Dawn Tan

A Validated Smartphone-Based Assessment of Gait and Gait Variability in Parkinson’s Disease

Background A well-established connection exists between increased gait variability and greater fall likelihood in Parkinson’s disease (PD); however, a portable, validated means of quantifying gait variability (and testing the efficacy of any intervention) remains lacking. Furthermore, although rhythmic auditory cueing continues to receive attention as a promising gait therapy for PD, its widespread delivery remains bottlenecked. The present paper describes a smartphone-based mobile application (“SmartMOVE”) to address both needs. Methods The accuracy of smartphone-based gait analysis (utilizing the smartphone’s built-in tri-axial accelerometer and gyroscope to calculate successive step times and step lengths) was validated against two heel contact–based measurement devices: heel-mounted footswitch sensors (to capture step times) and an instrumented pressure sensor mat (to capture step lengths). 12 PD patients and 12 age-matched healthy controls walked along a 26-m path during self-paced and metronome-cued conditions, with all three devices recording simultaneously. Results Four outcome measures of gait and gait variability were calculated. Mixed-factorial analysis of variance revealed several instances in which between-group differences (e.g., increased gait variability in PD patients relative to healthy controls) yielded medium-to-large effect sizes (eta-squared values), and cueing-mediated changes (e.g., decreased gait variability when PD patients walked with auditory cues) yielded small-to-medium effect sizes—while at the same time, device-related measurement error yielded small-to-negligible effect sizes. Conclusion These findings highlight specific opportunities for smartphone-based gait analysis to serve as an alternative to conventional gait analysis methods (e.g., footswitch systems or sensor-embedded walkways), particularly when those methods are cost-prohibitive, cumbersome, or inconvenient.

Is Nintendo Wii an Effective Intervention for Individuals With Stroke? A Systematic Review and Meta-Analysis

OBJECTIVE To investigate the effectiveness of Nintendo Wii compared with no intervention or other exercise interventions in the rehabilitation of adults with stroke. DATA SOURCES Seven electronic databases were systematically searched to source for full-text studies published in peer-reviewed journals up to July 2014. Hand searches of reference lists were performed. STUDY SELECTION Randomized controlled trials (RCTs) comparing Wii with no intervention or other exercise interventions, in patients with stroke, were selected. DATA EXTRACTION Methodological quality was assessed by 2 independent reviewers. Data pertaining to participants, interventions, outcomes, and clinical effectiveness were independently extracted by 2 reviewers using a standardized form and compared for accuracy. We calculated mean or standardized mean differences for analysis of continuous variables. Risk ratios were derived and 95% confidence intervals (CIs) calculated. DATA SYNTHESIS Six studies were included. Three trials (64 participants) compared Wii and conventional rehabilitation versus conventional rehabilitation alone. Three trials (102 participants) compared Wii with other exercise interventions. The addition of Wii to conventional rehabilitation resulted in significant mean differences in favor of additional Wii compared with standard care for Timed Up and Go test (TUG) (0.81 points, CI 0.29-1.33, P = .002), but not for other mobility and functional outcomes: Functional Independence Measure (FIM) score (0.45, CI -0.21-1.11, P = .18), Berg Balance Score (-0.64, CI -3.66-2.39, P = .68), anteroposterior postural sway (0.23, CI -0.38-0.84, P = .46). No serious adverse events were reported, and when Wii was compared with exercise alone, we demonstrated a decreased risk of participants dropping out of follow-up (RR 0.40, CI 0.20-0.78, P = .007). CONCLUSIONS The addition of Wii gaming to conventional rehabilitation in patients with chronic stroke significantly improved performance in TUG and not in the other physical measures. The pooled effect was small and not beyond the minimal detectable change. However, Wii can be used safely in patients with stroke and participants were less likely to drop out in the Wii group. This review highlights the need for further high-quality studies to demonstrate the efficacy of Wii in stroke rehabilitation.

