highest rate of significance (i.e., 84% or 16/19). Due to the high commonality of balance/motion-related measures, we further analyzed these factors. We identified a trend reflecting that subjective tools are increasingly being replaced by simple objective measures (e.g., 10-m walk), and most recently by quantitative measures based on detailed motion analysis.Conclusion: There remains a gap for a standardized systematic approach for selecting relevant FRFs in stroke fall risk literature. This study provides an evidence-based methodology to identify the relevant risk factors, as well as their commonalities and trends. Three significant areas for future research on post stroke fall risk assessment have been identified: 1) further exploration the efficacy of quantitative detailed motion analysis; 2) implementation of inertial measurement units as a cost-effective and accessible tool in clinics and beyond; and 3) investigation of the capability of cognitive-motor dual-task paradigms and their association with FRFs.

Background: Controlling pelvic excursions is the focus of stabilization exercises such as legs loading tasks in rehabilitation of non-specific chronic low back pain (NSCLBP) patients. Progression of these exercises is based on the ability to perform tasks with minimal sagittal pelvic excursions. In spite of emphasis on minimizing pelvic motions, no previous studies have investigated kinematic analysis of the pelvic excursions during leg loading exercises in NSCLBP patients. Objective: This study aims to investigate the sagittal pelvis excursion during performing asymmetric leg loading tasks in individuals with and without NSCLBP.Material and Methods: In this cross-sectional study, kinematic data were collected from 15 NSCLBP patients and 15 asymptomatic participants by a motion analysis system during right and left leg loading tasks with 2 levels of difficulty. Pelvis segments were modeled using Visual3D motion analysis software. Maximum pelvic excursion in the sagittal plane was calculated during each task. Mixed model analysis of variances (group, task difficulty level, side) was performed for statistical analysis.Results: The maximum sagittal pelvic excursion values of all tasks in NSCLBP were smaller than those in the control group; however, no significant main effects and interactions were found between two groups. Conclusion: These results suggest that NSCLBP patients completed loading tasks without differences in sagittal pelvic excursions as compared to controls. Assessment of NSCLBP patients only based on pelvic angular excursion may not be sufficient for clinical decision making. Furthermore, asymptomatic individuals may need to practice for controlling pelvic excursion during leg loading exercises similar to the CLBP patients.

Abstract Background Return to sport (RTS) criteria are widely being used to identify anterior cruciate ligament reconstructed (ACLR) athletes ready to return to sportive activity and reduce risk of ACL re-injury. However, studies show a high rate of ACL re-injury in athletes who passed RTS criteria. This indicates that the current RTS criteria might not be sufficient to determine return to sport time in ACLR athletes. Previous studies have reported a close association between altered lower limb kinematics and ACL re-injury. However, it is not clear how lower extremity kinematics differs between ACLR athletes who passed the RTS-criteria and who failed. This study compared lower extremity kinematics in a jump-landing task between ACLR athletes who passed the RTS criteria (Limb symmetry in hop tests, quadriceps strength and questionnaires) to those who failed and to the healthy individuals. Methods Participants were 27 male football players with unilateral ACLR including 14 who passed -RTS criteria and 13 failed, and 15 healthy football players. A 3D motion capture system recorded participants’ lower extremity motion while performing 10 trials of a bilateral jump-landing task. Hip, knee and ankle angular motion were examined at initial contact. Two-way mixed analysis of variances (2 limbs × 3 groups) and Bonferroni post-hoc tests were performed to compare the joint angles between the limbs and groups. Results lower hip abduction angle was found in the failed (involved limb 4.1 ° ± 4.2) and passed RTS (involved limb 6.8° ± 3.3) groups compared to the healthy group (non-dominant limb 10.7° ± 3.7). Ankle inversion in the failed RTS (0.4° ± 4.9) group was significantly lower than both passed RTS (4.8° ± 4.8, p = 0.05) and healthy (8.2° ± 8.1, p

