Reliability, validity and discriminant ability of the instrumental indices provided by a novel planar robotic device for upper limb rehabilitation.

BACKGROUND: In the last few years, there has been an increasing interest in the use of robotic devices to objectively quantify motor performance of patients after brain damage. Although these robot-derived measures can potentially add meaningful information about the patient's dexterity, as well as be used as outcome measurements after the rehabilitation treatment, they need to be validated before being used in clinical practice. The present work aims to evaluate the reliability, the validity and the discriminant ability of the metrics provided by a novel robotic device for upper limb rehabilitation. METHODS: Forty-eight patients with sub-acute stroke and 40 age-matched healthy subjects were involved in this study. Clinical evaluation included: Fugl-Meyer Assessment for the upper limb, Action Research Arm Test, and Barthel Index. Robotic evaluation of the upper limb performance consisted of 14 measures of motor ability quantifying the dexterity in performing planar reaching movements. Patients were evaluated twice, one day apart, to assess the reliability of the robotic metrics, using the Intraclass Correlation Coefficient. Validity was assessed by analyzing the correlation of the robotic metrics with the clinical scales, by means of the Spearman's Correlation Coefficient. Finally, the ability of the robotic metrics to distinguish between patients with stroke and healthy subjects was investigated with t-tests and the Effect Size. RESULTS: Reliability was found to be excellent for 12 measures and from moderate to good for the remaining 2. Most of the robotic indices were strongly correlated with the clinical scales, while a few showed a moderate correlation and only one was not correlated with the Barthel Index and weakly correlated with the remain two. Finally, all but one the provided metrics were able to discriminate between the two groups, with large effect sizes for most of them. CONCLUSION: We found that all the robotic indices except one provided by a novel robotic device for upper limb rehabilitation are reliable, sensitive and strongly correlated both with motor and disability clinical scales. Therefore, this device is suitable as evaluation tool for the upper limb motor performance of patients with sub-acute stroke in clinical practice. TRIAL REGISTRATION: NCT02879279 .

Identification of modified dynamic gait index cutoff scores for assessing fall risk in people with Parkinson disease, stroke and multiple sclerosis.

BACKGROUND: Balance and gait impairments increase fall rate and injury in people with neurological disorders(PwND). The modified Dynamic Gait Index(mDGI) is a scale assessing dynamic balance during walking, however its ability in identifying Fallers and Recurrent Fallers has not been studied. RESEARCH QUESTION: To evaluate mDGI's ability in identifying retrospective Fallers and Recurrent Fallers establishing cut-off scores for its use in clinical practice. METHOD: In this cross-sectional study, the number of retrospective falls and mDGI scores were collected. PwND were categorised as Non-Fallers or Fallers (falls≥1) and as Recurrent Fallers(falls≥2) or Non-Recurrent/Non-Fallers(falls<2) according to their number of retrospective falls over two months. Two generalised linear logistic models were developed using a machine learning method to detect Fallers (Model 1) and Recurrent Fallers (Model 2) based on mDGI scores. ROC curves were used to identify mDGI cut-off scores to distinguish between different fall categories. RESULTS: 58 PwND (mean ± standard deviation age: 63.4 ± 12 years) including 28 people with Multiple Sclerosis, 15 people with Parkinson's disease and 15 people with Stroke were analysed. The mDGI score(median (IQR)) for Non-Fallers, Fallers, Recurrent Fallers and Non-Recurrent/Non-Fallers was respectively 50(22), 37(22), 26.5(20.25) and 46.5(20.5)points. The cut-off to identify Fallers from Non-Fallers was 49 points(sensitivity:100 %, specificity:50 %, post-test probability with mDGI ≤ cut-off: 53.2 %, post-test probability with mDGI > cut-off: 0%, AUC:0.68), while 29 points(sensitivity:60 %, specificity:79 %, post-test probability with mDGI ≤ cut-off:52.1 %, post-test probability with mDGI > cut-off:16.1 %, AUC:0.70) was the best cut-off to identify Recurrent Fallers. SIGNIFICANCE: People with mDGI score>49 points have low or minimal fall risk, while people with mDGI score≤49 points should be further investigated with other scales before starting a balance-focused rehabilitation intervention. People scoring ≤29 points on the mDGI scale may need a fall prevention intervention, regardless of the results of other balance clinical measures.

Minimal clinically important difference of modified dynamic gait index in people with neurological disorders.

BACKGROUND: The minimal clinically important difference (MCID) of modified Dynamic Gait Index (mDGI) has not yet been determined for People with Neurological Disorders (PwND). RESEARCH QUESTION: To establish the MCID of the mDGI to determine clinically meaningful improvement in balance and gait in PwND. METHODS: In this longitudinal study from a randomised clinical trial, 55 participants both in and outpatients with neurological disorders, received fifteen 40-minute rehabilitation sessions. Inpatients received daily treatments over a period of three weeks while outpatients received three treatments/week over a period of five weeks. An anchor-based method using percentage rating of improvement in balance (Activities Balance Confidence scale, ABC) was used to determine the MCID of mDGI. The MCID was defined as the minimum change in mDGI total score (post - pre intervention) that was needed to perceive at least a 10 % improvement on the ABC scale. A Receiver Operating Characteristic curve was used to define the cut-off for the optimal MCID of the mDGI discriminating between improved and not improved participants. RESULTS: The MCID of the mDGI total score was 6 points and Area under the Curve was 0.64. For the mDGI time sub-scores the MCID was 2 points and Area under the Curve was 0.6. SIGNIFICANCE: The MCID of balance and gait improvement measured by mDGI was prudently establish at ≥7 points, meaning that this is the minimum improvement score PwND need to get to perceive a clinically relevant change in their balance and gait confidence. These reference values can be a tool incorporated into clinicians daily practice to interpret mDGI change scores helping to determine whether the intervention is effective; to develop clinical tailored intervention goals and to establish meaningful perceived change in PwND.

Validity of six balance disorders scales in persons with multiple sclerosis.

PURPOSE: The aim of this study was to test concurrent and discriminant validity of several tests of static and dynamic balance in a sample of subjects suffering from MS. METHOD: A group of 51 patients were enrolled in the study. The following tests were administered: Berg Balance Scale (BBS), Timed Up and Go Test (TUG), Dynamic Gait Index (DGI), Hauser Deambulation Index (DI), Dizziness Handicap Inventory (DHI), and Activities-specific Balance Confidence (ABC). The scales used in this study were initially translated into Italian. RESULTS: The sample of subjects reported a mean of 0.98 (1.8 SD) falls in the month prior to evaluation. The tests demonstrated good concurrent validity: Higher correlation coefficients among tests tapping the same aspect and lower correlation coefficients among tests tapping slightly different aspects. ABC and DHI tests discriminated better than the others between fallers and non-fallers and appeared the best predictors of fall status. BBS and DGI were not as efficient in discriminating between groups. Conversely all tests showed good difference validity in the prediction of patients who used an assistive device. CONCLUSION: BBS, TUG, DI, DGI, ABC, DHI have acceptable concurrent validity. The scales have poor performance in discriminating between faller and non-faller.