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Objective: This study aimed to compare sensory organization test and postural control strategies between individuals with mild and moderate-to-severe forward head posture (FHP)., Methods: A sensory organization test (SOT) was performed in 6 conditions using computerized dynamic posturography, to assess postural control. Equilibrium scores representing overall balance, strategy analysis to assess ankle vs hip strategy dominance, and sensory analysis (Somatosensory, visual, vestibular, visual preference ratio) as an indicator of the use of sensory systems were obtained., Results: Our results revealed a significant difference between the 2 groups in terms of equilibrium score (P < .05) and strategy scores (P < .05) in conditions of 4 to 6 of the SOT. The results of sensory analysis of SOT showed visual and vestibular ratios were significantly different between the 2 study groups (P < .05), but somatosensory and visual preference ratios were not significantly different between these 2 groups (P > .05)., Conclusion: Individuals with moderate-to-severe FHP swayed more in comparison with mild FHP ones in conditions with the Sway-referenced platform of the SOT. They tended to rely on the hip strategy more than the ankle strategy excessively when sensory difficulty increased. Overall, it can be concluded that individuals with moderate-to-severe FHP are more likely to have postural deficits., (Copyright © 2024. Published by Elsevier Inc.)

Objective: To assess the efficacy of virtual reality (VR)-based vs conventional balance training on the improvement of balance and reduction of falls in people with multiple sclerosis (PwMS)., Design: Single-blinded, randomized, controlled trial., Setting: Musculoskeletal Rehabilitation Research Center, Ahvaz Jundishapur University of Medical Sciences., Participants: PwMS (N=39), randomized into VR (n=19) and control (n=20) groups., Intervention: The VR group performed exergames using Kinect, while the control group accomplished conventional balance exercises. Both groups received 18 training sessions for 6 weeks., Main Outcome Measures: Limits of stability, timed Up and Go (TUG) test, and 10-m walk tests with and without cognitive task and their dual-task costs (DTCs), Berg Balance Scale, Multiple Sclerosis Walking Scale-12, Fall Efficacy Scale-International, Activities-specific Balance Confidence Scale, and fall history were obtained pre- and post intervention and after a 3-month follow-up., Results: At both post intervention and follow-up, TUG cognitive and DTCs on the TUG were significantly lower and the 10-m walk cognitive was significantly higher in the VR group. At follow-up, reaction time and the number of falls demonstrated significant differences favoring the VR group, whereas the directional control revealed significant difference in favor of the control group (P<.05). The other outcomes showed no statistically significant difference at post intervention or follow-up., Conclusions: Both the VR-based and conventional balance exercises improved balance and mobility in PwMS, while each acted better in improving certain aspects. VR-based training was more efficacious in enhancing cognitive-motor function and reducing falls, whereas conventional exercises led to better directional control. Further studies are needed to confirm the effectiveness of recruiting VR-based exercises in clinical settings., (Copyright © 2020 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

