Showing papers by "Mohamad Parnianpour published in 2009"
TL;DR: Mean total velocity and phase plane portrait parameters are suggested as good candidates to use for quantification and assessment of balance performance and identifying those with MSDs.
197 citations
TL;DR: Digital videofluoroscopy can assist in identifying better criteria for diagnosis of LSI in otherwise nonspecific low back pain patients in hope of providing more specific treatment.
Abstract: 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 to investigate kinematics of lumbar motion segments during flexion and extension movements in vivo. Intersegmental linear translation and angular displacement, and pathway of instantaneous center of rotation (PICR) were calculated for each lumbar motion segment. Movement pattern of lumbar spine between two groups and during the full sagittal plane range of motion were analyzed using ANOVA with repeated measures design. Intersegmental linear translation was significantly higher in patients during both flexion and extension movements at L5–S1 segment (p < 0.05). Arc length of PICR was significantly higher in patients for L1–L2 and L5–S1 motion segments during extension movement (p < 0.05). This study determined some kinematic differences between two groups during the full range of lumbar spine. Devices, such as digital videofluoroscopy can assist in identifying better criteria for diagnosis of LSI in otherwise nonspecific low back pain patients in hope of providing more specific treatment.
81 citations
TL;DR: The dual-tasking did not change the postural performance of nonspecific LBP subjects with low level of pain and disability differently compared to healthy subjects.
Abstract: Study design Three factors mixed-design with 1 between-subject and 2 within-subject factors. Objective To compare the main effects and interactions of postural and cognitive difficulty on quiet stance between subjects with and without nonspecific low back pain (LBP). Summary of background data The interference between postural control and cognitive tasks depends on factors such as sensorimotor/cognitive integrity. Changes in peripheral sensory and muscular systems as well as cognitive processes have been observed in LBP patients. It was hypothesized that the effect of cognitive task on postural performance might be different in subjects with nonspecific LBP as compared with healthy individuals. To the authors' knowledge this has not been investigated before. Methods Postural stability was measured by center of pressure parameters while nonspecific LBP (n = 22) and healthy (n = 22) subjects randomly performed quiet standing task with 3 levels of difficulty (rigid-surface eyes open, rigid-surface eyes-closed, and foam-surface eyes-closed) in isolation or concurrently with an easy or difficult digits backward cognitive task. Results Subjects with nonspecific LBP had less postural sway than healthy subjects, while postural sway decreased with increase in the level of cognitive difficulty. Nonspecific LBP and healthy subjects had larger postural sway at more difficult sensory conditions such as rigid-surface eyes-closed and foam-surface eyes-closed. The response to dual-tasking was not significantly different between the 2 groups. Conclusion The dual-tasking did not change the postural performance of nonspecific LBP subjects with low level of pain and disability differently compared to healthy subjects.
75 citations
TL;DR: This cognitive task did not appear to compromise postural control in ACL injured patients to a greater extent than unimpaired people and future studies should examine ACL patients with more severe disabilities and expose them to more demanding dynamic balance conditions to further explore dual-tasking effects.
65 citations
TL;DR: This book aims to provide a history of physical therapy in Iran from the 1950s to the present day and describes the development of modern physical therapy techniques in the country.
56 citations
13 Nov 2009
TL;DR: A robotic device was designed and developed for rehabilitation of upper limbs of post stroke patients and a novel force feedback bimanual working mode provided real-time dynamic sensation of the paretic hand.
Abstract: Robot-mediated rehabilitation is a rapidly advancing discipline that seeks to develop improved treatment procedures using new technologies, e.g., robotics, coupled with modern theories in neuroscience and rehabilitation. A robotic device was designed and developed for rehabilitation of upper limbs of post stroke patients. A novel force feedback bimanual working mode provided real-time dynamic sensation of the paretic hand. Results of the preliminary clinical tests revealed a quantitative evaluation of the patient’s level of paresis and disability.
27 citations
01 Aug 2009
TL;DR: The extensive capabilities and high reliability of the new triaxial isometric trunk strength measurement system are promising for more comprehensive investigations on the trunk biomechanics in future, e.g. isometric strength measurement at symmetric and asymmetric postures, muscle endurance, and recruitment pattern analysis.
