Walking Performance during Concurrent Cognitive and Motor Tasks in Individuals with Nonspecific Chronic Low Back Pain: A Case-Control Study.

Background: The present study aimed to compare the effects of simultaneous cognitive and motor tasks on walking performance between individuals with nonspecific chronic low back pain (NSCLBP) and healthy controls. Methods: A total of 20 patients with NSCLBP and 20 healthy controls participated in this study. They walked at their self-selected speed on a treadmill under 3 walking conditions in a randomized order: walking only, walking while performing a concurrent cognitive task, and walking while performing a concurrent motor task. Two-way repeated measure analysis of variance with additional post hoc comparison (Bonferroni test) was used to evaluate the effects of group and walking conditions on gait parameters. Results: The result showed a significant main effect of the group for swing time ( P = 0.012) and double support time (P = 0.021) in those with NSCLBP compared with healthy controls. Moreover, there was a significant interaction between the group and condition for cadence ( P = 0.004) and step width variability (P = 0.016).Regarding stride length variability and stride time variability, the analysis indicated a significant effect of condition (P = 0.002 and P = 0.030, respectively). In both groups, no significant differences were observed in gait parameters between motor dual task and single walking ( P > 0.05). Conclusion: Our findings indicated that those with NSCLBP adapted successfully to walking performance to maintain the performance of the concurrent cognitive task under the cognitive dual-task walking condition. Moreover, the present study observed no dual-task interference under the motor dual-task condition.

The Western Ontario and McMaster Universities Osteoarthritis, Lequesne Algofunctional index, Arthritis Impact Measurement Scale-short form, and Visual Analogue Scale in patients with knee osteoarthritis: responsiveness and minimal clinically important differences.

PURPOSE: The goal of this study was to see whether the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC), Lequesne Algofunctional index and the Arthritis Impact Measurement Scale-short form (AIMS2-SF) could changes after physiotherapy interventions (i.e., responsiveness) and to determine Minimal Clinically Important Difference (MCID) in the performance of the people with knee osteoarthritis. MATERIALS AND METHODS: A convenient sample of 116 people with knee osteoarthritis completed the tools at baseline and then again after 10 sessions physiotherapy intervention. Two techniques were used to determine responsiveness: The receiver operating characteristics (ROC) method and the correlation analysis. RESULT: All of the tools showed the AUC of greater than 0.70 (AUC ranges = 0.72 - 0.83). For the WOMAC, Lequesne Algofunctional index, AIMS2-SF and VAS-pain, optimal cutoff points were 12.5, 2.75, 4.5 and 2.5 points, respectively. The gamma correlation between WOMAC, Lequesne Algofunctional index, AIMS2-SF, VAS-pain, and Global Rating Change (GRC) scores was 0.55, 0.52, 0.40, and 0.46, respectively. CONCLUSION: In people with knee osteoarthritis, the WOMAC has the maximum responsiveness to clinical changes. The MCID values identify in this study will aid in determining whether or not an individual with knee osteoarthritis has undergone a true improvement since receiving physiotherapy. IMPLICATIONS FOR REHABILITATIONThe results of this study provide valuable information regarding to the ability of outcome measures to detect treatment effects in patients with knee osteoarthritis.The WOMAC questionnaire is a responsive tool to measure the changes in functional activity due to physiotherapy intervention in patients with knee osteoarthritis.A patient with knee osteoarthritis had to change at least 12.5 scores on the WOMAC to be judged as having clinically changed.

Validity and reliability of the Persian version of the STarT musculoskeletal tool.

BACKGROUND: The Subgrouping for Targeted Treatment (STarT) musculoskeletal (MSK) tool stratifies patients with MSK disorders (MSDs) into prognostic categories based on poor outcomes. PURPOSE: This study aimed at investigating the validity and reliability of the Persian STarT MSK tool in people suffering from painful MSDs in Iran. METHODS: A total of 593 subjects with painful MSDs including neck, shoulder, low back, knee, and multisite pain received and completed the STarT MSK tool, visual analog scale (VAS), EuroQol five-dimensions three-levels questionnaire (EQ-5D-3 L), short form-36 health survey questionnaire (SF-36), and Örebro musculoskeletal pain screening questionnaire (ÖMPSQ) in the first visit. To examine test-retest reliability, 234 patients completed the STarT MSK tool 2 days after the initial visit. RESULTS: In this study, 139 (23.5%), 266 (44.9%), and 188 (31.7%) participants were classified as low-, medium-, and high-risk groupings for poor outcomes, respectively. Spearman's correlation coefficient showed a strong relationship among Persian STarT MSK tool and EQ-5D-3 L (-0.78), SF-36 (-0.76), and OMPSQ (0.70). The results of known-group validity indicated that this tool could distinguish among the participants in different risk subgroups based on the scores of the ÖMPSQ, VAS, SF36, and EQ-5D-5 L (p < .001). No ceiling and floor effects were observed. Cronbach's alpha and intra-class correlation coefficient (ICC2,1) were acceptable (0.71) and excellent (0.98), respectively. CONCLUSION: The Persian version of STarT MSK tool has shown to be a valid and reliable instrument to stratify people with painful MSDs into low-, medium-, and high-risk subgroups based on persistent pain disability.

Complexity and variability of the center of pressure time series during quiet standing in patients with knee osteoarthritis.

BACKGROUND: While several studies have investigated the traditional linear measures in patients with knee osteoarthritis, no study has yet reported the non-linear structure of postural sway in these patients. METHODS: We used two non-linear methods, recurrence quantification analysis (percent of determinism-%DET) and central tendency measure, to respectively investigate differences in the complexity and variability of sway dynamics between two groups of knee osteoarthritis patients (n=27) and healthy controls (n=27) under different conditions of postural and cognitive tasks. The experimental conditions included standing on (1) rigid surface with open eyes; (2) rigid surface with closed eyes; (3) foam surface with open eyes; and (4) foam surface with closed eyes. All these conditions were performed isolated (single-task) and while performing concurrent cognitive task (dual-task). FINDINGS: The results showed greater %DET and lesser central tendency measure (both in mediolateral direction) in patients compared with healthy subjects. Moreover, in both groups, the %DET increased and central tendency measure decreased with increasing postural difficulty while %DET decreased and central tendency measure increased when moving from single- to dual-task conditions. INTERPRETATIONS: The complexity loss was observed in patients compared with healthy controls. The observed increase in the variability coupled with a decrease in the complexity could be explained by the exploratory behavior of postural control system to gather information during difficult postural conditions relative to the easy ones. Moreover, the observed increase in the complexity coupled with the decrease in the amount of variability may enhance the flow of information to facilitate the perceptual control of standing balance during dual-task conditions.

Posture-cognition interaction during quiet standing in patients with knee osteoarthritis.

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.