Comparison of the Effects of Cognitive Dual-Task and Single-Task Balance Exercises on Static Balance among People with Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial.

Objectives: The anterior cruciate ligament (ACL) reconstruction surgery improves mechanical stability; however, functional stability remains impaired. Balance exercises can help improve functional stability. The effect of cognitive dual-task balance exercises has not been studied in people with ACL reconstruction surgery; therefore, this study aimed to compare the effect of cognitive dual-task and single-task balance exercises on the static balance indices in these individuals. Methods: This study was a randomized clinical trial. After a period of conventional physiotherapy and applying inclusion criteria, 28 patients with ACL reconstruction surgery were randomly divided into two groups of cognitive dual-task and single-task balance exercises. Each group received the relevant exercises for four weeks, three times a week, with each session lasting 20 min. Center of pressure variables, including mean displacement in anterior-posterior and medial-lateral directions, total path length, mean velocity of displacement, root mean square of displacement and velocity, and the elliptical area, were measured using the FDM pressure platform before and after the interventions as the primary outcomes. Knee Injury and Osteoarthritis Outcome Score (KOOS) scale was completed by the participants before and after the interventions. Results: The measured static balance variables and KOOS subscales had significant differences before and after intervention in both groups (P<0.05); however, no statistically significant difference was observed in these variables between the two groups. There was no significant correlation between KOOS subscales and measured static balance variables. Conclusion: Both cognitive dual-task and single-task balance exercises improved the indicators related to static balance and the level of functional disability of the knee. However, cognitive dual-task balance exercises had no superiority over single-task balance exercises in ACL-reconstructed individuals.

Oswestry Disability Index, Roland-Morris Disability Questionnaire, and Quebec Back Pain Disability Scale: Responsiveness and Minimal Clinically Important Changes in Iranian People with Lumbar Disc Herniation Following Physiotherapy.

Objectives: The present study aimed to investigate the responsiveness of the Persian version of the Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RMDQ), and Quebec Back Pain Disability Scale (QBPDS) and detect minimal clinically important changes (MCICs) of these questionnaires in people with lumbar disc herniation. Methods: Ninety-two patients with lumbar herniated disc completed the Persianversion of the ODI, RMDQ, and QBPDS before and after the physiotherapy intervention. Additionally, they completed a global rating of change scale after the final physiotherapy session to give an account of non-improved and improved outcomes. The responsiveness of these three disability questionnaires was represented by Receiver Operating Characteristic (ROC) and correlation analyses. The MCIC was defined as the best cut-off when sensitivity and specificity were optimally balanced. Results: Area under the ROC curves are in the acceptable range for ODI and QBPDS (0.78 and 0.70, respectively). Moreover, ODI, RMDQ, and QBPDS have significant positive fair to moderate correlation with the external anchor (P<0.001). The MCIC values for ODI, RMDQ, and QBPDS were 13, 5.5, and 14.5 points, respectively. Conclusion: Our results revealed that the ODI and QBPDS questionnaires have adequate responsiveness to detect improvements in the functional status of lumbar herniated disc patients following a physiotherapy treatment. Therefore, the ODI and QBPDS seem to be superior to the RMDQ for use in randomized clinical trials and clinical settings in patients with herniated lumbar discs. The MCIC scores of 13 and 14.5 obtained for the ODI and QBPDS can help to identify important changes in the clinical status of an individual patient and treatment efficacy.

Cross-cultural adaptation, reliability, and validity of the Persian version of the Lower Limb Functional Index.

