Background and Purpose—: Functional community ambulation requires the ability to perform mobility and cognitive task simultaneously (dual-tasking). This single-blinded randomized controlled study aimed to examine the effects of dual-task exercise in chronic stroke patients. Methods—: Eighty-four chronic stroke patients (24 women; age, 61.2±6.4 years; time since stroke onset, 75.3±64.9 months) with mild to moderate motor impairment (Chedoke-McMaster leg motor score: median, 5; interquartile range, 4–6) were randomly allocated to the dual-task balance/mobility training group, single-task balance/mobility group, or upper-limb exercise (control) group. Each group exercised for three 60-minute sessions per week for 8 weeks. The dual-task interference effect was measured for the time to completion of 3 mobility tests (forward walking, timed-up-and-go, and obstacle crossing) and for the correct response rate during serial-3-subtractions and verbal fluency task. Secondary outcomes included the Activities-specific Balance Confidence Scale, Frenchay Activities Index, and Stroke-specific Quality of Life Scale. The above outcomes were measured at baseline, immediately after, and 8 weeks after training. Fall incidence was recorded for a 6-month period posttraining. Results—: Only the dual-task group exhibited reduced dual-task interference in walking time posttraining (forward walking combined with verbal fluency [9.5%, P =0.014], forward walking with serial-3-subtractions [9.6%, P =0.035], and the timed-up-and-go with verbal fluency [16.8%, P =0.001]). The improvements in dual-task walking were largely maintained at the 8-week follow-up. The dual-task cognitive performance showed no significant changes. The dual-task program reduced the risk of falls and injurious falls by 25.0% (95% CI, 3.1%–46.9%; P =0.037) and 22.2% (95% CI, 4.0%–38.4%; P =0.023), respectively, during the 6-month follow-up period compared with controls. There was no significant effect on other secondary outcomes ( P >0.05). Conclusions—: The dual-task program was effective in improving dual-task mobility, reducing falls and fall-related injuries in ambulatory chronic stroke patients with intact cognition. It had no significant effect on activity participation or quality of life. Clinical trial registration—: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02270398.

Background: Individuals with total knee arthroplasty (TKA) often experience pain and reduced balance control, which may predispose them to greater fall risk.Objective: The objective of this study was to determine the frequency and circumstance of falls and fall-related risk factors within a 6-month follow-up period in individuals after TKA.Design: This study was a prospective cohort study.Methods: Knee proprioception, the Balance Systems Evaluation Test, knee pain, knee extension and flexion muscle strength, knee range of motion, and balance confidence were evaluated in 134 individuals (39 men, 95 women; mean age = 66.3 years [SD = 6.6 years]) 4 weeks after TKA. Monthly follow-up sessions, via face-to-face or telephone interviews, were implemented to obtain data on fall incidence over 6 months.Results: Twenty-three individuals after TKA (17.2%) sustained at least 1 fall during the 6-month follow-up period. The median time of the first fall episode was 15 weeks after TKA. Of the 31 fall episodes, most occurred during walking (67.7%). Slipping (35.5%) and tripping (35.5%) were identified as the most frequent causes of falling. Most falls occurred at home (45.2%) or another indoor environment (29.0%). Multivariate binary logistic regression revealed that younger age (odds ratio: 0.91), reduced proprioception of the knee that had undergone surgery (“operated knee”) (odds ratio: 1.62), reduced sensory orientation (odds ratio: 0.92), and greater operated knee pain (odds ratio: 1.68) were significantly associated with more falls during the follow-up period.Limitations: The results of this study may be generalizable up to 6 months after TKA.Conclusions: Intervention efforts should target deficits in knee proprioception and sensory orientation and operated knee pain to prevent future falls in individuals with TKA.

Flexible and appropriate allocation of attention resources is important during dual-tasking to achieve task goals while maintaining postural safety. This pilot study aimed to examine the influence of explicit prioritization of attention on the dual-task paradigm by employing two levels of difficulty for the postural tasks and reaction time (RT) tasks in healthy young adults. The task entailed standing on a force platform on two feet or on one foot, attending to posture or RT, and completing a simple or choice RT task. Participants verbally responded “top” as soon as the light cue illuminated. In general, attending to RT produced faster RTs (F(1,19) = 30.9, p < 0.001) and improved center of pressure (COP) Displacement (F(1,19) = 5.1, p < 0.05) and 95% Area Ellipse (F(1,19) = 7.1, p < 0.05). These findings suggest that prioritizing attention away from posture may be beneficial for postural performance when completing a second task.

Introduction: Executive function is responsive to exercise and predictive of subsequent falls. Minimal clinically important differences (MCIDs) are critical for understanding whether observed changes are meaningful. However, MCIDs of many cognitive measures are not established. We aimed to determine MCIDs of the Digit Symbol Substitution Test ([DSST] processing speed measure), Stroop (inhibition measure), and Trail Making Test B-A (TMT; set-shifting measure), using anchor- and distribution-based approaches in older adults who have fallen and received the Otago Exercise Program (OEP) relative to usual care only (CON). Our secondary aim was to establish construct (convergent and divergent) validity of these measures. Methods: Complete case analyses of cognitive outcomes (DSST, Stroop, TMT, and Montreal Cognitive Assessment [MoCA]) were acquired at baseline and 1 year (NCT01029171; NCT003235960); participants were randomized to the OEP (n = 114/172; Age: 80.6 ± 6.1 years; 64.9% Female) or CON (n = 128/172; Age: 82.3 ± 5.8 years; 71.9% Female)]. The MoCA was used as the anchor. We estimated MCIDs using anchor- and distribution-based approaches. Anchor-based executive function change differences ([CD] 1 year minus baseline) observed in participants with meaningful changes in the MoCA (≥3 or ≤ −3 points) receiving the OEP were subtracted from the CON. An anchor-based receiver operator characteristic (ROC) curve was employed to identify optimal cut-off scores of the 3 executive function measures. The distribution-based approach (DA) accounted for variability in baseline and follow-up data. MCID ranges were estimated using these approaches. We used Spearman’s correlations to explore convergent validity between executive function measures and other measures involving the same construct (DSST, Stroop, TMT, MoCA, and Mini-Mental State Examination), and divergent validity between executive function measures and variables reflecting different constructs (Geriatric Depression Scale, Instrumental Activities of Daily Living, sex, and body mass index). Results: Based on the 3 approaches, MCID improvement ranges were 3–5 symbols for the DSST (CD = 5; ROC = 2.5; DA = 3.3 symbols), and −11.5 to −26.0 s for the Stroop (CD = −26.0; ROC = −11.5; DA = −20.6 s). MCID decline ranges were −3 to −6 symbols for the DSST (CD = −5.2; ROC = −2.5; DA = −3.3 symbols) and 5.4–30.6 s for the Stroop (CD = 30.6; ROC = 5.4; DA = 20.6 s). MCIDs for the TMT were not meaningful due to high variability (Improvement: CD = −106.6; ROC = −18.4; DA = −69.1 s; Decline: CD = 69.1; ROC = 14.5; DA = 69.1 s). The executive function measures exhibited good convergent (r = −0.22 to r = 0.42) and divergent (r < −0.01 to r = 0.16) validity. Conclusions: These established MCIDs will allow clinicians to interpret meaningful changes in executive function following exercise amongst older adults who have fallen. The DSST, Stroop, and TMT demonstrated good construct validity, supporting their use in comprehensive fall-risk assessments in older adults who fall.