Search for: joint-instability
Article Computer Methods in Biomechanics and Biomedical Engineering ; Volume 11, Issue 3 , 2008 , Pages 291-299 ; 10255842 (ISSN) ; Shirazi Adl, A ; Parnianpour, M ; Sharif University of Technology
Using an iterative kinematics-driven nonlinear finite element model, relative efficiency of individual abdominal muscles in spinal stability in upright standing posture was investigated. Effect of load height on stability and muscle activities was also computed under different coactivity levels in abdominal muscles. The internal oblique was the most efficient muscle (compared with the external oblique and rectus abdominus) in providing stability while generating smaller spinal loads with lower fatigue rate of muscles. As the weight was held higher, stability deteriorated requiring additional flexor-extensor activities. The stabilising efficacy of abdominal muscles diminished at higher...
Test-retest reliabty of center of pressure measures of postural stability during quiet standing in a group with musculoskeletal disorders consisting of low back pain, anterior cruciate ligament injury and functional ankle instability, Article Gait and Posture ; Volume 29, Issue 3 , 2009 , Pages 460-464 ; 09666362 (ISSN) ; Hadian, M. R ; Mazaheri, M ; Negahban, H ; Ebrahimi, I ; Talebian, S ; Jafari, A. H ; Sanjari, M. A ; Sohani, S. M ; Parnianpour, M ; Sharif University of Technology
Reliability is a population-specific property, but to the authors' knowledge there has been no study to determine the test-retest reliability of the postural stability measures such as center of pressure (COP) measures in the population of patients with musculoskeletal disorders (MSDs), while their clinical applications have been presented in literature. So, 33 patients with low back pain (LBP), anterior cruciate ligament (ACL) injury and functional ankle instability (FAI) randomly completed postural measurements with three levels of difficulty (rigid surface-eyes open, rigid surface-eyes closed, and foam surface-eyes closed) in two sessions. COP data were used to calculate standard...
Kinematic analysis of dynamic lumbar motion in patients with lumbar segmental instability using digital videofluoroscopy, Article European Spine Journal ; Volume 18, Issue 11 , 2009 , Pages 1677-1685 ; 09406719 (ISSN) ; Maroufi, N ; Behtash, H ; Zekavat, H ; Parnianpour, M ; Sharif University of Technology
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...
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...
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...
Comparison of kinematics of ACL-deficient and healthy knees during passive flexion and isometric leg press, Article Knee ; Volume 20, Issue 6 , December , 2013 , Pages 505-510 ; 09680160 (ISSN) ; Shakourirad, A ; Talebian Moghaddam, S ; Olyaei, G ; Eslami, A ; Farahmand, F ; Sharif University of Technology
Background: Studying the kinematics of the ACL deficient (ACLD) knees, during different physiological activities and muscle contraction patterns, can improve our understanding of the joint's altered biomechanics due to ACL deficiency as well as the efficacy and safety of the rehabilitations exercises. Methods: Twenty-five male volunteers, including 11 normal and 14 unilateral ACLD subjects, participated in this study. The kinematics of the injured knees of the ACLD subjects was compared with their intact knees and the healthy group during passive flexion and isometric leg press with the knees flexed from full extension to 45° flexion, with 15° intervals. An accurate registration algorithm...
Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 222, Issue 1 , 2008 , Pages 75-88 ; 09544119 (ISSN) ; Farahmand, F ; Meghdari, A ; Sharif University of Technology
The effect of the variation in the femoral groove geometry on patellofemoral joint stability was studied using a two dimensional transverse plane model with deformable articular surfaces. The femoral and patellar bony structures were modelled as rigid bodies with their profiles expressed by splines. The articular cartilage was discretized into compression springs, distributed along the femoral and patellar profiles, based on the rigid-body spring model. The medial and lateral retinacula were modelled as linear tensile springs, and the quadriceps muscles and patellar tendon as strings with known tension. The anatomical data were obtained from the transverse plane magnetic resonance images of...
The effect of functional bracing on the arthrokinematics of anterior cruciate ligament injured knees during lunge exercise, Article Gait and Posture ; Volume 63 , 2018 , Pages 52-57 ; 09666362 (ISSN) ; Farahmand, F ; Esfandiarpour, F ; Golestanha, S. A ; Akbar, M ; Eskandari, A ; Mousavi, S. E ; Sharif University of Technology
Elsevier B.V 2018
Background: Functional knee braces are extensively used for partially and completely torn anterior cruciate ligament (ACL) patients and those who have undergone ACL graft reconstruction, in order to support the healing ACL, improve the joint's functional stability, and restore the normal joint kinematics. Research question: Does wearing braces alter the arthrokinematics of the ACL deficient knees during lung exercise? Methods: For ten male unilateral ACL deficient subjects, 3D knee models were reconstructed from CT images, acquired in rest position. Sagittal plane fluoroscopy was then performed throughout a complete cycle of lunge in braced and non-braced conditions. The 3D kinematics of the...