A systematic review of the diagnostic utility of simple tests of change after trial removal of cerebrospinal fluid in adults with normal pressure hydrocephalus

Objective: To synthesize the evidence regarding the diagnostic value of simple ancillary tests post cerebrospinal fluid drainage in normal pressure hydrocephalus. Data sources: MEDLINE, CINAHL, PsycINFO, Scopus, Web of Science, and Cochrane library databases; last searched on 12 September 2017. Review methods: This review was performed applying the steps of the PRISMA statement. The QUADAS 2 tool was used to assess the risk of bias. Prospective and retrospective trials were systematically reviewed, and data on diagnostic accuracy were extracted. Meta-analysis (where possible) was performed. Hierarchical summary receiver operating characteristic package was used to calculate pooled estimates of included diagnostic studies. Results: Seventeen trials (with 812 subjects in total) were identified for inclusion in the meta-analyses for the 18-meter walk test, video-recorded gait performance, cognitive test, and Timed Up and Go Test. The summary estimates of sensitivity and specificity for the 18-meter walk test was 0.83 (95% CI 0.57 to 0.99) and 0.67 (95% CI 0.33 to 0.95), video-recorded gait performance was 0.85 (95% CI 0.47 to 0.99) and 0.68 (95% CI 0.33 to 0.96), cognitive test was 0.82 (95% CI 0.41–0.99) and 0.75 (95% CI 0.39–0.99), and Timed Up and Go Test was 0.89 (95% CI 0.79–0.95) and 0.63 (95% CI 0.24–0.90), respectively. Conclusion: This review highlights the diagnostic value of the 18-meter walk test, video-recorded gait performance, cognitive test, and Timed Up and Go Test in predicting shunt outcomes among adults with normal pressure hydrocephalus.

Regression analysis of gait parameters and mobility measures in a healthy cohort for subject-specific normative values

Background Deviation in gait performance from normative data of healthy cohorts is used to quantify gait ability. However, normative data is influenced by anthropometry and such differences among subjects impede accurate assessment. De-correlation of anthropometry from gait parameters and mobility measures is therefore desirable. Methods 87 (42 male) healthy subjects varying form 21 to 84 years of age were assessed on gait parameters (cadence, ankle velocity, stride time, stride length) and mobility measures (the 3-meter/7-meter Timed Up-and-Go, 10-meter Walk Test). Multiple linear regression models were derived for each gait parameter and mobility measure, with anthropometric measurements (age, height, body mass, gender) and self-selected walking speed as independent variables. The resulting models were used to normalize the gait parameters and mobility measures. The normalization’s capability in de-correlating data and reducing data dispersion were evaluated. Results Gait parameters were predominantly influenced by height and walking speed, while mobility measures were affected by age and walking speed. Normalization de-correlated data from anthropometric measurements from |rs| < 0.74 to |rs| < 0.23, and reduced data dispersion by up to 69%. Conclusion Normalization of gait parameters and mobility measures through linear regression models augment the capability to compare subjects with varying anthropometric measurements.

Assessment of isometric muscle strength and rate of torque development with hand-held dynamometry: Test-retest reliability and relationship with gait velocity after stroke

Isometric rate of torque development examines how quickly force can be exerted and may resemble everyday task demands more closely than isometric strength. Rate of torque development may provide further insight into the relationship between muscle function and gait following stroke. Aims of this study were to examine the test-retest reliability of hand-held dynamometry to measure isometric rate of torque development following stroke, to examine associations between strength and rate of torque development, and to compare the relationships of strength and rate of torque development to gait velocity. Sixty-three post-stroke adults participated (60 years, 34 male). Gait velocity was assessed using the fast-paced 10 m walk test. Isometric strength and rate of torque development of seven lower-limb muscle groups were assessed with hand-held dynamometry. Intraclass correlation coefficients were calculated for reliability and Spearmans rho correlations were calculated for associations. Regression analyses using partial F-tests were used to compare strength and rate of torque development in their relationship with gait velocity. Good to excellent reliability was shown for strength and rate of torque development (0.82-0.97). Strong associations were found between strength and rate of torque development (0.71-0.94). Despite high correlations between strength and rate of torque development, rate of torque development failed to provide significant value to regression models that already contained strength. Assessment of isometric rate of torque development with hand-held dynamometry is reliable following stroke, however isometric strength demonstrated greater relationships with gait velocity. Further research should examine the relationship between dynamic measures of muscle strength/torque and gait after stroke.