Effect of teaching with or without mirror on balance in young female ballet students.

PubMed

Notarnicola, Angela; Maccagnano, Giuseppe; Pesce, Vito; Di Pierro, Silvia; Tafuri, Silvio; Moretti, Biagio

2014-07-04

In literature there is a general consensus that the use of the mirror improves proprioception. During rehabilitation the mirror is an important instrument to improve stability. In some sports, such as dancing, mirrors are widely used during training. The purpose of this study is to evaluate the effectiveness of the use of a mirror on balance in young dancers. Sixty-four young dancers (ranging from 9-10 years) were included in this study. Thirty-two attending lessons with a mirror (mirror- group) were compared to 32 young dancers that attended the same lessons without a mirror (non-mirror group). Balance was evaluated by BESS (Balance Error Scoring System), which consists of three stances (double limb, single limb, and tandem) on two surfaces (firm and foam). The errors were assessed at each stance and summed to create the two subtotal scores (firm and foam surface) and the final total score (BESS). The BESS was performed at recruitment (T0) and after 6 months of dance lessons (T1). The repeated measures ANOVA analysis showed that for the BESS total score there is a difference due to the time (F = 3.86; p < 0.05). No other differences due to the group or to the time of measurement were found (p > 0.05). The analysis of the multiple regression model showed the influence of the values at T0 for every BESS items and the dominance of limb for stability on an unstable surface standing on one or two legs. These preliminary results suggest that the use of a mirror in a ballet classroom does not improve balance acquisition of the dancer. On the other hand, improvement found after 6 months confirms that at the age of the dancers studied motor skills and balance can easily be trained and improved.

Extended use of Kinesiology Tape and Balance in Participants with Chronic Ankle Instability.

PubMed

Jackson, Kristen; Simon, Janet E; Docherty, Carrie L

2016-01-01

Participants with chronic ankle instability (CAI) have been shown to have balance deficits related to decreased proprioception and neuromuscular control. Kinesiology tape (KT) has been proposed to have many benefits, including increased proprioception. To determine if KT can help with balance deficits associated with CAI. Cohort study. Research laboratory. Thirty participants with CAI were recruited for this study. Balance was assessed using the Balance Error Scoring System (BESS). Participants were pretested and then randomly assigned to either the control or KT group. The participants in the KT group had 4 strips applied to the foot and lower leg and were instructed to leave the tape on until they returned for testing. All participants returned 48 hours later for another BESS assessment. The tape was then removed, and all participants returned 72 hours later to complete the final BESS assessment. Total BESS errors. Differences between the groups occurred at 48 hours post-application of the tape (mean difference = 4.7 ± 1.4 errors, P < .01; 95% confidence interval = 2.0, 7.5) and at 72 hours post-removal of the tape (mean difference = 2.3 ± 1.1 errors, P = .04; 95% confidence interval = 0.1, 4.6). The KT improved balance after it had been applied for 48 hours when compared with the pretest and with the control group. One of the most clinically important findings is that balance improvements were retained even after the tape had been removed for 72 hours.

Effects of postexercise ice-water and room-temperature water immersion on the sensory organization of balance control and lower limb proprioception in amateur rugby players: A randomized controlled trial.

PubMed

Chow, Gary C C; Yam, Timothy T T; Chung, Joanne W Y; Fong, Shirley S M

2017-02-01

This single-blinded, three-armed randomized controlled trial aimed to compare the effects of postexercise ice-water immersion (IWI), room-temperature water immersion (RWI), and no water immersion on the balance performance and knee joint proprioception of amateur rugby players. Fifty-three eligible amateur rugby players (mean age ± standard deviation: 21.6 ± 2.9 years) were randomly assigned to the IWI group (5.3 °C), RWI group (25.0 °C), or the no immersion control group. The participants in each group underwent the same fatigue protocol followed by their allocated recovery intervention, which lasted for 1 minute. Measurements were taken before and after the fatigue-recovery intervention. The primary outcomes were the sensory organization test (SOT) composite equilibrium score (ES) and the condition-specific ES, which were measured using a computerized dynamic posturography machine. The secondary outcome was the knee joint repositioning error. Two-way repeated measures analysis of variance was used to test the effect of water immersion on each outcome variable. There were no significant within- and between-group differences in the SOT composite ESs or the condition-specific ESs. However, there was a group-by-time interaction effect on the knee joint repositioning error. It seems that participants in the RWI group had lower errors over time, but those in the IWI and control groups had increased errors over time. The RWI group had significantly lower error score than the IWI group at postintervention. One minute of postexercise IWI or RWI did not impair rugby players' sensory organization of balance control. RWI had a less detrimental effect on knee joint proprioception to IWI at postintervention.

Effects of postexercise ice-water and room-temperature water immersion on the sensory organization of balance control and lower limb proprioception in amateur rugby players

PubMed Central

Chow, Gary C.C.; Yam, Timothy T.T.; Chung, Joanne W.Y.; Fong, Shirley S.M.

2017-01-01

Abstract Background: This single-blinded, three-armed randomized controlled trial aimed to compare the effects of postexercise ice-water immersion (IWI), room-temperature water immersion (RWI), and no water immersion on the balance performance and knee joint proprioception of amateur rugby players. Methods: Fifty-three eligible amateur rugby players (mean age ± standard deviation: 21.6 ± 2.9 years) were randomly assigned to the IWI group (5.3 °C), RWI group (25.0 °C), or the no immersion control group. The participants in each group underwent the same fatigue protocol followed by their allocated recovery intervention, which lasted for 1 minute. Measurements were taken before and after the fatigue-recovery intervention. The primary outcomes were the sensory organization test (SOT) composite equilibrium score (ES) and the condition-specific ES, which were measured using a computerized dynamic posturography machine. The secondary outcome was the knee joint repositioning error. Two-way repeated measures analysis of variance was used to test the effect of water immersion on each outcome variable. Results: There were no significant within- and between-group differences in the SOT composite ESs or the condition-specific ESs. However, there was a group-by-time interaction effect on the knee joint repositioning error. It seems that participants in the RWI group had lower errors over time, but those in the IWI and control groups had increased errors over time. The RWI group had significantly lower error score than the IWI group at postintervention. Conclusion: One minute of postexercise IWI or RWI did not impair rugby players’ sensory organization of balance control. RWI had a less detrimental effect on knee joint proprioception to IWI at postintervention. PMID:28207546

Effects of Hip Strengthening on Neuromuscular Control, Hip Strength, and Self-Reported Functional Deficits in Individuals With Chronic Ankle Instability.

PubMed

Smith, Brent I; Curtis, Denice; Docherty, Carrie L

2018-06-12

Deficits in ankle and hip strength and lower-extremity postural control are associated with chronic ankle instability (CAI). Following strength training, muscle groups demonstrate increased strength. This change is partially credited to improved neuromuscular control, and many studies have investigated ankle protocols for subjects with CAI. The effects of isolating hip musculature in strength training protocols in this population are not well understood. To examine the effects of hip strengthening on clinical and self-reported outcomes in patients with CAI. Prospective randomized controlled clinical trial. Athletic training facility. Twenty-six participants with CAI (12 males and 14 females; age = 20.9 [1.5] y, height = 170.0 [12.7] cm, and mass = 77.5 [17.5] kg) were randomly assigned to training or control groups. Participants completed either 4 weeks of supervised hip strengthening (resistance bands 3 times a week) or no intervention. Participants were assessed on 4 clinical measures (Star Excursion Balance Test in the anterior, posteromedial, and posterolateral directions; Balance Error Scoring System; hip external rotation strength; and hip abduction strength) and a patient-reported measure (the Foot and Ankle Ability Measure activities of daily living and sports subscales) before and after the 4-week training period. The training group displayed significantly improved posttest measures compared with the control group for hip abduction strength (training: 446.3 [77.4] N, control: 314.7 [49.6] N, P < .01); hip external rotation strength (training: 222.1 [48.7] N, control: 169.4 [34.6] N, P < .01); Star Excursion Balance Test reach in the anterior (training: 93.1% [7.4%], control: 90.2% [7.9%], P < .01), posteromedial (training: 96.3% [8.9%], control: 88.0% [8.8%], P < .01), and posterolateral (training: 95.4% [11.1%], control: 86.6% [9.6%], P < .01) directions; Balance Error Scoring System total errors (training: 9.9 [6.3] errors, control: 21.2 [6.3] errors, P < .01); and the Foot and Ankle Ability Measure-sports score (training: 88.0 [12.6], control: 84.8 [10.9], P < .01). Improved clinical and patient-reported outcomes in the training group suggest hip strengthening is beneficial in the management and prevention of recurrent symptoms associated with CAI.

Performance of high school male athletes on the Functional Movement Screen™.

PubMed

Smith, Laura J; Creps, James R; Bean, Ryan; Rodda, Becky; Alsalaheen, Bara

2017-09-01

(1) Describe the performance of the Functional Movement Screen™ (FMS™) by reporting the proportion of adolescents with a score of ≤14 and the frequency of asymmetries in a cross-sectional sample; (2) explore associations between FMS™ to age and body mass, and explore the construct validity of the FMS™ against common postural stability measures; (3) examine the inter-rater and test-retest reliability of the FMS™ in adolescents. Cross-sectional. Field-setting. 94 male high-school athletes. The FMS™, Y-Balance Test (YBT) and Balance Error Scoring System (BESS). The median FMS™ composite score was 16 (9-21), 33% of participants scored below the suggested injury risk cutoff composite score of ≤14, and 62.8% had at least one asymmetry. No relationship was observed between the FMS™ to common static/dynamic balance tests. The inter-rater reliability of the FMS™ composite score suggested good reliability (ICC = 0.88, CI 95%:0.77, 0.94) and test-retest reliability for FMS™ composite scores was good with ICC = 0.83 (CI 95%:0.56, 0.95). FMS™ results should be interpreted cautiously with attention to the asymmetries identified during the screen, regardless of composite score. The lack of relationship between the FMS™ and other balance measures supports the notion that multiple screening tests should be used in order to provide a comprehensive picture of the adolescent athlete. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trunk repositioning errors are increased in balance-impaired older adults.

PubMed

Goldberg, Allon; Hernandez, Manuel Enrique; Alexander, Neil B

2005-10-01

Controlling the flexing trunk is critical in recovering from a loss of balance and avoiding a fall. To investigate the relationship between trunk control and balance in older adults, we measured trunk repositioning accuracy in young and balance-impaired and unimpaired older adults. Young adults (N = 8, mean age 24.3 years) and two groups of community-dwelling older adults defined by unipedal stance time (UST)-a balance-unimpaired group (UST > 30 seconds, N = 7, mean age 73.9 years) and a balance-impaired group (UST < 5 seconds, N = 8, mean age 79.6 years)-were tested in standing trunk control ability by reproducing a approximately 30 degrees trunk flexion angle under three visual-surface conditions: eyes opened and closed on the floor, and eyes opened on foam. Errors in reproducing the angle were defined as trunk repositioning errors (TREs). Clinical measures related to balance, trunk extensor strength, and self-reported disability were obtained. TREs were significantly greater in the balance-impaired group than in the other groups, even when controlling for trunk extensor strength and body mass. In older adults, there were significant correlations between TREs and three clinical measures of balance and fall risk, UST and maximum step length (-0.65 to -0.75), and Timed Up & Go score (0.55), and between TREs and age (0.63-0.76). In each group TREs were similar under the three visual-surface conditions. Test-retest reliability for TREs was good to excellent (intraclass correlation coefficients > or =0.74). Older balance-impaired adults have larger TREs, and thus poorer trunk control, than do balance-unimpaired older individuals. TREs are reliable and valid measures of underlying balance impairment in older adults, and may eventually prove to be useful in predicting the ability to recover from losses of balance and to avoid falls.

Sensitivity of the Balance Error Scoring System and the Sensory Organization Test in the Combat Environment.

PubMed

Haran, F Jay; Slaboda, Jill C; King, Laurie A; Wright, W Geoff; Houlihan, Daniel; Norris, Jacob N

2016-04-01

This study evaluated the utility of the Balance Error Scoring System (BESS) and the Sensory Organization Test (SOT) as tools for the screening and monitoring of Service members (SMs) with mild traumatic brain injury (mTBI) in a deployed setting during the acute and subacute phases of recovery. Patient records (N = 699) were reviewed for a cohort of SMs who sustained a blast-related mTBI while deployed to Afghanistan and were treated at the Concussion Restoration Care Center (CRCC) at Camp Leatherneck. On initial intake into the CRCC, participants completed two assessments of postural control, the BESS, and SOT. SMs with mTBI performed significantly worse on the BESS and SOT when compared with comparative samples. When the SOT data were further examined using sensory ratios, the results indicated that postural instability was primarily a result of vestibular and visual integration dysfunction (r > 0.62). The main finding of this study was that the sensitivity of the SOT composite score (50-58%) during the acute phase was higher than previous sensitivities found in the sports medicine literature for impact-related trauma.

Ten years of preanalytical monitoring and control: Synthetic Balanced Score Card Indicator

PubMed Central

López-Garrigós, Maite; Flores, Emilio; Santo-Quiles, Ana; Gutierrez, Mercedes; Lugo, Javier; Lillo, Rosa; Leiva-Salinas, Carlos

2015-01-01

Introduction Preanalytical control and monitoring continue to be an important issue for clinical laboratory professionals. The aim of the study was to evaluate a monitoring system of preanalytical errors regarding not suitable samples for analysis, based on different indicators; to compare such indicators in different phlebotomy centres; and finally to evaluate a single synthetic preanalytical indicator that may be included in the balanced scorecard management system (BSC). Materials and methods We collected individual and global preanalytical errors in haematology, coagulation, chemistry, and urine samples analysis. We also analyzed a synthetic indicator that represents the sum of all types of preanalytical errors, expressed in a sigma level. We studied the evolution of those indicators over time and compared indicator results by way of the comparison of proportions and Chi-square. Results There was a decrease in the number of errors along the years (P < 0.001). This pattern was confirmed in primary care patients, inpatients and outpatients. In blood samples, fewer errors occurred in outpatients, followed by inpatients. Conclusion We present a practical and effective methodology to monitor unsuitable sample preanalytical errors. The synthetic indicator results summarize overall preanalytical sample errors, and can be used as part of BSC management system. PMID:25672466

Interrater and Test-Retest Reliability and Minimal Detectable Change of the Balance Evaluation Systems Test (BESTest) and Subsystems With Community-Dwelling Older Adults.

PubMed

Wang-Hsu, Elizabeth; Smith, Susan S

2017-01-10

Falls are a common cause of injuries and hospital admissions in older adults. Balance limitation is a potentially modifiable factor contributing to falls. The Balance Evaluation Systems Test (BESTest), a clinical balance measure, categorizes balance into 6 underlying subsystems. Each of the subsystems is scored individually and summed to obtain a total score. The reliability of the BESTest and its individual subsystems has been reported in patients with various neurological disorders and cancer survivors. However, the reliability and minimal detectable change (MDC) of the BESTest with community-dwelling older adults have not been reported. The purposes of our study were to (1) determine the interrater and test-retest reliability of the BESTest total and subsystem scores; and (2) estimate the MDC of the BESTest and its individual subsystem scores with community-dwelling older adults. We used a prospective cohort methodological design. Community-dwelling older adults (N = 70; aged 70-94 years; mean = 85.0 [5.5] years) were recruited from a senior independent living community. Trained testers (N = 3) administered the BESTest. All participants were tested with the BESTest by the same tester initially and then retested 7 to 14 days later. With 32 of the participants, a second tester concurrently scored the retest for interrater reliability. Testers were blinded to each other's scores. Intraclass correlation coefficients [ICC(2,1)] were used to determine the interrater and test-retest reliability. Test-retest reliability was also analyzed using method error and the associated coefficients of variation (CVME). MDC was calculated using standard error of measurement. Interrater reliability (N = 32) of the BESTest total score was ICC(2, 1) = 0.97 (95% confidence interval [CI], 0.94-0.99). The ICCs for the individual subsystem scores ranged from 0.85 to 0.94. Test-retest reliability (N = 70) of the BESTest total score was ICC(2,1) = 0.93 (95% CI, 0.89-0.96). ICCs for the individual subsystem scores ranged from 0.72 to 0.89. The CVME (N = 70) of the BESTest total score was 4.1%. The CVME for the subsystem scores ranged from 5.0% to 10.7%. MDC (N = 70) for the BESTest total score at the 95% CI was 7.6%, or 8.2 points. MDC at the 95% CI for subsystem scores ranged from 11.7% to 19.0% (2.1-3.4 points). Results demonstrated generally good to excellent interrater and test-retest reliability in both the BESTest total and subsystem scores with community-dwelling older adults. The BESTest total and individual subsystem scores demonstrate good to excellent interrater and test-retest reliability with community-dwelling older adults. A change of 7.6% (8.2 points) or more in the BESTest total and a percentage change ranged from 11.7% to 19.0% (2.1-3.4 points) in the subsystem scores are suggested for clinicians to be 95% confident of true change when evaluating change in this population.

Bilateral improvements in lower extremity function after unilateral balance training in individuals with chronic ankle instability.

PubMed

Hale, Sheri A; Fergus, Andrea; Axmacher, Rachel; Kiser, Kimberly

2014-01-01

Bilateral improvements in postural control have been reported among individuals with acute lateral ankle sprains and individuals with chronic ankle instability (CAI) when only the unstable ankle is rehabilitated. We do not know if training the stable ankle will improve function on the unstable side. To explore the effects of a unilateral balance-training program on bilateral lower extremity balance and function in individuals with CAI when only the stable limb is trained. Cohort study. University clinical research laboratory. A total of 34 volunteers (8 men, 26 women; age = 24.32 ± 4.95 years, height = 167.01 ± 9.45 cm, mass = 77.54 ± 23.76 kg) with CAI were assigned to the rehabilitation (n = 17) or control (n = 17) group. Of those, 27 (13 rehabilitation group, 14 control group) completed the study. Balance training twice weekly for 4 weeks. Foot and Ankle Disability Index (FADI), FADI Sport (FADI-S), Star Excursion Balance Test, and Balance Error Scoring System. The rehabilitation and control groups differed in changes in FADI-S and Star Excursion Balance Test scores over time. Only the rehabilitation group improved in the FADI-S and in the posteromedial and anterior reaches of the Star Excursion Balance Test. Both groups demonstrated improvements in posterolateral reach; however, the rehabilitation group demonstrated greater improvement than the control group. When the groups were combined, participants reported improvements in FADI and FADI-S scores for the unstable ankle but not the stable ankle. Our data suggest training the stable ankle may result in improvements in balance and lower extremity function in the unstable ankle. This further supports the existence of a centrally mediated mechanism in the development of postural-control deficits after injury, as well as improved postural control after rehabilitation.

Local alignment of two-base encoded DNA sequence

PubMed Central

Homer, Nils; Merriman, Barry; Nelson, Stanley F

2009-01-01

Background DNA sequence comparison is based on optimal local alignment of two sequences using a similarity score. However, some new DNA sequencing technologies do not directly measure the base sequence, but rather an encoded form, such as the two-base encoding considered here. In order to compare such data to a reference sequence, the data must be decoded into sequence. The decoding is deterministic, but the possibility of measurement errors requires searching among all possible error modes and resulting alignments to achieve an optimal balance of fewer errors versus greater sequence similarity. Results We present an extension of the standard dynamic programming method for local alignment, which simultaneously decodes the data and performs the alignment, maximizing a similarity score based on a weighted combination of errors and edits, and allowing an affine gap penalty. We also present simulations that demonstrate the performance characteristics of our two base encoded alignment method and contrast those with standard DNA sequence alignment under the same conditions. Conclusion The new local alignment algorithm for two-base encoded data has substantial power to properly detect and correct measurement errors while identifying underlying sequence variants, and facilitating genome re-sequencing efforts based on this form of sequence data. PMID:19508732

Can binary early warning scores perform as well as standard early warning scores for discriminating a patient's risk of cardiac arrest, death or unanticipated intensive care unit admission?

PubMed

Jarvis, Stuart; Kovacs, Caroline; Briggs, Jim; Meredith, Paul; Schmidt, Paul E; Featherstone, Peter I; Prytherch, David R; Smith, Gary B

2015-08-01

Although the weightings to be summed in an early warning score (EWS) calculation are small, calculation and other errors occur frequently, potentially impacting on hospital efficiency and patient care. Use of a simpler EWS has the potential to reduce errors. We truncated 36 published 'standard' EWSs so that, for each component, only two scores were possible: 0 when the standard EWS scored 0 and 1 when the standard EWS scored greater than 0. Using 1564,153 vital signs observation sets from 68,576 patient care episodes, we compared the discrimination (measured using the area under the receiver operator characteristic curve--AUROC) of each standard EWS and its truncated 'binary' equivalent. The binary EWSs had lower AUROCs than the standard EWSs in most cases, although for some the difference was not significant. One system, the binary form of the National Early Warning System (NEWS), had significantly better discrimination than all standard EWSs, except for NEWS. Overall, Binary NEWS at a trigger value of 3 would detect as many adverse outcomes as are detected by NEWS using a trigger of 5, but would require a 15% higher triggering rate. The performance of Binary NEWS is only exceeded by that of standard NEWS. It may be that Binary NEWS, as a simplified system, can be used with fewer errors. However, its introduction could lead to significant increases in workload for ward and rapid response team staff. The balance between fewer errors and a potentially greater workload needs further investigation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Postural stability does not differ among female sports with high risk of anterior cruciate ligament injury.

PubMed

Cortes, Nelson; Porter, Larissa D; Ambegaonkar, Jatin P; Caswell, Shane V

2014-12-01

Dancers have a lower incidence of anterior cruciate ligament (ACL) injury compared to athletes in sports that involve cutting and landing motions. Balance can impact ACL injury risk and is related to neuromuscular control during movement. The purpose of this study was to investigate whether balance differences exist among female dancers and female soccer and basketball athletes. Fifty-eight female dancers, soccer, and basketball athletes (16.5 ± 1.6 yrs, 1.6 ± 0.2 m, 60.2 ± 14.1 kg) completed the Stability Evaluation Test (SET) on the NeuroCom VSR Sport (NeuroCom International, Clackamas, OR) to measure sway velocity. Video records of the SET test were used for Balance Error Scoring System (BESS) test scoring. A oneway ANCOVA compared composite sway velocity and BESS scores among sports. There was no statistically significant difference for sway velocity or BESS among sports (sway velocity soccer 2.3 ± 0.4, dance 2.2 ± 0.4, and basketball 2.4 ± 0.4; BESS soccer 13.6 ± 5.0, dance 11.9 ± 5.5, and basketball 14.9 ± 5.1, p>0.05). Balance was similar among athletes participating in different sports (dance, basketball, and soccer). Quasi-static balance may not play a significant role in neuromuscular control during movement and not be a significant risk factor to explain the disparity in ACL injury incidence among sports. Future research should examine the effects of dynamic balance and limb asymmetries among sports to elucidate on the existing differences on ACL injury incidence rates.

Predicting Recovery Patterns After Sport-Related Concussion

PubMed Central

Teel, Elizabeth F.; Marshall, Stephen W.; Shankar, Viswanathan; McCrea, Michael; Guskiewicz, Kevin M.

2017-01-01

Context: Clinicians sometimes treat concussed individuals who have amnesia, loss of consciousness (LOC), a concussion history, or certain symptom types more conservatively, but it is unclear whether recovery patterns differ in individuals with these characteristics. Objective: To determine whether (1) amnesia, LOC, and concussion history influence the acute recovery of symptoms, cognition, and balance; and (2) cognition and balance are influenced by acute symptom type. Design: Cohort study. Setting: Seven sports at 26 colleges and 210 high schools. Patients or Other Participants: A total of 8905 collegiate (n = 1392) and high school (n = 7513) athletes. Main Outcome Measure(s): The Graded Symptom Checklist, Standardized Assessment of Concussion, and Balance Error Scoring System were administered to all athletes during the preseason. To allow us to track recovery patterns, athletes diagnosed with a concussion (n = 375) repeated these assessments immediately after the injury, 3 hours postinjury, 1 day postinjury, and at 2, 3, 5, 7, and 90 days after injury. Results: Athletes who experienced amnesia had markedly greater deficits in and a slower recovery trajectory on measures of symptoms, cognition, and balance. Athletes with 2 or more prior concussions demonstrated poorer balance than those with no previous history. Otherwise, LOC and concussion history largely did not affect symptoms, cognition, or balance. Greater deficits in balance scores were observed in athletes with all symptom types. Regardless of these characteristics, most athletes recovered within 7 to 10 days. Conclusions: Athletes who experienced amnesia had more symptoms and greater deficits in cognition and balance. Symptoms and cognitive or balance deficits were not consistently associated with LOC or concussion history. Acute symptoms had a strong influence on balance scores and, to a lesser extent, on cognition. However, we found no evidence to support more cautious return-to-play decisions for athletes with these characteristics, as group recovery occurred within normal timelines. Our study supports current clinical practice: recommending that athletes be withheld from activity until they are asymptomatic, followed by a graduated return-to-play progression. PMID:28387552

Predicting Recovery Patterns After Sport-Related Concussion.

PubMed

Teel, Elizabeth F; Marshall, Stephen W; Shankar, Viswanathan; McCrea, Michael; Guskiewicz, Kevin M

2017-03-01

Clinicians sometimes treat concussed individuals who have amnesia, loss of consciousness (LOC), a concussion history, or certain symptom types more conservatively, but it is unclear whether recovery patterns differ in individuals with these characteristics. To determine whether (1) amnesia, LOC, and concussion history influence the acute recovery of symptoms, cognition, and balance; and (2) cognition and balance are influenced by acute symptom type. Cohort study. Seven sports at 26 colleges and 210 high schools. A total of 8905 collegiate (n = 1392) and high school (n = 7513) athletes. The Graded Symptom Checklist, Standardized Assessment of Concussion, and Balance Error Scoring System were administered to all athletes during the preseason. To allow us to track recovery patterns, athletes diagnosed with a concussion (n = 375) repeated these assessments immediately after the injury, 3 hours postinjury, 1 day postinjury, and at 2, 3, 5, 7, and 90 days after injury. Athletes who experienced amnesia had markedly greater deficits in and a slower recovery trajectory on measures of symptoms, cognition, and balance. Athletes with 2 or more prior concussions demonstrated poorer balance than those with no previous history. Otherwise, LOC and concussion history largely did not affect symptoms, cognition, or balance. Greater deficits in balance scores were observed in athletes with all symptom types. Regardless of these characteristics, most athletes recovered within 7 to 10 days. Athletes who experienced amnesia had more symptoms and greater deficits in cognition and balance. Symptoms and cognitive or balance deficits were not consistently associated with LOC or concussion history. Acute symptoms had a strong influence on balance scores and, to a lesser extent, on cognition. However, we found no evidence to support more cautious return-to-play decisions for athletes with these characteristics, as group recovery occurred within normal timelines. Our study supports current clinical practice: recommending that athletes be withheld from activity until they are asymptomatic, followed by a graduated return-to-play progression.

Interobserver Reliability of Peripheral Muscle Strength Tests and Short Physical Performance Battery in Patients With Chronic Obstructive Pulmonary Disease: A Prospective Observational Study.

PubMed

Medina-Mirapeix, Francesc; Bernabeu-Mora, Roberto; Llamazares-Herrán, Eduardo; Sánchez-Martínez, Ma Piedad; García-Vidal, José Antonio; Escolar-Reina, Pilar

2016-11-01

To evaluate the interobserver reliability of the Short Physical Performance Battery (SPPB) and hand dynamometry when measuring isometric muscle strength in people with chronic obstructive pulmonary disease (COPD). Reliability study. Each patient was assessed by a pulmonology physician and a physical therapist in 2 separate sessions 7 to 14 days apart (mean, 9.8±0.8d). Each rater was blinded to the other's results. Pneumology unit of a public hospital. Random sample of outpatients with stable COPD (N=30). Not applicable. SPPB and muscle strength (kg) using electronic handgrip and handheld dynamometers. Reliability was assessed with intraclass correlation coefficients (ICCs), standard error of measurement values, and Bland-Altman plots. ICCs were calculated for the SPPB summary score and for its 3 subscales. The ICCs for the overall reliability of the SPPB summary score and for grip and quadriceps strength were .82 (95% confidence interval [CI], .62-.91), .97 (95% CI, .93-.98), and .76 (95% CI, .49-.88), respectively. The standard error of measurement values were .55 points, 1.30kg, and 1.22kg, respectively. The mean differences between the rater's scores were near zero for grip strength and SPPB summary score measures. The ICCs for the SPPB subscales were .84 (95% CI, .66-.92) for the chair subscale, .75 (95% CI, .48-.88) for gait, and .33 (95% CI, -.42 to .68) for balance. Interobserver reliability was good for quadriceps and handgrip dynamometry and for the SPPB summary score and its chair stand and gait speed subscales. Both pulmonary physicians and physical therapists can obtain and exchange the scores. Because the reliability of the balance subscale was questionable, it is better to use the SPPB summary score. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Sex Differences in Vestibular/Ocular and Neurocognitive Outcomes After Sport-Related Concussion.

PubMed

Sufrinko, Alicia M; Mucha, Anne; Covassin, Tracey; Marchetti, Greg; Elbin, R J; Collins, Michael W; Kontos, Anthony P

2017-03-01

To examine sex differences in vestibular and oculomotor symptoms and impairment in athletes with sport-related concussion (SRC). The secondary purpose was to replicate previously reported sex differences in total concussion symptoms, and performance on neurocognitive and balance testing. Prospective cross-sectional study of consecutively enrolled clinic patients within 21 days of a SRC. Specialty Concussion Clinic. Included male (n = 36) and female (n = 28) athletes ages 9 to 18 years. Vestibular symptoms and impairment was measured with the Vestibular/Ocular Motor Screening (VOMS). Participants completed the Immediate Post-concussion Assessment and Cognitive Test (ImPACT), Post-concussion Symptom Scale (PCSS), and Balance Error Scoring System (BESS). Sex differences on clinical measures. Females had higher PCSS scores (P = 0.01) and greater VOMS vestibular ocular reflex (VOR) score (P = 0.01) compared with males. There were no sex differences on BESS or ImPACT. Total PCSS scores together with female sex accounted for 45% of the variance in VOR scores. Findings suggest higher VOR scores after SRC in female compared with male athletes. Findings did not extend to other components of the VOMS tool suggesting that sex differences may be specific to certain types of vestibular impairment after SRC. Additional research on the clinical significance of the current findings is needed.

Bilateral Improvements in Lower Extremity Function After Unilateral Balance Training in Individuals With Chronic Ankle Instability

PubMed Central

Hale, Sheri A.; Fergus, Andrea; Axmacher, Rachel; Kiser, Kimberly

2014-01-01

Context: Bilateral improvements in postural control have been reported among individuals with acute lateral ankle sprains and individuals with chronic ankle instability (CAI) when only the unstable ankle is rehabilitated. We do not know if training the stable ankle will improve function on the unstable side. Objective: To explore the effects of a unilateral balance-training program on bilateral lower extremity balance and function in individuals with CAI when only the stable limb is trained. Design: Cohort study. Setting: University clinical research laboratory. Patients or Other Participants: A total of 34 volunteers (8 men, 26 women; age = 24.32 ± 4.95 years, height = 167.01 ± 9.45 cm, mass = 77.54 ± 23.76 kg) with CAI were assigned to the rehabilitation (n = 17) or control (n = 17) group. Of those, 27 (13 rehabilitation group, 14 control group) completed the study. Intervention(s): Balance training twice weekly for 4 weeks. Main Outcome Measure(s): Foot and Ankle Disability Index (FADI), FADI Sport (FADI-S), Star Excursion Balance Test, and Balance Error Scoring System. Results: The rehabilitation and control groups differed in changes in FADI-S and Star Excursion Balance Test scores over time. Only the rehabilitation group improved in the FADI-S and in the posteromedial and anterior reaches of the Star Excursion Balance Test. Both groups demonstrated improvements in posterolateral reach; however, the rehabilitation group demonstrated greater improvement than the control group. When the groups were combined, participants reported improvements in FADI and FADI-S scores for the unstable ankle but not the stable ankle. Conclusions: Our data suggest training the stable ankle may result in improvements in balance and lower extremity function in the unstable ankle. This further supports the existence of a centrally mediated mechanism in the development of postural-control deficits after injury, as well as improved postural control after rehabilitation. PMID:24568231

Static Postural Stability in Chronic Ankle Instability, An Ankle Sprain and Healthy Ankles.

PubMed

Kwon, Yong Ung

2018-05-18

To identify the single leg balance (SLB) test that discriminates among healthy, coper, and chronic ankle instability (CAI) groups and to determine effects of ankle muscles on the balance error scoring system (BESS) among the three populations. 60 subjects (20 per group) performed the SLB test with eyes open (EO) and eyes closed (EC). Normalized mean amplitude (NMA) of the tibia anterior (TA), fibularis longus (FL), and medial gastrocnemius (MG) muscles and BESS were measured while performing the SLB test. The coper group had a lower error score than the CAI group in the EC. NMA was greater in the CAI group compared to in the healthy and coper groups regardless of muscle type. NMA of the TA was less than the PL and MG regardless of the group in the EO. The CAI group demonstrated greater NMAs of the PL and MG than the healthy and coper groups in the EC. The CAI group demonstrated greater NMA of the PL and MG by compensating their ankle muscles in the EO and EC. BESS suggests that the coper group may have coping mechanisms to stabilize static postural control compared to the CAI group. The EC may be better to detect static postural instability in the CAI or coper group. © Georg Thieme Verlag KG Stuttgart · New York.

Interpretability of Change Scores in Measures of Balance in People With COPD.

PubMed

Beauchamp, Marla K; Harrison, Samantha L; Goldstein, Roger S; Brooks, Dina

2016-03-01

Balance deficits and an increased fall risk are well documented in individuals with COPD. Despite evidence that balance training programs can improve performance on clinical balance tests, their minimal clinically important difference (MCID) is unknown. The aim of this study was to determine the MCID of the Berg Balance Scale (BBS), Balance Evaluation Systems Test (BESTest), and Activities-Specific Balance Confidence (ABC) scale in patients with COPD undergoing pulmonary rehabilitation. We performed a secondary analysis of data from two studies of balance training in COPD (n = 55). The MCID for each balance measure was estimated using the following anchor and distribution-based approaches: (1) mean change scores on a patient-reported global change in balance scale, (2) optimal cut-point from receiver operating characteristic curves (ROCs), and (3) the minimal detectable change with 95% confidence (MDC95). Data from 55 patients with COPD (mean age, 71.2 ± 7.1 y; mean FEV1, 39.2 ± 15.8% predicted) were used in the analysis. The smallest estimate of MCID was from the ROC method. Anchor-based estimates of the MCID ranged from 3.5 to 7.1 for the BBS, 10.2 to 17.4 for the BESTest, and 14.2 to 18.5 for the ABC scale; their MDC95 values were 5.0, 13.1, and 18.9, respectively. Among patients with COPD undergoing pulmonary rehabilitation, a change of 5 to 7 points for the BBS, 13 to 17 points for the BESTest, and 19 points for the ABC scale is required to be both perceptible to patients and beyond measurement error. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Skylab water balance error analysis

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1977-01-01

Estimates of the precision of the net water balance were obtained for the entire Skylab preflight and inflight phases as well as for the first two weeks of flight. Quantitative estimates of both total sampling errors and instrumentation errors were obtained. It was shown that measurement error is minimal in comparison to biological variability and little can be gained from improvement in analytical accuracy. In addition, a propagation of error analysis demonstrated that total water balance error could be accounted for almost entirely by the errors associated with body mass changes. Errors due to interaction between terms in the water balance equation (covariances) represented less than 10% of the total error. Overall, the analysis provides evidence that daily measurements of body water changes obtained from the indirect balance technique are reasonable, precise, and relaible. The method is not biased toward net retention or loss.

Dynamic balance in children with attention-deficit hyperactivity disorder and its relationship with cognitive functions and cerebellum.

