title: Instrumented Test of Sensory Integration for Balance: A Validation Study Minimal Detectable Change of the Timed “Up & Go” Test and the Dynamic Gait Index in People With Parkinson Disease Test-Retest Reliability and Minimal Detectable Change on Balance and Ambulation Tests, the 36-Item Short-Form Health Survey, and the Unified Parkinson Disease Rating Scale in People With Parkinsonism Accuracy of Fall Prediction in Parkinson Disease: Six-Month and 12-Month Prospective Analyses Short-distance walking speed tests in people with Parkinson disease: reliability, responsiveness, and validity. External validation of a simple clinical tool used to predict falls in people with Parkinson disease. Reliability of measurements obtained with the Timed "Up & Go" test in people with Parkinson disease. Validity of the Functional Gait Assessment in Patients With Parkinson Disease: Construct, Concurrent, and Predictive Validity Comparison of Self-report and Performance-Based Balance Measures for Predicting Recurrent Falls in People With Parkinson Disease: Cohort Study Comparison of the Fullerton Advanced Balance Scale, Mini-BESTest, and Berg Balance Scale to Predict Falls in Parkinson Disease Validating the Berg Balance Scale for patients with Parkinson's disease: a key to rehabilitation evaluation. Three simple clinical tests to accurately predict falls in people with Parkinson's disease. The Four Square Step Test in individuals with Parkinson's disease: association with executive function and comparison with older adults. Diagnosis of Fall Risk in Parkinson Disease: An Analysis of Individual and Collective Clinical Balance Test Interpretation Validity of the Nintendo Wii® balance board for the assessment of standing balance in Parkinson’s disease
abstract: Background and Purpose : Abnormal postural sway is associated with an increase in risk of falls but is difficult for clinicians to accurately quantify without access to laboratory equipment . Instrumenting clinical outcome measures using body-worn movement monitors is a low-cost alternative . This is the first study to compare the modified Clinical Test of Sensory Integration for Balance ( i-mCTSIB ) to the laboratory test of the Sensory Organization Test ( SOT ) with dynamic posturography in a group of participants with Parkinson 's disease ( PD ) and subtle balance limitations . The purpose of this study was to ( 1 ) determine the concurrent validity of the i-mCTSIB with the SOT ( 6 and 4 conditions ) and ( 2 ) compare the i-mCTSIB and the SOT to differentiate between individuals with and without recent falls within the previous 6 months . Methods : This cross-sectional study examined 26 participants with idiopathic PD who had a Motor Unified Parkinson 's Disease Rating Scale score of 32.7 ( 13.5 ) out of 108 . Results : The composite and conditions 1 and 4 of the i-mCTSIB and SOT scores were significantly correlated : composite scores r = −0.64 ( P ⩽ .001 ) , C1 r = −0.43 ( P = .03 ) , C3 r = −0.60 ( P ⩽ .01 ) , and C4 r = −0.54 ( P ⩽ .001 ) . A significant difference was observed in mean i-mCTSIB composite scores between fallers and nonfallers ( P = .04 ) . In contrast , the SOT composite was not significantly different between fallers and nonfallers ( P = 0.31 ) . Discussion : The results suggest that the i-mCTSIB may be a valid and clinical ly meaningful measure of sensory organization in persons with PD , even those with mild postural instability as measured by the median Hoehn and Yahr score ( 2.0 ) . Future research should evaluate predictive validity of the i-mCTSIB for prospect i ve falls . Conclusion : The instrumented mCTSIB with portable , body-worn movement allows clinicians to quantify abnormal postural sway without the ceiling effects of clinical balance testing or the expense and importability of force plate technology in the SOT . Instrumenting mCTSIB may also distinguish between fallers and nonfallers Background The minimal detectable change ( MDC ) is the smallest amount of difference in individual scores that represents true change ( beyond r and om measurement error ) . The MDCs of the Timed “ Up & Go ” Test ( TUG ) and the Dynamic Gait Index ( DGI ) in people with Parkinson disease ( PD ) are largely unknown , limiting the interpretability of the change scores of both measures . Objective The purpose of this study was to estimate the MDCs of the TUG and the DGI in people with PD . Design This investigation was a prospect i ve cohort study . Methods Seventy-two participants were recruited from special clinics for movement disorders at a university hospital . Their mean age was 67.5 years , and 61 % were men . All participants completed the TUG and the DGI assessment s twice , about 14 days apart . The MDC was calculated from the st and ard error of measurement . The percentage MDC ( MDC% ) was calculated as the MDC divided by the mean of all scores for the sample . Furthermore , the intraclass correlation coefficient was used to examine the reproducibility between testing sessions ( test-retest reliability ) . Results The respective MDC and MDC% of the TUG were 3.5 seconds and 29.8 , and those of the DGI were 2.9 points and 13.3 . The test-retest reliability values for the TUG and the DGI were high ; the intraclass correlation coefficients were .80 and .84 , respectively . Limitations The study sample was a convenience sample , and the participants had mild to moderately severe PD . Conclusions The results showed that the TUG and the DGI have generally acceptable r and om measurement error and test-retest reliability . These findings should help clinicians and research ers determine whether a change in an individual patient with PD is a true change Background and Purpose : Distinguishing between a clinical ly significant change and change due to measurement error can be difficult . The purpose of this study was to determine test-retest reliability and minimal detectable change for the Berg Balance Scale ( BBS ) , forward and backward functional reach , the  Romberg Test and the Sharpened Romberg Test ( SRT ) with eyes open and closed , the Activities-specific Balance Confidence ( ABC ) Scale , the  Six-Minute Walk Test ( 6MWT ) , comfortable and fast gait speed , the  Timed “ Up & Go ” Test ( TUG ) , the Medical Outcomes Study 36-Item Short-Form Health Survey ( SF-36 ) , and the Unified Parkinson Disease Rating Scale ( UPDRS ) in people with parkinsonism . Subjects : Thirty-seven community-dwelling adults with parkinsonism ( mean age=71 years ) participated . The Hoehn and Yahr Scale median score of 2 was on the lower end of the scale ; however , the scores ranged from 1 to 4 . Methods : Subjects were tested twice by the same raters , with 1 week between tests . Test-retest reliability was calculated using intraclass correlation coefficients ( ICCs ) . Minimal detectable change was calculated using a 95 % confidence interval ( MDC95 ) . Results : The ICCs for test-retest reliability were above .90 for the BBS , ABC Scale , SRT with eyes closed , 6MWT , and comfortable and fast gait speeds . The MDC95 values for those functional tests were : BBS=5/56 , ABC Scale=13 % , SRT with eyes closed=19 seconds , 6MWT=82 m , comfortable gait speed=0.18 m/s , and fast gait speed=0.25 m/s . The ICCs for test-retest reliability of SF-36 scores were above .80 , with the exception of the social functioning subscale . The MDC95 values for the SF-36 ranged between 19 % and 45 % . The MDC95 values for the UPDRS Activities of Daily Living section , Motor Examination section , and total scores were 4/52 , 11/108 , and 13/176 , respectively . Discussion and Conclusion : Minimal detectable change values are useful to therapists in rehabilitation and wellness programs in determining whether change during or after intervention is clinical ly significant . High test-retest reliability of scores for the BBS , ABC Scale , SRT with eyes closed , 6MWT , and gait speed make them trustworthy functional assessment s in people with parkinsonism . The SF-36 and UPDRS provide quality -of-life and disease severity rating values in the ongoing assessment of people with parkinsonism Introduction . We analyzed the ability of four balance assessment s to predict falls in people with Parkinson Disease ( PD ) prospect ively over six and 12 months . Material s and Methods . The BESTest , Mini-BESTest , Functional Gait Assessment ( FGA ) , and Berg Balance Scale ( BBS ) were administered to 80 participants with idiopathic PD at baseline . Falls were then tracked for 12 months . Ability of each test to predict falls at six and 12 months was assessed using ROC curves and likelihood ratios ( LR ) . Results . Twenty-seven percent of the sample had fallen at six months , and 32 % of the sample had fallen at 12 months . At six months , areas under the ROC curve ( AUC ) for the tests ranged from 0.8 ( FGA ) to 0.89 ( BESTest ) with LR+ of 3.4 ( FGA ) to 5.8 ( BESTest ) . At 12 months , AUCs ranged from 0.68 ( BESTest , BBS ) to 0.77 ( Mini-BESTest ) with LR+ of 1.8 ( BESTest ) to 2.4 ( BBS , FGA ) . Discussion . The various balance tests were effective in predicting falls at six months . All tests were relatively ineffective at 12 months . Conclusion . This pilot study suggests that people with PD should be assessed biannually for fall risk PURPOSE The aims of this study were to determine test-retest reliability and responsiveness of short-distance walking speed tests for persons with Parkinson disease ( PD ) . Discriminant and convergent validity of walking speed tests were also examined . METHODS Eighty-eight participants with PD ( mean age , 66 years ) with mild to moderate