Abstract: Maximal strength measurements of the trunk have been used to evaluate the maximum functional capacity of muscles and the potential mechanical overload or overuse of the lumbar spine tissues in order to estimate the risk of developing musculoskeletal injuries. A new triaxial isometric trunk strength measurement system was designed and developed in the present study, and its reliability and performance was investigated. The system consisted of three main revolute joints, equipped with torque sensors, which intersect at L5-S1 and adjustment facilities to fit the body anthropometry and to accommodate both symmetric and asymmetric postures in both seated and standing positions. The dynamics of the system was formulated to resolve validly the moment generated by trunk muscles in the three anatomic planes. The optimal gain and offset of the system were obtained using deadweights based on the least-squares linear regression analysis. The R2 results of calibration for all loading courses of all joints were higher than 0.99, which indicated an excellent linear correlation. The results of the validation analysis of the regression model suggested that the mean absolute error and the r.m.s. error were less than 2 per cent of the applied load. The maximum value of the minimum detectable change was found to be 1.63 Nm for the sagittal plane torque measurement, 0.8 per cent of the full-scale load. The trial-to-trial variability analysis of the device using deadweights provided intra-class correlation coefficients of higher than 0.99, suggesting excellent reliability. The cross-talk analysis of the device indicated maximum cross-talks of 1.7 per cent and 3.4 per cent when the system was subjected to flexion-extension and lateral bending torques respectively. The trial-to-trial variability of the system during in-vivo strength measurement tests resulted in good to excellent reliability, with intra-class correlation coefficients ranging from 0.69 to 0.91. The results of the maximum voluntary isometric torques exertion measurements for 30 subjects indicated good agreement with the previously published data in the literature. The extensive capabilities and high reliability of the system are promising for more comprehensive investigations on the trunk biomechanics in future, e.g. isometric strength measurement at symmetric and asymmetric postures, muscle endurance, and recruitment pattern analysis.
25 citations
TL;DR: Results indicate that higher abdominal coactivities should be avoided during heavier lifting tasks as they reduce stability margin while increasing spinal loads.
Abstract: A novel optimisation algorithm is developed to predict coactivity of abdominal muscles while accounting for both trunk stability via the lowest buckling load (P cr) and tissue loading via the axial compression (F c). A nonlinear multi-joint kinematics-driven model of the spine along with the response surface methodology are used to establish empirical expressions for P cr and F c as functions of abdominal muscle coactivities and external load magnitude during lifting in upright standing posture. A two-component objective function involving F c and P cr is defined. Due to opposite demands, abdominal coactivities that simultaneously maximise P cr and minimise F c cannot exist. Optimal solutions are thus identified while striking a compromise between requirements on trunk stability and risk of injury. The oblique muscles are found most efficient as compared with the rectus abdominus. Results indicate that higher abdominal coactivities should be avoided during heavier lifting tasks as they reduce stability ma...
20 citations
TL;DR: Predictions indicate the potential of the kinematics-driven model in ergonomics as well as training and rehabilitation programs and the trunk was found quite stable before release and in early post-release period.
18 citations
TL;DR: The results suggested that combined exertions and more strenuous efforts may impair trunk neuromuscular control, increasing the risk of low back pain.
Abstract: 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 exertion levels. METHODS Eighteen asymptomatic young male subjects performed isometric contractions of trunk muscles in 8 angles and 3 levels of exertion. The tracking system included a target, which was a thick line with a round endpoint. Subjects were asked to track the target line (path) and match the endpoint while maintaining torque for 3 seconds by exerting isometric contraction against B200 Isostation. The initial part of the tracking task was named path tracking phase and the final part, endpoint matching phase. Trunk capability was determined by measuring peak torque values obtained during maximal voluntary exertions. Trunk controllability was determined by measuring constant error and variable error during tracking tasks. Analysis of variance with repeated measures design was used to test the effects of angle and level of exertion on trunk capability and controllability. RESULTS Trunk capability was significantly decreased during biaxial exertions (P < 0.001). Constant error and variable error were significantly affected by angle (P < 0.001) and level (P < 0.001) of exertion during both phases of the tracking task. CONCLUSION Trunk capability and controllability were significantly decreased during biaxial exertions. Higher exertion levels had a major negative impact on trunk controllability in both uniaxial and biaxial exertions. The results suggested that combined exertions and more strenuous efforts may impair trunk neuromuscular control, increasing the risk of low back pain.
13 citations
TL;DR: The results of the present study showed that the Persian AIMS2-SF has reasonably good convergent validity, internal consistency, and test–retest reliability in patients with RA, and can now be applied in clinical settings and future outcome studies in Iran.
Abstract: Cultural adaptation and validation of the Persian version of the Arthritis Measurement Scales 2-Short Form (AIMS2-SF). The translation and cultural adaptation of the original questionnaire was carried out in accordance with published guidelines. Three hundred and fifty consecutive Persian-speaking patients with rheumatoid arthritis (RA) were asked to complete the AIMS2-SF, the Short Form Health Survey (SF-36), and four visual analog scales (VAS) for pain, joint stiffness, and patient’s and physician’s global assessment to test convergent validity. In addition, 90 randomly selected patients were asked to complete the questionnaire 48 h later for the second time. Moderate to high correlation were found between the AIMS2-SF and subscales of the SF-36 and VAS for pain, morning stiffness, and patient’s and physician’s global assessment. Cronbach’s alpha coefficient for the Persian AIMS2-SF scales ranged from 0.74 to 0.89. The Persian AIMS2-SF scales showed excellent test–retest reliability with Intraclass Correlation Coefficient ranging from 0.83–0.93 (p < 0.01). The results of the present study showed that the Persian AIMS2-SF has reasonably good convergent validity, internal consistency, and test–retest reliability in patients with RA. It can now be applied in clinical settings and future outcome studies in Iran.