PubMed

Goetz, Michal; Schwabova, Jaroslava Paulasova; Hlavka, Zdenek; Ptacek, Radek; Surman, Craig Bh

2017-01-01

Attention-deficit hyperactivity disorder (ADHD) is linked to the presence of motor deficiencies, including balance deficits. The cerebellum serves as an integrative structure for balance control and is also involved in cognition, including timing and anticipatory regulation. Cerebellar development may be delayed in children and adolescents with ADHD, and inconsistent reaction time is commonly seen in ADHD. We hypothesized that dynamic balance deficits would be present in children with ADHD and they would correlate with attention and cerebellar functions. Sixty-two children with ADHD and no other neurological conditions and 62 typically developing (TD) children were examined with five trials of the Phyaction Balance Board, an electronic balancing platform. Cerebellar clinical symptoms were evaluated using an international ataxia rating scale. Conners' Continuous Performance Test was used to evaluate patterns of reaction. Children with ADHD had poorer performance on balancing tasks, compared to TD children ( P <0.001). They exhibited significantly greater sway amplitudes than TD children ( P <0.001) in all of the five balancing trials. The effect size of the difference between the groups increased continuously from the first to the last trial. Balance score in both groups was related to the variation in the reaction time, including reaction time standard error ( r =0.25; P =0.0409, respectively, r =0.31; P =0.0131) and Variability of Standard Error ( r =0.28; P =0.0252, respectively, r =0.41; P <0.001). The burden of cerebellar symptoms was strongly related to balance performance in both groups ( r =0.50, P <0.001; r =0.49, P =0.001). This study showed that ADHD may be associated with poor dynamic balance control. Furthermore, we showed that maintaining balance correlates with neuropsychological measures of consistency of reaction time. Balance deficits and impaired cognitive functioning could reflect a common cerebellar dysfunction in ADHD children.

Dynamic balance in children with attention-deficit hyperactivity disorder and its relationship with cognitive functions and cerebellum

PubMed Central

Goetz, Michal; Schwabova, Jaroslava Paulasova; Hlavka, Zdenek; Ptacek, Radek; Surman, Craig BH

2017-01-01

Background Attention-deficit hyperactivity disorder (ADHD) is linked to the presence of motor deficiencies, including balance deficits. The cerebellum serves as an integrative structure for balance control and is also involved in cognition, including timing and anticipatory regulation. Cerebellar development may be delayed in children and adolescents with ADHD, and inconsistent reaction time is commonly seen in ADHD. We hypothesized that dynamic balance deficits would be present in children with ADHD and they would correlate with attention and cerebellar functions. Methods Sixty-two children with ADHD and no other neurological conditions and 62 typically developing (TD) children were examined with five trials of the Phyaction Balance Board, an electronic balancing platform. Cerebellar clinical symptoms were evaluated using an international ataxia rating scale. Conners’ Continuous Performance Test was used to evaluate patterns of reaction. Results Children with ADHD had poorer performance on balancing tasks, compared to TD children (P<0.001). They exhibited significantly greater sway amplitudes than TD children (P<0.001) in all of the five balancing trials. The effect size of the difference between the groups increased continuously from the first to the last trial. Balance score in both groups was related to the variation in the reaction time, including reaction time standard error (r =0.25; P=0.0409, respectively, r =0.31; P=0.0131) and Variability of Standard Error (r =0.28; P=0.0252, respectively, r =0.41; P<0.001). The burden of cerebellar symptoms was strongly related to balance performance in both groups (r =0.50, P<0.001; r =0.49, P=0.001). Conclusion This study showed that ADHD may be associated with poor dynamic balance control. Furthermore, we showed that maintaining balance correlates with neuropsychological measures of consistency of reaction time. Balance deficits and impaired cognitive functioning could reflect a common cerebellar dysfunction in ADHD children. PMID:28356743

The Examination of Patient-Reported Outcomes and Postural Control Measures in Patients With and Without a History of ACL Reconstruction: A Case Control Study.

PubMed

Hoch, Johanna M; Sinnott, Cori W; Robinson, Kendall P; Perkins, William O; Hartman, Jonathan W

2018-03-01

There is a lack of literature to support the diagnostic accuracy and cut-off scores of commonly used patient-reported outcome measures (PROMs) and clinician-oriented outcomes such as postural-control assessments (PCAs) when treating post-ACL reconstruction (ACLR) patients. These scores could help tailor treatments, enhance patient-centered care and may identify individuals in need of additional rehabilitation. To determine if differences in 4-PROMs and 3-PCAs exist between post-ACLR and healthy participants, and to determine the diagnostic accuracy and cut-off scores of these outcomes. Case control. Laboratory. A total of 20 post-ACLR and 40 healthy control participants. The participants completed 4-PROMs (the Disablement in the Physically Active Scale [DPA], The Fear-Avoidance Belief Questionnaire [FABQ], the Knee Osteoarthritis Outcomes Score [KOOS] subscales, and the Tampa Scale of Kinesiophobia [TSK-11]) and 3-PCAs (the Balance Error Scoring System [BESS], the modified Star Excursion Balance Test [SEBT], and static balance on an instrumented force plate). Mann-Whitney U tests examined differences between groups. Receiver operating characteristic (ROC) curves were employed to determine sensitivity and specificity. The Area Under the Curve (AUC) was calculated to determine the diagnostic accuracy of each instrument. The Youdin Index was used to determine cut-off scores. Alpha was set a priori at P < 0.05. There were significant differences between groups for all PROMs (P < 0.05). There were no differences in PCAs between groups. The cut-off scores should be interpreted with caution for some instruments, as the scores may not be clinically applicable. Post-ACLR participants have decreased self-reported function and health-related quality of life. The PROMs are capable of discriminating between groups. Clinicians should consider using the cut-off scores in clinical practice. Further use of the instruments to examine detriments after completion of standard rehabilitation may be warranted.

Impact of lossy compression on diagnostic accuracy of radiographs for periapical lesions

NASA Technical Reports Server (NTRS)

Eraso, Francisco E.; Analoui, Mostafa; Watson, Andrew B.; Rebeschini, Regina

2002-01-01

OBJECTIVES: The purpose of this study was to evaluate the lossy Joint Photographic Experts Group compression for endodontic pretreatment digital radiographs. STUDY DESIGN: Fifty clinical charge-coupled device-based, digital radiographs depicting periapical areas were selected. Each image was compressed at 2, 4, 8, 16, 32, 48, and 64 compression ratios. One root per image was marked for examination. Images were randomized and viewed by four clinical observers under standardized viewing conditions. Each observer read the image set three times, with at least two weeks between each reading. Three pre-selected sites per image (mesial, distal, apical) were scored on a five-scale score confidence scale. A panel of three examiners scored the uncompressed images, with a consensus score for each site. The consensus score was used as the baseline for assessing the impact of lossy compression on the diagnostic values of images. The mean absolute error between consensus and observer scores was computed for each observer, site, and reading session. RESULTS: Balanced one-way analysis of variance for all observers indicated that for compression ratios 48 and 64, there was significant difference between mean absolute error of uncompressed and compressed images (P <.05). After converting the five-scale score to two-level diagnostic values, the diagnostic accuracy was strongly correlated (R (2) = 0.91) with the compression ratio. CONCLUSION: The results of this study suggest that high compression ratios can have a severe impact on the diagnostic quality of the digital radiographs for detection of periapical lesions.

Training for improved neuro-muscular control of balance in middle aged females.

PubMed

Anderson, Gregory S; Deluigi, Fabio; Belli, Guido; Tentoni, Claudio; Gaetz, Michael B

2016-01-01

This study examined improvements in static balance and muscle electromyographic (EMG) activity following a four week progressive training program in 16 middle aged females (mean age = 46.9 ± 8.7 yrs; height 161.1 ± 6.0 cm; weight 65.4 ± 11.2 kg). Participants trained 3 times per week for 4 weeks, for 50 min per session, progressing base of support, stability, vision, resistance and torque in each of six basic exercises. Pre and post training measures of balance included feet together standing, a tandem stance and a one-leg stand (unsupported leg in the saggital plane) performed with the eyes closed, and a Stork Stand (unsupported leg in the frontal plane) with both eyes open and closed. In each position postural deviations were tallied for each individual while muscle recruitment was determined using root mean squared (RMS) EMG activity for the soleus, biceps femoris, erector spinae, rectus abdominis and internal oblique muscles of the dominant foot side. Balance scores were significantly improved post training in both the Balance Error Score System (p < 0.05) and stork stand positions (p < 0.01). Muscle activity was reduced post-training in all muscles in each condition except the soleus in the tandem position, although not all significantly. Reduced biceps femoris activity suggest that improved core stability allowed participants to move from a hip to an ankle postural control strategy through improved coordination of muscles involved in balance and reduced body sway. The core muscles were able to control body position with less activity post training suggesting improved muscle coordination and efficiency. These results suggest that short term progressive floor to BOSU™ balance training can improve standing balance in middle aged women. Copyright © 2015 Elsevier Ltd. All rights reserved.

Landing Technique and Performance in Youth Athletes After a Single Injury-Prevention Program Session

PubMed Central

Root, Hayley; Trojian, Thomas; Martinez, Jessica; Kraemer, William; DiStefano, Lindsay J.

2015-01-01

Context Injury-prevention programs (IPPs) performed as season-long warm-ups improve injury rates, performance outcomes, and jump-landing technique. However, concerns regarding program adoption exist. Identifying the acute benefits of using an IPP compared with other warm-ups may encourage IPP adoption. Objective To examine the immediate effects of 3 warm-up protocols (IPP, static warm-up [SWU], or dynamic warm-up [DWU]) on jump-landing technique and performance measures in youth athletes. Design Randomized controlled clinical trial. Setting Gymnasiums. Patients or Other Participants Sixty male and 29 female athletes (age = 13 ± 2 years, height = 162.8 ± 12.6 cm, mass = 37.1 ± 13.5 kg) volunteered to participate in a single session. Intervention(s) Participants were stratified by age, sex, and sport and then were randomized into 1 protocol: IPP, SWU, or DWU. The IPP consisted of dynamic flexibility, strengthening, plyometric, and balance exercises and emphasized proper technique. The SWU consisted of jogging and lower extremity static stretching. The DWU consisted of dynamic lower extremity flexibility exercises. Participants were assessed for landing technique and performance measures immediately before (PRE) and after (POST) completing their warm-ups. Main Outcome Measure(s) One rater graded each jump-landing trial using the Landing Error Scoring System. Participants performed a vertical jump, long jump, shuttle run, and jump-landing task in randomized order. The averages of all jump-landing trials and performance variables were used to calculate 1 composite score for each variable at PRE and POST. Change scores were calculated (POST − PRE) for all measures. Separate 1-way (group) analyses of variance were conducted for each dependent variable (α < .05). Results No differences were observed among groups for any performance measures (P > .05). The Landing Error Scoring System scores improved after the IPP (change = −0.40 ± 1.24 errors) compared with the DWU (0.27 ± 1.09 errors) and SWU (0.43 ± 1.35 errors; P = .04). Conclusions An IPP did not impair sport performance and may have reduced injury risk, which supports the use of these programs before sport activity. PMID:26523663

The multiple hop test: a discriminative or evaluative instrument for chronic ankle instability?

PubMed

Eechaute, Christophe; Bautmans, Ivan; De Hertogh, Willem; Vaes, Peter

2012-05-01

To determine whether the multiple hop test should be used as an evaluative or a discriminative instrument for chronic ankle instability (CAI). Blinded case-control study. : University research laboratory. Twenty-nine healthy subjects (21 men, 8 women, mean age 21.8 years) and 29 patients with CAI (17 men, 12 women, mean age 24.9 years) were selected. Subjects performed a multiple hop test and hopped on 10 different tape markers while trying to avoid any postural correction. Minimal detectable changes (MDC) of the number of balance errors, the time value, and the visual analog scale (VAS) score (perceived difficulty) were calculated as evaluative measures. For the discriminative properties, a receiver operating characteristic curve was determined and the area under curve (AUC), the sensitivity, specificity, diagnostic accuracy (DA), and likelihood ratios (LR) were calculated whether 1, 2, or 3 outcomes were positive. Based on their MDC, outcomes should, respectively, change by more than 7 errors (41%), 6 seconds (15%), and 27 mm (55%, VAS score) before considering it as a real change. Area under curves were, respectively, 79% (errors), 77% (time value), and 65% (VAS score). The most optimal cutoff point was, respectively, 13.5 errors, 35 seconds, and 32.5 mm. When 2 of 3 outcomes were positive, the sensitivity was 86%, the specificity was 79%, the DA was 83%, the positive LR was 4.2, and the negative LR was 0.17. The multiple hop test seems to be more a discriminative instrument for CAI, and its responsiveness needs to be demonstrated.

Sustained Improvements in Dynamic Balance and Landing Mechanics After a 6-Week Neuromuscular Training Program in College Women's Basketball Players.

PubMed

Pfile, Kate R; Gribble, Phillip A; Buskirk, Gretchen E; Meserth, Sara M; Pietrosimone, Brian G

2016-08-01

Epidemiological data demonstrate the need for lower-extremity injury-prevention training. Neuromuscular-control (NMC) programs are immediately effective at minimizing lower-extremity injury risk and improving sport-related performance measures. Research investigating lasting effects after an injury-prevention program is limited. To determine whether dynamic balance, landing mechanics, and hamstring and quadriceps strength could be improved after a 6-wk NMC intervention and maintained for a season. Prospective case series. Controlled laboratory. 11 Division I women's basketball players (age 19.40 ± 1.35 y, height 178.05 ± 7.52 cm, mass 72.86 ± 10.70 kg). Subjects underwent testing 3 times, completing the Star Excursion Balance Test (SEBT), Landing Error Scoring System (LESS), and isometric strength testing for the hamstrings and quadriceps muscles. Pretest and posttest 1 occurred immediately before and after the intervention, respectively, and posttest 2 at the end of the competitive season, 9 mo after posttest 1. Subjects participated in eighteen 30-min plyometric and NMC-training sessions over a 6-wk period. The normalized SEBT composite score, normalized peak isometric hamstrings:quadriceps (H:Q) ratio, and the LESS total score. The mean composite reach significantly improved over time (F2,10 = 6.96, P = .005) where both posttest scores were significantly higher than pretest (70.41% ± 4.08%) (posttest 1 73.48% ± 4.19%, t10 = -3.11, P = .011) and posttest 2 (74.2% ± 4.77%, t10 = -3.78, P = .004). LESS scores significantly improved over time (F2,10 = 6.29, P = .009). The pretest LESS score (7.30 ± 3.40) was higher than posttest 1 (4.9 ± 1.20, t10 = 2.71, P = .024) and posttest 2 (5.44 ± 1.83, t10 = 2.58, P = .030). There were no statistically significant differences (P > .05) over time for the H:Q ratio when averaging both legs (F2,10 = 0.83, P = .45). A 6-wk NMC program improved landing mechanics and dynamic balance over a 9-mo period in women's basketball players. NMC adaptations can be retained without an in-season maintenance program.

Text Classification for Assisting Moderators in Online Health Communities

PubMed Central

Huh, Jina; Yetisgen-Yildiz, Meliha; Pratt, Wanda

2013-01-01

Objectives Patients increasingly visit online health communities to get help on managing health. The large scale of these online communities makes it impossible for the moderators to engage in all conversations; yet, some conversations need their expertise. Our work explores low-cost text classification methods to this new domain of determining whether a thread in an online health forum needs moderators’ help. Methods We employed a binary classifier on WebMD’s online diabetes community data. To train the classifier, we considered three feature types: (1) word unigram, (2) sentiment analysis features, and (3) thread length. We applied feature selection methods based on χ2 statistics and under sampling to account for unbalanced data. We then performed a qualitative error analysis to investigate the appropriateness of the gold standard. Results Using sentiment analysis features, feature selection methods, and balanced training data increased the AUC value up to 0.75 and the F1-score up to 0.54 compared to the baseline of using word unigrams with no feature selection methods on unbalanced data (0.65 AUC and 0.40 F1-score). The error analysis uncovered additional reasons for why moderators respond to patients’ posts. Discussion We showed how feature selection methods and balanced training data can improve the overall classification performance. We present implications of weighing precision versus recall for assisting moderators of online health communities. Our error analysis uncovered social, legal, and ethical issues around addressing community members’ needs. We also note challenges in producing a gold standard, and discuss potential solutions for addressing these challenges. Conclusion Social media environments provide popular venues in which patients gain health-related information. Our work contributes to understanding scalable solutions for providing moderators’ expertise in these large-scale, social media environments. PMID:24025513

Time course and dimensions of postural control changes following neuromuscular training in youth field hockey athletes.

PubMed

Zech, Astrid; Klahn, Philipp; Hoeft, Jon; zu Eulenburg, Christine; Steib, Simon

2014-02-01

Injury prevention effects of neuromuscular training have been partly attributed to postural control adaptations. Uncertainty exists regarding the magnitude of these adaptations and on how they can be adequately monitored. The objective was to determine the time course of neuromuscular training effects on functional, dynamic and static balance measures. Thirty youth (14.9 ± 3 years) field hockey athletes were randomised to an intervention or control group. The intervention included a 20-min neuromuscular warm-up program performed twice weekly for 10 weeks. Balance assessments were performed at baseline, week three, week six and post-intervention. They included the star excursion balance test (SEBT), balance error scoring system (BESS), jump-landing time to stabilization (TTS) and center of pressure (COP) sway velocity during single-leg standing. No baseline differences were found between groups in demographic data and balance measures. Adherence was at 86%. All balance measures except the medial-lateral TTS improved significantly over time (p < 0.05) in both groups. Significant group by time interactions were found for the BESS score (p < 0.001). The intervention group showed greater improvements (69.3 ± 10.3%) after 10 weeks in comparison to controls (31.8 ± 22.1%). There were no significant group by time interactions in the SEBT, TTS and COP sway velocity. Neuromuscular training was effective in improving postural control in youth team athletes. However, this effect was not reflected in all balance measures suggesting that the neuromuscular training did not influence all dimensions of postural control. Further studies are needed to confirm the potential of specific warm-up programs to improve postural control.

Quantification of errors in ordinal outcome scales using shannon entropy: effect on sample size calculations.

PubMed

Mandava, Pitchaiah; Krumpelman, Chase S; Shah, Jharna N; White, Donna L; Kent, Thomas A

2013-01-01

Clinical trial outcomes often involve an ordinal scale of subjective functional assessments but the optimal way to quantify results is not clear. In stroke, the most commonly used scale, the modified Rankin Score (mRS), a range of scores ("Shift") is proposed as superior to dichotomization because of greater information transfer. The influence of known uncertainties in mRS assessment has not been quantified. We hypothesized that errors caused by uncertainties could be quantified by applying information theory. Using Shannon's model, we quantified errors of the "Shift" compared to dichotomized outcomes using published distributions of mRS uncertainties and applied this model to clinical trials. We identified 35 randomized stroke trials that met inclusion criteria. Each trial's mRS distribution was multiplied with the noise distribution from published mRS inter-rater variability to generate an error percentage for "shift" and dichotomized cut-points. For the SAINT I neuroprotectant trial, considered positive by "shift" mRS while the larger follow-up SAINT II trial was negative, we recalculated sample size required if classification uncertainty was taken into account. Considering the full mRS range, error rate was 26.1%±5.31 (Mean±SD). Error rates were lower for all dichotomizations tested using cut-points (e.g. mRS 1; 6.8%±2.89; overall p<0.001). Taking errors into account, SAINT I would have required 24% more subjects than were randomized. We show when uncertainty in assessments is considered, the lowest error rates are with dichotomization. While using the full range of mRS is conceptually appealing, a gain of information is counter-balanced by a decrease in reliability. The resultant errors need to be considered since sample size may otherwise be underestimated. In principle, we have outlined an approach to error estimation for any condition in which there are uncertainties in outcome assessment. We provide the user with programs to calculate and incorporate errors into sample size estimation.

On the Performance of the Marginal Homogeneity Test to Detect Rater Drift.

PubMed

Sgammato, Adrienne; Donoghue, John R

2018-06-01

When constructed response items are administered repeatedly, "trend scoring" can be used to test for rater drift. In trend scoring, raters rescore responses from the previous administration. Two simulation studies evaluated the utility of Stuart's Q measure of marginal homogeneity as a way of evaluating rater drift when monitoring trend scoring. In the first study, data were generated based on trend scoring tables obtained from an operational assessment. The second study tightly controlled table margins to disentangle certain features present in the empirical data. In addition to Q , the paired t test was included as a comparison, because of its widespread use in monitoring trend scoring. Sample size, number of score categories, interrater agreement, and symmetry/asymmetry of the margins were manipulated. For identical margins, both statistics had good Type I error control. For a unidirectional shift in margins, both statistics had good power. As expected, when shifts in the margins were balanced across categories, the t test had little power. Q demonstrated good power for all conditions and identified almost all items identified by the t test. Q shows substantial promise for monitoring of trend scoring.

Normative scores on the Berg Balance Scale decline after age 70 years in healthy community-dwelling people: a systematic review.

PubMed

Downs, Stephen; Marquez, Jodie; Chiarelli, Pauline

2014-06-01

What is the mean Berg Balance Scale score of healthy elderly people living in the community and how does it vary with age? How much variability in Berg Balance Scale scores is present in groups of healthy elderly people and how does this vary with age? Systematic review with meta-analysis. Any group of healthy community-dwelling people with a mean age of 70 years or greater that has undergone assessment using the Berg Balance Scale. Mean and standard deviations of Berg Balance Scale scores within cohorts of elderly people of known mean age. The search yielded 17 relevant studies contributing data from a total of 1363 participants. The mean Berg Balance Scale scores ranged from 37 to 55 out of a possible maximum score of 56. The standard deviation of Berg Balance Scale scores varied from 1.0 to 9.2. Although participants aged around 70 years had very close to normal Berg Balance Scale scores, there was a significant decline in balance with age at a rate of 0.7 points on the 56-point Berg Balance Scale per year. There was also a strong association between increasing age and increasing variability in balance (R(2) = 0.56, p < 0.001). Healthy community-dwelling elderly people have modest balance deficits, as measured by the Berg Balance Scale, although balance scores deteriorate and become more variable with age. Copyright © 2014. Published by Elsevier B.V.

Dehydration and performance on clinical concussion measures in collegiate wrestlers.

PubMed

Weber, Amanda Friedline; Mihalik, Jason P; Register-Mihalik, Johna K; Mays, Sally; Prentice, William E; Guskiewicz, Kevin M

2013-01-01

The effects of dehydration induced by wrestling-related weight-cutting tactics on clinical concussion outcomes, such as neurocognitive function, balance performance, and symptoms, have not been adequately studied. To evaluate the effects of dehydration on the outcome of clinical concussion measures in National Collegiate Athletic Association Division I collegiate wrestlers. Repeated-measures design. Clinical research laboratory. Thirty-two Division I healthy collegiate male wrestlers (age = 20.0 ± 1.4 years; height = 175.0 ± 7.5 cm; baseline mass = 79.2 ± 12.6 kg). Participants completed preseason concussion baseline testing in early September. Weight and urine samples were also collected at this time. All participants reported to prewrestling practice and postwrestling practice for the same test battery and protocol in mid-October. They had begun practicing weight-cutting tactics a day before prepractice and postpractice testing. Differences between these measures permitted us to evaluate how dehydration and weight-cutting tactics affected concussion measures. Sport Concussion Assessment Tool 2 (SCAT2), Balance Error Scoring System, Graded Symptom Checklist, and Simple Reaction Time scores. The Simple Reaction Time was measured using the Automated Neuropsychological Assessment Metrics. The SCAT2 measurements were lower at prepractice (P = .002) and postpractice (P < .001) when compared with baseline. The BESS error scores were higher at postpractice when compared with baseline (P = .015). The GSC severity scores were higher at prepractice (P = .011) and postpractice (P < .001) than at baseline and at postpractice when than at prepractice (P = .003). The number of Graded Symptom Checklist symptoms reported was also higher at prepractice (P = .036) and postpractice (P < .001) when compared with baseline, and at postpractice when compared with prepractice (P = .003). Our results suggest that it is important for wrestlers to be evaluated in a euhydrated state to ensure that dehydration is not influencing the outcome of the clinical measures.

Dehydration and Performance on Clinical Concussion Measures in Collegiate Wrestlers

PubMed Central

Weber, Amanda Friedline; Mihalik, Jason P.; Register-Mihalik, Johna K.; Mays, Sally; Prentice, William E.; Guskiewicz, Kevin M.

2013-01-01

Context: The effects of dehydration induced by wrestling-related weight-cutting tactics on clinical concussion outcomes, such as neurocognitive function, balance performance, and symptoms, have not been adequately studied. Objective: To evaluate the effects of dehydration on the outcome of clinical concussion measures in National Collegiate Athletic Association Division I collegiate wrestlers. Design: Repeated-measures design. Setting: Clinical research laboratory. Patients or Other Participants: Thirty-two Division I healthy collegiate male wrestlers (age = 20.0 ± 1.4 years; height = 175.0 ± 7.5 cm; baseline mass = 79.2 ± 12.6 kg). Intervention(s): Participants completed preseason concussion baseline testing in early September. Weight and urine samples were also collected at this time. All participants reported to prewrestling practice and postwrestling practice for the same test battery and protocol in mid-October. They had begun practicing weight-cutting tactics a day before prepractice and postpractice testing. Differences between these measures permitted us to evaluate how dehydration and weight-cutting tactics affected concussion measures. Main Outcome Measures: Sport Concussion Assessment Tool 2 (SCAT2), Balance Error Scoring System, Graded Symptom Checklist, and Simple Reaction Time scores. The Simple Reaction Time was measured using the Automated Neuropsychological Assessment Metrics. Results: The SCAT2 measurements were lower at prepractice (P = .002) and postpractice (P < .001) when compared with baseline. The BESS error scores were higher at postpractice when compared with baseline (P = .015). The GSC severity scores were higher at prepractice (P = .011) and postpractice (P < .001) than at baseline and at postpractice when than at prepractice (P = .003). The number of Graded Symptom Checklist symptoms reported was also higher at prepractice (P = .036) and postpractice (P < .001) when compared with baseline, and at postpractice when compared with prepractice (P = .003). Conclusions: Our results suggest that it is important for wrestlers to be evaluated in a euhydrated state to ensure that dehydration is not influencing the outcome of the clinical measures. PMID:23672379

Reference values and equations reference of balance for children of 8 to 12 years.

PubMed

Libardoni, Thiele de Cássia; Silveira, Carolina Buzzi da; Sinhorim, Larissa Milani Brognoli; Oliveira, Anamaria Siriani de; Santos, Márcio José Dos; Santos, Gilmar Moraes

2018-02-01

There are still no normative data in balance sway for school-age children in Brazil. We aimed to establish the reference ranges for balance scores and to develop prediction equations for estimation of balance scores in children aged 8 to 12 years old. The study included 165 healthy children (83 boys and 82 girls; age, 8-12 years) recruited from a public school in the city of Florianópolis, Santa Catarina, Brazil. We used the Sensory Organization Test to assess the balance scores and both a digital scale and a stadiometer to measure the anthropometric variables. We tested a stepwise multiple-regression model with sex, height, weight, and mid-thigh circumference of the dominant leg as predictors of the balance score. For all experimental conditions, girls' age accounted for over 85% of the variability in balance scores; while, boys' age accounted only 55% of the variability in balance scores. Therefore, balance scores increase with age for boys and girls. This study described the ranges of age- and sex-specific normative values for balance scores in children during 6 different testing conditions established by the sensory organization test. We confirmed that age was the predictor that best explained the variability in balance scores in children between 8 and 12 years old. This study stimulates a new and more comprehensive study to estimate balance scores from prediction equations for overall Brazilian pediatric population. Copyright © 2017 Elsevier B.V. All rights reserved.

The effects of error augmentation on learning to walk on a narrow balance beam.

PubMed

Domingo, Antoinette; Ferris, Daniel P

2010-10-01

Error augmentation during training has been proposed as a means to facilitate motor learning due to the human nervous system's reliance on performance errors to shape motor commands. We studied the effects of error augmentation on short-term learning of walking on a balance beam to determine whether it had beneficial effects on motor performance. Four groups of able-bodied subjects walked on a treadmill-mounted balance beam (2.5-cm wide) before and after 30 min of training. During training, two groups walked on the beam with a destabilization device that augmented error (Medium and High Destabilization groups). A third group walked on a narrower beam (1.27-cm) to augment error (Narrow). The fourth group practiced walking on the 2.5-cm balance beam (Wide). Subjects in the Wide group had significantly greater improvements after training than the error augmentation groups. The High Destabilization group had significantly less performance gains than the Narrow group in spite of similar failures per minute during training. In a follow-up experiment, a fifth group of subjects (Assisted) practiced with a device that greatly reduced catastrophic errors (i.e., stepping off the beam) but maintained similar pelvic movement variability. Performance gains were significantly greater in the Wide group than the Assisted group, indicating that catastrophic errors were important for short-term learning. We conclude that increasing errors during practice via destabilization and a narrower balance beam did not improve short-term learning of beam walking. In addition, the presence of qualitatively catastrophic errors seems to improve short-term learning of walking balance.

Mass-balance measurements in Alaska and suggestions for simplified observation programs

USGS Publications Warehouse

Trabant, D.C.; March, R.S.

1999-01-01

US Geological Survey glacier fieldwork in Alaska includes repetitious measurements, corrections for leaning or bending stakes, an ability to reliably measure seasonal snow as deep as 10 m, absolute identification of summer surfaces in the accumulation area, and annual evaluation of internal accumulation, internal ablation, and glacier-thickness changes. Prescribed field measurement and note-taking techniques help eliminate field errors and expedite the interpretative process. In the office, field notes are transferred to computerized spread-sheets for analysis, release on the World Wide Web, and archival storage. The spreadsheets have error traps to help eliminate note-taking and transcription errors. Rigorous error analysis ends when mass-balance measurements are extrapolated and integrated with area to determine glacier and basin mass balances. Unassessable errors in the glacier and basin mass-balance data reduce the value of the data set for correlations with climate change indices. The minimum glacier mass-balance program has at least three measurement sites on a glacier and the measurements must include the seasonal components of mass balance as well as the annual balance.

Supporting diagnosis of attention-deficit hyperactive disorder with novelty detection.

PubMed

Lee, Hyoung-Joo; Cho, Sungzoon; Shin, Min-Sup

2008-03-01

Computerized continuous performance test (CPT) is a widely used diagnostic tool for attention-deficit hyperactivity disorder (ADHD). It measures the number of correctly detected stimuli as well as response times. Typically, when calculating a cut-off score for discriminating between normal and abnormal, only the normal children's data are collected. Then the average and standard deviation of each measure or variable is computed. If any of variables is larger than 2 sigma above the average, that child is diagnosed as abnormal. We will call this approach as "T-score 70" classifier. However, its performance has a lot to be desired due to a high false negative error. In order to improve the classification accuracy we propose to use novelty detection approaches for supporting ADHD diagnosis. Novelty detection is a model building framework where a classifier is constructed using only one class of training data and a new input pattern is classified according to its similarity to the training data. A total of eight novelty detectors are introduced and applied to our ADHD datasets collected from two modes of tests, visual and auditory. They are evaluated and compared with the T-score model on validation datasets in terms of false positive and negative error rates, and area under receiver operating characteristics curve (AuROC). Experimental results show that the cut-off score of 70 is suboptimal which leads to a low false positive error but a very high false negative error. A few novelty detectors such as Parzen density estimators yield much more balanced classification performances. Moreover, most novelty detectors outperform the T-score method for most age groups statistically with a significance level of 1% in terms of AuROC. In particular, we recommend the Parzen and Gaussian density estimators, kernel principal component analysis, one-class support vector machine, and K-means clustering novelty detector which can improve upon the T-score method on average by at least 30% for the visual test and 40% for the auditory test. In addition, their performances are relatively stable over various parameter values as long as they are within reasonable ranges. The proposed novelty detection approaches can replace the T-score method which has been considered the "gold standard" for supporting ADHD diagnosis. Furthermore, they can be applied to other psychological tests where only normal data are available.

Pre-Test Assessment of the Upper Bound of the Drag Coefficient Repeatability of a Wind Tunnel Model

NASA Technical Reports Server (NTRS)

Ulbrich, N.; L'Esperance, A.

2017-01-01

A new method is presented that computes a pre{test estimate of the upper bound of the drag coefficient repeatability of a wind tunnel model. This upper bound is a conservative estimate of the precision error of the drag coefficient. For clarity, precision error contributions associated with the measurement of the dynamic pressure are analyzed separately from those that are associated with the measurement of the aerodynamic loads. The upper bound is computed by using information about the model, the tunnel conditions, and the balance in combination with an estimate of the expected output variations as input. The model information consists of the reference area and an assumed angle of attack. The tunnel conditions are described by the Mach number and the total pressure or unit Reynolds number. The balance inputs are the partial derivatives of the axial and normal force with respect to all balance outputs. Finally, an empirical output variation of 1.0 microV/V is used to relate both random instrumentation and angle measurement errors to the precision error of the drag coefficient. Results of the analysis are reported by plotting the upper bound of the precision error versus the tunnel conditions. The analysis shows that the influence of the dynamic pressure measurement error on the precision error of the drag coefficient is often small when compared with the influence of errors that are associated with the load measurements. Consequently, the sensitivities of the axial and normal force gages of the balance have a significant influence on the overall magnitude of the drag coefficient's precision error. Therefore, results of the error analysis can be used for balance selection purposes as the drag prediction characteristics of balances of similar size and capacities can objectively be compared. Data from two wind tunnel models and three balances are used to illustrate the assessment of the precision error of the drag coefficient.

The Interrelationship of Common Clinical Movement Screens: Establishing Population-Specific Norms in a Large Cohort of Military Applicants.

PubMed

de la Motte, Sarah J; Gribbin, Timothy C; Lisman, Peter; Beutler, Anthony I; Deuster, Patricia

2016-11-01

 Musculoskeletal injuries (MSK-Is) are a leading cause of missed duty time and morbidity in the military. Modifiable risk factors for MSK-Is, such as inadequate core stability, poor movement patterns, and dynamic balance deficits, have not been identified in military applicants on entering service.  To establish normative functional movement data using a series of screens in military applicants entering basic training and explore relationships among several movement tests.  Cross-sectional study.  Military Entrance Processing Station.  A total of 1714 (1434 male, 280 female) military applicants entering the US Army (n = 546), Navy (n = 414), Air Force (n = 229), or Marine Corps (n = 525).  We conducted the Functional Movement Screen (FMS), Y-Balance Test (YBT), overhead squat (OHS), and Landing Error Scoring System (LESS). Movements were assessed using the scoring convention for each screen.  The FMS, YBT, OHS, and LESS scores and associations among the movement screens as well as clinical meaningfulness.  A total of 1037 of the 1714 enrolled applicants were screened on the day they left for basic training. Normative means for this population were established: FMS = 14.7 ± 1.8, YBT anterior-reach difference = 3.1 ± 3.0 cm, mean YBT composite differences = 8.0 ± 6.8 cm, mean YBT composite percentage = 90.9% ± 8.3%, OHS errors = 5.0 ± 2.8, and LESS score = 5.7 ± 2.1. Backward regression results revealed that the YBT composite percentage was related to the FMS and OHS scores in males and to the FMS and LESS results in females. However, clinically meaningful relationships between the tests varied for both males and females.  Sex-normative values for the FMS, YBT, OHS, and LESS screens were established for US military applicants, and some of the assessments overlapped. Overall, males performed better on the OHS and LESS and achieved a greater YBT composite percentage than females. The regression results revealed movement screen performance relationships that varied by sex and clinical meaningfulness. In future studies, we will determine if performance on any of the screens is associated with MSK-Is in basic trainees.

Assessing the performance of the generalized propensity score for estimating the effect of quantitative or continuous exposures on binary outcomes

PubMed Central

2018-01-01

Propensity score methods are increasingly being used to estimate the effects of treatments and exposures when using observational data. The propensity score was initially developed for use with binary exposures. The generalized propensity score (GPS) is an extension of the propensity score for use with quantitative or continuous exposures (eg, dose or quantity of medication, income, or years of education). We used Monte Carlo simulations to examine the performance of different methods of using the GPS to estimate the effect of continuous exposures on binary outcomes. We examined covariate adjustment using the GPS and weighting using weights based on the inverse of the GPS. We examined both the use of ordinary least squares to estimate the propensity function and the use of the covariate balancing propensity score algorithm. The use of methods based on the GPS was compared with the use of G‐computation. All methods resulted in essentially unbiased estimation of the population dose‐response function. However, GPS‐based weighting tended to result in estimates that displayed greater variability and had higher mean squared error when the magnitude of confounding was strong. Of the methods based on the GPS, covariate adjustment using the GPS tended to result in estimates with lower variability and mean squared error when the magnitude of confounding was strong. We illustrate the application of these methods by estimating the effect of average neighborhood income on the probability of death within 1 year of hospitalization for an acute myocardial infarction. PMID:29508424

Assessing the performance of the generalized propensity score for estimating the effect of quantitative or continuous exposures on binary outcomes.