Background: Spinal load and muscle activity in occupation settings is an area of increasing concern. Regarding technological advancements, in diverse occupations the spinal loads have increased through constrained seated postures. Back belts are consequently used in prophylactic and conservative management of occupational low back pain (LBP) in two distinct settings, prevention in industry, and treatment in LBP management. Industrial sites utilize belts for LBPprophylaxis on a large scale with their design and user experience (UE) influencing both the effectiveness and the workers’ compliance. This pilot study aims at determining the effectiveness of the new Tehran Back Belt (TBB) and assesses both UE and biomechanical effect (BE) on paraspinal muscle activity in healthy subjects. Methods: A pretest-posttest study. Stage-1, design and fabrication of the TBB. Stage-2, the UE of the designed belt evaluated in healthy volunteers (n=30) via a checklist. The BE was determined from the level of lumbar extensor and trunk flexor muscle activity gauged during two test conditions of sitting posture (with and without belt) over 35-minute periods. Results: Most subjects (>90%) reported high ‘ease of use’ and ‘comfort’ while wearing the TBB.The BE statistical analysis showed significantly reduced EMG activity levels for the longissimus(P = 0.012, η2=0.24), rectus abdominis (P=0.024, η2=0.18) and internal oblique (P=0.001,η2=0.44) muscles in belt-use conditions. Conclusion: Decreased muscle activity while using the TBB is potentially advantageous for workers as spinal muscle activity is significantly reduced. Further investigations for longer duration effects and during real work office-based activities are warranted.

Central nervous system (CNS) uses vision, vestibular, and somatosensory information to maintain body stability. Research has shown that there is more lumbar proprioception error among low back pain (LBP) individuals as compared to healthy people. In this study, two groups of 20 healthy people and 20 non-specific low back pain (NSLBP) participants took part in this investigation. This investigation focused on somatosensory sensors and in order to alter proprioception, a vibrator (frequency of 70 Hz, amplitude of 0.5 mm) was placed on the soleus muscle area of each leg and two vibrators were placed bilaterally across the lower back muscles. Individuals, whose vision was occluded, were placed on two surfaces (foam and rigid) on force plate, and trunk angles were recorded simultaneously. Tests were performed in eight separate trials; the independent variables were vibration (four levels) and surface (two levels) for within subjects and two groups (healthy and LBP) for between subjects (4 × 2 × 2). MANOVA and multi-factor ANOVA tests were done. Linear parameters for center of pressure (COP) [deviation of amplitude, deviation of velocity, phase plane portrait (PPP), and overall mean velocity] and non-linear parameters for COP and trunk angle [recurrence quantification analysis (RQA) and Lyapunov exponents] were chosen as dependent variables. Results indicated that NSLBP individuals relied more on ankle proprioception for postural stability. Similarly, RQA parameters for the COP on both sides and for the trunk sagittal angle indicated more repeated patterns of movement among the LBP cohort. Analysis of short and long Lyapunov exponents showed that people with LBP caused no use of all joints in their bodies (non-flexible), are less stable than healthy subjects.

Low back pain (LBP), the leading cause of disability worldwide, remains one of the most common and challenging problems in occupational musculoskeletal disorders. The effective assessment of LBP injury risk, and the design of appropriate treatment modalities and rehabilitation protocols, require accurate estimation of the mechanical spinal loads during different activities. This study aimed to: (1) develop a novel 2D beam-column finite element control-based model of the lumbar spine and compare its predictions for muscle forces and spinal loads to those resulting from a geometrically matched equilibrium-based model; (2) test, using the foregoing control-based finite element model, the validity of the follower load (FL) concept suggested in the geometrically matched model; and (3) investigate the effect of change in the magnitude of the external load on trunk muscle activation patterns. A simple 2D continuous beam-column model of the human lumbar spine, incorporating five pairs of Hill’s muscle models, was developed in the frontal plane. Bio-inspired fuzzy neuro-controllers were used to maintain a laterally bent posture under five different external loading conditions. Muscle forces were assigned based on minimizing the kinematic error between target and actual postures, while imposing a penalty on muscular activation levels. As compared to the geometrically matched model, our control-based model predicted similar patterns for muscle forces, but at considerably lower values. Moreover, irrespective of the external loading conditions, a near (

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.

