Search for: postural-balance
Article Disability and Rehabilitation: Assistive Technology ; Volume 13, Issue 2 , 2018 , Pages 173-177 ; 17483107 (ISSN) ; Arazpour, M ; Farahmand, F ; Bahramizadeh, M ; Fadayevatan, R ; Abdollahi, E ; Sharif University of Technology
Taylor and Francis Ltd 2018
Background and Aim: Aging often results in a decline in somatosensory function, and such changes are associated with diminished motor performance. Input noise can enhance sensory and motor function through a mechanism known as stochastic resonance (SR). This paper describes the development and testing of a new vibrating shoe to possibly assist the elderly patients in controlling their balance and decreasing their falling risks. Technique: The new vibrating shoe was evaluated to ascertain its ability to generate appropriate random and nonlinear vibrations. The vibratory shoe performance in two young subjects with decreased foot sensation and two elderly subjects in different static and...
Immediate effects of lumbosacral orthosis on postural stability in patients with low back pain: A preliminary study, Article Archives of Bone and Joint Surgery ; Volume 7, Issue 4 , 2019 , Pages 360-366 ; 23454644 (ISSN) ; Ebrahimi Takamjani, I ; Kamyab, M ; Asgari, M ; Parnianpour, M ; Sharif University of Technology
Mashhad University of Medical Sciences 2019
Background: Lumbosacral orthosis (LSO) is commonly used for the treatment of back pain. The clinical and mechanical effectiveness of this device has been repeatedly investigated in several studies; however, its sensorimotor effectiveness has been rarely considered. Regarding this, the aim of the current study was to investigate the effect of a non-extensible LSO on postural stability (as a construct of sensorimotor function) in patients with nonspecific chronic low back pain (LBP). Methods: This preliminary study was conducted on 17 patients with nonspecific chronic LBP using a single-group quasi-experimental design. Postural stability was measured while the participants were placed in a...
Article Topics in Stroke Rehabilitation ; Volume 22, Issue 5 , 2015 , Pages 335-341 ; 10749357 (ISSN) ; Taghizadeh, G ; Ghomashchi, H ; Parnianpour, M ; Khalaf, K ; Salehi, R ; Esteki, A ; Ebrahimi, I ; Sangelaji, B ; Sharif University of Technology
Taylor and Francis Ltd 2015
Background: Many studies have been conducted on the changes in the balance capabilities of stroke patients. However, results regarding the effects of dual-task activities on postural control in these patients have been variable. Objective: To evaluate the effects of a short-term memory task on the sway characteristics of stroke patients. Method: Center of pressure (COP) fluctuations were measured in three levels of postural difficulty (rigid surface with closed and open eyes and foamsurface with closed eyes), aswell as two levels of cognitive difficulty (easy and difficult). COP parameters included mean velocity, standard deviation of velocity in both medial-lateral (M.L) and...
Effects of human stature and muscle strength on the standing strategies: A computational biomechanical study, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 234, Issue 7 , 2020 , Pages 674-685 ; Azghani, M. R ; Parnianpour, M ; Khalaf, K ; Sharif University of Technology
SAGE Publications Ltd 2020
It has been hypothesized that the muscular efforts exerted during standing may be altered by changes in personal factors, such as the body stature and muscular strength. The goal of this work was to assess the contribution of leg muscles using a biomechanical model in different physical conditions and various initial postures. An optimized inverse dynamics model was employed to find the maximum muscular effort in 23,040 postures. The simulation results showed that mid-range knee flexion could help the healthy and strong individuals maintain balance, but those with weaker muscle strength required more knee flexion. Individuals of weak muscular constitution as well as those with tall stature...
Nonlinear dynamical structure of sway path during standing in patients with multiple sclerosis and in healthy controls is affected by changes in sensory input and cognitive load, Article Neuroscience Letters ; Volume 553 , 2013 , Pages 126-131 ; 03043940 (ISSN) ; Sanjari, M. A ; Mofateh, R ; Parnianpour, M ; Sharif University of Technology
Although several studies have applied traditional linear measures to evaluate postural control of patients with multiple sclerosis (MS), little is known about the nonlinear dynamics of this patient group. In this study, recurrence quantification analysis (RQA), a well documented nonlinear method, was used to compare the nonlinear dynamical structure of postural sway in two groups consisting of MS patients (. n=. 23) and healthy matched controls (. n=. 23). The study focuses on three levels of postural difficulty consisting of (1) standing on a rigid surface (force platform) with eyes open, (2) standing on a rigid surface with eyes closed, and (3) standing on a foam surface with eyes closed....