PubMed

Austin, Peter C

2018-05-20

Propensity score methods are increasingly being used to estimate the effects of treatments and exposures when using observational data. The propensity score was initially developed for use with binary exposures. The generalized propensity score (GPS) is an extension of the propensity score for use with quantitative or continuous exposures (eg, dose or quantity of medication, income, or years of education). We used Monte Carlo simulations to examine the performance of different methods of using the GPS to estimate the effect of continuous exposures on binary outcomes. We examined covariate adjustment using the GPS and weighting using weights based on the inverse of the GPS. We examined both the use of ordinary least squares to estimate the propensity function and the use of the covariate balancing propensity score algorithm. The use of methods based on the GPS was compared with the use of G-computation. All methods resulted in essentially unbiased estimation of the population dose-response function. However, GPS-based weighting tended to result in estimates that displayed greater variability and had higher mean squared error when the magnitude of confounding was strong. Of the methods based on the GPS, covariate adjustment using the GPS tended to result in estimates with lower variability and mean squared error when the magnitude of confounding was strong. We illustrate the application of these methods by estimating the effect of average neighborhood income on the probability of death within 1 year of hospitalization for an acute myocardial infarction. © 2018 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

Systematic study of error sources in supersonic skin-friction balance measurements

NASA Technical Reports Server (NTRS)

Allen, J. M.

1976-01-01

An experimental study was performed to investigate potential error sources in data obtained with a self-nulling, moment-measuring, skin-friction balance. The balance was installed in the sidewall of a supersonic wind tunnel, and independent measurements of the three forces contributing to the balance output (skin friction, lip force, and off-center normal force) were made for a range of gap size and element protrusion. The relatively good agreement between the balance data and the sum of these three independently measured forces validated the three-term model used. No advantage to a small gap size was found; in fact, the larger gaps were preferable. Perfect element alignment with the surrounding test surface resulted in very small balance errors. However, if small protrusion errors are unavoidable, no advantage was found in having the element slightly below the surrounding test surface rather than above it.

Prognostic score–based balance measures for propensity score methods in comparative effectiveness research

PubMed Central

Stuart, Elizabeth A.; Lee, Brian K.; Leacy, Finbarr P.

2013-01-01

Objective Examining covariate balance is the prescribed method for determining when propensity score methods are successful at reducing bias. This study assessed the performance of various balance measures, including a proposed balance measure based on the prognostic score (also known as the disease-risk score), to determine which balance measures best correlate with bias in the treatment effect estimate. Study Design and Setting The correlations of multiple common balance measures with bias in the treatment effect estimate produced by weighting by the odds, subclassification on the propensity score, and full matching on the propensity score were calculated. Simulated data were used, based on realistic data settings. Settings included both continuous and binary covariates and continuous covariates only. Results The standardized mean difference in prognostic scores, the mean standardized mean difference, and the mean t-statistic all had high correlations with bias in the effect estimate. Overall, prognostic scores displayed the highest correlations of all the balance measures considered. Prognostic score measure performance was generally not affected by model misspecification and performed well under a variety of scenarios. Conclusion Researchers should consider using prognostic score–based balance measures for assessing the performance of propensity score methods for reducing bias in non-experimental studies. PMID:23849158

Validity and reliability of Nintendo Wii Fit balance scores.

PubMed

Wikstrom, Erik A

2012-01-01

Interactive gaming systems have the potential to help rehabilitate patients with musculoskeletal conditions. The Nintendo Wii Balance Board, which is part of the Wii Fit game, could be an effective tool to monitor progress during rehabilitation because the board and game can provide objective measures of balance. However, the validity and reliability of Wii Fit balance scores remain unknown. To determine the concurrent validity of balance scores produced by the Wii Fit game and the intrasession and intersession reliability of Wii Fit balance scores. Descriptive laboratory study. Sports medicine research laboratory. Forty-five recreationally active participants (age = 27.0 ± 9.8 years, height = 170.9 ± 9.2 cm, mass = 72.4 ± 11.8 kg) with a heterogeneous history of lower extremity injury. Participants completed a single-limb-stance task on a force plate and the Star Excursion Balance Test (SEBT) during the first test session. Twelve Wii Fit balance activities were completed during 2 test sessions separated by 1 week. Postural sway in the anteroposterior (AP) and mediolateral (ML) directions and the AP, ML, and resultant center-of-pressure (COP) excursions were calculated from the single-limb stance. The normalized reach distance was recorded for the anterior, posteromedial, and posterolateral directions of the SEBT. Wii Fit balance scores that the game software generated also were recorded. All 96 of the calculated correlation coefficients among Wii Fit activity outcomes and established balance outcomes were interpreted as poor (r < 0.50). Intrasession reliability for Wii Fit balance activity scores ranged from good (intraclass correlation coefficient [ICC] = 0.80) to poor (ICC = 0.39), with 8 activities having poor intrasession reliability. Similarly, 11 of the 12 Wii Fit balance activity scores demonstrated poor intersession reliability, with scores ranging from fair (ICC = 0.74) to poor (ICC = 0.29). Wii Fit balance activity scores had poor concurrent validity relative to COP outcomes and SEBT reach distances. In addition, the included Wii Fit balance activity scores generally had poor intrasession and intersession reliability.

Balancing Score Adjusted Targeted Minimum Loss-based Estimation

PubMed Central

Lendle, Samuel David; Fireman, Bruce; van der Laan, Mark J.

2015-01-01

Adjusting for a balancing score is sufficient for bias reduction when estimating causal effects including the average treatment effect and effect among the treated. Estimators that adjust for the propensity score in a nonparametric way, such as matching on an estimate of the propensity score, can be consistent when the estimated propensity score is not consistent for the true propensity score but converges to some other balancing score. We call this property the balancing score property, and discuss a class of estimators that have this property. We introduce a targeted minimum loss-based estimator (TMLE) for a treatment-specific mean with the balancing score property that is additionally locally efficient and doubly robust. We investigate the new estimator’s performance relative to other estimators, including another TMLE, a propensity score matching estimator, an inverse probability of treatment weighted estimator, and a regression-based estimator in simulation studies. PMID:26561539

Decreasing scoring errors on Wechsler Scale Vocabulary, Comprehension, and Similarities subtests: a preliminary study.

PubMed

Linger, Michele L; Ray, Glen E; Zachar, Peter; Underhill, Andrea T; LoBello, Steven G

2007-10-01

Studies of graduate students learning to administer the Wechsler scales have generally shown that training is not associated with the development of scoring proficiency. Many studies report on the reduction of aggregated administration and scoring errors, a strategy that does not highlight the reduction of errors on subtests identified as most prone to error. This study evaluated the development of scoring proficiency specifically on the Wechsler (WISC-IV and WAIS-III) Vocabulary, Comprehension, and Similarities subtests during training by comparing a set of 'early test administrations' to 'later test administrations.' Twelve graduate students enrolled in an intelligence-testing course participated in the study. Scoring errors (e.g., incorrect point assignment) were evaluated on the students' actual practice administration test protocols. Errors on all three subtests declined significantly when scoring errors on 'early' sets of Wechsler scales were compared to those made on 'later' sets. However, correcting these subtest scoring errors did not cause significant changes in subtest scaled scores. Implications for clinical instruction and future research are discussed.

Smartphone virtual reality to increase clinical balance assessment responsiveness.

PubMed

Rausch, Matthew; Simon, Janet E; Starkey, Chad; Grooms, Dustin R

2018-05-22

To determine if a low cost smartphone based, clinically applicable virtual reality (VR) modification to the standard Balance Error Scoring System (BESS) can challenge postural stability beyond the traditional BESS. Cross-sectional study. University research laboratory. 28 adults (mean age 23.36 ± 2.38 years, mean height 1.74 m ± 0.13, mean weight 77.95 kg ± 16.63). BESS postural control errors and center of pressure (CoP) velocity were recorded during the BESS test and a VR modified BESS (VR-BESS). The VR-BESS used a headset and phone to display a rollercoaster ride to induce a visual and vestibular challenge to postural stability. The VR-BESS significantly increased total errors (20.93 vs. 11.42, p < 0.05) and CoP velocity summed across all stances and surfaces (52.96 cm/s vs. 37.73 cm/s, p < 0.05) beyond the traditional BESS. The VR-BESS provides a standardized, and effective way to increase postural stability challenge in the clinical setting. The VR-BESS can use any smartphone technology to induce postural stability deficits that may otherwise normalize with traditional testing. Thus, providing a unique relatively inexpensive and simple to operate clinical assessment tool and∖or training stimulus. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of Exercise on Sport Concussion Assessment Tool-Third Edition Performance in Professional Athletes.

PubMed

Lee, Jin H; Howell, David R; Meehan, William P; Iverson, Grant L; Gardner, Andrew J

2017-09-01

The Sport Concussion Assessment Tool-Third Edition (SCAT3) is currently considered the standard sideline assessment for concussions. In-game exercise, however, may affect SCAT3 performance and the diagnosis of concussions. To examine the influence of exercise on SCAT3 performance in professional male athletes. Controlled laboratory study. We examined the SCAT3 performance of 82 professional male athletes under 2 conditions: at rest and after exercise. Athletes reported significantly fewer total symptoms (mean, 1.0 ± 1.5 vs 1.6 ± 2.3 total symptoms, respectively; P = .008; Cohen d = 0.34), committed significantly fewer errors on the modified Balance Error Scoring System (mean, 3.5 ± 3.5 vs 4.6 ± 4.1 errors, respectively; P = .017; d = 0.31), and required significantly less time to complete the tandem gait test (mean, 9.5 ± 1.4 vs 9.9 ± 1.7 seconds, respectively; P = .02; d = 0.30) during the at-rest condition compared with the postexercise condition. The interpretation of in-game (sideline) SCAT3 results should consider the effects of postexercise fatigue levels on an athlete's performance, particularly if preseason baseline data have been collected when the athlete was well rested. Exercise appears to affect symptom burden and physical abilities, such as balance and tandem gait, more so than the cognitive components of the SCAT3.

Tests of stepping as indicators of mobility, balance, and fall risk in balance-impaired older adults.

PubMed

Cho, Be-long; Scarpace, Diane; Alexander, Neil B

2004-07-01

To determine the relationships between two tests of stepping ability (the maximal step length (MSL) and rapid step test (RST)) and standard tests of standing balance, gait, mobility, and functional impairment in a group of at-risk older adults. Cross-sectional study. University-based laboratory. One hundred sixty-seven mildly balance-impaired older adults recruited for a balance-training and fall-reduction program (mean age 78, range 65-90). Measures of stepping maximally (MSL, the ability to maximally step out and return to the initial position) and rapidly (RST, the time taken to step out and return in multiple directions as fast as possible); standard measures of balance, gait, and mobility including timed tandem stance (TS), tandem walk (TW, both timing and errors), timed unipedal stance (US), timed up and go (TUG), performance oriented mobility assessment (POMA), and 6-minute walk (SMW); measures of leg strength (peak knee and ankle torque and power at slow and fast speeds); self-report measures of frequent falls (>2 per 12 months), disability (Established Population for Epidemiologic Studies of the Elderly (EPESE) physical function), and confidence to avoid falls (Activity-specific Balance Confidence (ABC) Scale). Spearman and Pearson correlation, intraclass correlation coefficient, logistic regression, and linear regression were used for data analysis. MSL consistently predicted a number of self-report and performance measures at least as well as other standard balance measures. MSL correlations with EPESE physical function, ABC, TUG, and POMA scores; SMW; and peak maximum knee and ankle torque and power were at least as high as those correlations seen with TS, TW, or US. MSL score was associated with the risk of being a frequent faller. In addition, the six MSL directions were highly correlated (up to 0.96), and any one of the leg directions yielded similar relationships with functional measures and a history of falls. Relationships between RST and these measures were relatively modest. MSL is as good a predictor of mobility performance, frequent falls, self-reported function, and balance confidence as standard stance tests such as US. MSL simplified to one direction may be a useful clinical indicator of mobility, balance, and fall risk in older adults.

Estimation of mean response via effective balancing score

PubMed Central

Hu, Zonghui; Follmann, Dean A.; Wang, Naisyin

2015-01-01

Summary We introduce effective balancing scores for estimation of the mean response under a missing at random mechanism. Unlike conventional balancing scores, the effective balancing scores are constructed via dimension reduction free of model specification. Three types of effective balancing scores are introduced: those that carry the covariate information about the missingness, the response, or both. They lead to consistent estimation with little or no loss in efficiency. Compared to existing estimators, the effective balancing score based estimator relieves the burden of model specification and is the most robust. It is a near-automatic procedure which is most appealing when high dimensional covariates are involved. We investigate both the asymptotic and the numerical properties, and demonstrate the proposed method in a study on Human Immunodeficiency Virus disease. PMID:25797955

Predicting balance improvements following STARS treatments in chronic ankle instability participants.

PubMed

Wikstrom, Erik A; McKeon, Patrick O

2017-04-01

Sensory Targeted Ankle Rehabilitation Strategies that stimulate sensory receptors improve postural control in chronic ankle instability participants. However, not all participants have equal responses. Therefore, identifying predictors of treatment success is needed to improve clinician efficiency when treating chronic ankle instability. Therefore, the purpose was to identify predictors of successfully improving postural control in chronic ankle instability participants. Secondary data analysis. Fifty-nine participants with self-reported chronic ankle instability participated. The condition was defined as a history of at least two episodes of "giving way" within the past 6 months; and limitations in self-reported function as measured by the Foot and Ankle Ability Measure. Participants were randomized into three treatment groups (plantar massage, ankle joint mobilization, calf stretching) that received 6, 5-min treatment sessions over a 2-week period. The main outcome measure was treatment success, defined as a participant exceeding the minimal detectable change score for a clinician-oriented single limb balance test. Participants with ≥3 balance test errors had a 73% probability of treatment success following ankle joint mobilizations. Participants with a self-reported function between limb difference <16.07% and who made >2.5 errors had a 99% probability of treatment success following plantar massage. Those who sustained ≥11 ankle sprains had a 94% treatment success probability following calf stretching. Self-reported functional deficits, worse single limb balance, and number of previous ankle sprains are important characteristics when determining if chronic ankle instability participants will have an increased probability of treatment success. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Evaluation of subset matching methods and forms of covariate balance.

PubMed

de Los Angeles Resa, María; Zubizarreta, José R

2016-11-30

This paper conducts a Monte Carlo simulation study to evaluate the performance of multivariate matching methods that select a subset of treatment and control observations. The matching methods studied are the widely used nearest neighbor matching with propensity score calipers and the more recently proposed methods, optimal matching of an optimally chosen subset and optimal cardinality matching. The main findings are: (i) covariate balance, as measured by differences in means, variance ratios, Kolmogorov-Smirnov distances, and cross-match test statistics, is better with cardinality matching because by construction it satisfies balance requirements; (ii) for given levels of covariate balance, the matched samples are larger with cardinality matching than with the other methods; (iii) in terms of covariate distances, optimal subset matching performs best; (iv) treatment effect estimates from cardinality matching have lower root-mean-square errors, provided strong requirements for balance, specifically, fine balance, or strength-k balance, plus close mean balance. In standard practice, a matched sample is considered to be balanced if the absolute differences in means of the covariates across treatment groups are smaller than 0.1 standard deviations. However, the simulation results suggest that stronger forms of balance should be pursued in order to remove systematic biases due to observed covariates when a difference in means treatment effect estimator is used. In particular, if the true outcome model is additive, then marginal distributions should be balanced, and if the true outcome model is additive with interactions, then low-dimensional joints should be balanced. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Integrating Solar PV in Utility System Operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mills, A.; Botterud, A.; Wu, J.

2013-10-31

This study develops a systematic framework for estimating the increase in operating costs due to uncertainty and variability in renewable resources, uses the framework to quantify the integration costs associated with sub-hourly solar power variability and uncertainty, and shows how changes in system operations may affect these costs. Toward this end, we present a statistical method for estimating the required balancing reserves to maintain system reliability along with a model for commitment and dispatch of the portfolio of thermal and renewable resources at different stages of system operations. We estimate the costs of sub-hourly solar variability, short-term forecast errors, andmore » day-ahead (DA) forecast errors as the difference in production costs between a case with “realistic” PV (i.e., subhourly solar variability and uncertainty are fully included in the modeling) and a case with “well behaved” PV (i.e., PV is assumed to have no sub-hourly variability and can be perfectly forecasted). In addition, we highlight current practices that allow utilities to compensate for the issues encountered at the sub-hourly time frame with increased levels of PV penetration. In this analysis we use the analytical framework to simulate utility operations with increasing deployment of PV in a case study of Arizona Public Service Company (APS), a utility in the southwestern United States. In our analysis, we focus on three processes that are important in understanding the management of PV variability and uncertainty in power system operations. First, we represent the decisions made the day before the operating day through a DA commitment model that relies on imperfect DA forecasts of load and wind as well as PV generation. Second, we represent the decisions made by schedulers in the operating day through hour-ahead (HA) scheduling. Peaking units can be committed or decommitted in the HA schedules and online units can be redispatched using forecasts that are improved relative to DA forecasts, but still imperfect. Finally, we represent decisions within the operating hour by schedulers and transmission system operators as real-time (RT) balancing. We simulate the DA and HA scheduling processes with a detailed unit-commitment (UC) and economic dispatch (ED) optimization model. This model creates a least-cost dispatch and commitment plan for the conventional generating units using forecasts and reserve requirements as inputs. We consider only the generation units and load of the utility in this analysis; we do not consider opportunities to trade power with neighboring utilities. We also do not consider provision of reserves from renewables or from demand-side options. We estimate dynamic reserve requirements in order to meet reliability requirements in the RT operations, considering the uncertainty and variability in load, solar PV, and wind resources. Balancing reserve requirements are based on the 2.5th and 97.5th percentile of 1-min deviations from the HA schedule in a previous year. We then simulate RT deployment of balancing reserves using a separate minute-by-minute simulation of deviations from the HA schedules in the operating year. In the simulations we assume that balancing reserves can be fully deployed in 10 min. The minute-by-minute deviations account for HA forecasting errors and the actual variability of the load, wind, and solar generation. Using these minute-by-minute deviations and deployment of balancing reserves, we evaluate the impact of PV on system reliability through the calculation of the standard reliability metric called Control Performance Standard 2 (CPS2). Broadly speaking, the CPS2 score measures the percentage of 10-min periods in which a balancing area is able to balance supply and demand within a specific threshold. Compliance with the North American Electric Reliability Corporation (NERC) reliability standards requires that the CPS2 score must exceed 90% (i.e., the balancing area must maintain adequate balance for 90% of the 10-min periods). The combination of representing DA forecast errors in the DA commitments, using 1-min PV data to simulate RT balancing, and estimates of reliability performance through the CPS2 metric, all factors that are important to operating systems with increasing amounts of PV, makes this study unique in its scope.« less

Relationships of Measurement Error and Prediction Error in Observed-Score Regression

ERIC Educational Resources Information Center

Moses, Tim

2012-01-01

The focus of this paper is assessing the impact of measurement errors on the prediction error of an observed-score regression. Measures are presented and described for decomposing the linear regression's prediction error variance into parts attributable to the true score variance and the error variances of the dependent variable and the predictor…

A variable acceleration calibration system

NASA Astrophysics Data System (ADS)

Johnson, Thomas H.

2011-12-01

A variable acceleration calibration system that applies loads using gravitational and centripetal acceleration serves as an alternative, efficient and cost effective method for calibrating internal wind tunnel force balances. Two proof-of-concept variable acceleration calibration systems are designed, fabricated and tested. The NASA UT-36 force balance served as the test balance for the calibration experiments. The variable acceleration calibration systems are shown to be capable of performing three component calibration experiments with an approximate applied load error on the order of 1% of the full scale calibration loads. Sources of error are indentified using experimental design methods and a propagation of uncertainty analysis. Three types of uncertainty are indentified for the systems and are attributed to prediction error, calibration error and pure error. Angular velocity uncertainty is shown to be the largest indentified source of prediction error. The calibration uncertainties using a production variable acceleration based system are shown to be potentially equivalent to current methods. The production quality system can be realized using lighter materials and a more precise instrumentation. Further research is needed to account for balance deflection, forcing effects due to vibration, and large tare loads. A gyroscope measurement technique is shown to be capable of resolving the balance deflection angle calculation. Long term research objectives include a demonstration of a six degree of freedom calibration, and a large capacity balance calibration.

A Retrospective Analysis of Post-Stroke Berg Balance Scale Scores: How Should Normal and At-Risk Scores Be Interpreted?

PubMed Central

Inness, Elizabeth; McIlroy, William E.; Mansfield, Avril

2017-01-01

Purpose: The Berg Balance Scale (BBS) is a performance-based measure of standing balance commonly used by clinicians working with individuals post-stroke. Performance on the BBS can be influenced by compensatory strategies, but measures derived from two force plates can isolate compensatory strategies and thus better indicate balance impairment. This study examined BBS scores that reflect “normal” and disordered balance with respect to dual force-plate measures of standing balance in individuals post-stroke. Methods: BBS and force-plate measures were extracted from 75 patient charts. Individuals were classified by BBS score with respect to (1) age-matched normative values and (2) values that suggested increased risk of falls. Multiple analysis of variance was used to examine the effect of group assignment on force-plate measures of standing balance. Results: Individuals with BBS scores within and below normative values did not differ in force-plate measures. Individuals with BBS scores below the falls risk cutoff loaded their affected leg less than individuals with BBS scores above the cutoff. There were no other differences in force-plate measures between these two groups. Conclusions: BBS scores indicating either normal or disordered balance function are not necessarily associated with normal or disordered quiet standing-balance control measured by two force plates. This finding suggests that the BBS may reflect a capacity for compensation rather than any underlying impairments. PMID:28539694

Effects of Flexibility and Balance on Driving Distance and Club Head Speed in Collegiate Golfers.

PubMed

Marshall, Kelsey J; Llewellyn, Tamra L

2017-01-01

Good balance, flexibility, and strength are all required to maintain a steady stance during the kinematic chain to produce successful golf shots. When the body can produce more power, more club head speed is generated. This formation of power translates into greater distance and accuracy. Athletes today are seeking exercise programs to enhance these qualities of their golf swing. The purpose of this study is to investigate the correlations between flexibility and balance with club head speed and driving distance in the golf swing of male and female collegiate golfers. Five male and five female collegiate golfers participated in the study. They completed multiple range of motion tests, the Balance Error System Test, and multiple flexibility tests. Subjects then participated in a short hitting session. Ten shots were hit with the subject's own driver. The Optishot simulator measured distance and club head speed generated. There was a significant negative correlation between the BESS test score and average distance for male subjects (r=-0.850, p=0.034). There were also a few trends between the balance, flexibility, and club head speed findings of both male and female subjects. This data shows there is a significant relationship between better balance and driving the ball farther. Other trends show better balance and flexibility will result in greater driving distance and club head speed. Balance and flexibility exercises should be incorporated into a golfer's practice or workout regiment.

Validity and Reliability of Nintendo Wii Fit Balance Scores

PubMed Central

Wikstrom, Erik A.

2012-01-01

Context: Interactive gaming systems have the potential to help rehabilitate patients with musculoskeletal conditions. The Nintendo Wii Balance Board, which is part of the Wii Fit game, could be an effective tool to monitor progress during rehabilitation because the board and game can provide objective measures of balance. However, the validity and reliability of Wii Fit balance scores remain unknown. Objective: To determine the concurrent validity of balance scores produced by the Wii Fit game and the intrasession and intersession reliability of Wii Fit balance scores. Design: Descriptive laboratory study. Setting: Sports medicine research laboratory. Patients or Other Participants: Forty-five recreationally active participants (age  =  27.0 ± 9.8 years, height  =  170.9 ± 9.2 cm, mass  =  72.4 ± 11.8 kg) with a heterogeneous history of lower extremity injury. Intervention(s): Participants completed a single-limb–stance task on a force plate and the Star Excursion Balance Test (SEBT) during the first test session. Twelve Wii Fit balance activities were completed during 2 test sessions separated by 1 week. Main Outcome Measure(s): Postural sway in the anteroposterior (AP) and mediolateral (ML) directions and the AP, ML, and resultant center-of-pressure (COP) excursions were calculated from the single-limb stance. The normalized reach distance was recorded for the anterior, posteromedial, and posterolateral directions of the SEBT. Wii Fit balance scores that the game software generated also were recorded. Results: All 96 of the calculated correlation coefficients among Wii Fit activity outcomes and established balance outcomes were interpreted as poor (r < 0.50). Intrasession reliability for Wii Fit balance activity scores ranged from good (intraclass correlation coefficient [ICC]  =  0.80) to poor (ICC  =  0.39), with 8 activities having poor intrasession reliability. Similarly, 11 of the 12 Wii Fit balance activity scores demonstrated poor intersession reliability, with scores ranging from fair (ICC  =  0.74) to poor (ICC  =  0.29). Conclusions: Wii Fit balance activity scores had poor concurrent validity relative to COP outcomes and SEBT reach distances. In addition, the included Wii Fit balance activity scores generally had poor intrasession and intersession reliability. PMID:22892412

Comparison of the Wii Balance Board and the BESS tool measuring postural stability in collegiate athletes.

PubMed

Guzman, Jill; Aktan, Nadine

2016-02-01

Concussions are a major health concern for athletes given the potential for these injuries in a wide range of sport activities. The leading concern for clinicians is that athletes are at risk for devastating consequences if they are not evaluated properly and cleared too early to return to play or competition. The evaluation of postural stability has been identified as an important aspect to the comprehensive management of such injuries. Clinicians are in need of a portable tool they can use in various settings to aid in decision making and health care delivery for concussed athletes. The Nintendo Wii Balance Board (Nintendo of America Inc., Redmond, Washington) is a portable, cost-effective tool that has the potential to aid in the evaluation of postural stability in concussed individuals. The purpose of this study was to evaluate the Wii Balance Board as an objective, user-friendly, cost effective, valid alternative tool for the measurement of postural stability in college athletes. This study questioned whether the Wii Balance Board, when compared to the Balance Error Scoring System (BESS), is an objective tool that can be used as an acceptable measurement of postural stability in college athletes. Copyright © 2015 Elsevier Inc. All rights reserved.

Conditional Standard Errors of Measurement for Composite Scores Using IRT

ERIC Educational Resources Information Center

Kolen, Michael J.; Wang, Tianyou; Lee, Won-Chan

2012-01-01

Composite scores are often formed from test scores on educational achievement test batteries to provide a single index of achievement over two or more content areas or two or more item types on that test. Composite scores are subject to measurement error, and as with scores on individual tests, the amount of error variability typically depends on…

The Interrelationship of Common Clinical Movement Screens: Establishing Population-Specific Norms in a Large Cohort of Military Applicants

PubMed Central

de la Motte, Sarah J.; Gribbin, Timothy C.; Lisman, Peter; Beutler, Anthony I.; Deuster, Patricia

2016-01-01

Context: Musculoskeletal injuries (MSK-Is) are a leading cause of missed duty time and morbidity in the military. Modifiable risk factors for MSK-Is, such as inadequate core stability, poor movement patterns, and dynamic balance deficits, have not been identified in military applicants on entering service. Objective: To establish normative functional movement data using a series of screens in military applicants entering basic training and explore relationships among several movement tests. Design: Cross-sectional study. Setting: Military Entrance Processing Station. Patients or Other Participants: A total of 1714 (1434 male, 280 female) military applicants entering the US Army (n = 546), Navy (n = 414), Air Force (n = 229), or Marine Corps (n = 525). Intervention(s): We conducted the Functional Movement Screen (FMS), Y-Balance Test (YBT), overhead squat (OHS), and Landing Error Scoring System (LESS). Movements were assessed using the scoring convention for each screen. Main Outcome Measure(s): The FMS, YBT, OHS, and LESS scores and associations among the movement screens as well as clinical meaningfulness. Results: A total of 1037 of the 1714 enrolled applicants were screened on the day they left for basic training. Normative means for this population were established: FMS = 14.7 ± 1.8, YBT anterior-reach difference = 3.1 ± 3.0 cm, mean YBT composite differences = 8.0 ± 6.8 cm, mean YBT composite percentage = 90.9% ± 8.3%, OHS errors = 5.0 ± 2.8, and LESS score = 5.7 ± 2.1. Backward regression results revealed that the YBT composite percentage was related to the FMS and OHS scores in males and to the FMS and LESS results in females. However, clinically meaningful relationships between the tests varied for both males and females. Conclusions: Sex-normative values for the FMS, YBT, OHS, and LESS screens were established for US military applicants, and some of the assessments overlapped. Overall, males performed better on the OHS and LESS and achieved a greater YBT composite percentage than females. The regression results revealed movement screen performance relationships that varied by sex and clinical meaningfulness. In future studies, we will determine if performance on any of the screens is associated with MSK-Is in basic trainees. PMID:27831746

Relationships of Functional Tests Following ACL Reconstruction: Exploratory Factor Analyses of the Lower Extremity Assessment Protocol.

PubMed

DiFabio, Melissa; Slater, Lindsay V; Norte, Grant; Goetschius, John; Hart, Joseph M; Hertel, Jay

2018-03-01

After ACL reconstruction (ACLR), deficits are often assessed using a variety of functional tests, which can be time consuming. It is unknown whether these tests provide redundant or unique information. To explore relationships between components of a battery of functional tests, the Lower Extremity Assessment Protocol (LEAP) was created to aid in developing the most informative, concise battery of tests for evaluating ACLR patients. Descriptive, cross-sectional. Laboratory. 76 ACLR patients (6.86±3.07 months postoperative) and 54 healthy participants. Isokinetic knee flexion and extension at 90 and 180 degrees/second, maximal voluntary isometric contraction for knee extension and flexion, single leg balance, 4 hopping tasks (single, triple, crossover, and 6-meter timed hop), and a bilateral drop vertical jump that was scored with the Landing Error Scoring System (LESS). Peak torque, average torque, average power, total work, fatigue indices, center of pressure area and velocity, hop distance and time, and LESS score. A series of factor analyses were conducted to assess grouping of functional tests on the LEAP for each limb in the ACLR and healthy groups and limb symmetry indices (LSI) for both groups. Correlations were run between measures that loaded on retained factors. Isokinetic and isometric strength tests for knee flexion and extension, hopping, balance, and fatigue index were identified as unique factors for all limbs. The LESS score loaded with various factors across the different limbs. The healthy group LSI analysis produced more factors than the ACLR LSI analysis. Individual measures within each factor had moderate to strong correlations. Isokinetic and isometric strength, hopping, balance, and fatigue index provided unique information. Within each category of measures, not all tests may need to be included for a comprehensive functional assessment of ACLR patients due to the high amount of shared variance between them.

Effects of Exercise on Sport Concussion Assessment Tool–Third Edition Performance in Professional Athletes

PubMed Central

Lee, Jin H.; Howell, David R.; Meehan, William P.; Iverson, Grant L.; Gardner, Andrew J.

2017-01-01

Background: The Sport Concussion Assessment Tool–Third Edition (SCAT3) is currently considered the standard sideline assessment for concussions. In-game exercise, however, may affect SCAT3 performance and the diagnosis of concussions. Purpose: To examine the influence of exercise on SCAT3 performance in professional male athletes. Study Design: Controlled laboratory study. Methods: We examined the SCAT3 performance of 82 professional male athletes under 2 conditions: at rest and after exercise. Results: Athletes reported significantly fewer total symptoms (mean, 1.0 ± 1.5 vs 1.6 ± 2.3 total symptoms, respectively; P = .008; Cohen d = 0.34), committed significantly fewer errors on the modified Balance Error Scoring System (mean, 3.5 ± 3.5 vs 4.6 ± 4.1 errors, respectively; P = .017; d = 0.31), and required significantly less time to complete the tandem gait test (mean, 9.5 ± 1.4 vs 9.9 ± 1.7 seconds, respectively; P = .02; d = 0.30) during the at-rest condition compared with the postexercise condition. Conclusion: The interpretation of in-game (sideline) SCAT3 results should consider the effects of postexercise fatigue levels on an athlete’s performance, particularly if preseason baseline data have been collected when the athlete was well rested. Clinical Relevance: Exercise appears to affect symptom burden and physical abilities, such as balance and tandem gait, more so than the cognitive components of the SCAT3. PMID:28944251

Comparing motor performance, praxis, coordination, and interpersonal synchrony between children with and without Autism Spectrum Disorder (ASD).

PubMed

Kaur, Maninderjit; M Srinivasan, Sudha; N Bhat, Anjana

2018-01-01

Children with Autism Spectrum Disorder (ASD) have basic motor impairments in balance, gait, and coordination as well as autism-specific impairments in praxis/motor planning and interpersonal synchrony. Majority of the current literature focuses on isolated motor behaviors or domains. Additionally, the relationship between cognition, symptom severity, and motor performance in ASD is unclear. We used a comprehensive set of measures to compare gross and fine motor, praxis/imitation, motor coordination, and interpersonal synchrony skills across three groups of children between 5 and 12 years of age: children with ASD with high IQ (HASD), children with ASD with low IQ (LASD), and typically developing (TD) children. We used the Bruininks-Oseretsky Test of Motor Proficiency and the Bilateral Motor Coordination subtest of the Sensory Integration and Praxis Tests to assess motor performance and praxis skills respectively. Children were also examined while performing simple and complex rhythmic upper and lower limb actions on their own (solo context) and with a social partner (social context). Both ASD groups had lower gross and fine motor scores, greater praxis errors in total and within various error types, lower movement rates, greater movement variability, and weaker interpersonal synchrony compared to the TD group. In addition, the LASD group had lower gross motor scores and greater mirroring errors compared to the HASD group. Overall, a variety of motor impairments are present across the entire spectrum of children with ASD, regardless of their IQ scores. Both, fine and gross motor performance significantly correlated with IQ but not with autism severity; however, praxis errors (mainly, total, overflow, and rhythmicity) strongly correlated with autism severity and not IQ. Our study findings highlight the need for clinicians and therapists to include motor evaluations and interventions in the standard-of-care of children with ASD and for the broader autism community to recognize dyspraxia as an integral part of the definition of ASD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Suboptimal schemes for atmospheric data assimilation based on the Kalman filter

NASA Technical Reports Server (NTRS)

Todling, Ricardo; Cohn, Stephen E.

1994-01-01

This work is directed toward approximating the evolution of forecast error covariances for data assimilation. The performance of different algorithms based on simplification of the standard Kalman filter (KF) is studied. These are suboptimal schemes (SOSs) when compared to the KF, which is optimal for linear problems with known statistics. The SOSs considered here are several versions of optimal interpolation (OI), a scheme for height error variance advection, and a simplified KF in which the full height error covariance is advected. To employ a methodology for exact comparison among these schemes, a linear environment is maintained, in which a beta-plane shallow-water model linearized about a constant zonal flow is chosen for the test-bed dynamics. The results show that constructing dynamically balanced forecast error covariances rather than using conventional geostrophically balanced ones is essential for successful performance of any SOS. A posteriori initialization of SOSs to compensate for model - data imbalance sometimes results in poor performance. Instead, properly constructed dynamically balanced forecast error covariances eliminate the need for initialization. When the SOSs studied here make use of dynamically balanced forecast error covariances, the difference among their performances progresses naturally from conventional OI to the KF. In fact, the results suggest that even modest enhancements of OI, such as including an approximate dynamical equation for height error variances while leaving height error correlation structure homogeneous, go a long way toward achieving the performance of the KF, provided that dynamically balanced cross-covariances are constructed and that model errors are accounted for properly. The results indicate that such enhancements are necessary if unconventional data are to have a positive impact.

Normative Values of the Sport Concussion Assessment Tool 3 (SCAT3) in High School Athletes.