severity ( stages 1 - 4 on the Hoehn and Yahr Scale ) were tested on medications . Measures of activity included the  comfortable and fast 10-m walk tests ( CWT , FWT ) , 6-min walk test ( 6MWT ) , mini balance evaluations systems test ( mini-BEST Test ) , fear of falling ( FoF ) , and the Activity-Specific Balance Confidence Scale ( ABC ) . The mobility subsection of the PD quality of life-39 ( PDQ39-M ) served as a participation-based measure . RESULTS Test-retest reliability was high for both walking speed measures ( CWT , ICC(2,1 ) = 0.98 ; FWT , ICC(2,1 ) = 0.99 ) . Minimal detectable change ( MDC(95 ) ) for the CWT and FWT was 0.09 m/s and 0.13 m/s respectively . Participants at Hoehn & Yahr levels 3/4 demonstrated significantly slower walking speed with the CWT and FWT than participants at Hoehn & Yahr levels 1 and 2 ( P < .01 ) . The CWT and FWT were both significantly ( P ≤ .002 ) correlated with all activity and participation-based measures . CONCLUSIONS Short-distance walking speed tests are clinical ly useful measures for persons with PD . The CWT and FWT are highly reliable and responsive to change in persons with PD . Short distance walking speed can be used to discriminate differences in gait function between persons with mild and moderate PD severity . The CWT and FWT had moderate to strong associations with other activity and participation based measures demonstrating convergent validity BACKGROUND Assessment of fall risk in an individual with Parkinson disease ( PD ) is a critical yet often time consuming component of patient care . Recently a simple clinical prediction tool based only on fall history in the previous year , freezing of gait in the past month , and gait velocity < 1.1 m/s was developed and accurately predicted future falls in a sample of individuals with PD . METHODS We sought to externally vali date the utility of the tool by administering it to a different cohort of 171 individuals with PD .  Falls were monitored prospect ively for 6 months following predictor assessment . RESULTS The tool accurately discriminated future fallers from non-fallers ( area under the curve [ AUC ] = 0.83 ; 95 % CI 0.76 - 0.89 ) , comparable to the developmental study . CONCLUSION The results vali date d the utility of the tool for allowing clinicians to quickly and accurately identify an individual 's risk of an impending fall BACKGROUND AND PURPOSE The Timed " Up & Go " Test ( TUG ) is used to measure the ability of patients to perform sequential locomotor tasks that incorporate walking and turning . This study investigated the retest reliability , interrater reliability , and sensitivity of scores obtained with the TUG in detecting changes in mobility in subjects with idiopathic Parkinson disease ( PD ) . SUBJECTS The performance of 12 people with PD was compared with that of 12 age-matched comparison subjects without PD . METHODS The subjects with PD completed 5 trials of the TUG after withdrawal of levodopa for 12 hours ( " off " phase of the medication cycle ) as well as an additional 5 trials 1 hour after levodopa was administered ( " on " phase of the medication cycle ) . They were scored on the Modified Webster Scale at both sessions . The comparison subjects also performed 5 TUG trials . All trials were videotaped and timed by 2 experienced raters . The videotape was later rated by 3 experienced clinicians and 3 inexperienced clinicians . RESULTS For the subjects with PD , within-session performance was highly consistent , with correlations ( r ) ranging from.80 to.98 for the " off " phase and from.73 to.99 for the " on " phase . The performance of the comparison subjects across the 5 trials was also highly consistent ( r=.90-.97 ) . Comparisons showed differences between trials 1 and 2 on the TUG for both groups . Removal of data for trial 1 ( the practice trial ) further enhanced retest reliability . There was close agreement in TUG scores among raters despite different levels of experience ( intraclass correlation coefficient [3,1]=.87-.99 ) . Mean TUG scores were different between the " on " and " off " phases of the levodopa cycle and between subjects with PD and comparison subjects during the " on " phase . CONCLUSION AND DISCUSSION Retest reliability and interrater reliability of the TUG measurements were high , and the measurements reflected changes in performance according to levodopa use . The TUG can also be used to detect differences in performance between people with PD and elderly people without PD Background The Functional Gait Assessment ( FGA ) is a vali date d measurement of gait-related activities in certain population s and may be potentially useful to assess balance and gait disorders in patients with Parkinson disease ( PD ) . Objective The purpose of this study was to determine the construct , concurrent , and predictive validity of the FGA in in patients with PD . Design This was a prospect i ve cohort study . Methods One hundred twenty-one in patients with PD were prospect ively enrolled . The FGA and other relevant appraisal s of gait , balance , disease severity , and activities of daily living were performed . Six months later , the patients were interviewed by telephone to have their fall information collected . Principal component analysis was used to determine construct validity . Spearman correlation coefficients were used to determine concurrent validity between the FGA and other measures . Cutoff point , sensitivity , specificity , and positive likelihood ratio were calculated for predictive validity based on the receiver operating characteristic curve . Results One common factor was extracted for construct validity , which cumulatively explained 64.0 % of the total variance . Correlation coefficients for the FGA compared with other measures ranged from .57 to .85 . The cutoff point for predicting falls was 18 , with sensitivity of 80.6 % , specificity of 80.0 % , and positive likelihood ratio of 4.03 . Limitations This study was limited by the length of time of follow-up and self-reports of falls without the requirement of a fall diary . Medication adjustment after the FGA evaluation may have led to a different cutoff score for identifying those patients who were at risk of falling . Conclusions The FGA demonstrated good construct validity in patients with PD . It had moderate to strong correlations with other balance and gait appraisal s. The FGA can be used to predict falls within the subsequent 6 months Background Balance confidence and fear of falling are factors associated with recurrent falls in people with Parkinson disease ( PD ) . However , the accuracy for predicting falls on the basis of self-report measures has not been widely investigated . Objective The study objectives were : ( 1 ) to compare the accuracy of the  Activities-specific Balance Confidence Scale ( ABC )  and the  Falls Efficacy Scale – International ( FES-I )  with that of the  Berg Balance Scale  ( BBS ) , Dynamic Gait Index  ( DGI ) , Functional Reach Test ( FRT ) , and Timed “ Up & Go ” Test ( TUG ) for predicting recurrent falls in people with PD and ( 2 ) to explore the ability of combinations of up to 3 tests to predict recurrent falls . Design This was a prospect i ve cohort study involving 225 people with PD . Methods Participants were assessed with the  ABC , FES-I , BBS , FRT , TUG , and DGI . Participants who reported 2 or more falls in the 12-month follow-up period were classified as recurrent fallers . Areas under the receiver operating characteristic curves were determined , and the Akaike information criterion was used to select the best predictive model . Results Eighty-four participants ( 37.3 % ) were classified as recurrent fallers . Areas under the receiver operating characteristic curves for the ABC , FES-I , TUG , FRT , DGI , and BBS were 0.73 , 0.74 , 0.72 , 0.74 , 0.76 , and 0.79 , respectively . Two-test models provided additional discriminating ability compared with individual measures and had Akaike information criterion values similar to those of 3-test models , particularly the combination of the BBS with the FES-I. Limitations The lack of an external validation sample was a limitation of this study . Conclusions The ABC and FES-I demonstrated moderate accuracy in predicting recurrent falls and a predictive ability similar to that of performance-based balance measures , especially the FRT and the TUG . Two-test models showed performance similar to that of 3-test models , suggesting that a combination of 2 measures may improve the ability to predict recurrent falls in people with PD . Specifically , the combination of the BBS with the FES-I may be considered Background The correct identification of patients with Parkinson disease ( PD ) at risk for falling is important to initiate appropriate treatment early . Objective This study compared the Fullerton Advanced Balance ( FAB ) scale with the Mini-Balance Evaluation Systems Test ( Mini-BESTest ) and Berg Balance Scale ( BBS ) to identify individuals with PD at risk for falls and to analyze which of the items of the scales best predict future falls . Design This was a prospect i ve study to assess predictive criterion-related validity . Setting The study was conducted at a university hospital in an urban community . Patients Eighty-five patients with idiopathic PD ( Hoehn and Yahr stages : 1–4 ) participated in the study . Measurements Measures were number of falls ( assessed prospect ively over 6 months ) , FAB scale , Mini-BESTest , BBS , and Unified Parkinson 's Disease Rating Scale . Results The FAB scale , Mini-BESTest , and BBS showed similar accuracy to predict future