The successful clinical application of patient-specific personalized medicine for the management of low back patients remains elusive. This study aimed to classify chronic nonspecific low back pain (NSLBP) patients using our previously developed and validated wearable inertial sensor (SHARIF-HMIS) for the assessment of trunk kinematic parameters. One hundred NSLBP patients consented to perform repetitive flexural movements in five different planes of motion (PLM): 0° in the sagittal plane, as well as 15° and 30° lateral rotation to the right and left, respectively. They were divided into three subgroups based on the STarT Back Screening Tool. The sensor was placed on the trunk of each patient. An ANOVA mixed model was conducted on the maximum and average angular velocity, linear acceleration and maximum jerk, respectively. The effect of the three-way interaction of Subgroup by direction by PLM on the mean trunk acceleration was significant. Subgrouping by STarT had no main effect on the kinematic indices in the sagittal plane, although significant effects were observed in the asymmetric directions. A significant difference was also identified during pre-rotation in the transverse plane, where the velocity and acceleration decreased while the jerk increased with increasing asymmetry. The acceleration during trunk flexion was significantly higher than that during extension, in contrast to the velocity, which was higher in extension. A Linear Discriminant Analysis, utilized for classification purposes, demonstrated that 51% of the total performance classifying the three STarT subgroups (65% for high risk) occurred at a position of 15° of rotation to the right during extension. Greater discrimination (67%) was obtained in the classification of the high risk vs. low-medium risk. This study provided a smart “sensor-based” practical methodology for quantitatively assessing and classifying NSLBP patients in clinical settings. The outcomes may also be utilized by leveraging cost-effective inertial sensors, already available in today’s smartphones, as objective tools for various health applications towards personalized precision medicine.

Objectives: To evaluate the reliability of head and trunk acceleration measured by MTx sensors during walking on Level and Irregular surfaces and to compare the differences between healthy young and old adults. Methods: Participants were 20 young female university students and 20 non-faller elderly women in Iran, 2013. Two MTX sensors were used to measure head and trunk accelerations in the vertical (VT), anterior-posterior (AP), and medial-lateral (ML) directions while participants walked on a 7-meter walkway. Results: ICC values in young group were higher as compared to non- faller elderly group; ICC was greater than 0.7 for 89.47%(34.38) of variables in young group and for 60.52%(23.38) in non- faller. Intersession reliability for upper trunk coordination indices in regular surface and in young group showed highest values as compared with other conditions in both groups, whereas the lowest intersession reliability was found in irregular floor surface indices in non-faller elderly group. Discussion: The calculated ICC, SEM, CV%, MDC values suggest that the MTX sensors provide precise recordings and detect small changes in upper trunk accelerometric parameters. ICC values were influenced by the age and the floor condition. In healthy young, all ICC values in regular surface were higher than 0.7. Floor condition effect was noticeable in elderly especially in ML direction. During walking on irregular surface, ML acceleration, velocity and harmonic ratio in elderly showed lower repeatability.

Although anxiety is a common non-motor outcome of Parkinson's disease (PD) affecting 40% of patients, little attention has been paid so far to its effects on balance impairment and postural control. Improvement of postural control through focusing on the environment (i.e. external focus) has been reported, but the role of anxiety, as a confounding variable, remains unclear.This study aimed to investigate the influence of anxiety and attentional focus instruction on the standing postural control of PD patients.Thirty-four patients with PD (17 with high anxiety (HA-PD) and 17 with low anxiety (LA-PD)), as well as 17 gender- and age-matched healthy control subjects (HC) participated in the study. Postural control was evaluated using a combination of two levels of postural difficulty (standing on a rigid force plate surface with open eyes (RO) and standing on a foam surface with open eyes (FO)), as well as three attentional focus instructions (internal, external and no focus).Only the HA-PD group demonstrated significant postural control impairment as compared to the control, as indicated by significantly greater postural sway measures. Moreover, external focus significantly reduced postural sway in all participants especially during the FO condition.The results of the current study provide evidence that anxiety influences balance control and postural stability in patients with PD, particularly those with high levels of anxiety. The results also confirmed that external focus is a potential strategy that significantly improves the postural control of these patients. Further investigation of clinical applicability is warranted towards developing effective therapeutic and rehabilitative treatment plans.