PubMed

Snedden, Traci R; Brooks, Margaret Alison; Hetzel, Scott; McGuine, Tim

2017-09-01

Establish sex, age, and concussion history-specific normative baseline sport concussion assessment tool 3 (SCAT3) values in adolescent athletes. Prospective cohort. Seven Wisconsin high schools. Seven hundred fifty-eight high school athletes participating in 19 sports. Sex, age, and concussion history. Sport Concussion Assessment Tool 3 (SCAT3): total number of symptoms; symptom severity; total Standardized Assessment of Concussion (SAC); and each SAC component (orientation, immediate memory, concentration, delayed recall); Balance Error Scoring System (BESS) total errors (BESS, floor and foam pad). Males reported a higher total number of symptoms [median (interquartile range): 0 (0-2) vs 0 (0-1), P = 0.001] and severity of symptoms [0 (0-3) vs 0 (0-2), P = 0.001] and a lower mean (SD) total SAC [26.0 (2.3) vs 26.4 (2.0), P = 0.026], and orientation [5 (4-5) vs 5 (5-5), P = 0.021]. There was no difference in baseline scores between sex for immediate memory, concentration, delayed recall or BESS total errors. No differences were found for any test domain based on age. Previously, concussed athletes reported a higher total number of symptoms [1 (0-4) vs 0 (0-2), P = 0.001] and symptom severity [2 (0-5) vs 0 (0-2), P = 0.001]. BESS total scores did not differ by concussion history. This study represents the first published normative baseline SCAT3 values in high school athletes. Results varied by sex and history of previous concussion but not by age. The normative baseline values generated from this study will help clinicians better evaluate and interpret SCAT3 results of concussed adolescent athletes.

Covariate Balance in Bayesian Propensity Score Approaches for Observational Studies

ERIC Educational Resources Information Center

Chen, Jianshen; Kaplan, David

2015-01-01

Bayesian alternatives to frequentist propensity score approaches have recently been proposed. However, few studies have investigated their covariate balancing properties. This article compares a recently developed two-step Bayesian propensity score approach to the frequentist approach with respect to covariate balance. The effects of different…

Diagnostic performance of short portable mental status questionnaire for screening dementia among patients attending cognitive assessment clinics in Singapore.

PubMed

Malhotra, Chetna; Chan, Angelique; Matchar, David; Seow, Dennis; Chuo, Adeline; Do, Young Kyung

2013-07-01

The Short Portable Mental Status Questionnaire (SPMSQ) is a brief cognitive screening instrument, which is easy to use by a healthcare worker with little training. However, the validity of this instrument has not been established in Singapore. Thus, the primary aim of this study was to determine the diagnostic performance of SPMSQ for screening dementia among patients attending outpatient cognitive assessment clinics and to assess whether the appropriate cut-off score varies by patient's age and education. A secondary aim of the study was to map the SPMSQ scores with Mini-Mental State Examination (MMSE) scores. SPMSQ and MMSE were administered by a trained interviewer to 127 patients visiting outpatient cognitive assessment clinics at the Singapore General Hospital, Changi General Hospital and Tan Tock Seng Hospital. The geriatricians at these clinics then diagnosed these patients with dementia or no dementia (reference standard). Sensitivity and specificity of SPMSQ with different cut-off points (number of errors) were calculated and compared to the reference standard using the Receiver Operator Characteristic (ROC) analysis. Correlation coefficient was also calculated between MMSE and SPMSQ scores. Based on the ROC analysis and a balance of sensitivity and specificity, the appropriate cut-off for SPMSQ was found to be 5 or more errors (sensitivity 78%, specificity 75%). The cut-off varied by education, but not by patient's age. There was a high correlation between SPMSQ and MMSE scores (r = 0.814, P <0.0001). Despite the advantage of being a brief screening instrument for dementia, the use of SPMSQ is limited by its low sensitivity and specificity, especially among patients with less than 6 years of education.

Standard Errors and Confidence Intervals of Norm Statistics for Educational and Psychological Tests.

PubMed

Oosterhuis, Hannah E M; van der Ark, L Andries; Sijtsma, Klaas

2016-11-14

Norm statistics allow for the interpretation of scores on psychological and educational tests, by relating the test score of an individual test taker to the test scores of individuals belonging to the same gender, age, or education groups, et cetera. Given the uncertainty due to sampling error, one would expect researchers to report standard errors for norm statistics. In practice, standard errors are seldom reported; they are either unavailable or derived under strong distributional assumptions that may not be realistic for test scores. We derived standard errors for four norm statistics (standard deviation, percentile ranks, stanine boundaries and Z-scores) under the mild assumption that the test scores are multinomially distributed. A simulation study showed that the standard errors were unbiased and that corresponding Wald-based confidence intervals had good coverage. Finally, we discuss the possibilities for applying the standard errors in practical test use in education and psychology. The procedure is provided via the R function check.norms, which is available in the mokken package.

A comparison of 12 algorithms for matching on the propensity score.

PubMed

Austin, Peter C

2014-03-15

Propensity-score matching is increasingly being used to reduce the confounding that can occur in observational studies examining the effects of treatments or interventions on outcomes. We used Monte Carlo simulations to examine the following algorithms for forming matched pairs of treated and untreated subjects: optimal matching, greedy nearest neighbor matching without replacement, and greedy nearest neighbor matching without replacement within specified caliper widths. For each of the latter two algorithms, we examined four different sub-algorithms defined by the order in which treated subjects were selected for matching to an untreated subject: lowest to highest propensity score, highest to lowest propensity score, best match first, and random order. We also examined matching with replacement. We found that (i) nearest neighbor matching induced the same balance in baseline covariates as did optimal matching; (ii) when at least some of the covariates were continuous, caliper matching tended to induce balance on baseline covariates that was at least as good as the other algorithms; (iii) caliper matching tended to result in estimates of treatment effect with less bias compared with optimal and nearest neighbor matching; (iv) optimal and nearest neighbor matching resulted in estimates of treatment effect with negligibly less variability than did caliper matching; (v) caliper matching had amongst the best performance when assessed using mean squared error; (vi) the order in which treated subjects were selected for matching had at most a modest effect on estimation; and (vii) matching with replacement did not have superior performance compared with caliper matching without replacement. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

A comparison of 12 algorithms for matching on the propensity score

PubMed Central

Austin, Peter C

2014-01-01

Propensity-score matching is increasingly being used to reduce the confounding that can occur in observational studies examining the effects of treatments or interventions on outcomes. We used Monte Carlo simulations to examine the following algorithms for forming matched pairs of treated and untreated subjects: optimal matching, greedy nearest neighbor matching without replacement, and greedy nearest neighbor matching without replacement within specified caliper widths. For each of the latter two algorithms, we examined four different sub-algorithms defined by the order in which treated subjects were selected for matching to an untreated subject: lowest to highest propensity score, highest to lowest propensity score, best match first, and random order. We also examined matching with replacement. We found that (i) nearest neighbor matching induced the same balance in baseline covariates as did optimal matching; (ii) when at least some of the covariates were continuous, caliper matching tended to induce balance on baseline covariates that was at least as good as the other algorithms; (iii) caliper matching tended to result in estimates of treatment effect with less bias compared with optimal and nearest neighbor matching; (iv) optimal and nearest neighbor matching resulted in estimates of treatment effect with negligibly less variability than did caliper matching; (v) caliper matching had amongst the best performance when assessed using mean squared error; (vi) the order in which treated subjects were selected for matching had at most a modest effect on estimation; and (vii) matching with replacement did not have superior performance compared with caliper matching without replacement. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd. PMID:24123228

The relationship between balance confidence and control in individuals with Parkinson's disease

PubMed Central

Lee, Hyo Keun; Altman, Lori J.P.; McFarland, Nikolaus; Hass, Chris J.

2016-01-01

Introduction A broad range of subjective and objective assessments have been used to assess balance confidence and balance control in persons with Parkinson's disease (PD). However, little is known about the relationship between self-perceived balance confidence and actual balance control in PD. The purpose of this investigation was to determine the relationship between self-perceived balance confidence and objectively measured static/dynamic balance control abilities. Methods Forty-four individuals with PD participated in the study. Patients were stratified into 2 groups based on the modified Hoehn and Yahr (H&Y) disability score: early stage, H&Y≤2.0 and moderate stage, H&Y ≥2.5. All participants completed the activities-specific balance confidence (ABC) scale and performed standing balance and gait initiation tasks to assess static and dynamic balance control. The center of pressure (COP) sway (CE95%Sway) during static balance and the peak distance between the projections of the COP and the center of mass (COM) in the transverse plane (COPCOM) during gait initiation were calculated. Pearson correlation analyses were conducted relating the ABC score and CE95%Sway and COPCOM. Results For early stage PD, there was a moderate correlation between ABC score and CE95 %Sway (r=-0.56, R2=0.32, p=0.002), while no significant correlation was found between ABC score and COPCOM (r=-0.24, R2=0.06, p=0.227). For moderate stage PD, there was a moderate correlation between ABC score and COPCOM (r=0.49, R2=0.24, p=0.044), while no correlation was found between ABC score and CE95%Sway (r=-0.19, R2=0.04, p=0.478). Conclusion Individuals with different disease severities showed different relationships between balance confidence and actual static/dynamic balance control. PMID:26949065

Measurements of the toroidal torque balance of error field penetration locked modes

DOE PAGES

Shiraki, Daisuke; Paz-Soldan, Carlos; Hanson, Jeremy M.; ...

2015-01-05

Here, detailed measurements from the DIII-D tokamak of the toroidal dynamics of error field penetration locked modes under the influence of slowly evolving external fields, enable study of the toroidal torques on the mode, including interaction with the intrinsic error field. The error field in these low density Ohmic discharges is well known based on the mode penetration threshold, allowing resonant and non-resonant torque effects to be distinguished. These m/n = 2/1 locked modes are found to be well described by a toroidal torque balance between the resonant interaction with n = 1 error fields, and a viscous torque inmore » the electron diamagnetic drift direction which is observed to scale as the square of the perturbed field due to the island. Fitting to this empirical torque balance allows a time-resolved measurement of the intrinsic error field of the device, providing evidence for a time-dependent error field in DIII-D due to ramping of the Ohmic coil current.« less

The relationship between objective balance, perceived sense of balance, and fear of falling in stroke patients.

PubMed

Oguz, Semra; Demirbuken, Ilksan; Kavlak, Bahar; Acar, Gonul; Yurdalan, Saadet Ufuk; Polat, Mine Gulden

2017-10-01

The objective of our study was to investigate the relationship between objective balance, fear of falling, and perceived sense of balance (PSB) in stroke patients. Seventy patients aged 18-65 years with chronically developed hemiplegia or hemiparesis were enrolled in the study. Patients' objective balance scores, fear of falling, and PSB were obtained using the berg balance scale (BBS), the falls efficacy scale (FES), and a visual analog scale, respectively. The Standard Mini-Mental Examination was performed to exclude patients with mental disorders from the study. There was a moderate negative correlation between PSB and BBS scores (p = 0.001, ρ = -0.588); a strong negative correlation between BBS and FES scores (p = 0.001, ρ = -0.808); and a strong positive correlation between PSB and FES scores (p = 0.001, ρ = 0.714). We found that BBS scores had negative correlation with PBS scores in left hemiplegic patients while there was no any relationship between BBS and PBS scores in right hemiplegic patients. PSB assessment, besides the BBS, should be considered among the routine assessment methods that enable the rehabilitation team to be aware of patients' balance capacities.

Assessing covariate balance when using the generalized propensity score with quantitative or continuous exposures.

PubMed

Austin, Peter C

2018-01-01

Propensity score methods are increasingly being used to estimate the effects of treatments and exposures when using observational data. The propensity score was initially developed for use with binary exposures (e.g., active treatment vs. control). The generalized propensity score is an extension of the propensity score for use with quantitative exposures (e.g., dose or quantity of medication, income, years of education). A crucial component of any propensity score analysis is that of balance assessment. This entails assessing the degree to which conditioning on the propensity score (via matching, weighting, or stratification) has balanced measured baseline covariates between exposure groups. Methods for balance assessment have been well described and are frequently implemented when using the propensity score with binary exposures. However, there is a paucity of information on how to assess baseline covariate balance when using the generalized propensity score. We describe how methods based on the standardized difference can be adapted for use with quantitative exposures when using the generalized propensity score. We also describe a method based on assessing the correlation between the quantitative exposure and each covariate in the sample when weighted using generalized propensity score -based weights. We conducted a series of Monte Carlo simulations to evaluate the performance of these methods. We also compared two different methods of estimating the generalized propensity score: ordinary least squared regression and the covariate balancing propensity score method. We illustrate the application of these methods using data on patients hospitalized with a heart attack with the quantitative exposure being creatinine level.

Comparing Graphical and Verbal Representations of Measurement Error in Test Score Reports

ERIC Educational Resources Information Center

Zwick, Rebecca; Zapata-Rivera, Diego; Hegarty, Mary

2014-01-01

Research has shown that many educators do not understand the terminology or displays used in test score reports and that measurement error is a particularly challenging concept. We investigated graphical and verbal methods of representing measurement error associated with individual student scores. We created four alternative score reports, each…

Smarter Balanced Preliminary Performance Levels: Estimated MAP Scores Corresponding to the Preliminary Performance Levels of the Smarter Balanced Assessment Consortium (Smarter Balanced)

ERIC Educational Resources Information Center

Northwest Evaluation Association, 2015

2015-01-01

Recently, the Smarter Balanced Assessment Consortium (Smarter Balanced) released a document that established initial performance levels and the associated threshold scale scores for the Smarter Balanced assessment. The report included estimated percentages of students expected to perform at each of the four performance levels, reported by grade…

Multimodal impairment-based physical therapy for the treatment of patients with post-concussion syndrome: A retrospective analysis on safety and feasibility.

PubMed

Grabowski, Patrick; Wilson, John; Walker, Alyssa; Enz, Dan; Wang, Sijian

2017-01-01

Demonstrate implementation, safety and feasibility of multimodal, impairment-based physical therapy (PT) combining vestibular/oculomotor and cervical rehabilitation with sub-symptom threshold exercise for the treatment of patients with post-concussion syndrome (PCS). University hospital outpatient sports medicine facility. Twenty-five patients (12-20 years old) meeting World Health Organization criteria for PCS following sport-related concussion referred for supervised PT consisting of sub-symptom cardiovascular exercise, vestibular/oculomotor and cervical spine rehabilitation. Retrospective cohort. Post-Concussion Symptom Scale (PCSS) total score, maximum symptom-free heart rate (SFHR) during graded exercise testing (GXT), GXT duration, balance error scoring system (BESS) score, and number of adverse events. Patients demonstrated a statistically significant decreasing trend (p < 0.01) for total PCSS scores (pre-PT M = 18.2 (SD = 14.2), post-PT M = 9.1 (SD = 10.8), n = 25). Maximum SFHR achieved on GXT increased 23% (p < 0.01, n = 14), and BESS errors decreased 52% (p < 0.01, n = 13). Two patients reported mild symptom exacerbation with aerobic exercise at home, attenuated by adjustment of the home exercise program. Multimodal, impairment-based PT is safe and associated with diminishing PCS symptoms. This establishes feasibility for future clinical trials to determine viable treatment approaches to reduce symptoms and improve function while avoiding negative repercussions of physical inactivity and premature return to full activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of Balance Deficits in People with Parkinson Disease; is the Sensory Organization Test Enough?

PubMed

Gera, G; Freeman, D L; Blackinton, M T; Horak, F B; King, L

2016-02-01

Balance deficits in people with Parkinson's disease can affect any of the multiple systems encompassing balance control. Thus, identification of the specific deficit is crucial in customizing balance rehabilitation. The sensory organization test, a test of sensory integration for balance control, is sometimes used in isolation to identify balance deficits in people with Parkinson's disease. More recently, the Mini-Balance Evaluations Systems Test, a clinical scale that tests multiple domains of balance control, has begun to be used to assess balance in patients with Parkinson's disease. The purpose of our study was to compare the use of Sensory Organization Test and Mini-Balance Evaluations Systems Test in identifying balance deficits in people with Parkinson's disease. 45 participants (27M, 18F; 65.2 ± 8.2 years) with idiopathic Parkinson's disease participated in the cross-sectional study. Balance assessment was performed using the Sensory Organization Test and the Mini-Balance Evaluations Systems Test. People were classified into normal and abnormal balance based on the established cutoff scores (normal balance: Sensory Organization Test >69; Mini-Balance Evaluations Systems Test >73). More subjects were classified as having abnormal balance with the Mini-Balance Evaluations Systems Test (71% abnormal) than with the Sensory Organization Test (24% abnormal) in our cohort of people with Parkinson's disease. There were no subjects with a normal Mini-Balance Evaluations Systems Test score but abnormal Sensory Organization Test score. In contrast, there were 21 subjects who had an abnormal Mini-Balance Evaluations Systems Test score but normal Sensory Organization Test scores. Findings from this study suggest that investigation of sensory integration deficits, alone, may not be able to identify all types of balance deficits found in patients with Parkinson's disease. Thus, a comprehensive approach should be used to test of multiple balance systems to provide customized rehabilitation.

Adherence to balance tolerance limits at the Upper Mississippi Science Center, La Crosse, Wisconsin.

USGS Publications Warehouse

Myers, C.T.; Kennedy, D.M.

1998-01-01

Verification of balance accuracy entails applying a series of standard masses to a balance prior to use and recording the measured values. The recorded values for each standard should have lower and upper weight limits or tolerances that are accepted as verification of balance accuracy under normal operating conditions. Balance logbooks for seven analytical balances at the Upper Mississippi Science Center were checked over a 3.5-year period to determine if the recorded weights were within the established tolerance limits. A total of 9435 measurements were checked. There were 14 instances in which the balance malfunctioned and operators recorded a rationale in the balance logbook. Sixty-three recording errors were found. Twenty-eight operators were responsible for two types of recording errors: Measurements of weights were recorded outside of the tolerance limit but not acknowledged as an error by the operator (n = 40); and measurements were recorded with the wrong number of decimal places (n = 23). The adherence rate for following tolerance limits was 99.3%. To ensure the continued adherence to tolerance limits, the quality-assurance unit revised standard operating procedures to require more frequent review of balance logbooks.

Normobaric Hypoxia Effects on Balance Measured by Computerized Dynamic Posturography.

PubMed

Wagner, Dale R; Saunders, Skyler; Robertson, Brady; Davis, John E

2016-09-01

Wagner, Dale R., Skyler Saunders, Brady Robertson, and John E. Davis. Normobaric hypoxia effects on balance measured by computerized dynamic posturography. High Alt Med Biol. 17:222-227, 2016.-Background/Aim: Equilibrium was measured by computerized dynamic posturography at varying levels of normobaric hypoxia before and after exercise. Following a familiarization trial, 12 males (27.3 ± 7.1 years) completed three sessions in random order on a NeuroCom SMART Balance Master: a sham trial at the ambient altitude of 1500 m and simulated altitudes of 3000 and 5000 m created by a hypoxic generator. The NeuroCom provided composite scores for a sensory organization test of equilibrium and a motor control test to assess the appropriate motor response. Additional information on somatosensory, visual, and vestibular responses was obtained. Each session consisted of 20 minutes of rest followed by the NeuroCom test, then 10 minutes of exercise, and 10 minutes of recovery followed by a second NeuroCom test, all while connected to the hypoxic generator. Mean differences were identified with a two-way (pre/postexercise and altitude condition), repeated-measures analysis of variance. The composite sensory score was significantly lower (p < 0.001) during the 5000 m trial (73.4 ± 12.0) compared to the 1500 m (80.8 ± 7.0) and 3000 m (84.1 ± 5.0) altitudes. The inability to ignore inaccurate visual cues in a situation of visual conflict was the most common sensory error. Motor control was not affected by altitude or exercise. These results suggest that moderate hypoxia does not affect balance, but severe hypoxia significantly reduces equilibrium. Furthermore, it appears that the alterations in equilibrium are primarily from impairments in visual function.

Computer Health Score

DOE Office of Scientific and Technical Information (OSTI.GOV)

The algorithm develops a single health score for office computers, today just Windows, but we plan to extend this to Apple computers. The score is derived from various parameters, including: CPU Utilization; Memory Utilization; Various Error logs; Disk Problems; and Disk write queue length. It then uses a weighting scheme to balance these parameters and provide an overall health score. By using these parameters, we are not just assessing the theoretical performance of the components of the computer, rather we are using actual performance metrics that are selected to be a more realistic representation of the experience of the personmore » using the computer. This includes compensating for the nature of their use. If there are two identical computers and the user of one places heavy demands on their computer compared with the user of the second computer, the former will have a lower health score. This allows us to provide a 'fit for purpose' score tailored to the assigned user. This is very helpful data to inform the mangers when individual computers need to be replaced. Additionally it provides specific information that can facilitate the fixing of the computer, to extend it's useful lifetime. This presents direct financial savings, time savings for users transferring from one computer to the next, and better environmental stewardship.« less

Taking the Error Term of the Factor Model into Account: The Factor Score Predictor Interval

ERIC Educational Resources Information Center

Beauducel, Andre

2013-01-01

The problem of factor score indeterminacy implies that the factor and the error scores cannot be completely disentangled in the factor model. It is therefore proposed to compute Harman's factor score predictor that contains an additive combination of factor and error variance. This additive combination is discussed in the framework of classical…

AN INITIAL EVALUATION OF THE BTRACKS BALANCE PLATE AND SPORTS BALANCE SOFTWARE FOR CONCUSSION DIAGNOSIS

PubMed Central

Manyak, Kristin A.; Abdenour, Thomas E.; Rauh, Mitchell J.; Baweja, Harsimran S.

2016-01-01

Background As recently dictated by the American Medical Society, balance testing is an important component in the clinical evaluation of concussion. Despite this, previous research on the efficacy of balance testing for concussion diagnosis suggests low sensitivity (∼30%), based primarily on the popular Balance Error Scoring System (BESS). The Balance Tracking System (BTrackS, Balance Tracking Systems Inc., San Diego, CA, USA) consists of a force plate (BTrackS Balance Plate) and software (BTrackS Sport Balance) which can quickly (<2 min) perform concussion balance testing with gold standard accuracy. Purpose The present study aimed to determine the sensitivity of the BTrackS Balance Plate and Sports Balance Software for concussion diagnosis. Study Design Cross-Sectional Study Methods Preseason baseline balance testing of 519 healthy Division I college athletes playing sports with a relatively high risk for concussions was performed with the BTrackS Balance Test. Testing was administered by certified athletic training staff using the BTrackS Balance Plate and Sport Balance software. Of the baselined athletes, 25 later experienced a concussion during the ensuing sport season. Post-injury balance testing was performed on these concussed athletes within 48 of injury and the sensitivity of the BTrackS Balance Plate and Sport Balance software was estimated based on the number of athletes showing a balance decline according to the criteria specified in the Sport Balance software. This criteria is based on the minimal detectable change statistic with a 90% confidence level (i.e. 90% specificity). Results Of 25 athletes who experienced concussions, 16 had balance declines relative to baseline testing results according to the BTrackS Sport Balance software criteria. This corresponds to an estimated concussion sensitivity of 64%, which is twice as great as that reported previously for the BESS. Conclusions The BTrackS Balance Plate and Sport Balance software has the greatest concussion sensitivity of any balance testing instrument reported to date. Level of Evidence Level 2 (Individual cross sectional diagnostic study) PMID:27104048

A cognitive-balance control training paradigm using wii fit to reduce fall risk in chronic stroke survivors.

PubMed

Subramaniam, Savitha; Wan-Ying Hui-Chan, Christina; Bhatt, Tanvi

2014-10-01

The impaired ability to maintain balance while performing higher-level cognitive tasks (cognitive-motor interference) significantly predisposes stroke survivors to risk of falls. We investigated adherence and intervention-related effects of gaming to improve balance control and decrease cognitive-motor interference in stroke survivors. Community-dwelling individuals with hemiparetic stroke (N = 8) received balance control training using Wii Fit in conjunction with cognitive training for approximately 110 min/d for 5 consecutive days. Changes in balance and cognitive performance were evaluated by the limits of stability test performed under single-task (ST) and dual-task (DT) conditions. The outcome measures from the limits of stability test included reaction time and movement velocity of the center of pressure. The cognitive performance was quantified by the number of errors. The DT cost was computed for the balance and cognitive outcome measures using [(ST - DT)/ST × 100]. Adherence was assessed by change on the Intrinsic Motivation Inventory scores postintervention. No commercial party having a direct financial interest in the research findings reported here has conferred orwill confer. Posttraining, reaction time cost in the forward direction improved from 31 ± 8.02 to ±8.7 ± 6.6. Similarly, movement velocity cost improved from 33.7 ± 12.3 to 11 ± 1. Cognitive cost also decreased from 47.9 ± 13.9 to 20 ± 18.8. There were similar improvements in the backward direction for all the outcome measures. Scores on the Intrinsic Motivation Inventory improved from 16.6 ± 1.3 to 23.5 ± 1.5. The results demonstrate good adherence and evidence of clinical value of this high-intensity, short-duration protocol for reducing cognitive-motor interference and improving balance control in stroke survivors. Future studies should examine the dose-response effects and long-term changes of such DT training paradigm applied to improve fall efficacy.Video Abstract available. See Video (Supplemental Digital Content 1, http://links.lww.com/JNPT/A80) for more insights from the authors.

Validation of measures from the smartphone sway balance application: a pilot study.

PubMed

Patterson, Jeremy A; Amick, Ryan Z; Thummar, Tarunkumar; Rogers, Michael E

2014-04-01

A number of different balance assessment techniques are currently available and widely used. These include both subjective and objective assessments. The ability to provide quantitative measures of balance and posture is the benefit of objective tools, however these instruments are not generally utilized outside of research laboratory settings due to cost, complexity of operation, size, duration of assessment, and general practicality. The purpose of this pilot study was to assess the value and validity of using software developed to access the iPod and iPhone accelerometers output and translate that to the measurement of human balance. Thirty healthy college-aged individuals (13 male, 17 female; age = 26.1 ± 8.5 years) volunteered. Participants performed a static Athlete's Single Leg Test protocol for 10 sec, on a Biodex Balance System SD while concurrently utilizing a mobile device with balance software. Anterior/posterior stability was recorded using both devices, described as the displacement in degrees from level, and was termed the "balance score." There were no significant differences between the two reported balance scores (p = 0.818. Mean balance score on the balance platform was 1.41 ± 0.90, as compared to 1.38 ± 0.72 using the mobile device. There is a need for a valid, convenient, and cost-effective tool to objectively measure balance. Results of this study are promising, as balance score derived from the Smartphone accelerometers were consistent with balance scores obtained from a previously validated balance system. However, further investigation is necessary as this version of the mobile software only assessed balance in the anterior/posterior direction. Additionally, further testing is necessary on a healthy populations and as well as those with impairment of the motor control system. Level 2b (Observational study of validity)(1.)

Comparison of geodetic and glaciological mass-balance techniques, Gulkana Glacier, Alaska, U.S.A

USGS Publications Warehouse

Cox, L.H.; March, R.S.

2004-01-01

The net mass balance on Gulkana Glacier, Alaska, U.S.A., has been measured since 1966 by the glaciological method, in which seasonal balances are measured at three index sites and extrapolated over large areas of the glacier. Systematic errors can accumulate linearly with time in this method. Therefore, the geodetic balance, in which errors are less time-dependent, was calculated for comparison with the glaciological method. Digital elevation models of the glacier in 1974, 1993 and 1999 were prepared using aerial photographs, and geodetic balances were computed, giving - 6.0??0.7 m w.e. from 1974 to 1993 and - 11.8??0.7 m w.e. from 1974 to 1999. These balances are compared with the glaciological balances over the same intervals, which were - 5.8??0.9 and -11.2??1.0 m w.e. respectively; both balances show that the thinning rate tripled in the 1990s. These cumulative balances differ by <6%. For this close agreement, the glaciologically measured mass balance of Gulkana Glacier must be largely free of systematic errors and be based on a time-variable area-altitude distribution, and the photography used in the geodetic method must have enough contrast to enable accurate photogrammetry.

Does patient-perceived handicap correspond to the modified clinical test for the sensory interaction on balance?

PubMed

Loughran, Sean; Gatehouse, Stuart; Kishore, Ameet; Swan, Iain R C

2006-01-01

To determine whether patient self-reported handicap correlates with scores obtained from the modified Clinical Test for the Sensory Interaction on Balance as assessed by the Neurocom VSR Balance Master platform. Prospective observational. Balance clinic in tertiary referral center. Patients referred with dizziness or imbalance as their primary complaint. The modified Clinical Test for the Sensory Interaction on Balance scores as assessed by the Neurocom VSR Balance Master platform, the Dizziness Handicap Inventory, and the Health Utilities Index Marks 2 and 3. One hundred fifty-nine patients were entered into the study. The mean age of participants was 54.5 years, with a female-to-male ratio of 2.1:1. The scores for the Dizziness Handicap Inventory and Health Utilities Index are similar between sexes, and although the Dizziness Handicap Inventory score did not correlate with age, Health Utilities Index 2 and 3 scores did show a negative correlation with increasing age. There are weak, positive correlations between the Dizziness Handicap Inventory and the firm surface conditions of the modified Clinical Test for the Sensory Interaction on Balance but no useful correlation with the foam conditions. Similar weak negative correlations were found between the Health Utilities Index 2 and 3 and the modified Clinical Test for the Sensory Interaction on Balance scores. Patient-perceived handicap of imbalance appears to correlate poorly with assessment of postural stability using the modified Clinical Test for the Sensory Interaction on Balance.

Coil motion effects in watt balances: a theoretical check

NASA Astrophysics Data System (ADS)

Li, Shisong; Schlamminger, Stephan; Haddad, Darine; Seifert, Frank; Chao, Leon; Pratt, Jon R.

2016-04-01

A watt balance is a precision apparatus for the measurement of the Planck constant that has been proposed as a primary method for realizing the unit of mass in a revised International System of Units. In contrast to an ampere balance, which was historically used to realize the unit of current in terms of the kilogram, the watt balance relates electrical and mechanical units through a virtual power measurement and has far greater precision. However, because the virtual power measurement requires the execution of a prescribed motion of a coil in a fixed magnetic field, systematic errors introduced by horizontal and rotational deviations of the coil from its prescribed path will compromise the accuracy. We model these potential errors using an analysis that accounts for the fringing field in the magnet, creating a framework for assessing the impact of this class of errors on the uncertainty of watt balance results.

Conditional Standard Errors, Reliability and Decision Consistency of Performance Levels Using Polytomous IRT.

ERIC Educational Resources Information Center

Wang, Tianyou; And Others

M. J. Kolen, B. A. Hanson, and R. L. Brennan (1992) presented a procedure for assessing the conditional standard error of measurement (CSEM) of scale scores using a strong true-score model. They also investigated the ways of using nonlinear transformation from number-correct raw score to scale score to equalize the conditional standard error along…

A Comparison of Three Methods for Computing Scale Score Conditional Standard Errors of Measurement. ACT Research Report Series, 2013 (7)

ERIC Educational Resources Information Center

Woodruff, David; Traynor, Anne; Cui, Zhongmin; Fang, Yu

2013-01-01

Professional standards for educational testing recommend that both the overall standard error of measurement and the conditional standard error of measurement (CSEM) be computed on the score scale used to report scores to examinees. Several methods have been developed to compute scale score CSEMs. This paper compares three methods, based on…

Balance self-efficacy in older adults following inpatient rehabilitation.

PubMed

Kuys, Suzanne S; Donovan, Jacquelin; Mattin, Sarah; Low Choy, Nancy L

2015-06-01

Older adults discharging from inpatient rehabilitation were investigated to determine change in self-efficacy at 1 month after discharge, the relationship with discharge balance performance and physical function, and the influence of diagnosis. A prospective cohort of 101 adults older than 50 years of age, 43% men, average age 75.84 (SD 9.8) years, were recruited at discharge from inpatient rehabilitation. Balance self-efficacy was assessed using Activities-specific Balance Confidence (ABC) scale at discharge and 1 month following discharge. Balance and physical function were measured at discharge using the Functional Independence Measure, Balance Outcome Measure for Elder Rehabilitation, Modified Elderly Mobility Scale and gait speed. At discharge, balance self-efficacy was moderate (ABC score 62, SD 23) and did not change at follow-up. When grouped by discharge self-efficacy (ABC scores: low<50; moderate 51-80; high>80), significant between-group differences were found for balance (P=0.005) and physical function (P=0.035). At the 1-month follow-up, those with low discharge balance self-efficacy showed improvement (mean-change ABC score 12, 95% confidence interval 2-22) and those with high discharge balance self-efficacy had lower scores (mean-change ABC score 18, 95% confidence interval -8 to -28). Differences in ABC change scores were also found between diagnostic groups (F=3.740, P=0.03), with the orthopaedic group improving (ABC mean change=8) and the general frailty group showing a decrease in confidence (ABC mean change=10). The differences in balance self-efficacy change at 1 month following discharge were related to self-efficacy level at discharge and clinical group requiring rehabilitation. Clinicians need to be aware of these changes as patients are prepared for discharge.

An Algebraic Approach to Guarantee Harmonic Balance Method Using Gröbner Base

NASA Astrophysics Data System (ADS)

Yagi, Masakazu; Hisakado, Takashi; Okumura, Kohshi

Harmonic balance (HB) method is well known principle for analyzing periodic oscillations on nonlinear networks and systems. Because the HB method has a truncation error, approximated solutions have been guaranteed by error bounds. However, its numerical computation is very time-consuming compared with solving the HB equation. This paper proposes an algebraic representation of the error bound using Gröbner base. The algebraic representation enables to decrease the computational cost of the error bound considerably. Moreover, using singular points of the algebraic representation, we can obtain accurate break points of the error bound by collisions.

Using statistical text classification to identify health information technology incidents

PubMed Central

Chai, Kevin E K; Anthony, Stephen; Coiera, Enrico; Magrabi, Farah

2013-01-01

Objective To examine the feasibility of using statistical text classification to automatically identify health information technology (HIT) incidents in the USA Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE) database. Design We used a subset of 570 272 incidents including 1534 HIT incidents reported to MAUDE between 1 January 2008 and 1 July 2010. Text classifiers using regularized logistic regression were evaluated with both ‘balanced’ (50% HIT) and ‘stratified’ (0.297% HIT) datasets for training, validation, and testing. Dataset preparation, feature extraction, feature selection, cross-validation, classification, performance evaluation, and error analysis were performed iteratively to further improve the classifiers. Feature-selection techniques such as removing short words and stop words, stemming, lemmatization, and principal component analysis were examined. Measurements κ statistic, F1 score, precision and recall. Results Classification performance was similar on both the stratified (0.954 F1 score) and balanced (0.995 F1 score) datasets. Stemming was the most effective technique, reducing the feature set size to 79% while maintaining comparable performance. Training with balanced datasets improved recall (0.989) but reduced precision (0.165). Conclusions Statistical text classification appears to be a feasible method for identifying HIT reports within large databases of incidents. Automated identification should enable more HIT problems to be detected, analyzed, and addressed in a timely manner. Semi-supervised learning may be necessary when applying machine learning to big data analysis of patient safety incidents and requires further investigation. PMID:23666777

Monte Carlo simulation of expert judgments on human errors in chemical analysis--a case study of ICP-MS.

PubMed

Kuselman, Ilya; Pennecchi, Francesca; Epstein, Malka; Fajgelj, Ales; Ellison, Stephen L R

2014-12-01

Monte Carlo simulation of expert judgments on human errors in a chemical analysis was used for determination of distributions of the error quantification scores (scores of likelihood and severity, and scores of effectiveness of a laboratory quality system in prevention of the errors). The simulation was based on modeling of an expert behavior: confident, reasonably doubting and irresolute expert judgments were taken into account by means of different probability mass functions (pmfs). As a case study, 36 scenarios of human errors which may occur in elemental analysis of geological samples by ICP-MS were examined. Characteristics of the score distributions for three pmfs of an expert behavior were compared. Variability of the scores, as standard deviation of the simulated score values from the distribution mean, was used for assessment of the score robustness. A range of the score values, calculated directly from elicited data and simulated by a Monte Carlo method for different pmfs, was also discussed from the robustness point of view. It was shown that robustness of the scores, obtained in the case study, can be assessed as satisfactory for the quality risk management and improvement of a laboratory quality system against human errors. Copyright © 2014 Elsevier B.V. All rights reserved.

