Sharif Digital Repository

A previous review concluded that postural sway is increased in patients with low back pain (LBP). However, more detailed analysis of the literature shows that postural deficit may be dependent on experimental conditions in which patients with LBP have been assessed. The research question to be answered in this review was: " Is there any difference in postural sway between subjects with and without LBP across several sensory manipulation conditions?" A literature search in Pubmed, Scopus, Embase and PsychInfo was performed followed by hand search and contact with authors. Studies investigating postural sway during bipedal stance without applying external forces in patients with specific and... 

Objectives: Previous research has shown inconsistent findings regarding muscle endurance in chronic low back pain (CLBP). Questions also remain about muscle endurance in patients with clinical instability. The aim of this study was to investigate trunk muscles strength and endurance in CLBP patients with and without clinical instability. Methods: 32 CLBP patients (15 with and 17 without clinical instability) and 39 matched healthy subjects participated in this study. The standing extension test was performed to assess the strength and endurance of the lumbar extensors while recording their electromyographic activity. The patients' disability was evaluated using the Oswestry and Roland-Morris... 

The role of motor control in development of low back pain is subject of many researches both in theoretical and experimental fields. In this work flexion-extension movement of lumbar spine have been controlled by three different methods, including feedback linearization (FBL), PD control and their combinations. The model involves 7 links: 1 link for pelvis, 5 links for lumbar vertebrae and 1 link for trunk. Torque actuators have been used on each joint to make them follow desired trajectory. In linear control method, equations of motion have been linearized with respect to upright position and then control signals have been applied in the direction of eigenvectors. Robustness of each method... 

In biomechanical modeling of spine, the prediction of spinal loading during occupational activities is crucial in assessment of the risk of low back pain and injury of spine. Current biomechanical models are based on the average data. Hence, they are unable to predict the effects of the observed natural anatomical variations on muscles moment arms and lines of action, while these variations ultimately influence the required muscular forces for balancing the external moments of any given task. In this work, a methodology based on the Monte Carlo technique has been developed to simulate spine geometry from T12 to S1 vertebrae for males. The lordosis of the assembled spine ranged between 21° to... 

From an ergonomic point of view, quantitative assessment of the feasibility of the task performance is an intricate process, which combines the multidimensional task demand profile with the individual's multidimensional performance capacity profile. Trunk muscle strength is affected by the trunk posture but it is not clear how the variability of trunk muscle is affected by the trunk posture or exertion level. A validated triaxial dynamometer, Sharif-LIST, was used for to model the surface response of trunk muscle extension strength variability as a function of trunk posture in the sagittal, coronal and transverse planes in standing position. Fifteen healthy males with no history of low back... 

Background Motor control exercise was claimed to improve spinal stability in patients with chronic non-specific back pain, but to investigate the effectiveness of this exercise, other outcome measures have been used rather than spinal stability itself. The aim of our study is to assess motor control exercise effects on spinal stability using a biomechanical model. Methods Fifty-one patients were assigned to either motor control or general exercises. Before and after trainings, participants were tested for spinal stability at seven isometric tasks. Electromyography signals were recorded from ten superficial muscles, and a hybrid EMG-driven musculoskeletal model estimated spinal stability... 

Inter-segmental coordination can be influenced by chronic low back pain (CLBP). The sagittal plane lower extremities inter-segmental coordination pattern and variability, in conjunction with the pelvis and trunk, were assessed in subjects with and without non-specific CLBP during free-speed walking. Kinematic data were collected from 10 non-specific CLBP and 10 non-CLBP control volunteers while the subjects were walking at their preferred speed. Sagittal plane time-normalized segmental angles and velocities were used to calculate continuous relative phase for each data point. Mean absolute relative phase (MARP) and deviation phase (DP) were derived to quantify the trunk-pelvis and bilateral... 

Background Wearing lumbosacral orthosis (LSO) is one of the most common treatments prescribed for conservative management of low back pain. Although the results of randomized controlled trials suggest effectiveness of LSO in reducing pain and disability in these patients, there is a concern that prolonged use of LSO may lead to trunk muscle weakness and atrophy. Purpose The present review aimed to evaluate available evidence in literature to determine whether LSO results in trunk muscle weakness or atrophy. Study Design This is a systematic review. Methods A systematic search of electronic databases including PubMed, Scopus, ScienceDirect, and Medline (via Ovid) followed by hand search of... 

STUDY DESIGN.: To quantify trunk muscle capability and controllability in different angles and levels of isometric exertion using a torque tracking system. OBJECTIVE.: To investigate the effect of biaxial isometric exertions on the maximum capability of trunk and to examine the effect of angle and level of isometric exertion on trunk controllability during the tracking task in upright posture. SUMMARY OF BACKGROUND DATA.: Combined motions of trunk at varying exertion levels occur in most daily and occupational activities and are important risk factors of low back pain. Few studies have investigated trunk capability and controllability during multidirectional activities with different... 