BACKGROUND: the Lower Limb Functional Index (LLFI) is a regional patient reported outcome measure (PROM) for evaluation of lower limb musculoskeletal functional status. No Persian-language (LLFI-Pr) version is available. OBJECTIVES: LLFI translation and cross-cultural adaptation to Persian and psychometric property evaluation. STUDY DESIGN: prospective diagnostic assessment. METHODS: to establish the LLFI-Pr face and content validity, double forward-backward translation protocols were used plus cognitive interviews and the 'content validity index'(CVI). Psychometric properties were determined from a convenience sample (n = 307, age 47.18 ± 11.52 years, female = 58.3%) that concurrently completed the LLFI-Pr and Persian Lower Extremity Functional Scale (LEFS-Pr). Test-retest reliability (ICC2,1, sub-sample, n = 64) was determined during a non-intervention period of 3-7 days. Internal consistency used Cronbach's Alpha (α), error used MDC90/95 from the SEM, and construct validity used Pearson's r between the LLFI-Pr and LEFS-Pr. Construct validity used exploratory factor analysis (EFA, suppression = 0.30) with non-Gaussian distribution protocols. RESULTS: psychometric properties were high for test-retest reliability (ICC2,1 = 0.90) and internal consistency (α = 0.77), moderate for construct validity (r = 0.63), with no floor or ceiling effects, error found SEM = 1.60, MDC90 = 3.7% and MDC95 = 4.42%. A two-factor (EFA) structure (total-variance = 22.01%), that consequently cannot be summated, was determined where five-items failed consistent factor-loading leaving a 20-item version with a high original-LLFI total-equivalency (r = 0.97). However, the general/region-specific item-ratio reduced from the recognized 60/40 ratio to 50/50. CONCLUSION: the 20-item LLFI-Pr is a valid two-factor solution with sound psychometric properties for research and clinical Persian-language populations with lower limb disorders.

Inter-joint coordination during obstacle crossing in people with diabetic neuropathy.

Sensori-motor deficit due to diabetic peripheral neuropathy (DPN) alters the quality of obstacle-crossing which may increase the risk of falling. The aim of this study was to compare inter-joint coordination (IJC) during obstacle-crossing between people with DPN and healthy controls. Fifteen DPN and 15 healthy people crossed over obstacles with heights of 10% and 20% of the subject's leg length. The mean absolute relative phase (MARP) and deviation phase (DP) of both leading and trailing limbs were used to calculate the phase dynamic and variability of IJC. Furthermore, correlation between Berg Balance Scale (BBS), Fall Efficacy Scale (FES-I), Timed Up and Go (TUG) and MARP, DP were assessed in DPN group. There was no significant interaction between group and obstacle height on measured variables. However, Group had significant main effect on DP of hip-knee in leading limb (p < 0.05). Additionally, the main effects of the obstacle's height were significant on MARP of hip-knee of trailing limb (p < 0.01) and knee-ankle in leading limb (p < 0.05). FES-I was significantly correlated to hip-knee and knee-ankle MARPs of leading limb for crossing over 20% and knee-ankle MARP for crossing over 10% height obstacle (r = 0.68, 0.69, 0.59, respectively, p < 0.05). This score was also significantly correlated with hip-knee DP of both trailing and leading limbs when crossing 10% obstacle (r = 0.59, 0.57, respectively, p < 0.05). In conclusion, IJC during obstacle-crossing was less variable and more out-of-phase, as a result of DPN and obstacle height, respectively. Moreover, when crossing over lower obstacles, fear of falling is related to IJC dynamics and variability of more proximal segment, especially in the leading limb.

Deep white matter hyperintensities, microstructural integrity and dual task walking in older people.

To examine neural, physiological and cognitive influences on gait speed under single and dual-task conditions. Sixty-two community-dwelling older people (aged 80.0 ± 4.2 years) participated in our study. Gait speed was assessed with a timed 20-meter walk under single and dual-task (reciting alternate letters of the alphabet) conditions. Participants also underwent tests to estimate physiological fall risk based on five measures of sensorimotor function, cognitive function across five domains, brain white matter (WM) hyperintensities and WM microstructural integrity by measuring fractional anisotropy (FA). Univariate linear regression analyses showed that global physiological and cognitive measures were associated with single (ß = 0.594 and ß=-0.297, respectively) and dual-task gait speed (ß = 0.306 and ß=-0.362, respectively). Deep WMHs were associated with dual-task gait speed only (ß = 0.257). Multivariate mediational analyses showed that global and executive cognition reduced the strength of the association between deep WMHs and dual-task gait speed by 27% (ß = 0.188) and 44% (ß = 0.145) respectively. There was a significant linear association between single-task gait speed and mean FA values of the genu (ß=-0.295) and splenium (ß=-0.326) of the corpus callosum, and between dual-task gait speed and mean FA values of Superior Cerebellar Peduncle (ß=-0.284), splenium of the Corpus Callosum (ß=-0.286) and Cingulum (ß=-0.351). Greater deep WMH volumes are associated with slower walking speed under dual-task conditions, and this relationship is mediated in part by global cognition and executive abilities specifically. Furthermore, both cerebellum and cingulum are related to dual-task walking due to their role in motor skill performance and attention, respectively.