Reliability and Validity Evidence of Multiple Balance Assessments in Athletes With a Concussion

PubMed Central

Murray, Nicholas; Salvatore, Anthony; Powell, Douglas; Reed-Jones, Rebecca

2014-01-01

Context: An estimated 300 000 sport-related concussion injuries occur in the United States annually. Approximately 30% of individuals with concussions experience balance disturbances. Common methods of balance assessment include the Clinical Test of Sensory Organization and Balance (CTSIB), the Sensory Organization Test (SOT), the Balance Error Scoring System (BESS), and the Romberg test; however, the National Collegiate Athletic Association recommended the Wii Fit as an alternative measure of balance in athletes with a concussion. A central concern regarding the implementation of the Wii Fit is whether it is reliable and valid for measuring balance disturbance in athletes with concussion. Objective: To examine the reliability and validity evidence for the CTSIB, SOT, BESS, Romberg test, and Wii Fit for detecting balance disturbance in athletes with a concussion. Data Sources: Literature considered for review included publications with reliability and validity data for the assessments of balance (CTSIB, SOT, BESS, Romberg test, and Wii Fit) from PubMed, PsycINFO, and CINAHL. Data Extraction: We identified 63 relevant articles for consideration in the review. Of the 63 articles, 28 were considered appropriate for inclusion and 35 were excluded. Data Synthesis: No current reliability or validity information supports the use of the CTSIB, SOT, Romberg test, or Wii Fit for balance assessment in athletes with a concussion. The BESS demonstrated moderate to high reliability (interclass correlation coefficient = 0.87) and low to moderate validity (sensitivity = 34%, specificity = 87%). However, the Romberg test and Wii Fit have been shown to be reliable tools in the assessment of balance in Parkinson patients. Conclusions: The BESS can evaluate balance problems after a concussion. However, it lacks the ability to detect balance problems after the third day of recovery. Further investigation is needed to establish the use of the CTSIB, SOT, Romberg test, and Wii Fit for assessing balance in athletes with concussions. PMID:24933431

The relationship between balance confidence and control in individuals with Parkinson's disease.

PubMed

Lee, Hyo Keun; Altmann, Lori J P; McFarland, Nikolaus; Hass, Chris J

2016-05-01

A broad range of subjective and objective assessments have been used to assess balance confidence and balance control in persons with Parkinson's disease (PD). However, little is known about the relationship between self-perceived balance confidence and actual balance control in PD. The purpose of this investigation was to determine the relationship between self-perceived balance confidence and objectively measured static/dynamic balance control abilities. Forty-four individuals with PD participated in the study. Patients were stratified into 2 groups based on the modified Hoehn and Yahr (H&Y) disability score: early stage, H&Y ≤ 2.0 and moderate stage, H&Y ≥ 2.5. All participants completed the activities-specific balance confidence (ABC) scale and performed standing balance and gait initiation tasks to assess static and dynamic balance control. The center of pressure (COP) sway (CE95%Sway) during static balance and the peak distance between the projections of the COP and the center of mass (COM) in the transverse plane (COPCOM) during gait initiation were calculated. Pearson correlation analyses were conducted relating the ABC score and CE95%Sway and COPCOM. For early stage PD, there was a moderate correlation between ABC score and CE95%Sway (r = -0.56, R(2) = 0.32, p = 0.002), while no significant correlation was found between ABC score and COPCOM (r = -0.24, R(2) = 0.06, p = 0.227). For moderate stage PD, there was a moderate correlation between ABC score and COPCOM (r = 0.49, R(2) = 0.24, p = 0.044), while no correlation was found between ABC score and CE95%Sway (r = -0.19, R(2) = 0.04, p = 0.478). Individuals with different disease severities showed different relationships between balance confidence and actual static/dynamic balance control. Copyright © 2016 Elsevier Ltd. All rights reserved.

A global perspective of the limits of prediction skill based on the ECMWF ensemble

NASA Astrophysics Data System (ADS)

Zagar, Nedjeljka

2016-04-01

In this talk presents a new model of the global forecast error growth applied to the forecast errors simulated by the ensemble prediction system (ENS) of the ECMWF. The proxy for forecast errors is the total spread of the ECMWF operational ensemble forecasts obtained by the decomposition of the wind and geopotential fields in the normal-mode functions. In this way, the ensemble spread can be quantified separately for the balanced and inertio-gravity (IG) modes for every forecast range. Ensemble reliability is defined for the balanced and IG modes comparing the ensemble spread with the control analysis in each scale. The results show that initial uncertainties in the ECMWF ENS are largest in the tropical large-scale modes and their spatial distribution is similar to the distribution of the short-range forecast errors. Initially the ensemble spread grows most in the smallest scales and in the synoptic range of the IG modes but the overall growth is dominated by the increase of spread in balanced modes in synoptic and planetary scales in the midlatitudes. During the forecasts, the distribution of spread in the balanced and IG modes grows towards the climatological spread distribution characteristic of the analyses. The ENS system is found to be somewhat under-dispersive which is associated with the lack of tropical variability, primarily the Kelvin waves. The new model of the forecast error growth has three fitting parameters to parameterize the initial fast growth and a more slow exponential error growth later on. The asymptotic values of forecast errors are independent of the exponential growth rate. It is found that the asymptotic values of the errors due to unbalanced dynamics are around 10 days while the balanced and total errors saturate in 3 to 4 weeks. Reference: Žagar, N., R. Buizza, and J. Tribbia, 2015: A three-dimensional multivariate modal analysis of atmospheric predictability with application to the ECMWF ensemble. J. Atmos. Sci., 72, 4423-4444.

Validation of a virtual reality balance module for use in clinical concussion assessment and management.

PubMed

Teel, Elizabeth F; Slobounov, Semyon M

2015-03-01

To determine the criterion and content validity of a virtual reality (VR) balance module for use in clinical practice. Retrospective, VR balance module completed by participants during concussion baseline or assessment testing session. A Pennsylvania State University research laboratory. A total of 60 control and 28 concussed students and athletes from the Pennsylvania State University. None. This study examined: (1) the relationship between VR composite balance scores (final, stationary, yaw, pitch, and roll) and area of the center-of-pressure (eyes open and closed) scores and (2) group differences (normal volunteers and concussed student-athletes) on VR composite balance scores. With the exception of the stationary composite score, all other VR balance composite scores were significantly correlated with the center of pressure data obtained from a force platform. Significant correlations ranged from r = -0.273 to -0.704 for the eyes open conditions and from r = -0.353 to -0.876 for the eyes closed condition. When examining group differences on the VR balance composite modules, the concussed group did significantly (P < 0.01) worse on all measures compared with the control group. The VR balance module met or exceeded the criterion and content validity standard set by the current balance tools and may be appropriate for use in a clinical concussion setting. Virtual reality balance module is a valid tool for concussion assessment in clinical settings. This novel type of balance assessment may be more sensitive to concussion diagnoses, especially later (7-10 days) in the recovery phase than current clinical balance tools.

Conditional Standard Errors of Measurement for Scale Scores.

ERIC Educational Resources Information Center

Kolen, Michael J.; And Others

1992-01-01

A procedure is described for estimating the reliability and conditional standard errors of measurement of scale scores incorporating the discrete transformation of raw scores to scale scores. The method is illustrated using a strong true score model, and practical applications are described. (SLD)

A novel color vision test for detection of diabetic macular edema.

PubMed

Shin, Young Joo; Park, Kyu Hyung; Hwang, Jeong-Min; Wee, Won Ryang; Lee, Jin Hak; Lee, In Bum; Hyon, Joon Young

2014-01-02

To determine the sensitivity of the Seoul National University (SNU) computerized color vision test for detecting diabetic macular edema. From May to September 2003, a total of 73 eyes of 73 patients with diabetes mellitus were examined using the SNU computerized color vision test and optical coherence tomography (OCT). Color deficiency was quantified as the total error score on the SNU test and as error scores for each of four color quadrants corresponding to yellows (Q1), greens (Q2), blues (Q3), and reds (Q4). SNU error scores were assessed as a function of OCT foveal thickness and total macular volume (TMV). The error scores in Q1, Q2, Q3, and Q4 measured by the SNU color vision test increased with foveal thickness (P < 0.05), whereas they were not correlated with TMV. Total error scores, the summation of Q1 and Q3, the summation of Q2 and Q4, and blue-yellow (B-Y) error scores were significantly correlated with foveal thickness (P < 0.05), but not with TMV. The observed correlation between SNU color test error scores and foveal thickness indicates that the SNU test may be useful for detection and monitoring of diabetic macular edema.

Relationships among age, gender, anthropometric characteristics, and dynamic balance in children 5 to 12 years old.

PubMed

Butz, Sarah M; Sweeney, Jane K; Roberts, Pamela L; Rauh, Mitchell J

2015-01-01

To examine relationships among age, gender, anthropometrics, and dynamic balance. Height, weight, and arm and foot length were measured in 160 children with typical development aged 5 to 12 years. Dynamic balance was assessed using the Timed Up and Go (TUG) test, Pediatric Reach Test (PRT), and Pediatric Balance Scale (PBS). Moderate to good positive relationships (r = 0.61 and r = 0.56) were found between increasing age and PRT and PBS scores. A fair negative relationship (r = -0.49) was observed between age and TUG test. No significant gender-by-age group difference was observed. Age had the strongest influence on TUG and PBS scores; arm length had the strongest influence on PRT scores. Dynamic balance ability is directly related to chronological age. Age and arm length have the strongest relationships with balance scores. These findings may assist pediatric therapists in selecting dynamic balance tests according to age rather than specific diagnosis.

Balance Performance Is Task Specific in Older Adults.

PubMed

Dunsky, Ayelet; Zeev, Aviva; Netz, Yael

2017-01-01

Balance ability among the elderly is a key component in the activities of daily living and is divided into two types: static and dynamic. For clinicians who wish to assess the risk of falling among their elderly patients, it is unclear if more than one type of balance test can be used to measure their balance impairment. In this study, we examined the association between static balance measures and two dynamic balance field tests. One hundred and twelve community-dwelling older adults (mean age 74.6) participated in the study. They underwent the Tetrax static postural assessment and then performed the Timed Up and Go (TUG) and the Functional Reach (FR) Test as dynamic balance tests. In general, low-moderate correlations were found between the two types of balance tests. For women, age and static balance parameters explained 28.1-40.4% of the variance of TUG scores and 14.6-24% of the variance of FR scores. For men, age and static balance parameters explained 9.5-31.2% of the variance of TUG scores and 23.9-41.7% of the variance of FR scores. Based on our findings, it is suggested that a combination of both static and dynamic tests be used for assessing postural balance ability.

Validation of a Virtual Reality Balance Module for Use in Clinical Concussion Assessment and Management

PubMed Central

Teel, Elizabeth F.; Slobounov, Semyon M.

2014-01-01

Objective To determine the criterion and content validity of a virtual reality (VR) balance module for use in clinical practice. Design Retrospective, VR balance module completed by participants during concussion baseline or assessment testing session. Setting A Pennsylvania State University research laboratory Participants A total of 60 control and 28 concussed students and athletes from the Pennsylvania State University Interventions None Main Outcome Measures This study examined: (1) the relationship between VR composite balance scores (final, stationary, yaw, pitch, and roll) and area of the center-of-pressure (eyes open and closed) scores and (2) group differences (normal volunteers and concussed student-athletes) on VR composite balance scores. Results With the exception of the stationary composite score, all other VR balance composite scores were significantly correlated with the center of pressure (COP) data obtained from a force platform. Significant correlations for the eyes open conditions ranged from r= −.273 to −.704 and from r= −.353 to −.876 for the eyes closed condition. When examining group differences on the VR balance composite modules, the concussed group did significantly (p<.01) worse on all measures compared to the control group. Conclusions The VR balance module met or exceeded the criterion and content validity standard set by current balance tools and may be appropriate for use in a clinical concussion setting. PMID:24905539

Evaluating the prevalence and impact of examiner errors on the Wechsler scales of intelligence: A meta-analysis.

PubMed

Styck, Kara M; Walsh, Shana M

2016-01-01

The purpose of the present investigation was to conduct a meta-analysis of the literature on examiner errors for the Wechsler scales of intelligence. Results indicate that a mean of 99.7% of protocols contained at least 1 examiner error when studies that included a failure to record examinee responses as an error were combined and a mean of 41.2% of protocols contained at least 1 examiner error when studies that ignored errors of omission were combined. Furthermore, graduate student examiners were significantly more likely to make at least 1 error on Wechsler intelligence test protocols than psychologists. However, psychologists made significantly more errors per protocol than graduate student examiners regardless of the inclusion or exclusion of failure to record examinee responses as errors. On average, 73.1% of Full-Scale IQ (FSIQ) scores changed as a result of examiner errors, whereas 15.8%-77.3% of scores on the Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Working Memory Index (WMI), and Processing Speed Index changed as a result of examiner errors. In addition, results suggest that examiners tend to overestimate FSIQ scores and underestimate VCI scores. However, no strong pattern emerged for the PRI and WMI. It can be concluded that examiner errors occur frequently and impact index and FSIQ scores. Consequently, current estimates for the standard error of measurement of popular IQ tests may not adequately capture the variance due to the examiner. (c) 2016 APA, all rights reserved).

Analysis of difference between direct and geodetic mass balance measurements at South Cascade Glacier, Washington

USGS Publications Warehouse

Krimmel, R.M.

1999-01-01

Net mass balance has been measured since 1958 at South Cascade Glacier using the 'direct method,' e.g. area averages of snow gain and firn and ice loss at stakes. Analysis of cartographic vertical photography has allowed measurement of mass balance using the 'geodetic method' in 1970, 1975, 1977, 1979-80, and 1985-97. Water equivalent change as measured by these nearly independent methods should give similar results. During 1970-97, the direct method shows a cumulative balance of about -15 m, and the geodetic method shows a cumulative balance of about -22 m. The deviation between the two methods is fairly consistent, suggesting no gross errors in either, but rather a cumulative systematic error. It is suspected that the cumulative error is in the direct method because the geodetic method is based on a non-changing reference, the bedrock control, whereas the direct method is measured with reference to only the previous year's summer surface. Possible sources of mass loss that are missing from the direct method are basal melt, internal melt, and ablation on crevasse walls. Possible systematic measurement errors include under-estimation of the density of lost material, sinking stakes, or poorly represented areas.

Instance Analysis for the Error of Three-pivot Pressure Transducer Static Balancing Method for Hydraulic Turbine Runner

NASA Astrophysics Data System (ADS)

Weng, Hanli; Li, Youping

2017-04-01

The working principle, process device and test procedure of runner static balancing test method by weighting with three-pivot pressure transducers are introduced in this paper. Based on an actual instance of a V hydraulic turbine runner, the error and sensitivity of the three-pivot pressure transducer static balancing method are analysed. Suggestions about improving the accuracy and the application of the method are also proposed.

Rear shape in 3 dimensions summarized by principal component analysis is a good predictor of body condition score in Holstein dairy cows.

PubMed

Fischer, A; Luginbühl, T; Delattre, L; Delouard, J M; Faverdin, P

2015-07-01

Body condition is an indirect estimation of the level of body reserves, and its variation reflects cumulative variation in energy balance. It interacts with reproductive and health performance, which are important to consider in dairy production but not easy to monitor. The commonly used body condition score (BCS) is time consuming, subjective, and not very sensitive. The aim was therefore to develop and validate a method assessing BCS with 3-dimensional (3D) surfaces of the cow's rear. A camera captured 3D shapes 2 m from the floor in a weigh station at the milking parlor exit. The BCS was scored by 3 experts on the same day as 3D imaging. Four anatomical landmarks had to be identified manually on each 3D surface to define a space centered on the cow's rear. A set of 57 3D surfaces from 56 Holstein dairy cows was selected to cover a large BCS range (from 0.5 to 4.75 on a 0 to 5 scale) to calibrate 3D surfaces on BCS. After performing a principal component analysis on this data set, multiple linear regression was fitted on the coordinates of these surfaces in the principal components' space to assess BCS. The validation was performed on 2 external data sets: one with cows used for calibration, but at a different lactation stage, and one with cows not used for calibration. Additionally, 6 cows were scanned once and their surfaces processed 8 times each for repeatability and then these cows were scanned 8 times each the same day for reproducibility. The selected model showed perfect calibration and a good but weaker validation (root mean square error=0.31 for the data set with cows used for calibration; 0.32 for the data set with cows not used for calibration). Assessing BCS with 3D surfaces was 3 times more repeatable (standard error=0.075 versus 0.210 for BCS) and 2.8 times more reproducible than manually scored BCS (standard error=0.103 versus 0.280 for BCS). The prediction error was similar for both validation data sets, indicating that the method is not less efficient for cows not used for calibration. The major part of reproducibility error incorporates repeatability error. An automation of the anatomical landmarks identification is required, first to allow broadband measures of body condition and second to improve repeatability and consequently reproducibility. Assessing BCS using 3D imaging coupled with principal component analysis appears to be a very promising means of improving precision and feasibility of this trait measurement. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

On-farm estimation of energy balance in dairy cows using only frequent body weight measurements and body condition score.

PubMed

Thorup, V M; Edwards, D; Friggens, N C

2012-04-01

Precise energy balance estimates for individual cows are of great importance to monitor health, reproduction, and feed management. Energy balance is usually calculated as energy input minus output (EB(inout)), requiring measurements of feed intake and energy output sources (milk, maintenance, activity, growth, and pregnancy). Except for milk yield, direct measurements of the other sources are difficult to obtain in practice, and estimates contain considerable error sources, limiting on-farm use. Alternatively, energy balance can be estimated from body reserve changes (EB(body)) using body weight (BW) and body condition score (BCS). Automated weighing systems exist and new technology performing semi-automated body condition scoring has emerged, so frequent automated BW and BCS measurements are feasible. We present a method to derive individual EB(body) estimates from frequently measured BW and BCS and evaluate the performance of the estimated EB(body) against the traditional EB(inout) method. From 76 Danish Holstein and Jersey cows, parity 1 or 2+, on a glycerol-rich or a whole grain-rich total mixed ration, BW was measured automatically at each milking. The BW was corrected for the weight of milk produced and for gutfill. Changes in BW and BCS were used to calculate changes in body protein, body lipid, and EB(body) during the first 150 d in milk. The EB(body) was compared with the traditional EB(inout) by isolating the term within EB(inout) associated with most uncertainty; that is, feed energy content (FEC); FEC=(EB(body)+EMilk+EMaintenance+Eactivity)/dry matter intake, where the energy requirements are for milk produced (EMilk), maintenance (EMaintenance), and activity (EActivity). Estimated FEC agreed well with FEC values derived from tables (the mean estimate was 0.21 MJ of effective energy/kg of dry matter or 2.2% higher than the mean table value). Further, the FEC profile did not suggest systematic bias in EB(body) with stage of lactation. The EB(body) estimated from daily BW, adjusted for milk and meal-related gutfill and combined with frequent BCS, can provide a successful tool. This offers a pragmatic solution to on-farm calculation of energy balance with the perspective of improved precision under commercial conditions. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The effect of a senior jazz dance class on static balance in healthy women over 50 years of age: a pilot study.

PubMed

Wallmann, Harvey W; Gillis, Carrie B; Alpert, Patricia T; Miller, Sally K

2009-01-01

The purpose of this pilot study is to assess the impact of a senior jazz dance class on static balance for healthy women over 50 years of age using the NeuroCom Smart Balance Master System (Balance Master). A total of 12 healthy women aged 54-88 years completed a 15-week jazz dance class which they attended 1 time per week for 90 min per class. Balance data were collected using the Sensory Organization Test (SOT) at baseline (pre), at 7 weeks (mid), and after 15 weeks (post). An equilibrium score measuring postural sway was calculated for each of six different conditions. The composite equilibrium score (all six conditions integrated to 1 score) was used as an overall measure of balance. Repeated measures analyses of variance (ANOVAs) were used to compare the means of each participant's SOT composite equilibrium score in addition to the equilibrium score for each individual condition (1-6) across the 3 time points (pre, mid, post). There was a statistically significant difference among the means, p < .0005. Pairwise (Bonferroni) post hoc analyses revealed the following statistically significant findings for SOT composite equilibrium scores for the pre (67.33 + 10.43), mid (75.25 + 6.97), and post (79.00 + 4.97) measurements: premid (p = .008); prepost (p < .0005); midpost (p = .033). In addition, correlational statistics were used to determine any relationship between SOT scores and age. Results indicated that administration of a 15-week jazz dance class 1 time per week was beneficial in improving static balance as measured by the Balance Master SOT.

Career satisfaction and work-life balance of specialist orthodontists within the UK/ROI.

PubMed

Al-Junaid, S M; Hodges, S J; Petrie, A; Cunningham, S J

2017-07-07

Objectives To investigate factors affecting career satisfaction and work-life balance in specialist orthodontists in the UK/ROI.Design and setting Prospective questionnaire-based study.Subjects and methods The questionnaire was sent to specialist orthodontists who were members of the British Orthodontic Society.Results Orthodontists reported high levels of career satisfaction (median score 90/100). Career satisfaction was significantly higher in those who exhibited: i) satisfaction with working hours; ii) satisfaction with the level of control over their working day; iii) ability to manage unexpected home events; and iv) confidence in how readily they managed patient expectations. The work-life balance score was lower than the career satisfaction score but the median score was 75/100. Work-life balance scores were significantly affected by the same four factors, but additionally were higher in those who worked part-time.Conclusions Orthodontists in this study were highly satisfied with their career and the majority responded that they would choose orthodontics again. Work-life balance scores were lower than career satisfaction scores but still relatively high. It is important for the profession to consider ways of maintaining, or improving, career satisfaction and work-life balance; including maintaining flexibility of working hours and ensuring that all clinicians have ready access to appropriate training courses throughout their careers (for example, management of patient expectations).

The use of virtual reality for balance among individuals with chronic stroke: a systematic review and meta-analysis.

PubMed

Iruthayarajah, Jerome; McIntyre, Amanda; Cotoi, Andreea; Macaluso, Steven; Teasell, Robert

2017-01-01

Virtual reality (VR) is becoming a popular alternative to traditional upper and lower limb rehabilitation following a stroke. To conduct a systematic review and meta-analysis on the effectiveness of VR interventions for improving balance in a chronic stroke (≥6 months) population. A literature search of Pubmed, Scopus, CINAHL, Embase, Psycinfo, and Web of Science databases was conducted. English randomized controlled trials published up to September 2015 assessing balance with VR in chronic stroke participants. Mean and standard deviations from outcome measures were extracted. Pooled standard mean differences ± standard error were calculated for the Berg Balance Scale (BBS) and the Timed Up and Go test (TUG). In total, 20 studies were selected which assessed the Nintendo ® Wii Fit balance board (n = 7), treadmill training and VR (n = 7), and postural training using VR (n = 6). Significant improvements were found for VR interventions evaluating the BBS (n = 12; MD = 2.94 ± 0.57; p < 0.001) and TUG (n = 13; MD = 2.49 ± 0.57; p < 0.001). Sub-analyses revealed postural VR interventions had a significant effect on BBS (n = 5) and TUG (n = 3) scores (BBS: MD = 3.82 ± 0.79; p < 0.001 and TUG: MD = 3.74 ± 0.97; p < 0.001). VR and treadmill training (n = 5) had a significant effect on TUG scores (MD = 2.15 ± 0.89, p = 0.016). Overall, VR interventions compared to conventional rehabilitation had significant improvements. The meta-analyses also suggest that the Nintendo ® Wii Fit balance board may not be effective, although further confirmatory studies are necessary. Results should be interpreted with caution due to differences in therapy intensities and effect sizes within the included studies.

Functional Performance and Balance in the Oldest-Old.

PubMed

Kafri, Michal; Hutzler, Yeshayahu; Korsensky, Olga; Laufer, Yocheved

2017-06-01

The group of individuals 85 years and over (termed oldest-old) is the fastest-growing population in the Western world. Although daily functional abilities and balance capabilities are known to decrease as an individual grows older, little is known about the balance and functional characteristics of the oldest-old population. The aims of this study were to characterize balance control, functional abilities, and balance self-efficacy in the oldest-old, to test the correlations between these constructs, and to explore differences between fallers and nonfallers in this age group. Forty-five individuals living in an assisted living facility who ambulated independently participated in the study. The mean age was 90.3 (3.7) years. Function was tested using the Late-Life Function and Disability Instrument (LLFDI). Balance was tested with the mini-Balance Evaluation System Test (mini-BESTest) and the Timed Up and Go (TUG) test. Balance self-efficacy was tested with the Activities-Specific Balance Confidence (ABC) scale. The mean total function LLFDI score was 63.2 (11.4). The mean mini-BESTest score was 69.8% (18.6%) and the mean TUG time was 12.6 (6.9) seconds. The mean ABC score was 80.2% (14.2%). Good correlation (r > 0.7) was observed between the ABC and the function component of the LLFDI, as well as with the lower extremity domains. Correlations between the mini-BESTest scores and the LLFDI were fair to moderate (r's range: 0.38-0.62). Age and ABC scores were significant independent explanators of LLFDI score (P = .0141 and P = .0009, respectively). Fallers and nonfallers differed significantly across all outcome measures scores, except for TUG and for the "Reactive Postural Control" and "Sensory Orientation" domains of the mini-BESTest. The results of this study provide normative data regarding the balance and functional abilities of the oldest-old, and indicate a strong association between self-efficacy and function. These results emphasize the importance of incorporating strategies that maintain and improve balance self-efficacy in interventions aimed at enhancing the functional level of this cohort.

Effects of a program of cognitive-behavioural group therapy, vestibular rehabilitation, and psychoeducational explanations on patients with dizziness and no quantified balance deficit, compared to patients with dizziness and a quantified balance deficit.

PubMed

Schmid, D A; Allum, J H J; Sleptsova, M; Gross, S; Gaab, J; Welge-Lüssen, A; Schaefert, R; Langewitz, W

2018-02-01

We examined whether a program combining cognitive-behavioural therapy (CBT), vestibular rehabilitation (VR) and psychoeducation is equally effective in improving psychometric measures in patients with dizziness independent of a balance deficit. Measures of patients with dizziness only (DO) were compared to those of patients also having a quantified balance deficit (QBD). 32 patients (23 female, 9 male) with persistent dizziness were analysed as 2 groups based on stance and gait balance control: those with QBD (pathological balance) or DO (normal balance). Dizziness Handicap Inventory (DHI) and Brief Symptom Inventory (BSI) questionnaires were used pre- and post-therapy to assess psychometric measures. Patients then received the same combination therapy in a group setting. The QBD group mean age was 60.6, SD 8.3, and DO group mean age 44.8, SD 12.1, years. Pre-therapy, questionnaire scores were pathological but not different between groups. Balance improved significantly for the QBD group (p=0.003) but not for the DO group. DHI and BSI scores improved significantly in the DO group (0.001

Recovery of balance function among individuals with total knee arthroplasty: Comparison of responsiveness among four balance tests.

PubMed

Chan, Andy C M; Ouyang, Xi H; Jehu, Deborah A M; Chung, Raymond C K; Pang, Marco Y C

2018-01-01

Balance deficits are common after total knee arthroplasty (TKA); however the responsiveness of commonly used balance measurement tools has not been well defined. The objective of this prospective study was to compare the internal and external responsiveness of four measurement tools in assessing recovery of balance function following TKA. A total of 134 individuals with TKA (95 women; age: 66.3±6.6years) completed the Balance Evaluation Systems Test (BESTest), Mini-BESTest, Brief-BESTest, and Berg Balance Scale (BBS) at 2, 4, 8, 12, and 24 weeks post-TKA. The Functional Gait Assessment (FGA) served as the anchor measure, and was also measured across these time points. Internal responsiveness was indicated by the standardized response mean (SRM), while external responsiveness was reflected by the degree of association of the changes of balance scores with those of FGA. The SRM ranged from 0.60-1.14 for the BESTest, 0.40-0.94 for the Mini-BESTest, 0.27-0.91 for the Brief-BESTest, and 0.19-0.70 for the BBS, over time. The change in BESTest and Mini-BESTest scores predicted the change in the FGA scores across all time periods, except for the Mini-BESTest between weeks 12-24, accounting for 13-27%, and 12-24% of the variance, respectively. The Brief-BESTest scores only predicted FGA scores between the weeks 2-4 (R 2 =20%). The changes in BBS scores were not associated with the FGA. The BESTest is the most responsive in measuring recovery of balance among individuals with TKA. The Mini-BESTest is a reasonable option during time constraints. Copyright © 2017. Published by Elsevier B.V.

Graduate Students' Administration and Scoring Errors on the Woodcock-Johnson III Tests of Cognitive Abilities

ERIC Educational Resources Information Center

Ramos, Erica; Alfonso, Vincent C.; Schermerhorn, Susan M.

2009-01-01

The interpretation of cognitive test scores often leads to decisions concerning the diagnosis, educational placement, and types of interventions used for children. Therefore, it is important that practitioners administer and score cognitive tests without error. This study assesses the frequency and types of examiner errors that occur during the…

Psychometric properties for the Balanced Inventory of Desirable Responding: dichotomous versus polytomous conventional and IRT scoring.

PubMed

Vispoel, Walter P; Kim, Han Yi

2014-09-01

[Correction Notice: An Erratum for this article was reported in Vol 26(3) of Psychological Assessment (see record 2014-16017-001). The mean, standard deviation and alpha coefficient originally reported in Table 1 should be 74.317, 10.214 and .802, respectively. The validity coefficients in the last column of Table 4 are affected as well. Correcting this error did not change the substantive interpretations of the results, but did increase the mean, standard deviation, alpha coefficient, and validity coefficients reported for the Honesty subscale in the text and in Tables 1 and 4. The corrected versions of Tables 1 and Table 4 are shown in the erratum.] Item response theory (IRT) models were applied to dichotomous and polytomous scoring of the Self-Deceptive Enhancement and Impression Management subscales of the Balanced Inventory of Desirable Responding (Paulhus, 1991, 1999). Two dichotomous scoring methods reflecting exaggerated endorsement and exaggerated denial of socially desirable behaviors were examined. The 1- and 2-parameter logistic models (1PLM, 2PLM, respectively) were applied to dichotomous responses, and the partial credit model (PCM) and graded response model (GRM) were applied to polytomous responses. For both subscales, the 2PLM fit dichotomous responses better than did the 1PLM, and the GRM fit polytomous responses better than did the PCM. Polytomous GRM and raw scores for both subscales yielded higher test-retest and convergent validity coefficients than did PCM, 1PLM, 2PLM, and dichotomous raw scores. Information plots showed that the GRM provided consistently high measurement precision that was superior to that of all other IRT models over the full range of both construct continuums. Dichotomous scores reflecting exaggerated endorsement of socially desirable behaviors provided noticeably weak precision at low levels of the construct continuums, calling into question the use of such scores for detecting instances of "faking bad." Dichotomous models reflecting exaggerated denial of the same behaviors yielded much better precision at low levels of the constructs, but it was still less precision than that of the GRM. These results support polytomous over dichotomous scoring in general, alternative dichotomous scoring for detecting faking bad, and extension of GRM scoring to situations in which IRT offers additional practical advantages over classical test theory (adaptive testing, equating, linking, scaling, detecting differential item functioning, and so forth). PsycINFO Database Record (c) 2014 APA, all rights reserved.

Impairment of perception and recognition of faces, mimic expression and gestures in schizophrenic patients.

PubMed

Berndl, K; von Cranach, M; Grüsser, O J

1986-01-01

The perception and recognition of faces, mimic expression and gestures were investigated in normal subjects and schizophrenic patients by means of a movie test described in a previous report (Berndl et al. 1986). The error scores were compared with results from a semi-quantitative evaluation of psychopathological symptoms and with some data from the case histories. The overall error scores found in the three groups of schizophrenic patients (paranoic, hebephrenic, schizo-affective) were significantly increased (7-fold) over those of normals. No significant difference in the distribution of the error scores in the three different patient groups was found. In 10 different sub-tests following the movie the deficiencies found in the schizophrenic patients were analysed in detail. The error score for the averbal test was on average higher in paranoic patients than in the two other groups of patients, while the opposite was true for the error scores found in the verbal tests. Age and sex had some impact on the test results. In normals, female subjects were somewhat better than male. In schizophrenic patients the reverse was true. Thus female patients were more affected by the disease than male patients with respect to the task performance. The correlation between duration of the disease and error score was small; less than 10% of the error scores could be attributed to factors related to the duration of illness. Evaluation of psychopathological symptoms indicated that the stronger the schizophrenic defect, the higher the error score, but again this relationship was responsible for not more than 10% of the errors. The estimated degree of acute psychosis and overall sum of psychopathological abnormalities as scored in a semi-quantitative exploration did not correlate with the error score, but with each other. Similarly, treatment with psychopharmaceuticals, previous misuse of drugs or of alcohol had practically no effect on the outcome of the test data. The analysis of performance and test data of schizophrenic patients indicated that our findings are most likely not due to a "non-specific" impairment of cognitive function in schizophrenia, but point to a fairly selective defect in elementary cognitive visual functions necessary for averbal social communication. Some possible explanations of the data are discussed in relation to neuropsychological and neurophysiological findings on "face-specific" cortical areas located in the primate temporal lobe.

Balance and ankle range of motion in community-dwelling women aged 64 to 87 years: a correlational study.

PubMed

Mecagni, C; Smith, J P; Roberts, K E; O'Sullivan, S B

2000-10-01

This study investigated the relationship between balance measures and ankle range of motion (ROM) in community-dwelling elderly women with no health problems. Identification of modifiable factors associated with balance may enable clinicians to design treatments to help reduce the risk of falls in elderly people. The sample consisted of 34 women between the ages of 64 and 87 years (mean=74.7, SD=6.0). Goniometry was used to determine bilateral ankle active-assistive range of motion (AAROM) and passive range of motion. Balance capabilities were measured with the Functional Reach Test (FRT) and the Tinetti Performance-Oriented Mobility Assessment (POMA). Balance data for the FRT, POMA balance subtest, POMA gait subtest, and POMA total score were correlated with ankle ROM using the Pearson product moment correlation coefficient (PCC). Correlations between ROM and balance scores were found, ranging from.29 to.63. The POMA gait subtest and FRT resulted in higher correlations with ROM than did the POMA balance subtest (left total AAROM PCC=.63,.51, and.31). Correlations using composite ankle ROM scores were higher than individual motions. The strongest correlation existed between bilateral, total ankle AAROM and the POMA gait subtest scores (PCC=. 63) Correlations exist between ankle ROM and balance in community-dwelling elderly women. Additional research is needed to determine whether treatment directed at increasing ankle ROM can improve balance.

Error field detection in DIII-D by magnetic steering of locked modes

DOE PAGES

Shiraki, Daisuke; La Haye, Robert J.; Logan, Nikolas C.; ...

2014-02-20

Optimal correction coil currents for the n = 1 intrinsic error field of the DIII-D tokamak are inferred by applying a rotating external magnetic perturbation to steer the phase of a saturated locked mode with poloidal/toroidal mode number m/n = 2/1. The error field is detected non-disruptively in a single discharge, based on the toroidal torque balance of the resonant surface, which is assumed to be dominated by the balance of resonant electromagnetic torques. This is equivalent to the island being locked at all times to the resonant 2/1 component of the total of the applied and intrinsic error fields,more » such that the deviation of the locked mode phase from the applied field phase depends on the existing error field. The optimal set of correction coil currents is determined to be those currents which best cancels the torque from the error field, based on fitting of the torque balance model. The toroidal electromagnetic torques are calculated from experimental data using a simplified approach incorporating realistic DIII-D geometry, and including the effect of the plasma response on island torque balance based on the ideal plasma response to external fields. This method of error field detection is demonstrated in DIII-D discharges, and the results are compared with those based on the onset of low-density locked modes in ohmic plasmas. Furthermore, this magnetic steering technique presents an efficient approach to error field detection and is a promising method for ITER, particularly during initial operation when the lack of auxiliary heating systems makes established techniques based on rotation or plasma amplification unsuitable.« less

Testing Intelligently Includes Double-Checking Wechsler IQ Scores

ERIC Educational Resources Information Center

Kuentzel, Jeffrey G.; Hetterscheidt, Lesley A.; Barnett, Douglas

2011-01-01

The rigors of standardized testing make for numerous opportunities for examiner error, including simple computational mistakes in scoring. Although experts recommend that test scoring be double-checked, the extent to which independent double-checking would reduce scoring errors is not known. A double-checking procedure was established at a…

Validation of the Narrowing Beam Walking Test in Lower Limb Prosthesis Users.