falls , with values for area under the curve ( AUC ) of the receiver operating characteristic ( ROC ) curve of 0.68 , 0.65 , and 0.69 , respectively . A model combining the items “ t and em stance , ” “ rise to toes , ” “ one-leg stance , ” “ compensatory stepping backward , ” “ turning , ” and “ placing alternate foot on stool ” had an AUC of 0.84 of the ROC curve . Limitations There was a dropout rate of 19/85 participants . Conclusions The FAB scale , Mini-BESTest , and BBS provide moderate capacity to predict “ fallers ” ( people with one or more falls ) from “ nonfallers . ” Only some items of the 3 scales contribute to the detection of future falls . Clinicians should particularly focus on the item “ t and em stance ” along with the items “ one-leg stance , ” “ rise to toes , ” “ compensatory stepping backward , ” “ turning 360 ° , ” and “ placing foot on stool ” when analyzing postural control deficits related to fall risk . Future research should analyze whether balance training including the aforementioned items is effective in reducing fall risk OBJECTIVE To assess the criterion-related validity of the  Berg Balance Scale ( BBS ) in subjects with Parkinson 's disease ( PD ) . DESIGN Prospect i ve , correlational analysis between the BBS and accepted measures of PD motor and functional impairment . SETTING The federally funded PD research center , an interdisciplinary center of excellence for people with PD within a Veterans Affairs medical center . PARTICIPANTS Thirty-eight men ( average + /- st and ard deviation , 71.1+/-10.5 y ) with confirmed PD . Their initial diagnosis had been made on average 5.8+/-3.6 years earlier . All could st and or walk unassisted and had mild to moderate disability . Patients who could not ambulate without assistive devices were excluded . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Correlational analyses between the  BBS  and the Unified Parkinson 's Disease Rating Scale ( UPDRS ) motor scale , Modified Hoehn and Yahr Staging ( Hoehn and Yahr ) Scale , and the Modified Schwab and Engl and Capacity for Daily Living Scale ( S&E ADL Scale ) . RESULTS BBS score showed significant correlations with indicators of motor functioning , stage of disease , and daily living capacity . BBS score was inversely associated with the UPDRS motor score ( -.58 , P < .005 ) , Hoehn and Yahr Scale staging ( -.45 , P < .005 ) , and S&E ADL Scale rating ( .55 , P < .005 ) . In all 3 correlations , lower scores on the BBS ( indicating greater balance deficits ) correlated with higher UPDRS scores ( indicating greater motoric or functional impairment ) . CONCLUSIONS Results support the criterion-related validity of the BBS . Its utility in other balance conditions of older adults has been established . Rehabilitation interventions have been shown to improve the balance deficits associated with PD . Early referral and periodic re assessment is vital to achieving and maintaining improvements . Our research results agree with other published research in suggesting that the BBS may be used as a screening tool and ongoing assessment tool for patients with PD Falls are a major cause of morbidity in Parkinson 's disease ( PD ) . The objective of this study was to identify predictors of falls in PD and develop a simple prediction tool that would be useful in routine patient care . Potential predictor variables ( falls history , disease severity , cognition , leg muscle strength , balance , mobility , freezing of gait [ FOG ] , and fear of falling ) were collected for 205 community-dwelling people with PD .  Falls were monitored prospect ively for 6 months using monthly falls diaries . In total , 125 participants ( 59 % ) fell during follow-up . A model that included a history of falls , FOG , impaired postural sway , gait speed , sit-to-st and , st and ing balance with narrow base of support , and coordinated stability had high discrimination in identifying fallers ( area under the receiver-operating characteristic curve [ AUC ] , 0.83 ; 95 % confidence interval [ CI ] , 0.77 - 0.88 ) . A clinical tool that incorporated 3 predictors easily determined in a clinical setting ( falling in the previous year : odds ratio [ OR ] , 5.80 ; 95 % CI , 3.00 - 11.22 ; FOG in the past month : OR , 2.39 ; 95 % CI , 1.19 - 4.80 ; and self-selected gait speed < 1.1 meters per second : OR , 1.86 ; 95 % CI , 0.96 - 3.58 ) had similar discrimination ( AUC , 0.80 ; 95 % CI , 0.73 - 0.86 ) to the more complex model ( P = 0.14 for comparison of AUCs ) . The absolute probability of falling in the next 6 months for people with low , medium , and high risk using the simple , 3-test tool was 17 % , 51 % , and 85 % , respectively . In people who have PD without significant cognitive impairment , falls can be predicted with a high degree of accuracy using a