Balance recovery reactions in individuals with recurrent nonspecific low back pain: Effect of attention.

People who suffer from Low Back Pain (LBP) demonstrate impaired postural control. Deficits in sensory-motor systems have been proposed to be related to these changes. Considering higher cognitive process contribution to postural control, the aim of this study was to investigate the effects of cognitive load on balance control of patients with LBP. Twenty subjects with recurrent non-specific LBP and 20 healthy controls participated. They stood on a moveable platform with each foot placed on a separate force plate. They were asked to maintain their balance (a) while expecting translations of the support surface at two sizes of perturbation (b) with and without performing a cognitive (auditory Stroop) task. The outcomes included reaction time (RT), latency, initial velocity and amplitude of center of pressure response for balance, and RT for cognitive performance. Compared to the healthy group, LBP group demonstrated delayed RT and latency, and reduced initial velocity (P<0.05). Moreover, they had slower Stroop RT (F=70.88, P<0.001). Concurrent performance of tasks resulted in increased Stroop RT (F=3.42, P=0.03) and adaptation in initial velocity (F=6.70, P=0.01). At the smaller size of perturbation, cognitive load increased velocity in LBP group but decreased this variable in the healthy group. When the cognitive load was added at the larger size of perturbation, velocity of response decreased in LBP group (P<0.05). These findings imply altered cognitive regulation of dynamic balance in patients with LBP and suggest that the adopted strategy might alter depending upon the characteristics of the postural challenge.

Intra-limb coordination while walking is affected by cognitive load and walking speed.

Knowledge about intra-limb coordination (ILC) during challenging walking conditions provides insight into the adaptability of central nervous system (CNS) for controlling human gait. We assessed the effects of cognitive load and speed on the pattern and variability of the ILC in young people during walking. Thirty healthy young people (19 female and 11 male) participated in this study. They were asked to perform 9 walking trials on a treadmill, including walking at three paces (preferred, slower and faster) either without a cognitive task (single-task walking) or while subtracting 1׳s or 3׳s from a random three-digit number (simple and complex dual-task walking, respectively). Deviation phase (DP) and mean absolute relative phase (MARP) values-indicators of variability and phase dynamic of ILC, respectively-were calculated using the data collected by a motion capture system. We used a two-way repeated measure analysis of variance for statistical analysis. The results showed that cognitive load had a significant main effect on DP of right shank-foot and thigh-shank, left shank-foot and pelvis-thigh (p<0.05), and MARP of both thigh-shank segments (p<0.01). In addition, the main effect of walking speed was significant on DP of all segments in each side and MARP of both thigh-shank and pelvis-thigh segments (p<0.001). The interaction of cognitive load and walking speed was only significant for MARP values of left shank-foot and right pelvis-thigh (p<0.05 and p<0.001, respectively). We suggest that cognitive load and speed could significantly affect the ILC and variability and phase dynamic during walking.

Functional balance in elderly with diabetic neuropathy.

Distal Sensorimotor Polyneuropathy (DPN) is one of the most common long-term complications of diabetes mellitus. Patients with DPN are at a high risk for falling and its life-threatening consequences. The objective of present study was the evaluation of functional balance in patients with diabetic neuropathy and normal older adults. Thus, present case-control study was designed to test the ability of two fourteen DPN patients and healthy people to control functional balance using Berg Balance Scale (BBS). Furthermore, the correlation between DNE and BBS scores were calculated using the Spearman's correlation coefficient. Comparison of two groups showed a significant decline in the overall score of BBS in DPN patients versus to the healthy control group (P<0.001). The most challenging tasks for DNP patients were single leg stance, tandem standing and forward reaching (P<0.001), followed by standing unsupported with feet together, sit to stand, stand to sit, transfers, standing unsupported with closed eyes, and placing the alternative foot on step or stool while standing unsupported tasks (P<0.05). There was a significant (P<0.001) strong negative (r=-0.77) correlation between DNE and BBS scores. In conclusion, DPN results in a remarkable functional imbalance that may expose these patients to danger of falling during daily activities and becomes more severe as the severity of neuropathy aggravates.