PubMed

Sawers, Andrew; Hafner, Brian

2018-04-11

To evaluate the content, construct, and discriminant validity of the Narrowing Beam Walking Test (NBWT), a performance-based balance test for lower limb prosthesis users. Cross-sectional study. Research laboratory and prosthetics clinic. Unilateral transtibial and transfemoral prosthesis users (N=40). Not applicable. Content validity was examined by quantifying the percentage of participants receiving maximum or minimum scores (ie, ceiling and floor effects). Convergent construct validity was examined using correlations between participants' NBWT scores and scores or times on existing clinical balance tests regularly administered to lower limb prosthesis users. Known-groups construct validity was examined by comparing NBWT scores between groups of participants with different fall histories, amputation levels, amputation etiologies, and functional levels. Discriminant validity was evaluated by analyzing the area under each test's receiver operating characteristic (ROC) curve. No minimum or maximum scores were recorded on the NBWT. NBWT scores demonstrated strong correlations (ρ=.70‒.85) with scores/times on performance-based balance tests (timed Up and Go test, Four Square Step Test, and Berg Balance Scale) and a moderate correlation (ρ=.49) with the self-report Activities-specific Balance Confidence scale. NBWT performance was significantly lower among participants with a history of falls (P=.003), transfemoral amputation (P=.011), and a lower mobility level (P<.001). The NBWT also had the largest area under the ROC curve (.81) and was the only test to exhibit an area that was statistically significantly >.50 (ie, chance). The results provide strong evidence of content, construct, and discriminant validity for the NBWT as a performance-based test of balance ability. The evidence supports its use to assess balance impairments and fall risk in unilateral transtibial and transfemoral prosthesis users. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Understanding seasonal variability of uncertainty in hydrological prediction

NASA Astrophysics Data System (ADS)

Li, M.; Wang, Q. J.

2012-04-01

Understanding uncertainty in hydrological prediction can be highly valuable for improving the reliability of streamflow prediction. In this study, a monthly water balance model, WAPABA, in a Bayesian joint probability with error models are presented to investigate the seasonal dependency of prediction error structure. A seasonal invariant error model, analogous to traditional time series analysis, uses constant parameters for model error and account for no seasonal variations. In contrast, a seasonal variant error model uses a different set of parameters for bias, variance and autocorrelation for each individual calendar month. Potential connection amongst model parameters from similar months is not considered within the seasonal variant model and could result in over-fitting and over-parameterization. A hierarchical error model further applies some distributional restrictions on model parameters within a Bayesian hierarchical framework. An iterative algorithm is implemented to expedite the maximum a posterior (MAP) estimation of a hierarchical error model. Three error models are applied to forecasting streamflow at a catchment in southeast Australia in a cross-validation analysis. This study also presents a number of statistical measures and graphical tools to compare the predictive skills of different error models. From probability integral transform histograms and other diagnostic graphs, the hierarchical error model conforms better to reliability when compared to the seasonal invariant error model. The hierarchical error model also generally provides the most accurate mean prediction in terms of the Nash-Sutcliffe model efficiency coefficient and the best probabilistic prediction in terms of the continuous ranked probability score (CRPS). The model parameters of the seasonal variant error model are very sensitive to each cross validation, while the hierarchical error model produces much more robust and reliable model parameters. Furthermore, the result of the hierarchical error model shows that most of model parameters are not seasonal variant except for error bias. The seasonal variant error model is likely to use more parameters than necessary to maximize the posterior likelihood. The model flexibility and robustness indicates that the hierarchical error model has great potential for future streamflow predictions.

Analytic score distributions for a spatially continuous tridirectional Monte Carol transport problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Booth, T.E.

1996-01-01

The interpretation of the statistical error estimates produced by Monte Carlo transport codes is still somewhat of an art. Empirically, there are variance reduction techniques whose error estimates are almost always reliable, and there are variance reduction techniques whose error estimates are often unreliable. Unreliable error estimates usually result from inadequate large-score sampling from the score distribution`s tail. Statisticians believe that more accurate confidence interval statements are possible if the general nature of the score distribution can be characterized. Here, the analytic score distribution for the exponential transform applied to a simple, spatially continuous Monte Carlo transport problem is provided.more » Anisotropic scattering and implicit capture are included in the theory. In large part, the analytic score distributions that are derived provide the basis for the ten new statistical quality checks in MCNP.« less

Relationship Between Cognitive Assessment and Balance Measures in Adolescents Referred for Vestibular Physical Therapy After Concussion

PubMed Central

Alsalaheen, Bara A.; Whitney, Susan L.; Marchetti, Gregory F.; Furman, Joseph M.; Kontos, Anthony P.; Collins, Michael W.; Sparto, Patrick J.

2016-01-01

Objective To examine the relationship between cognitive and balance performance in adolescents with concussion. Design Retrospective case series. Setting Tertiary. Patients Sixty patients. Interventions Correlation analyses were performed to describe the relationship between symptoms, cognitive measure, and balance measure at the time of initiation of vestibular physical therapy. Main Outcome Measures Cognitive performance was assessed using the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT). The dizziness and balance function measures included dizziness severity rating, Activities-specific Balance Confidence scale (ABC), Dizziness Handicap Inventory (DHI), Functional Gait Assessment, gait speed, Timed “UP and GO,” Five Times Sit to Stand, and Sensory Organization Test (SOT). To account for multiple comparisons, the False Discovery Rate method was used. Results Performance measures of balance were significantly correlated with cognitive measures. Greater total symptom scores were related to greater impairment in the ABC and DHI (r = 0.35-0.39, P ≤ 0.008) and worse performance in condition 2 of the SOT (r = −0.48, P = 0.004). Among the ImPACT composite scores, lower memory scores were correlated with impaired balance performance measures (r = 0.37-0.59, P ≤ 0.012). Lower visual memory was also correlated with worse ABC scores. Conclusions The significant relationships reported between the cognitive performance scores and balance measures may reflect that similar levels of functioning exist across domains in individuals with protracted recovery who receive vestibular physical therapy. PMID:25706663

Interactive Sensor-Based Balance Training in Older Cancer Patients with Chemotherapy-Induced Peripheral Neuropathy: A Randomized Controlled Trial.

PubMed

Schwenk, Michael; Grewal, Gurtej S; Holloway, Dustin; Muchna, Amy; Garland, Linda; Najafi, Bijan

2016-01-01

Cancer patients with chemotherapy-induced peripheral neuropathy (CIPN) have deficits in sensory and motor skills leading to inappropriate proprioceptive feedback, impaired postural control, and fall risk. Balance training programs specifically developed for CIPN patients are lacking. This pilot study investigated the effect of an interactive motor adaptation balance training program based on wearable sensors for improving balance in older cancer patients with CIPN. Twenty-two patients (age: 70.3 ± 8.7 years) with objectively confirmed CIPN [vibration perception threshold (VPT) >25 V] were randomized to either an intervention (IG) or a control (CG) group. The IG received interactive game-based balance training including repetitive weight shifting and virtual obstacle crossing tasks. Wearable sensors provided real-time visual/auditory feedback from the lower limb trajectory and allowed the perception of motor errors during each motor action. The CG received no exercise intervention and continued their normal activity. Outcome measures were changes in sway of ankle, hip, and center of mass (CoM) in both mediolateral and anteroposterior (AP) directions during 30-second balance tests with increasing task difficulty [i.e. standing in feet-closed position with eyes open (EO) and eyes closed (EC), and in semi-tandem position with EO] at baseline and after the intervention. Additionally, gait performance (speed, variability) and fear of falling [Falls Efficacy Scale-International (FES-I)] were measured. Training was safe despite the participants' impaired health status, great severity of CIPN (VPT 49.6 ± 26.7 V), and great fear of falling (FES-I score 31.37 ± 11.20). After the intervention, sway of hip, ankle, and CoM was significantly reduced in the IG compared to the CG while standing in feet-closed position with EO (p = 0.010-0.022, except AP CoM sway) and in semi-tandem position (p = 0.008-0.035, except ankle sway). No significant effects were found for balance with EC, gait speed, and FES-I score (p > 0.05). This proof-of-concept study demonstrates that older cancer patients with CIPN can significantly improve their postural balance with specifically tailored, sensor-based exercise training. The training approach has potential as a therapy for improving CIPN-related postural control deficits. However, future studies comparing the proposed technology-based training with traditional balance training are required to evaluate the benefit of the interactive joint movement feedback. © 2015 S. Karger AG, Basel.

Improvements in Orientation and Balancing Abilities in Response to One Month of Intensive Slackline-Training. A Randomized Controlled Feasibility Study.

PubMed

Dordevic, Milos; Hökelmann, Anita; Müller, Patrick; Rehfeld, Kathrin; Müller, Notger G

2017-01-01

Background: Slackline-training has been shown to improve mainly task-specific balancing skills. Non-task specific effects were assessed for tandem stance and preferred one-leg stance on stable and perturbed force platforms with open eyes. It is unclear whether transfer effects exist for other balancing conditions and which component of the balancing ability is affected. Also, it is not known whether slackline-training can improve non-visual-dependent spatial orientation abilities, a function mainly supported by the hippocampus. Objective: To assess the effect of one-month of slackline-training on different components of balancing ability and its transfer effects on non-visual-dependent spatial orientation abilities. Materials and Methods: Fifty subjects aged 18-30 were randomly assigned to the training group (T) ( n = 25, 23.2 ± 2.5 years; 12 females) and the control group (C) ( n = 25, 24.4 ± 2.8 years; 11 females). Professional instructors taught the intervention group to slackline over four consecutive weeks with three 60-min-trainings in each week. Data acquisition was performed (within 2 days) by blinded investigators at the baseline and after the training. Main outcomes Improvement in the score of a 30-item clinical balance test (CBT) developed at our institute (max. score = 90 points) and in the average error distance (in centimeters) in an orientation test (OT), a triangle completion task with walking and wheelchair conditions for 60°, 90°, and 120°. Results: Training group performed significantly better on the closed-eyes conditions of the CBT (1.6 points, 95% CI: 0.6 to 2.6 points vs. 0.1 points, 95% CI: -1 to 1.1 points; p = 0.011, [Formula: see text] = 0.128) and in the wheelchair (vestibular) condition of the OT (21 cm, 95% CI: 8-34 cm vs. 1 cm, 95% CI: -14-16 cm; p = 0.049, [Formula: see text] = 0.013). Conclusion: Our results indicate that one month of intensive slackline training is a novel approach for enhancing clinically relevant balancing abilities in conditions with closed eyes as well as for improving the vestibular-dependent spatial orientation capability; both of the benefits are likely caused by positive influence of slackline-training on the vestibular system function.

Improvements in Orientation and Balancing Abilities in Response to One Month of Intensive Slackline-Training. A Randomized Controlled Feasibility Study

PubMed Central

Dordevic, Milos; Hökelmann, Anita; Müller, Patrick; Rehfeld, Kathrin; Müller, Notger G.

2017-01-01

Background: Slackline-training has been shown to improve mainly task-specific balancing skills. Non-task specific effects were assessed for tandem stance and preferred one-leg stance on stable and perturbed force platforms with open eyes. It is unclear whether transfer effects exist for other balancing conditions and which component of the balancing ability is affected. Also, it is not known whether slackline-training can improve non-visual-dependent spatial orientation abilities, a function mainly supported by the hippocampus. Objective: To assess the effect of one-month of slackline-training on different components of balancing ability and its transfer effects on non-visual-dependent spatial orientation abilities. Materials and Methods: Fifty subjects aged 18–30 were randomly assigned to the training group (T) (n = 25, 23.2 ± 2.5 years; 12 females) and the control group (C) (n = 25, 24.4 ± 2.8 years; 11 females). Professional instructors taught the intervention group to slackline over four consecutive weeks with three 60-min-trainings in each week. Data acquisition was performed (within 2 days) by blinded investigators at the baseline and after the training. Main outcomes Improvement in the score of a 30-item clinical balance test (CBT) developed at our institute (max. score = 90 points) and in the average error distance (in centimeters) in an orientation test (OT), a triangle completion task with walking and wheelchair conditions for 60°, 90°, and 120°. Results: Training group performed significantly better on the closed-eyes conditions of the CBT (1.6 points, 95% CI: 0.6 to 2.6 points vs. 0.1 points, 95% CI: –1 to 1.1 points; p = 0.011, ηp2 = 0.128) and in the wheelchair (vestibular) condition of the OT (21 cm, 95% CI: 8–34 cm vs. 1 cm, 95% CI: –14–16 cm; p = 0.049, ηp2 = 0.013). Conclusion: Our results indicate that one month of intensive slackline training is a novel approach for enhancing clinically relevant balancing abilities in conditions with closed eyes as well as for improving the vestibular-dependent spatial orientation capability; both of the benefits are likely caused by positive influence of slackline-training on the vestibular system function. PMID:28239345

The Role of Cognitive Factors in Predicting Balance and Fall Risk in a Neuro-Rehabilitation Setting.

PubMed

Saverino, A; Waller, D; Rantell, K; Parry, R; Moriarty, A; Playford, E D

2016-01-01

There is a consistent body of evidence supporting the role of cognitive functions, particularly executive function, in the elderly and in neurological conditions which become more frequent with ageing. The aim of our study was to assess the role of different domains of cognitive functions to predict balance and fall risk in a sample of adults with various neurological conditions in a rehabilitation setting. This was a prospective, cohort study conducted in a single centre in the UK. 114 participants consecutively admitted to a Neuro-Rehabilitation Unit were prospectively assessed for fall accidents. Baseline assessment included a measure of balance (Berg Balance Scale) and a battery of standard cognitive tests measuring executive function, speed of information processing, verbal and visual memory, visual perception and intellectual function. The outcomes of interest were the risk of becoming a faller, balance and fall rate. Two tests of executive function were significantly associated with fall risk, the Stroop Colour Word Test (IRR 1.01, 95% CI 1.00-1.03) and the number of errors on part B of the Trail Making Test (IRR 1.23, 95% CI 1.03-1.49). Composite scores of executive function, speed of information processing and visual memory domains resulted in 2 to 3 times increased likelihood of having better balance (OR 2.74 95% CI 1.08 to 6.94, OR 2.72 95% CI 1.16 to 6.36 and OR 2.44 95% CI 1.11 to 5.35 respectively). Our results show that specific subcomponents of executive functions are able to predict fall risk, while a more global cognitive dysfunction is associated with poorer balance.

The Role of Cognitive Factors in Predicting Balance and Fall Risk in a Neuro-Rehabilitation Setting

PubMed Central

Saverino, A.; Waller, D.; Rantell, K.; Parry, R.; Moriarty, A.; Playford, E. D.

2016-01-01

Introduction There is a consistent body of evidence supporting the role of cognitive functions, particularly executive function, in the elderly and in neurological conditions which become more frequent with ageing. The aim of our study was to assess the role of different domains of cognitive functions to predict balance and fall risk in a sample of adults with various neurological conditions in a rehabilitation setting. Methods This was a prospective, cohort study conducted in a single centre in the UK. 114 participants consecutively admitted to a Neuro-Rehabilitation Unit were prospectively assessed for fall accidents. Baseline assessment included a measure of balance (Berg Balance Scale) and a battery of standard cognitive tests measuring executive function, speed of information processing, verbal and visual memory, visual perception and intellectual function. The outcomes of interest were the risk of becoming a faller, balance and fall rate. Results Two tests of executive function were significantly associated with fall risk, the Stroop Colour Word Test (IRR 1.01, 95% CI 1.00–1.03) and the number of errors on part B of the Trail Making Test (IRR 1.23, 95% CI 1.03–1.49). Composite scores of executive function, speed of information processing and visual memory domains resulted in 2 to 3 times increased likelihood of having better balance (OR 2.74 95% CI 1.08 to 6.94, OR 2.72 95% CI 1.16 to 6.36 and OR 2.44 95% CI 1.11 to 5.35 respectively). Conclusions Our results show that specific subcomponents of executive functions are able to predict fall risk, while a more global cognitive dysfunction is associated with poorer balance. PMID:27115880

The Relationship Between Balance Measured With a Modified Bathroom Scale and Falls and Disability in Older Adults: A 6-Month Follow-Up Study

PubMed Central

2015-01-01

Background There are indications that older adults who suffer from poor balance have an increased risk for adverse health outcomes, such as falls and disability. Monitoring the development of balance over time enables early detection of balance decline, which can identify older adults who could benefit from interventions aimed at prevention of these adverse outcomes. An innovative and easy-to-use device that can be used by older adults for home-based monitoring of balance is a modified bathroom scale. Objective The objective of this paper is to study the relationship between balance scores obtained with a modified bathroom scale and falls and disability in a sample of older adults. Methods For this 6-month follow-up study, participants were recruited via physiotherapists working in a nursing home, geriatricians, exercise classes, and at an event about health for older adults. Inclusion criteria were being aged 65 years or older, being able to stand on a bathroom scale independently, and able to provide informed consent. A total of 41 nursing home patients and 139 community-dwelling older adults stepped onto the modified bathroom scale three consecutive times at baseline to measure their balance. Their mean balance scores on a scale from 0 to 16 were calculated—higher scores indicated better balance. Questionnaires were used to study falls and disability at baseline and after 6 months of follow-up. The cross-sectional relationship between balance and falls and disability at baseline was studied using t tests and Spearman rank correlations. Univariate and multivariate logistic regression analyses were conducted to study the relationship between balance measured at baseline and falls and disability development after 6 months of follow-up. Results A total of 128 participants with complete datasets—25.8% (33/128) male—and a mean age of 75.33 years (SD 6.26) were included in the analyses of this study. Balance scores of participants who reported at baseline that they had fallen at least once in the past 6 months were lower compared to nonfallers—8.9 and 11.2, respectively (P<.001). The correlation between mean balance score and disability sum-score at baseline was -.51 (P<.001). No significant associations were found between balance at baseline and falls after 6 months of follow-up. Baseline balance scores were significantly associated with the development of disability after 6 months of follow-up in the univariate analysis—odds ratio (OR) 0.86 (95% CI 0.76-0.98)—but not in the multivariate analysis when correcting for age, gender, baseline disability, and falls at follow-up—OR 0.94 (95% CI 0.79-1.11). Conclusions There is a cross-sectional relationship between balance measured by a modified bathroom scale and falls and disability in older adults. Despite this cross-sectional relationship, longitudinal data showed that balance scores have no predictive value for falls and might only have limited predictive value for disability development after 6 months of follow-up. PMID:26018423

40 CFR 1045.730 - What ABT reports must I send to EPA?

Code of Federal Regulations, 2010 CFR

2010-07-01

... volumes for the model year with a point of retail sale in the United States, as described in § 1045.701(j...) Show that your net balance of emission credits from all your participating families in each averaging... errors mistakenly decreased your balance of emission credits, you may correct the errors and recalculate...

40 CFR 1051.730 - What ABT reports must I send to EPA?

Code of Federal Regulations, 2010 CFR

2010-07-01

... the model year with a point of retail sale in the United States, as described in § 1051.701(d). For... following additional information: (1) Show that your net balance of emission credits in each averaging set... that errors mistakenly decreased your balance of emission credits, you may correct the errors and...

Soil moisture assimilation using a modified ensemble transform Kalman filter with water balance constraint

NASA Astrophysics Data System (ADS)

Wu, Guocan; Zheng, Xiaogu; Dan, Bo

2016-04-01

The shallow soil moisture observations are assimilated into Common Land Model (CoLM) to estimate the soil moisture in different layers. The forecast error is inflated to improve the analysis state accuracy and the water balance constraint is adopted to reduce the water budget residual in the assimilation procedure. The experiment results illustrate that the adaptive forecast error inflation can reduce the analysis error, while the proper inflation layer can be selected based on the -2log-likelihood function of the innovation statistic. The water balance constraint can result in reducing water budget residual substantially, at a low cost of assimilation accuracy loss. The assimilation scheme can be potentially applied to assimilate the remote sensing data.

Balance Training with Wii Fit Plus for Community-Dwelling Persons 60 Years and Older.

PubMed

Roopchand-Martin, Sharmella; McLean, Roshé; Gordon, Carron; Nelson, Gail

2015-06-01

This study sought to determine the effect of 6 weeks of training, using activities from the Nintendo(®) (Kyoto, Japan) "Wii™ Fit Plus" disc, on balance in community-dwelling Jamaicans 60 years and older. A single group pretest/posttest design was used. Thirty-three subjects enrolled and 28 completed the study. Participants completed 30-minute training sessions on the Nintendo "Wii Fit" twice per week for 6 weeks. Activities used included "Obstacle Course," "Penguin Slide," "Soccer Heading," "River Bubble," "Snow Board," "Tilt Table," "Skate Board," and "Yoga Single Tree Pose." Balance was assessed with the Berg Balance Scale, the Multi Directional Reach Test, the Star Excursion Balance Test and the Modified Clinical Test for Sensory Integration in Balance. There was significant improvement in the mean Berg Balance Scale score (P=0.004), Star Excursion Balance Test score (SEBT) (P<0.001 both legs), and Multi Directional Reach Test score (P=0.002). There was no significant change on the Modified Clinical Test for Sensory Integration in Balance. Balance games on the Nintendo "Wii Fit Plus" disc can be used as a tool for balance training in community-dwelling persons 60 years of age and older.

Fear of falling, balance confidence and health-related quality of life in individuals with postpolio syndrome.

PubMed

Legters, Kristine; Verbus, Nicole Barber; Kitchen, Sara; Tomecsko, Jennifer; Urban, Nicole

2006-06-01

The purposes of this study were to examine prevalence of fear of falling (FOF) and decreased balance confidence in individuals with postpolio syndrome (PPS) and to determine whether balance confidence was correlated with health-related quality of life (HRQOL) in this population. A survey, which included demographic questions, the Activities-specific Balance Confidence (ABC) Scale, and the MOS SF-36v2, was made available by mail and electronically to individuals with PPS. Descriptive and correlation statistics were used to analyze the responses. Fear of falling was reported in 95% of respondents, with 80% indicating that FOF affected their quality of life. Median ABC score (42 of 100), physical component score (27 of 100), and mental component score (47 of 100) were below average compared with the general population. A moderate correlation (r = 0.4; p < 0.001) was found between balance confidence and the physical component score of HRQOL in PPS. There was an overwhelming presence of FOF and severely impaired balance confidence in the majority of those with PPS. A fair correlation between the physical functioning component of HRQOL and balance confidence was noted in this population.

Pyrometer with tracking balancing

NASA Astrophysics Data System (ADS)

Ponomarev, D. B.; Zakharenko, V. A.; Shkaev, A. G.

2018-04-01

Currently, one of the main metrological noncontact temperature measurement challenges is the emissivity uncertainty. This paper describes a pyrometer with emissivity effect diminishing through the use of a measuring scheme with tracking balancing in which the radiation receiver is a null-indicator. In this paper the results of the prototype pyrometer absolute error study in surfaces temperature measurement of aluminum and nickel samples are presented. There is absolute error calculated values comparison considering the emissivity table values with errors on the results of experimental measurements by the proposed method. The practical implementation of the proposed technical solution has allowed two times to reduce the error due to the emissivity uncertainty.

Confidence Intervals for Weighted Composite Scores under the Compound Binomial Error Model

ERIC Educational Resources Information Center

Kim, Kyung Yong; Lee, Won-Chan

2018-01-01

Reporting confidence intervals with test scores helps test users make important decisions about examinees by providing information about the precision of test scores. Although a variety of estimation procedures based on the binomial error model are available for computing intervals for test scores, these procedures assume that items are randomly…

Determinants of sport-specific postural control strategy and balance performance of amateur rugby players.

PubMed

Chow, Gary C C; Fong, Shirley S M; Chung, Joanne W Y; Chung, Louisa M Y; Ma, Ada W W; Macfarlane, Duncan J

2016-11-01

Postural control strategy and balance performance of rugby players are important yet under-examined issues. This study aimed to examine the differences in balance strategy and balance performance between amateur rugby players and non-players, and to explore training- and injury-related factors that may affect rugby players' balance outcomes. Cross-sectional and exploratory study. Forty-five amateur rugby players and 41 healthy active individuals participated in the study. Balance performance and balance strategies were assessed using the sensory organization test (SOT) of the Smart Equitest computerized dynamic posturography machine. Rugby training history and injury history were solicited from the participants. The SOT strategy scores were 1.99-54.90% lower in the rugby group than in the control group (p<0.05), and the equilibrium scores were 1.06-14.29% lower in the rugby group than in the control group (p<0.05). After accounting for age, sex and body mass index, only length of rugby training (in years) was independently associated with the SOT condition 6 strategy score, explaining 15.7% of its variance (p=0.006). There was no association between SOT condition 6 strategy/equilibrium scores and injury history among the rugby players (p>0.05). Amateur rugby players demonstrated inferior balance strategy and balance performance compared to their non-training counterparts. Their suboptimal balance strategy was associated with insufficient training experience but not with history of injury. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Can weighing lysimeter ET represent surrounding field ET well enough to test flux station measurements of daily and sub-daily ET?

USDA-ARS?s Scientific Manuscript database

Weighing lysimeters and neutron probes are two tools used to determine the change in soil water storage that is needed to solve for evapotranspiration (ET) using the soil water balance equation. Errors in the soil water balance due to errors in determination of precipitation and irrigation are commo...

Gait and balance deterioration over a 12-month period in multiple sclerosis patients with EDSS scores ≤ 3.0.

PubMed

Galea, Mary P; Cofré Lizama, L Eduardo; Butzkueven, Helmut; Kilpatrick, Trevor J

2017-01-01

It is not currently known whether gait and balance measures are responsive to deterioration of motor function in multiple sclerosis (MS) patients with low EDSS scores (≤3.0). The aim of this study was to quantify MS-related gait and balance deterioration over a 12-month period. Thirty-eight participants with MS (33 female, mean age: 41.1 ± 8.3 years), mean time since diagnosis 2.2 ± 4.1 years, EDSS score ≤3.0 and without clinical evidence of gait deterioration, were recruited. Participants performed walking trials and Functional and Lateral Reach Tests. Kinematics of the ankle and knee, and electromyography of the tibialis anterior and medial gastrocnemius muscles were also measured. Three participants reported relapses with worsening EDSS scores and 4 non-relapsing participants had worse EDSS scores at 12 months. There were significant decreases in mean gait speed, stride length and balance scores, and a significant increase in double support. Marked changes in ankle kinematics, with decreased medial gastrocnemius activity were observed. Gait and balance performance of non-disabled RRMS participants may progressively decline, even in the absence of both acute clinical relapse and change in clinical status measured by the EDSS.

WISC-R Examiner Errors: Cause for Concern.

ERIC Educational Resources Information Center

Slate, John R.; Chick, David

1989-01-01

Clinical psychology graduate students (N=14) administered Wechsler Intelligence Scale for Children-Revised. Found numerous scoring and mechanical errors that influenced full-scale intelligence quotient scores on two-thirds of protocols. Particularly prone to error were Verbal subtests of Vocabulary, Comprehension, and Similarities. Noted specific…

Relationship of the functional movement screen in-line lunge to power, speed, and balance measures.

PubMed

Hartigan, Erin H; Lawrence, Michael; Bisson, Brian M; Torgerson, Erik; Knight, Ryan C

2014-05-01

The in-line lunge of the Functional Movement Screen (FMS) evaluates lateral stability, balance, and movement asymmetries. Athletes who score poorly on the in-line lunge should avoid activities requiring power or speed until scores are improved, yet relationships between the in-line lunge scores and other measures of balance, power, and speed are unknown. (1) Lunge scores will correlate with center of pressure (COP), maximum jump height (MJH), and 36.6-meter sprint time and (2) there will be no differences between limbs on lunge scores, MJH, or COP. Descriptive laboratory study. Level 3. Thirty-seven healthy, active participants completed the first 3 tasks of the FMS (eg, deep squat, hurdle step, in-line lunge), unilateral drop jumps, and 36.6-meter sprints. A 3-dimensional motion analysis system captured MJH. Force platforms measured COP excursion. A laser timing system measured 36.6-m sprint time. Statistical analyses were used to determine whether a relationship existed between lunge scores and COP, MJH, and 36.6-m speed (Spearman rho tests) and whether differences existed between limbs in lunge scores (Wilcoxon signed-rank test), MJH, and COP (paired t tests). Lunge scores were not significantly correlated with COP, MJH, or 36.6-m sprint time. Lunge scores, COP excursion, and MJH were not statistically different between limbs. Performance on the FMS in-line lunge was not related to balance, power, or speed. Healthy participants were symmetrical in lunging measures and MJH. Scores on the FMS in-line lunge should not be attributed to power, speed, or balance performance without further examination. However, assessing limb symmetry appears to be clinically relevant.

An error bound for a discrete reduced order model of a linear multivariable system

NASA Technical Reports Server (NTRS)

Al-Saggaf, Ubaid M.; Franklin, Gene F.

1987-01-01

The design of feasible controllers for high dimension multivariable systems can be greatly aided by a method of model reduction. In order for the design based on the order reduction to include a guarantee of stability, it is sufficient to have a bound on the model error. Previous work has provided such a bound for continuous-time systems for algorithms based on balancing. In this note an L-infinity bound is derived for model error for a method of order reduction of discrete linear multivariable systems based on balancing.

A Generalizability Analysis of Score Consistency for the Balanced Inventory of Desirable Responding

ERIC Educational Resources Information Center

Vispoel, Walter P.; Tao, Shuqin

2013-01-01

Our goal in this investigation was to evaluate the reliability of scores from the Balanced Inventory of Desirable Responding (BIDR) more comprehensively than in prior research using a generalizability-theory framework based on both dichotomous and polytomous scoring of items. Generalizability coefficients accounting for specific-factor, transient,…

Effects of coordination and manipulation therapy for patients with Parkinson disease.

PubMed

Zhao, Mingming; Hu, Caiyou; Wu, Zhixin; Chen, Yu; Li, Zhengming; Zhang, Mingsheng

2017-09-01

To determine the effects of a new exercise training regimen, i.e. coordination and manipulation therapy (CMT), on motor, balance, and cardiac functions in patients with Parkinson disease (PD). We divided 36 PD patients into the CMT (n = 22) and control (n = 14) groups. The patients in the CMT group performed dry-land swimming (imitation of the breaststroke) and paraspinal muscle stretching for 30 min/workday for 1 year. The control subjects did not exercise regularly. The same medication regimen was maintained in both groups during the study. Clinical characteristics, Unified Parkinson's Disease Rating Scale (UPDRS) scores, Berg balance scale (BBS) scores, mechanical balance measurements, timed up and go (TUG) test, and left ventricular ejection fraction (LVEF) were compared at 0 (baseline), 6, and 12 months. Biochemical test results were compared at 0 and 12 months. The primary outcome was motor ability. The secondary outcome was cardiac function. In the CMT group, UPDRS scores significantly improved, TUG test time and step number significantly decreased, BBS scores significantly increased, and most mechanical balance measurements significantly improved after 1 year of regular exercise therapy (all p < 0.05). In the control group, UPDRS scores significantly deteriorated, TUG test time and step number significantly increased, BBS scores significantly decreased, and most mechanical balance measurements significantly worsened after 1 year (all P < 0.05). LVEF improved in the CMT group only (P = 0.01). This preliminary study suggests that CMT effectively improved mobility disorder, balance, and cardiac function in PD patients over a 1-year period.

How Accurate Is a Test Score?

ERIC Educational Resources Information Center

Doppelt, Jerome E.

1956-01-01

The standard error of measurement as a means for estimating the margin of error that should be allowed for in test scores is discussed. The true score measures the performance that is characteristic of the person tested; the variations, plus and minus, around the true score describe a characteristic of the test. When the standard deviation is used…

Counting-backward test for executive function in idiopathic normal pressure hydrocephalus.

PubMed

Kanno, S; Saito, M; Hayashi, A; Uchiyama, M; Hiraoka, K; Nishio, Y; Hisanaga, K; Mori, E

2012-10-01

The aim of this study was to develop and validate a bedside test for executive function in patients with idiopathic normal pressure hydrocephalus (INPH). Twenty consecutive patients with INPH and 20 patients with Alzheimer's disease (AD) were enrolled in this study. We developed the counting-backward test for evaluating executive function in patients with INPH. Two indices that are considered to be reflective of the attention deficits and response suppression underlying executive dysfunction in INPH were calculated: the first-error score and the reverse-effect index. Performance on both the counting-backward test and standard neuropsychological tests for executive function was assessed in INPH and AD patients. The first-error score, reverse-effect index and the scores from the standard neuropsychological tests for executive function were significantly lower for individuals in the INPH group than in the AD group. The two indices for the counting-backward test in the INPH group were strongly correlated with the total scores for Frontal Assessment Battery and Phonemic Verbal Fluency. The first-error score was also significantly correlated with the error rate of the Stroop colour-word test and the score of the go/no-go test. In addition, we found that the first-error score highly distinguished patients with INPH from those with AD using these tests. The counting-backward test is useful for evaluating executive dysfunction in INPH and for differentiating between INPH and AD patients. In particular, the first-error score may reflect deficits in the response suppression related to executive dysfunction in INPH. © 2012 John Wiley & Sons A/S.

The quality of school wellness policies and energy-balance behaviors of adolescent mothers.

PubMed

Haire-Joshu, Debra; Yount, Byron W; Budd, Elizabeth L; Schwarz, Cynthia; Schermbeck, Rebecca; Green, Scoie; Elliott, Michael

2011-03-01

In this study, we 1) compared the quality of school wellness policies among schools participating in Moms for a Healthy Balance (BALANCE), a school- and home-based weight loss study conducted with postpartum adolescents in 27 states; and 2) assessed the relationship between policy quality with energy-balance behaviors and body mass index z scores of postpartum adolescents. As a part of BALANCE, we collected data on high-calorie food and beverage consumption, minutes spent walking, and height and weight for 647 participants. The School Wellness Policy Coding Tool was used to assess the strength and comprehensiveness of school district wellness policies from 251 schools attended by participating adolescent mothers. Schools averaged low scores for wellness policy comprehensiveness and strength. When compared with participants in schools with the lowest policy comprehensiveness scores, adolescent mothers in schools with the highest scores reported consuming significantly fewer daily calories from sweetened beverages while reporting higher consumption of water (P = .04 and P = .01, respectively). School wellness policy strength was associated with lower BMI z scores among adolescent mothers (P = .01). School wellness policies associated with BALANCE may be limited in their ability to promote a healthy school environment. Future studies are needed to evaluate the effect of the strength and comprehensiveness of policy language on energy balance in high-risk postpartum adolescents. Evidence from this work can provide additional guidance to federal or state government in mandating not only policy content, but also systematic evaluation.

Smartphone Applications to Perform Body Balance Assessment: a Standardized Review.

PubMed

Moral-Munoz, Jose A; Esteban-Moreno, Bernabe; Herrera-Viedma, Enrique; Cobo, Manuel J; Pérez, Ignacio J

2018-05-29

Body balance disorders are related to different injuries that contribute to a wide range of healthcare issues. The social and financial costs of these conditions are high. Therefore, quick and reliable body balance assessment can contribute to the prevention of injuries, as well as enhancement of clinical rehabilitation. Moreover, the use of smartphone applications is increasing rapidly since they incorporate different hardware components that allow for body balance assessment. The present study aims to show an analysis of the current applications available on Google Play Store TM and iTunes App Store TM to measure this physical condition, using the Mobile Application Rating Scale (MARS). Three iOS and two Android applications met the inclusion criteria. Three applications have scientific support, Balance test YMED, Balance Test by Slani, and Sway. Furthermore, according to MARS, the main scores for each evaluated domain were: Engagement (2.04), Functionality (3.8), Esthetics (3.53), and Information (3.80). The reviewed applications targeted to assess body balance obtained good mean scores. Sway is the app with highest scores in each MARS domain, followed by iBalance Fitness and Gyrobalance.

Towards reporting standards for neuropsychological study results: A proposal to minimize communication errors with standardized qualitative descriptors for normalized test scores.

