salman nazary

In line with health promotion plans, early intervention and fall prevention in geriatric population, it is important to study healthy individuals balance mechanisms. The aim of this research was to investigate the effect of adding and removing visual input and dual task on elderly balance.
Twenty healthy elderly recruited from four different senior citizen health club centers and from the University of Social Welfare and Rehabilitation Sciences (USWR) participated in this analytic cross-sectional study. At USWR’s Motor Control Laboratory, the participants’ postural sway were assessed using force plate in 4 distinct double leg standing conditions with and without presence of visual input and Stroop dual task. Postural and Stroop variables were compared.
Findings indicated that when the elderly encountered with either dual task or absence of visual input, they can still manage the situation in a way that changes in sway parameter would not become significant. But, when these two conditions occurred simultaneously, the participant’s balance strategy fluctuated. Therefore, the mean velocity showed a significant difference between the "single quiet standing" condition and the condition of standing with eyes closed while the participants were answering Stroop dual task (Mean difference = -0.007, 95% CI = -0.012, -0.002).
It appears that velocity parameter is sensitive to small changes, so it is recommended that researchers include this parameter in their future analyses. Balance in elderly can be manipulated by dual task and visual input deprivation.

The purpose of the present study was to examine the reliability of scapular kinematic measurements using motion analysis system in subjects with and without General Hypermobility Syndrome.
A methodological study was designed to assess the reliability of scapular movement measurement in two groups of females with and without General Hypermobility Syndrome. Upward rotation, superior- inferior translation, medial-lateral translation, posterior tilt and medial rotation were measured during arm elevation in both frontal and sagittal planes using a motion analysis system. Intraclass Correlation Coefficient (ICC) and Standard Error Measurement (SEM) were used to assess intra-rater within-day reliability of the scapular kinematics measurements in both groups.
The ICC values ranged from 0.72 to 0.98 and 0.69 to 0.98 for GHS and healthy subjects, respectively. In addition, the results showed that SEM for scapular rotation and translation are always lower than 1.72º and 1.65 cm, respectively.
Motion analysis system could be used as a reliable method to measure the scapular kinematics in subjects with and without General Hypermobility Syndrome.

The present study aimed to determine the effect of dual-tasking on spatiotemporal characteristics in subjects with and without Anterior Cruciate Ligament Deficiency (ACLD) using linear dynamics. In this mixed model design study, spatiotemporal parameters were measured in 22 patients with ACLD (25.95±4.69 y) and 22 control subjects (24.32±3.37 y) while they were walking with different levels of gait velocity (high velocity, self-selected velocity, low velocity) in isolation or concurrently with auditory Stroop task. Coefficient of Variation (CV) was used to calculate variability of step length, step time and step width as dependent variables using custommade MATLAB code. Mixed model of analysis of variance and post hoc analyses were used for data analysis. The results showed that interactions of group by gait velocity due to cognitive difficulty were not significant for all mentioned variables (P>0.05). Group Interactions due to cognitive task difficulty were significant only in CV of step width (P=0.05). Interactions of motor task difficulty by cognitive difficulty were significant for CV of step length, step time, and step width in all participants (P<0.05). The main effects of gait velocity in all dependent variables were significant (P<0.05). Results showed that step width variability is a more sensitive measure for detecting interaction of group due to cognitive task difficulty compared to variability of step length and step time. Future studies could test this hypothesis in ACL deficient subjects using different measures.

Numerous studies showed increasing incidence of acute or recurrent dislocations of the shoulder joint in people with General Hypermobility Syndrome (GHS). Given the critical role of scapular orientation in function of shoulder, the aim of this study is to compare the parameters indicating position and orientation of scapula between females with and without General Hypermobility Syndrome in frontal and sagital plane in arm elevation. In this cross sectional and case-control study, 16 females with General Hypermobility Syndrome were selected simply and conveniently and 16 healthy females were selected and matched by age, body mass index and menstrual status. A three dimensional motion analysis system (vicon 460) was used to measure scapular position (upper-lower and medial-lateral translations) and orientation (upward rotation, posterior tilt and internal rotation angle). Measurement were taken with the arm placed in different angles of arm elevation. Date analysis was performed with Independent T test. Upward rotation angles in sagital plane in 90º (P=0.03), 120º (P=0.01) and full range of arm elevation (P=0.04) were lower in case group as compared to control group. Also patients with General Hypermobility Syndrome showed a lesser amount of lateral scapular translation in 90º (P=0.02) and full range of sagital plane arm elevation (P=0.02). In addition, lateral scapular translation in 120º (P=0.02) and full range of frontal plane arm elevation (P=0.01) was lower in case group compared with control group. Altered kinematics in General Hypermobility Syndrome has a greater role in shoulder injuries and neuromuscular defect seems to be an underlying cause of scapular kinematic's changes in people with hypermobility syndrome.