Introduction: The effect of interventions in forms of changing body posture on Pelvic Floor Muscles (PFM) function is discussed in recent years. The present study was aimed to investigate the effects of changes in pelvic posture, also PFM and Transversus Abdominis Muscle (TrA) contractions on some continence ultrasonic parameters in women with and without Stress Urinary Incontinence (SUI). Materials and methods: Twenty-one women with SUI and twenty matched incontinent women, (mean age 42.7 and 39.2 years, respectively) were recruited to the study. We assessed some continence ultrasonic parameters via Trans Labial Ultrasonography (TLUS) in neutral standing position, during anterior and posterior pelvic tilt, PFM and TrA contractions. Shapiro-Wilk, Student t-test, Repeated measures ANOVA, Bonferroni post hoc paired comparisons, and Pearson tests were performed to analyze the data. The significance level was set as P < 0.05. Results: Regarding ultrasonic assessment, the main effect of intervention was significant on the angels of Alpha, Gamma and Levator plate (P < 0.05) with no significant effect on the Beta angle (P > 0.05). There was a significant difference in effect, of posterior pelvic tilt on Gamma and Levator plate angles between the two groups (P < 0.05). Anterior pelvic tilt resulted in an increase in Gamma angle in both groups ((P < 0.05). Conclusion: Posterior pelvic tilt results in changes in ultrasonic parameters towards increasing pelvic floor stability in comparison to the anterior pelvic tilt. Key Words: Pelvic Posture, Ultrasonography, Urinary Continence, Stress Urinary Incontinence.

مقدمه: کمردرد ناشی از فعاليت‌‌های باربرداری و نگهداشتن بار عامل مهمی در ايجاد ناتوانی عملکردی برای بيمار و ضررهای سنگين اقتصادی است. هنگام نگهداری بارهای متغير ديناميکي مقدار گشتاور وارده به ستون فقرات در حال تغيير است که می‌تواند تعادل را به مخاطره بيندازد. هدف از اين تحقيق، بررسی تکرارپذيری پايداری وضعيتي حين حفظ بار متغير ديناميکی به منظور ارزيابی دقيق‌تر ضايعات ستون فقرات کمری بود. مواد و روش‌ها: 24 مرد شامل 12 فرد مبتلا به کمردرد و 12 فرد سالم در اين مطالعه شرکت کردند. افراد بارهای ديناميکی را در دو وضعيت ايستاده و خميده تنه (8 حالت)، در زمان‌های مختلف يک جلسه آزمايش حفظ کردند. تکرارپذيری (Reliability) داده‌های صفحه نيرو شامل دامنه جابجايی (Displacement) و سرعت (Velocity) مرکز فشار (Center of pressure یا COP) و انحراف معيار آن‌ها در دو جهت قدامی- خلفی و طرفی طول مسير مرکز فشار مورد ارزيابی قرار گرفت. تکرارپذيری نسبی با استفاده از ضريب همبستگی درون گروهی (Intraclass correlation coefficient یا ICC) و تکرارپذيری مطلق با استفاده از خطای معيار اندازه‌گيری (SEM یا Standard error of measurement) و حداقل تغيير قابل اندازه‌گيري (Minimal metrically detectable change یا MMDC) محاسبه گرديد. یافته‌ها: از ميان پارامترهای مرکز فشار، سرعت مرکز فشار در جهت طرفی در افراد سالم (9/0-8/0)، سرعت و انحراف معيار سرعت مرکز فشار در جهت قدامی- خلفی در افراد مبتلا به کمردرد (9/0-7/0)، تکرارپذيری بالايی را نشان دادند. تکرارپذيری دامنه جابجايی مرکز فشار در جهت قدامی– خلفی و انحراف معيار سرعت مرکز فشار در جهت طرفی در هر دو گروه مشابه بود (9/0-6/0). تکرارپذيری دامنه جابجايی مرکز فشار و انحراف معيار آن در جهت طرفی و نيز طول مسير مرکز فشار در افراد سالم بيشتر از افراد مبتلا به کمردرد بود، ولي تفاوت معني‌دار نبود. نتیجه گیری: به نظر می‌رسد سرعت مرکز فشار در دو جهت قدامی- خلفی و طرفی پارامتر مناسبی جهت ارزيابی پايداری وضعيتي حين حفظ بار ديناميکی در افراد مبتلا به کمردرد و افراد سالم باشد. کلید واژه‌ها: پايداری وضعيتي، تکرارپذيری، کمردرد غير اختصاصي، بار ديناميک