Low back pain and postural sway during quiet standing with and without sensory manipulation: A systematic review, Article Gait and Posture ; Volume 37, Issue 1 , 2013 , Pages 12-22 ; 09666362 (ISSN) ; Coenen, P ; Parnianpour, M ; Kiers, H ; van Dieen, J. H ; Sharif University of Technology
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...
Trunk muscles strength and endurance in chronic low back pain patients with and without clinical instability, Article Journal of Back and Musculoskeletal Rehabilitation ; Volume 25, Issue 2 , 2012 , Pages 123-129 ; 10538127 (ISSN) ; Maroufi, N ; Ebrahimi, I ; Farahmand, F ; Parnianpour, M ; Sharif University of Technology
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...
Article Gait and Posture ; Volume 31, Issue 1 , 2010 , Pages 116-121 ; 09666362 (ISSN) ; Salavati, M ; Negahban, H ; Sanjari, M. A ; Parnianpour, M ; Sharif University of Technology
Recurrence quantification analysis (RQA), a nonlinear method of postural analysis, was used to explore the effects of dual-tasking on postural performance in people with nonspecific low back pain (LBP) compared with healthy participants. Postural performance was quantified by RQA % recurrence, % determinism, entropy and trend. People with nonspecific LBP (n = 22) and unimpaired individuals (n = 22) randomly performed quiet standing tasks with three levels of difficulty (rigid-surface eyes open, rigid-surface eyes closed and foam-surface eyes closed). These tasks were performed in isolation or concurrently with an easy or difficult cognitive task. Increasing postural difficulty was associated...
The effects of dual-tasking on postural control in people with unilateral anterior cruciate ligament injury, Article Gait and Posture ; Volume 30, Issue 4 , 2009 , Pages 477-481 ; 09666362 (ISSN) ; Hadian, M. R ; Salavati, M ; Mazaheri, M ; Talebian, S ; Jafari, A. H ; Parnianpour, M ; Sharif University of Technology
Several studies have investigated postural control in anterior cruciate ligament (ACL) deficient patients; yet the contribution of cognitive processing (attention) in the postural control of these patients is still unclear. A dual-task design was used to determine the effects of a concurrent digit span memory task on standing balance in a group of ACL patients (n = 27) compared with a group of matched, healthy participants (n = 27). In double limb stance, three levels of postural difficulty were studies on a force platform (rigid surface with eyes open, rigid surface with eyes closed, and foam surface with eyes closed). There were three cognitive conditions (no cognitive task, easy cognitive...
Article Spine ; Volume 34, Issue 13 , 2009 , Pages 1415-1421 ; 03622436 (ISSN) ; Mazaheri, M ; Negahban, H ; Ebrahimi, I ; Jafari, A. H ; Kazemnejad, A ; Parnianpour, M ; Sharif University of Technology
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...
Time-course investigation of postural sway variability: Does anxiety exacerbate the sensory reweighting impairment in chronic stroke survivors?, Article Neuropsychologia ; Volume 127 , 2019 , Pages 185-194 ; 00283932 (ISSN) ; Azad, A ; Mehdizadeh, H ; Doostdar, A ; Hoseinpour, F ; Mehdizadeh, M ; Niazi Khatoon, J ; Shokouhyan, M. R ; Parnianpour, M ; Taghizadeh, G ; Khalaf, K ; Sharif University of Technology
Elsevier Ltd 2019
Although anxiety is one of the most prevalent psychological disorders in stroke survivors, its effect on sensory reweighting has not yet been fully studied. The aim of this work was to investigate how anticipation of collision avoidance events affects sensory reweighting in chronic stroke survivors with low and high levels of anxiety (LA-stroke and HA-stroke, respectively), as compared with healthy controls (HC), under the condition of perturbed proprioception. Eighteen LA-stroke and 18 HA-stroke survivors, as well as 18 gender- and age-matched HC, participated in this study. Postural sway variability (i.e. Root Mean Square (RMS) of the COP velocity) was measured for a duration of 180 s...