The study design is a prospective, case-control. The aim of this study was to develop a reliable measurement technique for the assessment of lumbar spine kinematics using digital video fluoroscopy in a group of patients with low back pain (LBP) and a control group. Lumbar segmental instability (LSI) is one subgroup of nonspecific LBP the diagnosis of which has not been clarified. The diagnosis of LSI has traditionally relied on the use of lateral functional (flexion-extension) radiographs but use of this method has proven unsatisfactory. Fifteen patients with chronic low back pain suspected to have LSI and 15 matched healthy subjects were recruited. Pulsed digital videofluoroscopy was used... 

Background: A few clinical trials have examined the effect of treatment interventions on postural control in patients with chronic low back pain, all of which have exclusively evaluated postural stability using traditional linear measures of postural sway. However, postural control improvement cannot be determined by exclusively relying on linear measurements, because these parameters provide no information on underlying motor control mechanisms. Objective: This study aimed to compare the effect of using lumbosacral orthoses (LSO) together with routine physical therapy, compared to routine physical therapy alone on postural control, using nonlinear analysis techniques. Methods: Forty-four... 

The characteristics of postural sway were assessed in quiet standing under three different postural task conditions in 14 patients with nonspecific chronic low back pain and 12 healthy subjects using linear and nonlinear center of pressure parameters. The linear parameters consisted of area, the mean total velocity, sway amplitude, the SD of velocity, and the phase plane portrait. The nonlinear parameters included the Lyapunov exponent, sample entropy, and the correlation dimension. The results showed that the amount of postural sway was higher in the patients with low back pain compared with the healthy subjects. Assessing the nonlinear parameters of the center of pressure showed a lower... 

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... 

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... 

Background: Work-related risk factors of low back disorders have been identified to be external moments, awkward postures, and asymmetrical dynamic lifting amongst others. The distinct role of asymmetry of load versus posture is hard to discern from the literature. Hence, the aim of this study is to measure isometric trunk exertions at upright standing posture at different exertion level and degree of asymmetry to further delineate the effects of exertion level and asymmetry on neuromuscular capability response. Methods: Fifteen healthy volunteers randomly performed trunk exertions at three levels (30%, 60%, and 100% of maximum voluntary exertion and five different angles (0°, 45°, 90°,... 

STUDY DESIGN. A cross-sectional study in pregnancy. OBJECTIVES. To differentiate between pregnancy related pelvic girdle pain (PGP) and low back pain (LBP) in Iranian women, and investigate the prevalence of each syndrome. SUMMARY OF BACKGROUND DATA. Most of the information about PGP and LBP has been obtained in Western countries. There are few studies to investigate pregnancy related lumbopelvic pain, and, especially, differentiate between PGP and LBP in non-Western countries, particularly in the Middle East. METHODS. This study included 325 pregnant women, ranging in age from 16 to 42 years. All pregnant women were interviewed using a questionnaire. Two trained physical therapists... 

STUDY DESIGN. Cross-cultural translation and psychometric testing were performed. OBJECTIVES. To cross-culturally translate the Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RDQ), and Quebec Back Pain Disability Scale (QDS) into Persian, and then investigate the psychometric properties of the Persian versions produced. SUMMARY OF BACKGROUND DATA. To the authors' knowledge, there is no validated instrument to measure functional status in Persian-speaking patients with low back pain (LBP) in Iran. To our knowledge, the widely used back-specific measures, the ODI, RDQ, and QDS, have not been translated and validated for Persian-speaking patients with LBP. METHODS. The... 

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... 

Background: The Central Sensitization Inventory (CSI) is a patient-reported tool to assess symptoms associated with central sensitization (CS). It consists of two parts: Part A assesses 25 somatic and emotional CS-related health symptoms, and part B asks if one has previously been diagnosed with a list of 10 Central Sensitivity Syndromes and related conditions. Objectives: The aim of this study was to translate and cross-culturally adapt the CSI into Persian and to evaluate its psychometric properties. Design: Cross-sectional study. Method: After completing the Persian translation, the psychometric properties of the Persian CSI (CSI-Per) were evaluated in 256 patients with chronic pain and... 

Study Design.: A descriptive overview of the literature. Objective.: To present a comprehensive descriptive overview of the published papers about epidemiologic features, burden, and current management of low back pain (LBP) in Iran. Summary OF Background Data.: Little is known about the epidemiology, burden, and management of LBP in developing and low- to middle-income countries, such as Iran. Methods.: A literature search was carried out using MEDLINE database to assess existing literature about prevalence, disease burden, impact, and current management of nonspecific LBP in Iran. Results.: Twenty-six articles matched inclusion criteria and included in the study. The findings related to...