Human movement analysis is an important part of biomechanics and rehabilitation, for which many measurement systems are introduced. Among these, wearable devices have substantial biomedical applications, primarily since they can be implemented both in indoor and outdoor applications. In this study, a Trunk Motion System (TMS) using printed Body-Worn Sensors (BWS) is designed and developed. TMS can measure three-dimensional (3D) trunk motions, is lightweight, and is a portable and non-invasive system. After the recognition of sensor locations, twelve BWSs were printed on stretchable clothing with the purpose of measuring the 3D trunk movements. To integrate BWSs data, a neural network data fusion algorithm was used. The outcome of this algorithm along with the actual 3D anatomical movements (obtained by Qualisys system) were used to calibrate the TMS. Three healthy participants with different physical characteristics participated in the calibration tests. Seven different tasks (each repeated three times) were performed, involving five planar, and two multiplanar movements. Results showed that the accuracy of TMS system was less than 1.0°, 0.8°, 0.6°, 0.8°, 0.9°, and 1.3° for flexion/extension, left/right lateral bending, left/right axial rotation, and multi-planar motions, respectively. In addition, the accuracy of TMS for the identified movement was less than 2.7°. TMS, developed to monitor and measure the trunk orientations, can have diverse applications in clinical, biomechanical, and ergonomic studies to prevent musculoskeletal injuries, and to determine the impact of interventions.

Introduction: One of the most common diseases associated with musculo-skeletal ailment is low back pain which is epidemic among general public. If manual tasks are performed inappropriately by workers at workplaces, it may cause back pain in the lumbar spine. In recent years, a variety of assistive devices has been developed and employed to utilize a passive force generator which has been proved to be effective in decreasing lumbar moments and the force requirements by Erector Spinae muscles. In forward flexion, trunk muscles sustain a balance between the weight of upper body and external loads. Because of small moment arm of these muscles, they can create great forces that may lead to high intradiscal pressure and cause disc injury. The aim of this paper is to present a new Wearable Assistive Device that decreases trunk muscle activity during static holding task. The performance of this device is simulated biomechanically with link-segment model. Materials and Methods: Using ANYBODY software, compressive and shearing forces and also muscle activity of Lumbar were determined. To validate the results, electromyography (EMG) of fifteen males’ muscles participated in the study was analyzed. Results: Results of link-segment model indicated that there was a reduction in the Lumbar moment by 15- 23% using WAD. Moreover ANYBODY model demonstrated that compressive and shearing forces decreased by 24% and 29% respectively in average and muscle activities decreased by 18-25%, too. Statistical analysis indicated that normalized electromyography of right and left Lumbar, Thoracic Erector Spinae and Latissimus Dorsi muscles had significantly decreased by 21.9%, 20.4%, 23.6%, 20.4%, 23.7%, and 16.7% (p