External focus (EF) of attention and continuous cognitive task (CCT) reduced postural sway in young and adult people owing to the automatic process of postural control, but their effects on postural control in athletes with musculoskeletal injury like anterior cruciate ligament (ACL) reconstruction are unclear. The present study aimed to reveal the effects of EF of attention and CCT on postural control in ACL reconstructed (ACL-R) athletes by comparing the pattern of the condition-group interaction between ACL-R and healthy athletes. The participants included healthy athletes (n = 20) and ACL-R athletes (n = 20). Postural control was examined during an operated leg stance on a wobble board positioned on a force plate. Three conditions were performed: single postural task (control condition), postural task with EF of attention (focusing on a planar leveling app in a smartphone placed on the wobble board) and postural task concurrent with CCT (three-digit sequence task). Measurement parameters, including sway area, amplitude, velocity, and mean power frequency (MPF), were the traditional center of pressure (COP) variables. A significant difference was found between ACL-R athletes and healthy subjects for the AP amplitude in the control condition as well as the ML amplitude in the CCT condition. Furthermore, in the ACL-R group, cognitive demand significantly decreased postural sway, while postural sway was not different between the conditions for the healthy group. Results also indicated that CCT significantly decreased sway velocity and increased mean power frequency in both groups, while EF of attention did not change any COP measures. Concurrent CCT decreases postural sway in ACL-R athletes, while it does not have significant effects on healthy subjects. EF of attention did not affect postural control in both study groups., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Falling is a significant problem in patients with multiple sclerosis (MS) and the majority of falls occur during dynamic activities. Recently, there have been evidences focusing on falls and local stability of walking based on dynamic system theory in the elderly as well as patients with cerebral concussion. However, in patient with MS, this relationship has not been fully investigated. The aim of this study was to investigate local stability of walking as a risk factor for falling in patients with MS., Methods: Seventy patients were assessed while walking at their preferred speed on a treadmill under single and dual task conditions. A cognitive task (backward counting) was used to assess the importance of dual tasking to fall risk. Trunk kinematics were collected using a cluster marker over the level of T 7 and a 7-camera motion capture system. To quantify local stability of walking, maximal finite-time Lyapunov exponent was calculated from a 12-dimensional state space reconstruction based on 3-dimensional trunk linear and angular velocity time series. Participants were classified as fallers (≥1) and non-fallers based on their prospective fall occurrence., Findings: 30 (43%) participants recorded ≥1 falls and were classified as fallers. The results of multiple logistic regression analysis revealed that short-term local dynamic stability in the single task condition (P<0.05, odds ratio=2.214 (1.037-4.726)) was the significant fall predictor., Interpretation: The results may indicate that the assessment of local stability of walking can identify patients who would benefit from gait retraining and fall prevention programs., (Copyright © 2019. Published by Elsevier Ltd.)

Background: Clinicians need a reliable and accurate tools that can best identify and classify balance impairments between mild and moderate to severe grades of knee osteoarthritis (OA)., Research Question: This study was designed to investigate the accuracy of postural measurements to discriminate between these two groups of knee OA., Methods: A total of 130 patients with knee OA based on the Kellgren-Lawrence (KL) grading scale were categorized into 65 patients with mild (a KL grade≤ 2) and 65 patient with moderate to severe (a KL grade≥3) radiographic sign. Static postural control was assessed on the force plate in three conditions of double leg stance with open (DO) and closed eyes (DC) and single leg stance with open eyes (SO). The accuracy for static postural control parameters was determined by calculation of sensitivity, specificity, area under the Receiver Operating Characteristic (ROC) curve (AUC) and likelihood ratios (LRs)., Results: Our results showed that standard deviation (SD) of velocity in anterior-posterior (AP) direction had the highest sensitivity and specificity in conditions of DO and DC, respectively. ROC curve analysis indicated that measures of mean and SD velocity in medio-lateral (ML) direction in conditions of DO and DC had acceptable levels of accuracy (AUC > 0.70) in discriminating between the two groups of knee OA patients. Also, based on LR results, SD of velocity in AP direction had the best ability for ruling in and ruling out moderate to severe grade of knee OA patients in conditions of DC and DO, respectively., Significance: Our findings provide evidence for selection of mean velocity and SD of velocity in identifying and discriminating static postural performance in patients with mild and moderate to severe grades of knee OA., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Introduction: Evaluating responsiveness has an important role in design and interpretation of the interventional studies. The aim was to estimate the responsiveness and minimally important difference (MID) of postural performance measures following balance rehabilitation in patients with Multiple Sclerosis (MS, n = 38)., Methods: Postural measures were evaluated at baseline and after 4 weeks intervention. Laboratory-based measures were center of pressure parameters. Clinically-based measures were Activities-specific Balance Confidence (ABC), Berg Balance Scale (BBS), Functional Gait Assessment (FGA); and walking measures 2 Minute Walk (2 MW), 10 Meter Timed Walk (10 MTW) and Timed Up and Go (TUG) performed under single and dual-task conditions. To evaluate responsiveness, we calculated the Receiver Operating Characteristics (ROC) and the Area Under the ROC Curve (AUC). The optimal values for the MID were the cutoffs corresponding to the upper left corner of the ROC curve., Results: The AUCs for mean and standard deviation of sway velocity were above the cutoff of 0.50 in most conditions. For the clinically-based measures, the highest AUCs were found for the ABC, and cognitive-2MW, followed by the BBS and 10 MTW., Conclusions: In this preliminary study, the most appropriate postural performance measures and the MID values for detecting meaningful changes in MS undergoing balance rehabilitation have been provided., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