PubMed

Schoenberg, Mike R; Rum, Ruba S

2017-11-01

Rapid, clear and efficient communication of neuropsychological results is essential to benefit patient care. Errors in communication are a lead cause of medical errors; nevertheless, there remains a lack of consistency in how neuropsychological scores are communicated. A major limitation in the communication of neuropsychological results is the inconsistent use of qualitative descriptors for standardized test scores and the use of vague terminology. PubMed search from 1 Jan 2007 to 1 Aug 2016 to identify guidelines or consensus statements for the description and reporting of qualitative terms to communicate neuropsychological test scores was conducted. The review found the use of confusing and overlapping terms to describe various ranges of percentile standardized test scores. In response, we propose a simplified set of qualitative descriptors for normalized test scores (Q-Simple) as a means to reduce errors in communicating test results. The Q-Simple qualitative terms are: 'very superior', 'superior', 'high average', 'average', 'low average', 'borderline' and 'abnormal/impaired'. A case example illustrates the proposed Q-Simple qualitative classification system to communicate neuropsychological results for neurosurgical planning. The Q-Simple qualitative descriptor system is aimed as a means to improve and standardize communication of standardized neuropsychological test scores. Research are needed to further evaluate neuropsychological communication errors. Conveying the clinical implications of neuropsychological results in a manner that minimizes risk for communication errors is a quintessential component of evidence-based practice. Copyright © 2017 Elsevier B.V. All rights reserved.

Does a Relationship Exist Between Lower Body Power and Balance Scores Among Older Adults?

PubMed

Shim, Andrew; Harr, Brady; Waller, Mike

2018-03-12

Falls are the second-leading cause of unintentional injury and death worldwide. To determine if a relationship exists between lower body power scores and center of pressure (CoP) and limits of stability (LoS) scores. A one-shot case study design (n = 13) was selected for the investigation. All participants were assessed stability scores via computerized posturography to determine CoP and LoS balance scores. Participants stood on a perturbed surface with their eyes open and closed. An experimental stair ramp with a switch mat timing device was used to determine lower body power scores in watts. There was a strong correlation (r = 0.725, p = 0.005) between the posterior (LoS) plane and relative peak power. An intraclass R revealed a strong correlation among the three trials (R = 0.831) performed on the stair ramp. Muscle power output and LoS scores have moderate to strong correlations with balance scores in older adults.

Age-related differences in quality of standing balance using a composite score.

PubMed

Pasma, Jantsje H; Bijlsma, Astrid Y; van der Bij, Mark D W; Arendzen, J Hans; Meskers, Carel G M; Maier, Andrea B

2014-01-01

Age-related differences in standing balance are not detected by testing the ability to maintain balance. Quality of standing balance might be more sensitive to detect age-related differences. To study age-related differences in quality of standing balance, center of pressure (CoP) movement was evaluated using a wide range of CoP parameters in several standing conditions in healthy young and old participants. In 35 healthy young (18-30 years) and 75 healthy old (70-80 years) participants, CoP movement was assessed in eight standing conditions on a force plate, including side-by-side, one-leg, semi-tandem and tandem stance, both with eyes open and eyes closed. Direction-specific CoP composite scores were calculated from standardized single CoP parameters (mean amplitude, amplitude variability, mean velocity, velocity variability and range) in anterior-posterior (AP) and medial-lateral (ML) direction. Linear regression analysis was used to detect age-related differences in single CoP parameters and composite scores - adjusted for gender, height and weight. Overall, single CoP parameters were higher in old compared to young participants, but no single CoP parameter consistently demonstrated the largest effect size for all standing conditions. Age-related differences were demonstrated for CoP composite scores in AP direction (tandem eyes open; semi-tandem eyes closed; p < 0.001). CoP composite scores in ML direction were consistently higher for all standing conditions in old compared to young participants (p < 0.001). CoP composite scores in ML direction were the most consistent parameters to detect age-related differences in quality of standing balance in healthy participants and might be of clinical value to detect subtle changes in quality of standing balance. © 2014 S. Karger AG, Basel

The effect of single-task and dual-task balance exercise programs on balance performance in adults with osteoporosis: a randomized controlled preliminary trial.

PubMed

Konak, H E; Kibar, S; Ergin, E S

2016-11-01

Osteoporosis is a serious disease characterized by muscle weakness in the lower extremities, shortened length of trunk, and increased dorsal kyphosis leading to poor balance performance. Although balance impairment increases in adults with osteoporosis, falls and fall-related injuries have been shown to occur mainly during the dual-task performance. Several studies have shown that dual-task performance was improved with specific repetitive dual-task exercises. The aims of this study were to compare the effect of single- and dual-task balance exercise programs on static balance, dynamic balance, and activity-specific balance confidence in adults with osteoporosis and to assess the effectiveness of dual-task balance training on gait speed under dual-task conditions. Older adults (N = 42) (age range, 45-88 years) with osteoporosis were randomly assigned into two groups. Single-task balance training group was given single-task balance exercises for 4 weeks, whereas dual-task balance training group received dual-task balance exercises. Participants received 45-min individualized training session, three times a week. Static balance was evaluated by one-leg stance (OLS) and a kinesthetic ability trainer (KAT) device. Dynamic balance was measured by the Berg Balance Scale (BBS), Time Up and Go (TUG) test, and gait speed. Self-confidence was assessed with the Activities-specific Balance Confidence (ABC-6) scale. Assessments were performed at baseline and after the 4-week program. At the end of the treatment periods, KAT score, BBS score, time in OLS and TUG, gait speeds under single- and dual-task conditions, and ABC-6 scale scores improved significantly in all patients (p < 0.05). However, BBS and gait speeds under single- and dual-task conditions showed significantly greater improvement in the dual-task balance training group than in the single-task balance training group (p < 0.05). ABC-6 scale scores improved more in the single-task balance training group than in the dual-task balance training group (p < 0.05). A 4-week single- and dual-task balance exercise programs are effective in improving static balance, dynamic balance, and balance confidence during daily activities in older adults with osteoporosis. However, single- and dual-task gait speeds showed greater improvement following the application of a specific type of dual-task exercise programs. 24102014-2.

Side-to-side difference in dynamic unilateral balance ability and pitching performance in Japanese collegiate baseball pitchers.

PubMed

Yanagisawa, Osamu; Futatsubashi, Genki; Taniguchi, Hidenori

2018-01-01

[Purpose] To evaluate the side-to-side difference in dynamic unilateral balance ability and to determine the correlation of the balance ability with pitching performance in collegiate baseball pitchers. [Subjects and Methods] Twenty-five Japanese collegiate baseball pitchers participated in this study. Dynamic balance ability during a unilateral stance was bilaterally evaluated using the star excursion balance test (SEBT). The pitchers threw 20 fastballs at an official pitching distance; the maximal ball velocity and pitching accuracy (the number of strike/20 pitches × 100) were assessed. Side-to-side difference in scores of SEBT was assessed using a paired t-test. Correlations between SEBT scores and pitching performance were evaluated for both legs using a Pearson's correlation analysis. [Results] The pivot side showed significantly higher score of the SEBT in the anteromedial direction than the stride side. On the other hand, the SEBT scores in the pivot and stride legs did not have significant correlations with maximal ball velocity and pitching accuracy. [Conclusion] These findings suggest that marked side-to-side difference does not exist in the dynamic unilateral balance ability of collegiate baseball pitchers and that the dynamic unilateral balance ability of each leg is not directly related to maximal ball velocity and pitching accuracy.

A multimodal assessment of balance in elderly and young adults.

PubMed

King, Gregory W; Abreu, Eduardo L; Cheng, An-Lin; Chertoff, Keyna K; Brotto, Leticia; Kelly, Patricia J; Brotto, Marco

2016-03-22

Falling is a significant health issue among elderly adults. Given the multifactorial nature of falls, effective balance and fall risk assessment must take into account factors from multiple sources. Here we investigate the relationship between fall risk and a diverse set of biochemical and biomechanical variables including: skeletal muscle-specific troponin T (sTnT), maximal strength measures derived from isometric grip and leg extension tasks, and postural sway captured from a force platform during a quiet stance task. These measures were performed in eight young and eleven elderly adults, along with estimates of fall risk derived from the Tinetti Balance Assessment. We observed age-related effects in all measurements, including a trend toward increased sTnT levels, increased postural sway, reduced upper and lower extremity strength, and reduced balance scores. We observed a negative correlation between balance scores and sTnT levels, suggesting its use as a biomarker for fall risk. We observed a significant positive correlation between balance scores and strength measures, adding support to the notion that muscle strength plays a significant role in postural control. We observed a significant negative correlation between balance scores and postural sway, suggesting that fall risk is associated with more loosely controlled center of mass regulation.

A multimodal assessment of balance in elderly and young adults

PubMed Central

King, Gregory W.; Abreu, Eduardo L.; Cheng, An-Lin; Chertoff, Keyna K.; Brotto, Leticia; Kelly, Patricia J.; Brotto, Marco

2016-01-01

Falling is a significant health issue among elderly adults. Given the multifactorial nature of falls, effective balance and fall risk assessment must take into account factors from multiple sources. Here we investigate the relationship between fall risk and a diverse set of biochemical and biomechanical variables including: skeletal muscle-specific troponin T (sTnT), maximal strength measures derived from isometric grip and leg extension tasks, and postural sway captured from a force platform during a quiet stance task. These measures were performed in eight young and eleven elderly adults, along with estimates of fall risk derived from the Tinetti Balance Assessment. We observed age-related effects in all measurements, including a trend toward increased sTnT levels, increased postural sway, reduced upper and lower extremity strength, and reduced balance scores. We observed a negative correlation between balance scores and sTnT levels, suggesting its use as a biomarker for fall risk. We observed a significant positive correlation between balance scores and strength measures, adding support to the notion that muscle strength plays a significant role in postural control. We observed a significant negative correlation between balance scores and postural sway, suggesting that fall risk is associated with more loosely controlled center of mass regulation. PMID:26934319

Reliability and Validity of Computerized Force Platform Measures of Balance Function in Healthy Older Adults.

PubMed

Harro, Cathy C; Garascia, Chelsea

2018-01-10

Postural control declines with aging and is an independent risk factor for falls in older adults. Objective examination of balance function is warranted to direct fall prevention strategies. Force platform (FP) systems provide quantitative measures of postural control and analysis of different aspects of balance. The purpose of this study was to examine the reliability and validity of FP measures in healthy older adults. This study enrolled 46 healthy elderly adults, mean age 67.67 (5.1) years, who had no history of falls. They were assessed on 3 standardized tests on the NeuroCom Equitest FP system: limits of stability (LOS), motor control test (MCT), and sensory organization test (SOT). The test battery was administered twice within a 10-day period for test-retest reliability; intraclass correlation coefficients (ICCs), standard error of measurement (SEM), and minimal detectable change based on a 95% confidence interval (MDC95) were calculated. FP measures were compared with criterion clinical balance (Mini-BESTest and Functional Gait Assessment) and gait (10-m walk and 6-minute walk) measures to examine concurrent validity using Pearson correlation coefficients. Multiple linear regression analysis examined whether age and activity level were associated with FP performance. The α level was set at P < .05. SOT composite equilibrium scores, MCT average latency, and LOS end point excursion measures all demonstrated excellent test-retest reliability (ICC = 0.90, 0.85, and 0.77, respectively), whereas moderate to good reliability was found for SOT vestibular ratio score (ICC = 0.71). There was large variability in performance in this healthy elderly cohort, resulting in relatively large MDC95 for these measures, especially for the LOS test. Fair correlations were found between LOS end point excursion and clinical balance and gait measures (r = 0.31-0.49), and between MCT average latency and gait measures only (r = -0.32). No correlations were found between SOT measures and clinical balance and gait measures. Age was only marginally significantly (P = .055) associated with LOS end point excursion but was not associated with SOT or MCT measures, and activity level was not associated with any of the FP measures. FP measures provided reliable information on balance function in healthy older adults; however, small learning effects were evident, particularly for the SOT. The SEM and MDC95 for the LOS and SOT measures were relatively large for this healthy elderly cohort. A relationship between FP measures, which assess underlying balance mechanisms, and clinical balance and gait measures was not strongly supported in this study. Further research is needed to justify the value of adding FP measures to a test battery for balance assessment in older adults without a history of falls.

Anatomic, clinical, and neuropsychological correlates of spelling errors in primary progressive aphasia.

PubMed

Shim, Hyungsub; Hurley, Robert S; Rogalski, Emily; Mesulam, M-Marsel

2012-07-01

This study evaluates spelling errors in the three subtypes of primary progressive aphasia (PPA): agrammatic (PPA-G), logopenic (PPA-L), and semantic (PPA-S). Forty-one PPA patients and 36 age-matched healthy controls were administered a test of spelling. The total number of errors and types of errors in spelling to dictation of regular words, exception words and nonwords, were recorded. Error types were classified based on phonetic plausibility. In the first analysis, scores were evaluated by clinical diagnosis. Errors in spelling exception words and phonetically plausible errors were seen in PPA-S. Conversely, PPA-G was associated with errors in nonword spelling and phonetically implausible errors. In the next analysis, spelling scores were correlated to other neuropsychological language test scores. Significant correlations were found between exception word spelling and measures of naming and single word comprehension. Nonword spelling correlated with tests of grammar and repetition. Global language measures did not correlate significantly with spelling scores, however. Cortical thickness analysis based on MRI showed that atrophy in several language regions of interest were correlated with spelling errors. Atrophy in the left supramarginal gyrus and inferior frontal gyrus (IFG) pars orbitalis correlated with errors in nonword spelling, while thinning in the left temporal pole and fusiform gyrus correlated with errors in exception word spelling. Additionally, phonetically implausible errors in regular word spelling correlated with thinning in the left IFG pars triangularis and pars opercularis. Together, these findings suggest two independent systems for spelling to dictation, one phonetic (phoneme to grapheme conversion), and one lexical (whole word retrieval). Copyright © 2012 Elsevier Ltd. All rights reserved.

[Relationships of positive and negative affectivity to sleep quality in Japanese civil servants: 3-year follow-up study].

PubMed

Saeki, Urara; Nasermoaddeli, Ali; Sekine, Michikazu; Kagamimori, Sadanobu

2008-11-01

We conducted this longitudinal study to evaluate the relationships of positive and negative affectivity (Affect Balance Scale) to sleep quality among civil servants. For this study we evaluated 827 civil servants of T city in Toyama prefecture in the springs of 2001 (Baseline) and 2004 with complete information in both phases of the study. Based on the median score at each phase, we divided Affect Balance Scale (ABS) scores into high and low groups. We conducted logistic regression analysis to determine the odds ratios (OR) of 3-yr follow-up sleep quality by baseline and follow-up ABS scores. After adjusting for baseline sleep quality scores, age, sex, employment, job strain, and exercise habits, participants who had high ABS scores were more likely (OR: 3.13, 95% confidence interval (CI): 1.78-5.53) to have better sleep quality than those with low ABS scores at both phases. In addition, participants with low ABS scores at baseline and high ABS scores 3 yr later had better sleep quality (OR: 1.81, 95%CI: 1.02-3.20) than those with low ABS scores at both phases. These findings substantiate the relationships of positive and negative affectivity to sleep quality. Improving the affect balance condition as well as maintaining good affect balance condition may be important determinants of sleep quality in civil servants.

Normal aging increases postural preparation errors: Evidence from a two-choice response task with balance constraints.

PubMed

Verrel, Julius; Lisofsky, Nina; Kühn, Simone; Lindenberger, Ulman

2016-02-01

Correlational studies indicate an association between age-related decline in balance and cognitive control, but these functions are rarely addressed within a single task. In this study, we investigate adult age differences in a two-choice response task with balance constraints under three levels of response conflict. Sixteen healthy young (20-30 years) and 16 healthy older adult participants (59-74 years) were cued symbolically (letter L vs. R) to lift either the left or the right foot from the floor in a standing position. Response conflict was manipulated by task-irrelevant visual stimuli showing congruent, incongruent, or no foot lift movement. Preparatory weight shifts (PWS) and foot lift movements were recorded using force plates and optical motion capture. Older adults showed longer response times (foot lift) and more PWS errors than younger adults. Incongruent distractors interfered with performance (greater response time and PWS errors), but this compatibility effect did not reliably differ between age groups. Response time effects of age and compatibility were strongly reduced or absent in trials without PWS errors, and for the onset of the first (erroneous) PWS in trials with preparation error. In addition, in older adults only, compatibility effects in the foot lift task correlated significantly with compatibility effects in the Flanker task. The present results strongly suggest that adult age differences in response latencies in a task with balance constraints are related to age-associated increases in postural preparation errors rather than being an epiphenomenon of general slowing. Copyright © 2015 Elsevier B.V. All rights reserved.

The Cut-Score Operating Function: A New Tool to Aid in Standard Setting

ERIC Educational Resources Information Center

Grabovsky, Irina; Wainer, Howard

2017-01-01

In this essay, we describe the construction and use of the Cut-Score Operating Function in aiding standard setting decisions. The Cut-Score Operating Function shows the relation between the cut-score chosen and the consequent error rate. It allows error rates to be defined by multiple loss functions and will show the behavior of each loss…

Measurement Error and Bias in Value-Added Models. Research Report. ETS RR-17-25

ERIC Educational Resources Information Center

Kane, Michael T.

2017-01-01

By aggregating residual gain scores (the differences between each student's current score and a predicted score based on prior performance) for a school or a teacher, value-added models (VAMs) can be used to generate estimates of school or teacher effects. It is known that random errors in the prior scores will introduce bias into predictions of…

Assessing dangerous driving behavior during driving inattention: Psychometric adaptation and validation of the Attention-Related Driving Errors Scale in China.

PubMed

Qu, Weina; Ge, Yan; Zhang, Qian; Zhao, Wenguo; Zhang, Kan

2015-07-01

Driver inattention is a significant cause of motor vehicle collisions and incidents. The purpose of this study was to translate the Attention-Related Driving Error Scale (ARDES) into Chinese and to verify its reliability and validity. A total of 317 drivers completed the Chinese version of the ARDES, the Dula Dangerous Driving Index (DDDI), the Attention-Related Cognitive Errors Scale (ARCES) and the Mindful Attention Awareness Scale (MAAS) questionnaires. Specific sociodemographic variables and traffic violations were also measured. Psychometric results confirm that the ARDES-China has adequate psychometric properties (Cronbach's alpha=0.88) to be a useful tool for evaluating proneness to attentional errors in the Chinese driving population. First, ARDES-China scores were positively correlated with both DDDI scores and number of accidents in the prior year; in addition, ARDES-China scores were a significant predictor of dangerous driving behavior as measured by DDDI. Second, we found that ARDES-China scores were strongly correlated with ARCES scores and negatively correlated with MAAS scores. Finally, different demographic groups exhibited significant differences in ARDES scores; in particular, ARDES scores varied with years of driving experience. Copyright © 2015 Elsevier Ltd. All rights reserved.

Associations between communication climate and the frequency of medical error reporting among pharmacists within an inpatient setting.

PubMed

Patterson, Mark E; Pace, Heather A; Fincham, Jack E

2013-09-01

Although error-reporting systems enable hospitals to accurately track safety climate through the identification of adverse events, these systems may be underused within a work climate of poor communication. The objective of this analysis is to identify the extent to which perceived communication climate among hospital pharmacists impacts medical error reporting rates. This cross-sectional study used survey responses from more than 5000 pharmacists responding to the 2010 Hospital Survey on Patient Safety Culture (HSOPSC). Two composite scores were constructed for "communication openness" and "feedback and about error," respectively. Error reporting frequency was defined from the survey question, "In the past 12 months, how many event reports have you filled out and submitted?" Multivariable logistic regressions were used to estimate the likelihood of medical error reporting conditional upon communication openness or feedback levels, controlling for pharmacist years of experience, hospital geographic region, and ownership status. Pharmacists with higher communication openness scores compared with lower scores were 40% more likely to have filed or submitted a medical error report in the past 12 months (OR, 1.4; 95% CI, 1.1-1.7; P = 0.004). In contrast, pharmacists with higher communication feedback scores were not any more likely than those with lower scores to have filed or submitted a medical report in the past 12 months (OR, 1.0; 95% CI, 0.8-1.3; P = 0.97). Hospital work climates that encourage pharmacists to freely communicate about problems related to patient safety is conducive to medical error reporting. The presence of feedback infrastructures about error may not be sufficient to induce error-reporting behavior.

Balance Confidence and Falls in Non-Demented Essential Tremor Patients: The Role of Cognition

PubMed Central

Rao, Ashwini K.; Gilman, Arthur; Louis, Elan D.

2014-01-01

Objective To examine 1) the effect of cognitive ability on balance confidence and falls, 2) the relationship of balance confidence and falls with quantitative measures of gait, and 3) measures that predict falls, in people with Essential Tremor (ET). Design Cross-sectional study. Setting: General community. Participants One-hundred-eighty participants (132 people with ET and 48 controls). People with ET were divided into two groups based on the median score on the modified Mini Mental State Exam: ET-LCS vs. ET-HCS. Interventions Not applicable. Main Outcome Measures Activities of Balance Confidence-6 (ABC) scale and falls in the previous year. Results ET-LCS had lower ABC-6 scores and a greater number of falls than ET-HCS (p<0.05 for all measures) or controls (p<0.01 for all measures). Quantitative gait measures were significantly correlated with ABC-6 score and falls. Gait speed (p<0.007) and ABC-6 score (p<0.02) were significant predictors of falls. Receiver Operating Characteristic curve analysis revealed that gait speed < 0.9 m/s and ABC-6 score < 51% were associated with moderate sensitivity and specificity in identifying fallers. Conclusions People with ET with low cognitive scores have impaired gait, and report lower balance confidence, and higher number of falls than their counterparts with higher cognitive scores, and controls. We have identified assessments that are easily administered (gait speed and ABC-6 scale), and are associated with falls in ET. PMID:24769121

The relationship between the Activities-specific Balance Confidence Scale and the Dynamic Gait Index in peripheral vestibular dysfunction.

PubMed

Legters, Kristine; Whitney, Susan L; Porter, Rebecca; Buczek, Frank

2005-01-01

People with vestibular dysfunction experience dizziness, vertigo and postural instability. The persistence of these symptoms may result in decreased balance confidence. The purpose of the present study was to examine the relationship between decreased balance confidence and gait dysfunction in patients with unilateral peripheral vestibular dysfunction. A retrospective review of 137 charts with the Activities-specific Balance Confidence (ABC) Scale and the Dynamic Gait Index (DGI) scores was completed. Spearman rank-order correlation analysis was performed of the total sample, by age group and by degree of vestibular weakness. A moderate correlation of r = 0.58 (p < 0.001) was found between the ABC Scale score and the DGI score in the total sample. Those with mild or moderate vestibular weakness had a correlation of r = 0.72 (p < 0.001) between the ABC Scale score and the DGI score, compared with a correlation of r = 0.48 in those with severe or total vestibular weakness. Decreased balance confidence and increased fall risk are critical issues for people with vestibular dysfunction. The effects of aging did not have a significant impact on the relationship. The correlation between balance confidence and gait dysfunction was stronger in those with mild or moderate vestibular weakness, although those with severe or total weakness were more disabled by their vestibular symptoms.

Tailored balance exercises on people with multiple sclerosis: A pilot randomized, controlled study.

PubMed

Brichetto, Giampaolo; Piccardo, Elisa; Pedullà, Ludovico; Battaglia, Mario Alberto; Tacchino, Andrea

2015-07-01

Altered integration of signals from visual (VIS), somatosensory (PROP) and vestibular system (VEST) lead to balance control impairments affecting the daily living activities of patients with multiple sclerosis (PwMS). As a consequence, tailored interventions could be crucial in improving efficacy of balance rehabilitation treatments. The objective of this paper is to assess the efficacy of tailored rehabilitation treatments for balance disorders based on visual, somatosensory and vestibular deficits versus traditional rehabilitation exercises. Thirty-two PwMS were assessed with the Berg Balance Scale (BBS), the composite score (CS) obtained by computerized dynamic posturography (CDP) test and the Modified Fatigue Impact Scale (MFIS). Based on CDP analysis, prevalent VIS, PROP or VEST deficits were identified and patients randomly allocated to a personalized (PRG) or traditional (TRG) rehabilitation group. BBS score showed a significant difference between pre- and post-treatment scores of 6.3 and 2.0 points respectively for PRG and TRG. CS showed a significant difference between pre- and post-treatment scores of 16.6 and 7.6 points respectively for PRG and TRG. No interaction effect was found for MFIS score. BBS and CS showed changes in the PRG group that met clinical relevant difference, underlining that tailored rehabilitation interventions based on patient-specific sensory system impairment could improve balance and postural control in PwMS. © The Author(s), 2015.

Reliability and Repetition Effect of the Center of Pressure and Kinematics Parameters That Characterize Trunk Postural Control During Unstable Sitting Test.

PubMed

Barbado, David; Moreside, Janice; Vera-Garcia, Francisco J

2017-03-01

Although unstable seat methodology has been used to assess trunk postural control, the reliability of the variables that characterize it remains unclear. To analyze reliability and learning effect of center of pressure (COP) and kinematic parameters that characterize trunk postural control performance in unstable seating. The relationships between kinematic and COP parameters also were explored. Test-retest reliability design. Biomechanics laboratory setting. Twenty-three healthy male subjects. Participants volunteered to perform 3 sessions at 1-week intervals, each consisting of five 70-second balancing trials. A force platform and a motion capture system were used to measure COP and pelvis, thorax, and spine displacements. Reliability was assessed through standard error of measurement (SEM) and intraclass correlation coefficients (ICC 2,1 ) using 3 methods: (1) comparing the last trial score of each day; (2) comparing the best trial score of each day; and (3) calculating the average of the three last trial scores of each day. Standard deviation and mean velocity were calculated to assess balance performance. Although analyses of variance showed some differences in balance performance between days, these differences were not significant between days 2 and 3. Best result and average methods showed the greatest reliability. Mean velocity of the COP showed high reliability (0.71 < ICC < 0.86; 10.3 < SEM < 13.0), whereas standard deviation only showed a low to moderate reliability (0.37 < ICC < 0.61; 14.5 < SEM < 23.0). Regarding the kinematic variables, only pelvis displacement mean velocity achieved a high reliability using the average method (0.62 < ICC < 0.83; 18.8 < SEM < 23.1). Correlations between COP and kinematics were high only for mean velocity (0.45

INTRA-RATER RELIABILITY OF THE MULTIPLE SINGLE-LEG HOP-STABILIZATION TEST AND RELATIONSHIPS WITH AGE, LEG DOMINANCE AND TRAINING.

PubMed

Sawle, Leanne; Freeman, Jennifer; Marsden, Jonathan

2017-04-01

Balance is a complex construct, affected by multiple components such as strength and co-ordination. However, whilst assessing an athlete's dynamic balance is an important part of clinical examination, there is no gold standard measure. The multiple single-leg hop-stabilization test is a functional test which may offer a method of evaluating the dynamic attributes of balance, but it needs to show adequate intra-tester reliability. The purpose of this study was to assess the intra-rater reliability of a dynamic balance test, the multiple single-leg hop-stabilization test on the dominant and non-dominant legs. Intra-rater reliability study. Fifteen active participants were tested twice with a 10-minute break between tests. The outcome measure was the multiple single-leg hop-stabilization test score, based on a clinically assessed numerical scoring system. Results were analysed using an Intraclass Correlations Coefficient (ICC 2,1 ) and Bland-Altman plots. Regression analyses explored relationships between test scores, leg dominance, age and training (an alpha level of p = 0.05 was selected). ICCs for intra-rater reliability were 0.85 for the dominant and non-dominant legs (confidence intervals = 0.62-0.95 and 0.61-0.95 respectively). Bland-Altman plots showed scores within two standard deviations. A significant correlation was observed between the dominant and non-dominant leg on balance scores (R 2 =0.49, p<0.05), and better balance was associated with younger participants in their non-dominant leg (R 2 =0.28, p<0.05) and their dominant leg (R 2 =0.39, p<0.05), and a higher number of hours spent training for the non-dominant leg R 2 =0.37, p<0.05). The multiple single-leg hop-stabilisation test demonstrated strong intra-tester reliability with active participants. Younger participants who trained more, have better balance scores. This test may be a useful measure for evaluating the dynamic attributes of balance. 3.

Sympathetic nervous system activity measured by skin conductance quantifies the challenge of walking adaptability tasks after stroke.

PubMed

Clark, David J; Chatterjee, Sudeshna A; McGuirk, Theresa E; Porges, Eric C; Fox, Emily J; Balasubramanian, Chitralakshmi K

2018-02-01

Walking adaptability tasks are challenging for people with motor impairments. The construct of perceived challenge is typically measured by self-report assessments, which are susceptible to subjective measurement error. The development of an objective physiologically-based measure of challenge may help to improve the ability to assess this important aspect of mobility function. The objective of this study to investigate the use of sympathetic nervous system (SNS) activity measured by skin conductance to gauge the physiological stress response to challenging walking adaptability tasks in people post-stroke. Thirty adults with chronic post-stroke hemiparesis performed a battery of seventeen walking adaptability tasks. SNS activity was measured by skin conductance from the palmar surface of each hand. The primary outcome variable was the percent change in skin conductance level (ΔSCL) between the baseline resting and walking phases of each task. Task difficulty was measured by performance speed and by physical therapist scoring of performance. Walking function and balance confidence were measured by preferred walking speed and the Activities-specific Balance Confidence Scale, respectively. There was a statistically significant negative association between ΔSCL and task performance speed and between ΔSCL and clinical score, indicating that tasks with greater SNS activity had slower performance speed and poorer clinical scores. ΔSCL was significantly greater for low functioning participants versus high functioning participants, particularly during the most challenging walking adaptability tasks. This study supports the use of SNS activity measured by skin conductance as a valuable approach for objectively quantifying the perceived challenge of walking adaptability tasks in people post-stroke. Published by Elsevier B.V.

The effect of water-based exercises on balance in persons post-stroke: a randomized controlled trial.

PubMed

Chan, Kelvin; Phadke, Chetan P; Stremler, Denise; Suter, Lynn; Pauley, Tim; Ismail, Farooq; Boulias, Chris

2017-05-01

Water-based exercises have been used in the rehabilitation of people with stroke, but little is known about the impact of this treatment on balance. This study examined the effect of water-based exercises compared to land-based exercises on the balance of people with sub-acute stroke. In this single-blind randomized controlled study, 32 patients with first-time stroke discharged from inpatient rehabilitation at West Park Healthcare Centre were recruited. Participants were randomized into W (water-based + land; n = 17) or L (land only; n = 15) exercise groups. Both groups attended therapy two times per week for six weeks. Initial and progression protocols for the water-based exercises (a combination of balance, stretching, and strengthening and endurance training) and land therapy (balance, strength, transfer, gait, and stair training) were devised. Outcomes included the Berg Balance Score, Community Balance and Mobility Score, Timed Up and Go Test, and 2 Minute Walk Test. Baseline characteristics of groups W and L were similar in age, side of stroke, time since stroke, and wait time between inpatient discharge and outpatient therapy on all four outcomes. Pooled change scores from all outcomes showed that significantly greater number of patients in the W-group showed improvement post-training compared to the L-group (p < 0.05). More patients in W-group showed change scores exceeding the published minimal detectable change scores. A combination of water- and land-based exercises has potential for improving balance. The results of this study extend the work showing benefit of water-based exercise in chronic and less-impaired stroke groups to patients with sub-acute stroke.

Global optimization method based on ray tracing to achieve optimum figure error compensation

NASA Astrophysics Data System (ADS)

Liu, Xiaolin; Guo, Xuejia; Tang, Tianjin

2017-02-01

Figure error would degrade the performance of optical system. When predicting the performance and performing system assembly, compensation by clocking of optical components around the optical axis is a conventional but user-dependent method. Commercial optical software cannot optimize this clocking. Meanwhile existing automatic figure-error balancing methods can introduce approximate calculation error and the build process of optimization model is complex and time-consuming. To overcome these limitations, an accurate and automatic global optimization method of figure error balancing is proposed. This method is based on precise ray tracing to calculate the wavefront error, not approximate calculation, under a given elements' rotation angles combination. The composite wavefront error root-mean-square (RMS) acts as the cost function. Simulated annealing algorithm is used to seek the optimal combination of rotation angles of each optical element. This method can be applied to all rotational symmetric optics. Optimization results show that this method is 49% better than previous approximate analytical method.

ADEPT, a dynamic next generation sequencing data error-detection program with trimming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Shihai; Lo, Chien-Chi; Li, Po-E

Illumina is the most widely used next generation sequencing technology and produces millions of short reads that contain errors. These sequencing errors constitute a major problem in applications such as de novo genome assembly, metagenomics analysis and single nucleotide polymorphism discovery. In this study, we present ADEPT, a dynamic error detection method, based on the quality scores of each nucleotide and its neighboring nucleotides, together with their positions within the read and compares this to the position-specific quality score distribution of all bases within the sequencing run. This method greatly improves upon other available methods in terms of the truemore » positive rate of error discovery without affecting the false positive rate, particularly within the middle of reads. We conclude that ADEPT is the only tool to date that dynamically assesses errors within reads by comparing position-specific and neighboring base quality scores with the distribution of quality scores for the dataset being analyzed. The result is a method that is less prone to position-dependent under-prediction, which is one of the most prominent issues in error prediction. The outcome is that ADEPT improves upon prior efforts in identifying true errors, primarily within the middle of reads, while reducing the false positive rate.« less

ADEPT, a dynamic next generation sequencing data error-detection program with trimming

DOE PAGES

Feng, Shihai; Lo, Chien-Chi; Li, Po-E; ...

2016-02-29

Illumina is the most widely used next generation sequencing technology and produces millions of short reads that contain errors. These sequencing errors constitute a major problem in applications such as de novo genome assembly, metagenomics analysis and single nucleotide polymorphism discovery. In this study, we present ADEPT, a dynamic error detection method, based on the quality scores of each nucleotide and its neighboring nucleotides, together with their positions within the read and compares this to the position-specific quality score distribution of all bases within the sequencing run. This method greatly improves upon other available methods in terms of the truemore » positive rate of error discovery without affecting the false positive rate, particularly within the middle of reads. We conclude that ADEPT is the only tool to date that dynamically assesses errors within reads by comparing position-specific and neighboring base quality scores with the distribution of quality scores for the dataset being analyzed. The result is a method that is less prone to position-dependent under-prediction, which is one of the most prominent issues in error prediction. The outcome is that ADEPT improves upon prior efforts in identifying true errors, primarily within the middle of reads, while reducing the false positive rate.« less

SU-E-T-192: FMEA Severity Scores - Do We Really Know?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tonigan, J; Johnson, J; Kry, S

2014-06-01

Purpose: Failure modes and effects analysis (FMEA) is a subjective risk mitigation technique that has not been applied to physics-specific quality management practices. There is a need for quantitative FMEA data as called for in the literature. This work focuses specifically on quantifying FMEA severity scores for physics components of IMRT delivery and comparing to subjective scores. Methods: Eleven physical failure modes (FMs) for head and neck IMRT dose calculation and delivery are examined near commonly accepted tolerance criteria levels. Phantom treatment planning studies and dosimetry measurements (requiring decommissioning in several cases) are performed to determine the magnitude of dosemore » delivery errors for the FMs (i.e., severity of the FM). Resultant quantitative severity scores are compared to FMEA scores obtained through an international survey and focus group studies. Results: Physical measurements for six FMs have resulted in significant PTV dose errors up to 4.3% as well as close to 1 mm significant distance-to-agreement error between PTV and OAR. Of the 129 survey responses, the vast majority of the responders used Varian machines with Pinnacle and Eclipse planning systems. The average years of experience was 17, yet familiarity with FMEA less than expected. Survey reports perception of dose delivery error magnitude varies widely, in some cases 50% difference in dose delivery error expected amongst respondents. Substantial variance is also seen for all FMs in occurrence, detectability, and severity scores assigned with average variance values of 5.5, 4.6, and 2.2, respectively. Survey shows for MLC positional FM(2mm) average of 7.6% dose error expected (range 0–50%) compared to 2% error seen in measurement. Analysis of ranking in survey, treatment planning studies, and quantitative value comparison will be presented. Conclusion: Resultant quantitative severity scores will expand the utility of FMEA for radiotherapy and verify accuracy of FMEA results compared to highly variable subjective scores.« less

Measurements of Weight Bearing Asymmetry Using the Nintendo Wii Fit Balance Board Are Not Reliable for Older Adults and Individuals With Stroke.