Reliability of recurrence quantification analysis measures of the center of pressure during standing in individuals with musculoskeletal disorders, Article Medical Engineering and Physics ; Volume 32, Issue 7 , 2010 , Pages 808-812 ; 13504533 (ISSN) ; Negahban, H ; Salavati, M ; Sanjari, M. A ; Parnianpour, M ; Sharif University of Technology
Although the application of nonlinear tools including recurrence quantification analysis (RQA) has increasingly grown in the recent years especially in balance-disordered populations, there have been few studies which determine their measurement properties. Therefore, a methodological study was performed to estimate the intersession and intrasession reliability of some dynamic features provided by RQA for nonlinear analysis of center of pressure (COP) signals recorded during quiet standing in a sample of patients with musculoskeletal disorders (MSDs) including low back pain (LBP), anterior cruciate ligament (ACL) injury and functional ankle instability (FAI). The subjects completed postural...
Goal equivalent manifold analysis of task performance in non-specific LBP and healthy subjects during repetitive trunk movement; effect of load, velocity, symmetry, Article Human Movement Science ; Volume 51 , 2017 , Pages 72-81 ; 01679457 (ISSN) ; Sanjari, M. A ; Mokhtarinia, H. R ; Jamshidi, A. A ; Maroufi, N ; Parnianpour, M ; Sharif University of Technology
Motor abundance allows reliability of motor performance despite its variability. The nature of this variability provides important information on the flexibility of control strategies. This feature of control may be affected by low back pain (LPB) and trunk flexion/extension conditions. Goal equivalent manifold (GEM) analysis was used to quantify the ability to exploit motor abundance during repeated trunk flexion/extension in healthy individuals and people with chronic non-specific LBP (CNSLBP). Kinematic data were collected from 22 healthy volunteers and 22 CNSLBP patients during metronomically timed, repeated trunk flexion/extension in three conditions of symmetry, velocity, and loading;...
Article Aging Clinical and Experimental Research ; Volume 30, Issue 7 , 2018 , Pages 713-726 ; 15940667 (ISSN) ; Arazpour, M ; Bahramizadeh, M ; Farahmand, F ; Fadayevatan, R ; Sharif University of Technology
Springer International Publishing 2018
Background and aim: Gait and balance disorders are common in the elderly populations, and their prevalence increases with age. This systematic review was performed to summarize the current evidence for subthreshold vibration interventions on postural control and gait in elderly. Method: A review of intervention studies including the following words in the title/abstract: insole, foot and ankle appliances, vibration, noise and elderly related to balance and gait. Databases searched included PubMed, ISI Web of Knowledge, Ovid, Scopus, and Google Scholar. Fifteen articles were selected for final evaluation. The procedure was followed using the preferred reporting items for systematic reviews...
Magnitude, symmetry and attenuation of upper body accelerations during walking in women: The role of age, fall history and walking surface, Article Maturitas ; Volume 139 , 2020 , Pages 49-56 ; Mazaheri, M ; van Schooten, K. S ; Asgari, M ; Mosallanezhad, Z ; Salavati, M ; Sedaghat Nejad, E ; Parnianpour, M ; Sharif University of Technology
Elsevier Ireland Ltd 2020
Objectives: The present experiment examined the role of age and fall history in upper body accelerations when walking on an even and on an uneven surface. Study design: An observational cross-sectional study. Main outcome measures: The magnitude (root mean square [RMS]), symmetry (harmonic ratio) and attenuation (attenuation coefficient) of upper body accelerations were quantified as primary outcomes; gait spatiotemporal parameters were measured as secondary outcomes. Methods: Twenty young adults (mean ± SD age: 29.00 ± 4.51 yrs), 20 older non-fallers (66.60 ± 5.43 yrs) and 20 older fallers (68.55 ± 4.86 yrs) walked on an even and on an uneven surface, while wearing four accelerometers...
How does the central nervous system address the kinetic redundancy in the lumbar spine? Three-dimensional isometric exertions with 18 Hill-model-based muscle fascicles at the L4-L5 level, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 224, Issue 3 , 2010 , Pages 487-501 ; 09544119 (ISSN) ; Khalaf, K ; Nassajian, M. R ; Nasseroleslami, B ; Parnianpour, M ; Sharif University of Technology
The human motor system is organized for execution of various motor tasks in a different and flexible manner. The kinetic redundancy in the human musculoskeletal system is a significant property by which the central nervous system achieves many complementary goals. An equilibrium-based biomechanical model of isometric three-dimensional exertions of trunk muscles has been developed. Following the definition and role of the uncontrolled manifold, the kinetic redundancy concept is explored in mathematical terms. The null space of the kinetically redundant system when a certain joint moment and/or stiffness are needed is derived and discussed. The aforementioned concepts have been illustrated,...