While several studies have investigated the interaction between postural control and secondary cognitive tasks in stroke patients, little is known about the influence of secondary motor task on postural control in these patients. The current research was designed to further examine dual-task performance by comparing the effects of cognitive versus motor dual-tasks on postural performance and weight bearing asymmetry (WBA) in stroke patients (n=23) relative to healthy, matched controls (n=22). All participants stood on dual-force plate under 5 conditions: (1) free standing; (2) simple cognitive task (easy Stroop) while standing; (3) difficult cognitive task (difficult Stroop) while standing; (4) simple motor task (holding a tray while a cylinder lying on its flat side) while standing; and (5) difficult motor task (holding a tray while a cylinder lying on its round side) while standing. The center of pressure (COP) measures was greater in stroke patients than healthy controls. Also, the WBA of the patients was greater than the controls. The COP measures increased when moving from single-task to cognitive dual-task conditions. No significant effect of motor dual-tasking was seen when moving from single-task to motor dual-task conditions. However, in contrast to cognitive dual-tasking, stroke patients and healthy controls employed different strategies during simultaneous performance of postural and motor tasks. It can be suggested that performing a motor task while standing requires greater attentional resources compared to performing a cognitive task while standing and this resulted in greater dual-task interference on motor performance in the stroke patients., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The aim of this study was to determine the effects of cognitive task (silent backward counting) on postural control in patients with knee osteoarthritis (OA) (n = 25) as compared with asymptomatic controls (n = 25). Static postural control during quiet standing was assessed under different conditions including: (1) rigid surface-open eyes; (2) rigid surface-closed eyes; (3) foam surface-open eyes; and (4) foam surface-closed eyes. Dependent variables were center of pressure (COP) parameters and cognitive score. The results of this study showed that for most COP parameters, the patients with knee OA had greater postural sway than asymptomatic control subjects. Moreover, while cognitive loading affects postural sway in dual-task compared to single-task conditions, the pattern of change was not different between the two groups. Cognitive loading caused decreased postural sway in both groups. Future studies should select patients with more disability, choose more attention demanding cognitive tasks, and expose the subjects to dynamic balance situations to further explore the effect of cognitive loading on postural performance in this specific patient population.

The aim of this study was to investigate the amount of attention demands of postural control in patients with anterior cruciate ligament-reconstruction (ACL-R), by comparing the pattern of posture-cognition interaction between two groups of ACL-R patients (n=25) and healthy matched controls (n=25). All participants were examined during single-leg stance on a balance board under both single- and dual-task conditions in 4 dynamic balance tests. These tests were standing on the injured and uninjured legs with straight or flexed knees. The corresponding dominant and non-dominant legs of healthy group were considered as controls. Contact frequency and contact time were acquired as a measure of postural performance. Cognitive performance was assessed by counting the number of errors in a silent backward digit span task. The results of analysis of variance showed a significant higher contact frequency and longer contact time in patients with ACL-R compared to healthy matched controls (p<0.02). Moreover, the ACL-R patients showed a significantly higher contact frequency and longer contact time during dual-task compared to single-task conditions (p<0.01). This pattern of posture-cognition interference was not observed in the healthy control group. In conclusion, patients who had undergone ACL-R surgery demonstrated poorer balance stability during single-leg stance than healthy controls. Also, simultaneous execution of the cognitive task during standing caused a significant deterioration in postural stability which indicates decreased automaticity (increased attention demanding) of postural control in patients with ACL-R compared to healthy controls., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)