simple , 3-test clinical tool . This tool enables individualized quantification of the risk of falling . © 2013 Movement Disorder Society BACKGROUND In Parkinson 's disease ( PD ) , motor and cognitive impairments interact to affect functional performance adversely . A valid mobility test , the Four Square Step Test ( FSST ) involves multidirectional stepping over obstacles . FSST performance may also be associated with cognitive performance . OBJECTIVES This study determined the feasibility and reliability of an obstacle-based FSST in older individuals with versus without PD , and evaluated the association of PD performance of FSST with tests of cognition . METHODS Thirty-one individuals with mild-moderate PD , evaluated while ON medications , completed the obstacle-based FSST , other mobility and cognitive measures . FSST  performance was compared between a PD participant sub-set ( n = 24 ) and 24 age-matched older adults . Data were analyzed with independent t-tests , correlations , and linear regression . RESULTS Obstacle-based FSST was feasible and reliable within sessions in those with PD . Median best FSST time among individuals with PD was 11.72 s ( 9.99 , 13.98 ) and FSST had concurrent validity with tests of mobility , and cognitive dual-tasking . Among cognitive tests , Trails Making Test B , which evaluates executive function , emerged as a sole contributor ( 49 % ) of variance .  FSST performance did not differ between those with PD and older adults . CONCLUSION The obstacle-based FSST is feasible and reliable in those with PD . The relationship between cognitive status and performance on the FSST did not appear to be strongly disease-stage dependent . Using FSST in the clinic may help assess the health status of a motor-cognitive interaction in individuals with PD Background and Purpose : Parkinson disease ( PD ) results in an increased frequency of falls relative to the frequency in neurologically healthy people . The purpose of this study was to compare the accuracy of PD fall risk diagnosis based on one test with that based on the collective interpretation of multiple tests . Participants : Seventy people with PD ( mean age=73.91 years ) participated in this study . Method : Clinical balance tests were conducted during the initial examinations of people with PD .  Validity indices were calculated for individual tests and compared with validity indices calculated for a combination of multiple tests . Results : Thirty-six participants reported a fall history . Analysis of individual tests revealed broad variations in validity indices , whereas the collective interpretation of multiple tests improved sensitivity and negative likelihood ratios . Discussion and Conclusion : Collective interpretation of clinical balance tests result ed in fewer false-negative results and more substantial adjustments to the posttest probability of being a “ faller ” than the interpretation of one test alone . These results should be confirmed in a prospect i ve examination of fall risk in PD Background : Impaired postural stability places individuals with Parkinson ’s at an increased risk for falls . Given the high incidence of fall-related injuries within this population , ongoing assessment of postural stability is important . Objective : To evaluate the validity of the Nintendo Wii ® balance board as a measurement tool for the assessment of postural stability in individuals with Parkinson ’s . Subjects : Twenty individuals with Parkinson ’s participated . Intervention : Subjects completed testing on two balance tasks with eyes open and closed on a Wii ® balance board and biomechanical force platform . Main Measures : Bl and –Altman plots and a two-way , r and om-effects , single measure intraclass correlation coefficient model were used to assess concurrent validity of centre-of-pressure data . Results : Concurrent validity was demonstrated to be excellent across balance tasks ( intraclass correlation coefficients = 0.96 , 0.98 , 0.92 , 0.94 ) . Conclusions : This study suggests that the Wii ® balance board is a valid tool for the quantification of postural stability among individuals with Parkinson ’s
target: These measures assess balance and falls risk prediction at the body , structure and function level , falls risk and balance , and falls risk at the activity level .
  The motor examination of the Unified Parkinson ’s Disease Rating Scale ( UPDRS-ME ) with robust psychometric analysis is a condition-specific measure with acceptable properties .
  Conclusion : Six of the 68 outcome measures have strong psychometric properties for the assessment of balance and falls risk prediction in PD .
background: Objective : To investigate the psychometric properties of measures of balance and falls risk prediction in people with Parkinson ’s disease ( PD ) .