Journal Article•
TL;DR: The intra- and inter-observer reliability of the bony landmark determination on both image and image-based 3D models were excellent and showed no significant difference for within and between-subject comparisons.
Abstract: Background/Objective: Consistent determination of the anatomical landmarks on image or image-based three dimensional (3D) models is a basic requirement for reliable analysis of the human joint kinematics using imaging techniques. We examined the intra- and inter-observer reliability of determination of the medial and lateral epicondyle landmarks on 2D MR images and 3D MRI-based models of the knee. Materials and Methods: Sixteen coronal plane MRI recordings were taken from 18 healthy knees using a knee coil with T2-weighted fast spin-echo sequence and 512×512 pixel size. They were then processed by the Mimics software to provide the coronal and axial plane views and to create a 3D image-based model of the femur. Each image was reviewed twice, at least one-day apart. The interclass correlation coefficient, standard error of measurement, and coefficient of variation were calculated to assess the intra- and inter-observer reliability of the landmark determination by six experienced radiologists. A mixed model analysis of variance (ANOVA) with two days of observation as the within-subject factor, and observers (six radiologists) and methods (2D vs. 3D) as between-subject factors were used to test the effect of observer, two days of observation and method of evaluation on landmark determination. Results: The results indicated that the interclass correlation coefficients for the intraobserver and inter-observer determination of landmarks on images and image-based 3D models were above 0.97. The standard error of measurement ranged between 0.41 and 0.78 mm for x; 1.35 and 3.43 mm for y; and 1.03 and 4.71 mm for z coordinates. Furthermore, the results showed no significant difference for within and between-subject comparisons of each coordinate of the lateral epicondyle as well as x and z coordinates of the medial epicondyle. For the y coordinate of the medial epicondyle, the p value of within-subject comparison was borderlinely significant (p=0.049). Conclusion: It was concluded that the intra- and inter-observer reliability of the bony landmark determination on both image and image-based 3D models were excellent.
TL;DR: The results showed that the Persian AIMS2 had reasonably good internal consistency, test-retest reliability, and convergent validity in patients with osteoarthritis of the knee and can be applied in the future studies in Iran.
Abstract: The Arthritis Impact Measurement Scales 2 (AIMS2) has not been translated and validated for Persian-speaking patients with osteoarthritis of the knee. This was to provide a validated instrument to measure functional disability and health-related quality of life in patients with osteoarthritis of the knee in Iran. The aim of this study was to culturally adapt and validate the AIMS2 for Persian-speaking patients with osteoarthritis of the knee in Iran. A consecutive sample of patients with knee osteoarthritis were asked to complete the AIMS2, the Short Form Health Survey (SF-36) and four visual analog scales for pain, joint stiffness, patient's and physician's global assessment. Internal consistency and convergent validity were applied to examine psychometric properties of the AIMS2. In addition, 30 randomly selected patients were asked to complete the questionnaire two days later for the second time for test-retest reliability. Finally factor structure of the Persian AIMS2 was performed using the principal component factor analysis. In all 230 patients were entered into the study. The mean (SD) age of the participants was 56.9 (8.7) years and the mean (SD) duration of disease was 7.2 (3.5) years. Cronbach's alpha coefficient and intraclass correlation coefficient (ICC) for the Persian AIMS2 scales ranged from 0.74 to 0.92 and 0.85 to 0.96, respectively. The correlation between most of the Persian AIMS2 scales and the physical and mental summary scores of the SF-36 and the visual analogue scales for pain, joint stiffness, patient's and physician's global assessment were statistically significant indicating a good convergent validity (p < 0.05). The results obtained from factor analysis indicated three latent factors that jointly accounted for 67.5% of the total variance. The results showed that the Persian AIMS2 had reasonably good internal consistency, test-retest reliability, and convergent validity in patients with osteoarthritis of the knee. It is simple and easy to use and now can be applied in the future studies in Iran. However, its sensitivity to change needs still to be studied.
TL;DR: The Persian version of the AIMS2-SF is a reliable and valid instrument to measure functional disability and health-related quality of life in patients with OA of the knee in Iran and now can be applied in clinical settings and future outcome studies in Iran.
Abstract: Purpose. To translate and validate the Persian version of the Arthritis Measurement Scales 2-Short Form (AIMS2-SF) in patients with osteoarthritis (OA) of the knee.Method. The translation and cultural adaptation of the original questionnaire was carried out in accordance with published guidelines. One hundred and fourteen consecutive Persian-speaking patients with OA of the knee were participated in this study. The Short Form Health Survey (SF-36) and visual analogue scales (VAS) for pain and joint stiffness were used to test convergent validity of the Persian AIMS2-SF. In addition, 35 randomly selected patients were asked to complete the questionnaire 3 days later for the second time.Results. The Persian AIMS2-SF showed statistically significant good convergent validity, as assessed with the relevant subscales of the Persian SF-36 and VAS for pain and joint stiffness. Cronbach's alpha coefficient for the Persian AIMS2-SF components ranged from 0.68 to 0.80. The Persian AIMS2-SF components showed good to ...