PubMed

Liuzzo, Derek M; Peters, Denise M; Middleton, Addie; Lanier, Wes; Chain, Rebecca; Barksdale, Brittany; Fritz, Stacy L

Clinicians and researchers have used bathroom scales, balance performance monitors with feedback, postural scale analysis, and force platforms to evaluate weight bearing asymmetry (WBA). Now video game consoles offer a novel alternative for assessing this construct. By using specialized software, the Nintendo Wii Fit balance board can provide reliable measurements of WBA in healthy, young adults. However, reliability of measurements obtained using only the factory settings to assess WBA in older adults and individuals with stroke has not been established. To determine whether measurements of WBA obtained using the Nintendo Wii Fit balance board and default settings are reliable in older adults and individuals with stroke. Weight bearing asymmetry was assessed using the Nintendo Wii Fit balance board in 2 groups of participants-individuals older than 65 years (n = 41) and individuals with stroke (n = 41). Participants were given a standardized set of instructions and were not provided auditory or visual feedback. Two trials were performed. Intraclass correlation coefficients (ICC), standard error of measure (SEM), and minimal detectable change (MDC) scores were determined for each group. The ICC for the older adults sample was 0.59 (0.35-0.76) with SEM95 = 6.2% and MDC95 = 8.8%. The ICC for the sample including individuals with stroke was 0.60 (0.47-0.70) with SEM95 = 9.6% and MDC95 = 13.6%. Although measurements of WBA obtained using the Nintendo Wii Fit balance board, and its default factory settings, demonstrate moderate reliability in older adults and individuals with stroke, the relatively high associated SEM and MDC values substantially reduce the clinical utility of the Nintendo Wii Fit balance board as an assessment tool for WBA. Weight bearing asymmetry cannot be measured reliably in older adults and individuals with stroke using the Nintendo Wii Fit balance board without the use of specialized software.

Measurements of Weight Bearing Asymmetry Using the Nintendo Wii Fit Balance Board Are Not Reliable for Older Adults and Individuals With Stroke

PubMed Central

Liuzzo, Derek M.; Peters, Denise M.; Middleton, Addie; Lanier, Wes; Chain, Rebecca; Barksdale, Brittany; Fritz, Stacy L.

2015-01-01

Background Clinicians and researchers have used bathroom scales, balance performance monitors with feedback, postural scale analysis, and force platforms to evaluate weight bearing asymmetry (WBA). Now video game consoles offer a novel alternative for assessing this construct. By using specialized software, the Nintendo Wii Fit balance board can provide reliable measurements of WBA in healthy, young adults. However, reliability of measurements obtained using only the factory settings to assess WBA in older adults and individuals with stroke has not been established. Purpose To determine whether measurements of WBA obtained using the Nintendo Wii Fit balance board and default settings are reliable in older adults and individuals with stroke. Methods Weight bearing asymmetry was assessed using the Nintendo Wii Fit balance board in 2 groups of participants—individuals older than 65 years (n = 41) and individuals with stroke (n = 41). Participants were given a standardized set of instructions and were not provided auditory or visual feedback. Two trials were performed. Intraclass correlation coefficients (ICC), standard error of measure (SEM), and minimal detectable change (MDC) scores were determined for each group. Results The ICC for the older adults sample was 0.59 (0.35–0.76) with SEM95= 6.2% and MDC95= 8.8%. The ICC for the sample including individuals with stroke was 0.60 (0.47–0.70) with SEM95= 9.6% and MDC95= 13.6%. Discussion Although measurements of WBA obtained using the Nintendo Wii Fit balance board, and its default factory settings, demonstrate moderate reliability in older adults and individuals with stroke, the relatively high associated SEM and MDC values substantially reduce the clinical utility of the Nintendo Wii Fit balance board as an assessment tool for WBA. Conclusions Weight bearing asymmetry cannot be measured reliably in older adults and individuals with stroke using the Nintendo Wii Fit balance board without the use of specialized software. PMID:26288237

Berg Balance Scale score at admission can predict walking suitable for community ambulation at discharge from inpatient stroke rehabilitation.

PubMed

Louie, Dennis R; Eng, Janice J

2018-01-10

This retrospective cohort study identified inpatient rehabilitation admission variables that predict walking ability at discharge and established Berg Balance Scale cut-off scores to predict the extent of improvement in walking. Participants (n=123) were assessed for various cognitive and physical outcomes at admission to inpatient stroke rehabilitation. Multivariate logistic regression identified admission predictors of regaining community ambulation (gait speed ≥0.8 m/s) or unassisted ambulation (no physical assistance) after 4 weeks. Receiver operating characteristic curve analysis identified cut-off admission Berg Balance Scale scores. Mini-Mental State Examination (odds ratio (OR) 1.60, 95% confidence interval (95% CI) 1.19-2.14) was a significant predictor when coupled with admission walking speed for regaining community ambulation speed; stroke type (haemorrhagic/ischaemic) was a significant predictor (OR=0.19, 95% CI 0.05-0.77) when coupled with Berg Balance Scale (OR 1.14, 95% CI 1.09-1.20). Only Berg Balance Scale was a significant predictor of regaining unassisted ambulation (OR 1.11, 95% CI 1.05-1.17). A cut-off Berg Balance Scale score of 29 on admission predicts that an individual will go on to achieve community walking speed (n=123, area under the curve (AUC)=0.88, 95% CI 0.81-0.95); a cut-off score of 12 predicts a non-ambulator to regain unassisted ambulation (n=84, AUC 0.73, 95% CI 0.62-0.84). The Berg Balance Scale can be used at rehabilitation admission to predict the degree of improvement in walking for patients with stroke.

Imperfect practice makes perfect: error management training improves transfer of learning.

PubMed

Dyre, Liv; Tabor, Ann; Ringsted, Charlotte; Tolsgaard, Martin G

2017-02-01

Traditionally, trainees are instructed to practise with as few errors as possible during simulation-based training. However, transfer of learning may improve if trainees are encouraged to commit errors. The aim of this study was to assess the effects of error management instructions compared with error avoidance instructions during simulation-based ultrasound training. Medical students (n = 60) with no prior ultrasound experience were randomised to error management training (EMT) (n = 32) or error avoidance training (EAT) (n = 28). The EMT group was instructed to deliberately make errors during training. The EAT group was instructed to follow the simulator instructions and to commit as few errors as possible. Training consisted of 3 hours of simulation-based ultrasound training focusing on fetal weight estimation. Simulation-based tests were administered before and after training. Transfer tests were performed on real patients 7-10 days after the completion of training. Primary outcomes were transfer test performance scores and diagnostic accuracy. Secondary outcomes included performance scores and diagnostic accuracy during the simulation-based pre- and post-tests. A total of 56 participants completed the study. On the transfer test, EMT group participants attained higher performance scores (mean score: 67.7%, 95% confidence interval [CI]: 62.4-72.9%) than EAT group members (mean score: 51.7%, 95% CI: 45.8-57.6%) (p < 0.001; Cohen's d = 1.1, 95% CI: 0.5-1.7). There was a moderate improvement in diagnostic accuracy in the EMT group compared with the EAT group (16.7%, 95% CI: 10.2-23.3% weight deviation versus 26.6%, 95% CI: 16.5-36.7% weight deviation [p = 0.082; Cohen's d = 0.46, 95% CI: -0.06 to 1.0]). No significant interaction effects between group and performance improvements between the pre- and post-tests were found in either performance scores (p = 0.25) or diagnostic accuracy (p = 0.09). The provision of error management instructions during simulation-based training improves the transfer of learning to the clinical setting compared with error avoidance instructions. Rather than teaching to avoid errors, the use of errors for learning should be explored further in medical education theory and practice. © 2016 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

Establishing Baseline Normative Values for the Child Sport Concussion Assessment Tool.

PubMed

Brooks, M Alison; Snedden, Traci R; Mixis, Benjamin; Hetzel, Scott; McGuine, Timothy A

2017-07-01

The Child Sport Concussion Assessment Tool (SCAT3) is a postconcussion sideline assessment tool measuring symptoms, cognition, and balance in preadolescent children. Minimal normative baseline data exist to aid decision making in clinical and athletic settings. To collect normative baseline data for the Child SCAT3 in a large cohort of young athletes. A cross-sectional study was conducted from May 31 to August 12, 2014, at various sporting events (basketball, soccer, baseball, and swimming) in Central Wisconsin among children 5 to 13 years of age who were English-speaking and did not report a lower leg injury within the past 2 months or a concussion within the past month. Data were analyzed between October 8, 2014, and September 12, 2016. All Child SCAT3 components were assessed: child and parent report of symptom number and severity, cognition (Standardized Assessment of Concussion-child version [SAC-C]), and balance (modified Balance Error Scoring System [mBESS] and tandem gait). Summary statistics, mean differences, and effect sizes were calculated for each test component. Participants included 478 children (234 girls and 241 boys; mean [SD] age, 9.9 [1.9] years]) and their parents. Age had the largest effect on all Child SCAT3 components, with children 5 to 7 years of age reporting higher mean (SD) symptom severity scores compared with those 11 to 13 years of age (18.2 [10.0] vs 11.3 [9.0]; mean difference, 6.86 [95% CI, 4.22-9.50]; effect size, 0.74) and performing more poorly on the total SAC-C (mean [SD] score, 19.5 [5.1] vs 26.1 [2.1]; mean difference, -6.59 [95% CI, -7.49 to -5.68]; effect size, -2.1), mBESS (mean [SD] score, 1.67 [1.8] vs 0.76 [1.2]; mean difference, 0.91 [95% CI, 0.53-1.29]; effect size, 0.68), and tandem gait (mean [SD] time, 22.2 [8.3] vs 14.0 [3.7] seconds; mean difference, 8.23 seconds [95% CI, 6.63-9.82]; effect size, 1.55). Sex had a small effect on the mean (SD) number and severity of symptoms reported by the child (severity: boys, 15.1 [9.8] vs girls, 11.8 [9.2]; mean difference, 3.31 [95% CI, 1.60-5.02]; effect size, 0.35), mean (SD) number and severity of symptoms reported by the parent (severity: boys, 11.1 [7.7] vs girls, 9.4 [8.1]; mean difference, 1.63 [95% CI, 0.21-3.05]; effect size, 0.21), mean (SD) total SAC-C score (boys, 23.9 [3.9] vs girls, 24.9 [3.5]; mean difference, -0.92 [95% CI, -1.61 to -0.23]; effect size, -0.25), and mean (SD) mBESS score (boys, 1.21 [1.5] vs girls, 0.71 [1.0]; mean difference, 0.50 [95% CI, 0.27-0.74]; effect size, 0.38). Child SCAT3 baseline normative symptom, cognitive, and balance scores were different, with a large main effect for age and a small effect for sex. These findings may assist health care professionals with interpretation of Child SCAT3 scores for young athletes with a concussion in athletic and clinical settings.

Conditional standard errors of measurement for composite scores on the Wechsler Preschool and Primary Scale of Intelligence-Third Edition.

PubMed

Price, Larry R; Raju, Nambury; Lurie, Anna; Wilkins, Charles; Zhu, Jianjun

2006-02-01

A specific recommendation of the 1999 Standards for Educational and Psychological Testing by the American Educational Research Association, the American Psychological Association, and the National Council on Measurement in Education is that test publishers report estimates of the conditional standard error of measurement (SEM). Procedures for calculating the conditional (score-level) SEM based on raw scores are well documented; however, few procedures have been developed for estimating the conditional SEM of subtest or composite scale scores resulting from a nonlinear transformation. Item response theory provided the psychometric foundation to derive the conditional standard errors of measurement and confidence intervals for composite scores on the Wechsler Preschool and Primary Scale of Intelligence-Third Edition.

Investigating the role of background and observation error correlations in improving a model forecast of forest carbon balance using four dimensional variational data assimilation.

NASA Astrophysics Data System (ADS)

Pinnington, Ewan; Casella, Eric; Dance, Sarah; Lawless, Amos; Morison, James; Nichols, Nancy; Wilkinson, Matthew; Quaife, Tristan

2016-04-01

Forest ecosystems play an important role in sequestering human emitted carbon-dioxide from the atmosphere and therefore greatly reduce the effect of anthropogenic induced climate change. For that reason understanding their response to climate change is of great importance. Efforts to implement variational data assimilation routines with functional ecology models and land surface models have been limited, with sequential and Markov chain Monte Carlo data assimilation methods being prevalent. When data assimilation has been used with models of carbon balance, background "prior" errors and observation errors have largely been treated as independent and uncorrelated. Correlations between background errors have long been known to be a key aspect of data assimilation in numerical weather prediction. More recently, it has been shown that accounting for correlated observation errors in the assimilation algorithm can considerably improve data assimilation results and forecasts. In this paper we implement a 4D-Var scheme with a simple model of forest carbon balance, for joint parameter and state estimation and assimilate daily observations of Net Ecosystem CO2 Exchange (NEE) taken at the Alice Holt forest CO2 flux site in Hampshire, UK. We then investigate the effect of specifying correlations between parameter and state variables in background error statistics and the effect of specifying correlations in time between observation error statistics. The idea of including these correlations in time is new and has not been previously explored in carbon balance model data assimilation. In data assimilation, background and observation error statistics are often described by the background error covariance matrix and the observation error covariance matrix. We outline novel methods for creating correlated versions of these matrices, using a set of previously postulated dynamical constraints to include correlations in the background error statistics and a Gaussian correlation function to include time correlations in the observation error statistics. The methods used in this paper will allow the inclusion of time correlations between many different observation types in the assimilation algorithm, meaning that previously neglected information can be accounted for. In our experiments we compared the results using our new correlated background and observation error covariance matrices and those using diagonal covariance matrices. We found that using the new correlated matrices reduced the root mean square error in the 14 year forecast of daily NEE by 44 % decreasing from 4.22 g C m-2 day-1 to 2.38 g C m-2 day-1.

Does correction of preoperative coronal imbalance make a difference in outcomes of adult patients with deformity?

PubMed

Daubs, Michael D; Lenke, Lawrence G; Bridwell, Keith H; Kim, Yongjung J; Hung, Man; Cheh, Gene; Koester, Linda A

2013-03-15

Retrospective study with prospectively collected outcomes data. Determine the significance of coronal balance on spinal deformity surgery outcomes. Sagittal balance has been confirmed as an important radiographic parameter correlating with adult deformity treatment outcomes. The significance of coronal balance on functional outcomes is less clear. Eighty-five patients with more than 4 cm of coronal imbalance who underwent reconstructive spinal surgery were evaluated to determine the significance of coronal balance on functional outcomes as measured with the Oswestry Disability Index (ODI) and Scoliosis Research Society outcomes questionnaires. Sixty-two patients had combined coronal (>4 cm) and sagittal imbalance (>5 cm), while 23 patients had coronal imbalance alone. Postoperatively, 85% of patients demonstrated improved coronal balance. The mean improvement in the coronal C7 plumb line was 26 mm for a mean correction of 42%. The mean preoperative sagittal C7 plumb line in patients with combined coronal and sagittal imbalance was 118 mm (range, 50-310 mm) and improved to a mean 49 mm. The mean preoperative and postoperative ODI scores were 42 (range, 0-90) and 27 (range, 0-78), for a mean improvement of 15 (36%) (P = 0.00001; 95% CI, 12-20). The mean Scoliosis Research Society scores improved by 17 points (29%) (P = 0.00). Younger age (P = 0.008) and improvement in sagittal balance (P = 0.014) were positive predictors for improved ODI scores. Improvement in sagittal balance (P = 0.010) was a positive predictor for improved Scoliosis Research Society scores. In patients with combined coronal and sagittal imbalance, improvement in sagittal balance was the most significant predictor for improved ODI scores (P = 0.009). In patients with preoperative coronal imbalance alone, improvement in coronal balance trended toward, but was not a significant predictor for improved ODI (P = 0.092). Sagittal balance improvement is the strongest predictor of improved outcomes in patients with combined coronal and sagittal imbalance. In patients with coronal imbalance alone, improvement in coronal balance was not a factor for predicting improved functional outcomes.

Balancing the books - a statistical theory of prospective budgets in Earth System science

NASA Astrophysics Data System (ADS)

O'Kane, J. Philip

An honest declaration of the error in a mass, momentum or energy balance, ɛ, simply raises the question of its acceptability: "At what value of ɛ is the attempted balance to be rejected?" Answering this question requires a reference quantity against which to compare ɛ. This quantity must be a mathematical function of all the data used in making the balance. To deliver this function, a theory grounded in a workable definition of acceptability is essential. A distinction must be drawn between a retrospective balance and a prospective budget in relation to any natural space-filling body. Balances look to the past; budgets look to the future. The theory is built on the application of classical sampling theory to the measurement and closure of a prospective budget. It satisfies R.A. Fisher's "vital requirement that the actual and physical conduct of experiments should govern the statistical procedure of their interpretation". It provides a test, which rejects, or fails to reject, the hypothesis that the closing error on the budget, when realised, was due to sampling error only. By increasing the number of measurements, the discrimination of the test can be improved, controlling both the precision and accuracy of the budget and its components. The cost-effective design of such measurement campaigns is discussed briefly. This analysis may also show when campaigns to close a budget on a particular space-filling body are not worth the effort for either scientific or economic reasons. Other approaches, such as those based on stochastic processes, lack this finality, because they fail to distinguish between different types of error in the mismatch between a set of realisations of the process and the measured data.

Impact of Measurement Error on Statistical Power: Review of an Old Paradox.

ERIC Educational Resources Information Center

Williams, Richard H.; And Others

1995-01-01

The paradox that a Student t-test based on pretest-posttest differences can attain its greatest power when the difference score reliability is zero was explained by demonstrating that power is not a mathematical function of reliability unless either true score variance or error score variance is constant. (SLD)

Methods for Constructing and Assessing Propensity Scores

PubMed Central

Garrido, Melissa M; Kelley, Amy S; Paris, Julia; Roza, Katherine; Meier, Diane E; Morrison, R Sean; Aldridge, Melissa D

2014-01-01

Objectives To model the steps involved in preparing for and carrying out propensity score analyses by providing step-by-step guidance and Stata code applied to an empirical dataset. Study Design Guidance, Stata code, and empirical examples are given to illustrate (1) the process of choosing variables to include in the propensity score; (2) balance of propensity score across treatment and comparison groups; (3) balance of covariates across treatment and comparison groups within blocks of the propensity score; (4) choice of matching and weighting strategies; (5) balance of covariates after matching or weighting the sample; and (6) interpretation of treatment effect estimates. Empirical Application We use data from the Palliative Care for Cancer Patients (PC4C) study, a multisite observational study of the effect of inpatient palliative care on patient health outcomes and health services use, to illustrate the development and use of a propensity score. Conclusions Propensity scores are one useful tool for accounting for observed differences between treated and comparison groups. Careful testing of propensity scores is required before using them to estimate treatment effects. PMID:24779867

Preschool speech error patterns predict articulation and phonological awareness outcomes in children with histories of speech sound disorders.

PubMed

Preston, Jonathan L; Hull, Margaret; Edwards, Mary Louise

2013-05-01

To determine if speech error patterns in preschoolers with speech sound disorders (SSDs) predict articulation and phonological awareness (PA) outcomes almost 4 years later. Twenty-five children with histories of preschool SSDs (and normal receptive language) were tested at an average age of 4;6 (years;months) and were followed up at age 8;3. The frequency of occurrence of preschool distortion errors, typical substitution and syllable structure errors, and atypical substitution and syllable structure errors was used to predict later speech sound production, PA, and literacy outcomes. Group averages revealed below-average school-age articulation scores and low-average PA but age-appropriate reading and spelling. Preschool speech error patterns were related to school-age outcomes. Children for whom >10% of their speech sound errors were atypical had lower PA and literacy scores at school age than children who produced <10% atypical errors. Preschoolers who produced more distortion errors were likely to have lower school-age articulation scores than preschoolers who produced fewer distortion errors. Different preschool speech error patterns predict different school-age clinical outcomes. Many atypical speech sound errors in preschoolers may be indicative of weak phonological representations, leading to long-term PA weaknesses. Preschoolers' distortions may be resistant to change over time, leading to persisting speech sound production problems.

Is Coefficient Alpha Robust to Non-Normal Data?

PubMed Central

Sheng, Yanyan; Sheng, Zhaohui

2011-01-01

Coefficient alpha has been a widely used measure by which internal consistency reliability is assessed. In addition to essential tau-equivalence and uncorrelated errors, normality has been noted as another important assumption for alpha. Earlier work on evaluating this assumption considered either exclusively non-normal error score distributions, or limited conditions. In view of this and the availability of advanced methods for generating univariate non-normal data, Monte Carlo simulations were conducted to show that non-normal distributions for true or error scores do create problems for using alpha to estimate the internal consistency reliability. The sample coefficient alpha is affected by leptokurtic true score distributions, or skewed and/or kurtotic error score distributions. Increased sample sizes, not test lengths, help improve the accuracy, bias, or precision of using it with non-normal data. PMID:22363306

Relationships among measures of balance, gait, and community integration in people with brain injury.

PubMed

Perry, Susan B; Woollard, Jason; Little, Susan; Shroyer, Kathleen

2014-01-01

To examine the relationship among measures of gait, balance, and community integration in adults with brain injury. Two rehabilitation hospitals. Thirty-four community-dwelling individuals with brain injury, aged 18 to 61 years (mean = 32 years), who were able to walk at least 12 m independently or with supervision. Mean time post-brain injury was 52 ± 44 months. Cross-sectional study. Community Balance and Mobility Scale, Dynamic Gait Index, Ten-Meter Walk Test for gait speed, and the Community Integration Questionnaire (CIQ). Mean balance and gait scores were as follows: 54 ± 26 of 96 on the Community Balance and Mobility Scale; 19 ± 5 of 24 on the Dynamic Gait Index; and gait speed of 1.36 ± 0.88 m/s. Mean score on the CIQ was 16 ± 5 of 29. Correlations between the balance/gait measures and the total CIQ score ranged from 0.21 to 0.30 and were not significant. All 3 balance/gait measures correlated significantly with the CIQ Productivity subscale (range = 0.38-0.52). The ability of people with brain injury to engage in work/school/volunteer activity may be reduced by impairments in balance and mobility. Future research should explore this relationship and determine whether interventions that improve balance and mobility result in improved community productivity.

Administration and Scoring Errors of Graduate Students Learning the WISC-IV: Issues and Controversies

ERIC Educational Resources Information Center

Mrazik, Martin; Janzen, Troy M.; Dombrowski, Stefan C.; Barford, Sean W.; Krawchuk, Lindsey L.

2012-01-01

A total of 19 graduate students enrolled in a graduate course conducted 6 consecutive administrations of the Wechsler Intelligence Scale for Children, 4th edition (WISC-IV, Canadian version). Test protocols were examined to obtain data describing the frequency of examiner errors, including administration and scoring errors. Results identified 511…

Exploring the Effectiveness of a Measurement Error Tutorial in Helping Teachers Understand Score Report Results

ERIC Educational Resources Information Center

Zapata-Rivera, Diego; Zwick, Rebecca; Vezzu, Margaret

2016-01-01

The goal of this study was to explore the effectiveness of a short web-based tutorial in helping teachers to better understand the portrayal of measurement error in test score reports. The short video tutorial included both verbal and graphical representations of measurement error. Results showed a significant difference in comprehension scores…

Balance confidence and falls in nondemented essential tremor patients: the role of cognition.

PubMed

Rao, Ashwini K; Gilman, Arthur; Louis, Elan D

2014-10-01

To examine (1) the effect of cognitive ability on balance confidence and falls, (2) the relationship of balance confidence and falls with quantitative measures of gait, and (3) measures that predict falls, in people with essential tremor (ET). Cross-sectional study. General community. People with ET (n=132) and control subjects (n=48). People with ET were divided into 2 groups based on the median score on the Modified Mini-Mental State Examination: those with lower cognitive test scores (ET-LCS) and those with higher cognitive test scores (ET-HCS). Not applicable. Six-item Activities of Balance Confidence (ABC-6) Scale and falls in the previous year. Participants with ET-LCS had lower ABC-6 scores and a greater number of falls than those with ET-HCS (P<.05 for all measures) or control subjects (P<.01 for all measures). Quantitative gait measures were significantly correlated with ABC-6 score and falls. Gait speed (P<.007) and ABC-6 score (P<.02) were significant predictors of falls. Receiver operating characteristic curve analysis revealed that gait speed <0.9m/s and ABC-6 score <51% were associated with moderate sensitivity and specificity in identifying fallers. People with ET-LCS have impaired gait and report lower balance confidence and a higher number of falls than their counterparts (ET-HCS) and than control subjects. We have identified assessments that are easily administered (gait speed, ABC-6 Scale) and are associated with falls in ET. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Identification of patient information corruption in the intensive care unit: using a scoring tool to direct quality improvements in handover.

PubMed

Pickering, Brian W; Hurley, Killian; Marsh, Brian

2009-11-01

To use a handover assessment tool for identifying patient information corruption and objectively evaluating interventions designed to reduce handover errors and improve medical decision making. The continuous monitoring, intervention, and evaluation of the patient in modern intensive care unit practice generates large quantities of information, the platform on which medical decisions are made. Information corruption, defined as errors of distortion/omission compared with the medical record, may result in medical judgment errors. Identifying these errors may lead to quality improvements in intensive care unit care delivery and safety. Handover assessment instrument development study divided into two phases by the introduction of a handover intervention. Closed, 17-bed, university-affiliated mixed surgical/medical intensive care unit. Senior and junior medical members of the intensive care unit team. Electronic handover page. Study subjects were asked to recall clinical information commonly discussed at handover on individual patients. The handover score measured the percentage of information correctly retained for each individual doctor-patient interaction. The clinical intention score, a subjective measure of medical judgment, was graded (1-5) by three blinded intensive care unit experts. A total of 137 interactions were scored. Median (interquartile range) handover scores for phases 1 and 2 were 79.07% (67.44-84.50) and 83.72% (76.16-88.37), respectively. Score variance was reduced by the handover intervention (p < .05). Increasing median handover scores, 68.60 to 83.72, were associated with increases in clinical intention scores from 1 to 5 (chi-square = 23.59, df = 4, p < .0001). When asked to recall clinical information discussed at handover, medical members of the intensive care unit team provide data that are significantly corrupted compared with the medical record. Low subjective clinical judgment scores are significant associated with low handover scores. The handover/clinical intention scores may, therefore, be useful screening tools for intensive care unit system vulnerability to medical error. Additionally, handover instruments can identify interventions that reduce system vulnerability to error and may be used to guide quality improvements in handover practice.

Effects of walking with a cane on balance and social participation among community-dwelling post-stroke individuals.

PubMed

Hamzat, T K; Kobiri, A

2008-06-01

Walking devices such as canes and frames are often prescribed to post-stroke individuals to enhance their balance and walking, and thus facilitate community reintegration and social participation. The aim of this study was to observe social participation and balance in post-stroke hemiparetic patients and compare the performance of those walking with a cane (AD group) and without a cane (WAD group). The relationships between cane usage and activity participation and balance were also studied. In this ex post facto research study, balance and social participation were evaluated using the Berg Balance Scale (BBS) and the Craig Handicap Assessment and Reporting Technique (CHART) in 50 individuals with hemiparesis secondary to first incidence hemispheric stroke. The study included 25 AD subjects (mean age 59.88+/-12.04 years) and 25 WAD subjects (mean age 55.84+/-11.30 years) who were consecutively recruited from the physiotherapy units of Korle Bu Teaching Hospital (KBTH) and the 37 Military Hospital in Accra (Ghana). Before recruitment into the study, both groups of subjects were matched for age, height, weight, BBS and CHART scores at the point of discharge from the inpatient units of the two hospitals, the duration of stroke, and the duration of physiotherapy post-stroke. Mann-Whitney U statistics showed that the AD group had comparatively higher mean participation scores (U=22.37; P=0.00) and lower mean balance performance (BBS score U=30.68; P=0.00) than their WAD counterparts. Spearman's correlation coefficient also revealed a significant negative correlation between the BBS and CHART scores in both groups (AD rho=-0.063; P=0.00 and WAD rho=-0.037; P=0.05). These findings indicate that post-stroke individuals who used a cane to aid in walking had poorer balance and less social participation than their age-matched counterparts who walked unaided. As balance improved (higher BBS score), participation also improved (lower CHART score) in both groups. In spite of the small sample size, the outcome of this study suggests that prescription of a cane for a post-stroke individual should be carefully considered by the physiotherapist, especially if the focus of rehabilitation includes restoration of balance functions and social participation.

Effects of Nintendo Wii-Fit® video games on balance in children with mild cerebral palsy.

PubMed

Tarakci, Devrim; Ersoz Huseyinsinoglu, Burcu; Tarakci, Ela; Razak Ozdincler, Arzu

2016-10-01

This study compared the effects of Nintendo Wii-Fit ® balance-based video games and conventional balance training in children with mild cerebral palsy (CP). This randomized controlled trial involved 30 ambulatory pediatric patients (aged 5-18 years) with CP. Participants were randomized to either conventional balance training (control group) or to Wii-Fit balance-based video games training (Wii group). Both group received neuro-developmental treatment (NDT) during 24 sessions. In addition, while the control group received conventional balance training in each session, the Wii group played Nintendo Wii Fit games such as ski slalom, tightrope walk and soccer heading on balance board. Primary outcomes were Functional Reach Test (forward and sideways), Sit-to-Stand Test and Timed Get up and Go Test. Nintendo Wii Fit balance, age and game scores, 10 m walk test, 10-step climbing test and Wee-Functional Independence Measure (Wee FIM) were secondary outcomes. After the treatment, changes in balance scores and independence level in activities of daily living were significant (P < 0.05) in both groups. Statistically significant improvements were found in the Wii-based game group compared with the control group in all balance tests and total Wee FIM score (P < 0.05). Wii-fit balance-based video games are better at improving both static and performance-related balance parameters when combined with NDT treatment in children with mild CP. © 2016 Japan Pediatric Society.

Undergraduate paramedic students cannot do drug calculations.

PubMed

Eastwood, Kathryn; Boyle, Malcolm J; Williams, Brett

2012-01-01

Previous investigation of drug calculation skills of qualified paramedics has highlighted poor mathematical ability with no published studies having been undertaken on undergraduate paramedics. There are three major error classifications. Conceptual errors involve an inability to formulate an equation from information given, arithmetical errors involve an inability to operate a given equation, and finally computation errors are simple errors of addition, subtraction, division and multiplication. The objective of this study was to determine if undergraduate paramedics at a large Australia university could accurately perform common drug calculations and basic mathematical equations normally required in the workplace. A cross-sectional study methodology using a paper-based questionnaire was administered to undergraduate paramedic students to collect demographical data, student attitudes regarding their drug calculation performance, and answers to a series of basic mathematical and drug calculation questions. Ethics approval was granted. The mean score of correct answers was 39.5% with one student scoring 100%, 3.3% of students (n=3) scoring greater than 90%, and 63% (n=58) scoring 50% or less, despite 62% (n=57) of the students stating they 'did not have any drug calculations issues'. On average those who completed a minimum of year 12 Specialist Maths achieved scores over 50%. Conceptual errors made up 48.5%, arithmetical 31.1% and computational 17.4%. This study suggests undergraduate paramedics have deficiencies in performing accurate calculations, with conceptual errors indicating a fundamental lack of mathematical understanding. The results suggest an unacceptable level of mathematical competence to practice safely in the unpredictable prehospital environment.

Multiple diabetic complications, as well as impaired physical and mental function, are associated with declining balance function in older persons with diabetes mellitus

PubMed Central

Hong, Xiufang; Chen, Xujiao; Chu, Jiaojiao; Shen, Shanshan; Chai, Qichen; Lou, Gaobo; Chen, Lingyan

2017-01-01

Objective To investigate whether there is a difference in balance function between older persons with and without diabetes mellitus (DM), and to identify whether mediating factors, such as diabetic complications, Instrumental Activities of Daily Living (IADL) score, Mini-Mental State Examination (MMSE) score, as well as hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), serum total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL), are associated with balance function in older persons with DM. Methods In this cross-sectional study, a total of 208 older persons were divided into a DM group (n=80) and a control group who did not have DM (n=128). Balance function was evaluated with the Tinetti performance-oriented mobility assessment (POMA), which includes balance and gait subscales. Activities of daily living (ADL), IADL, and the MMSE were also measured. Fall incidents in last 12 months, the use of walking aids, fear of falling, comorbidities, and polypharmacy were recorded. Diabetic complications were recorded, and HbA1c, FPG, TC, TG, and LDL were measured in the patients of the DM group. Results Fall incidents in last 12 months were higher in the DM group than in the control group (P<0.01). POMA score as well as ADL and IADL scores were lower in the diabetic group than the control group (P<0.05). Within the diabetic group, the POMA score was positively related to the ADL score (odds ratio [OR], 11.7; 95% confidence interval [CI], 3.076–44.497; P<0.01), IADL score (OR, 16.286; 95% CI, 4.793–55.333; P<0.01), and MMSE score (OR, 10.524; 95% CI, 2.764–40.074; P<0.01), but was negatively related to age (OR, 7.707; 95% CI, 2.035–29.185; P<0.01) and diabetic complication (OR, 6.667; 95% CI, 2.279–19.504; P<0.01). Also, within the DM group, the decreased POMA score was associated with multiple diabetic complications (OR, 5.977; 95% CI, 1.378–25.926; P<0.05), decreased IADL score (OR, 10.288; 95% CI, 2.410–43.915; P<0.01), and MMSE score (OR, 13.757; 95% CI, 2.556–74.048; P<0.01). Conclusion Multiple diabetic complications, lower MMSE, ADL, and IADL scores were associated with declining balance function in the older persons with DM. These findings can alert physicians to detect and intervene earlier on declining balance in older persons with DM. PMID:28182146

Accurate optical vector network analyzer based on optical single-sideband modulation and balanced photodetection.

PubMed

Xue, Min; Pan, Shilong; Zhao, Yongjiu

2015-02-15

A novel optical vector network analyzer (OVNA) based on optical single-sideband (OSSB) modulation and balanced photodetection is proposed and experimentally demonstrated, which can eliminate the measurement error induced by the high-order sidebands in the OSSB signal. According to the analytical model of the conventional OSSB-based OVNA, if the optical carrier in the OSSB signal is fully suppressed, the measurement result is exactly the high-order-sideband-induced measurement error. By splitting the OSSB signal after the optical device-under-test (ODUT) into two paths, removing the optical carrier in one path, and then detecting the two signals in the two paths using a balanced photodetector (BPD), high-order-sideband-induced measurement error can be ideally eliminated. As a result, accurate responses of the ODUT can be achieved without complex post-signal processing. A proof-of-concept experiment is carried out. The magnitude and phase responses of a fiber Bragg grating (FBG) measured by the proposed OVNA with different modulation indices are superimposed, showing that the high-order-sideband-induced measurement error is effectively removed.

The effect of nintendo wii on balance: a pilot study supporting the use of the wii in occupational therapy for the well elderly.

PubMed

Williams, Barbara; Doherty, Nicole L; Bender, Andrew; Mattox, Holly; Tibbs, Jesse R

2011-01-01

ABSTRACT This study explored the benefits that Nintendo's Wii Fit activities may have on the balance of 22 community living older adults. Over 4 weeks, participants completed twelve 20-min sessions using various programs in the Wii Fit. Pretest and posttest measurements were obtained using the Berg Balance Scale with participants scoring an average of 9.14 points higher on the postintervention. Posttest balance scores were significantly greater [t (21) = -9.861, p < .01] than pretest scores. Reports from the participants supported the positive use and possible improvements in quality of life. The results of this study suggest the potential effectiveness of utilizing the Nintendo Wii as a therapeutic agent in occupational therapy practice.

Preschool speech error patterns predict articulation and phonological awareness outcomes in children with histories of speech sound disorders

PubMed Central

Preston, Jonathan L.; Hull, Margaret; Edwards, Mary Louise

2012-01-01

Purpose To determine if speech error patterns in preschoolers with speech sound disorders (SSDs) predict articulation and phonological awareness (PA) outcomes almost four years later. Method Twenty-five children with histories of preschool SSDs (and normal receptive language) were tested at an average age of 4;6 and followed up at 8;3. The frequency of occurrence of preschool distortion errors, typical substitution and syllable structure errors, and atypical substitution and syllable structure errors were used to predict later speech sound production, PA, and literacy outcomes. Results Group averages revealed below-average school-age articulation scores and low-average PA, but age-appropriate reading and spelling. Preschool speech error patterns were related to school-age outcomes. Children for whom more than 10% of their speech sound errors were atypical had lower PA and literacy scores at school-age than children who produced fewer than 10% atypical errors. Preschoolers who produced more distortion errors were likely to have lower school-age articulation scores. Conclusions Different preschool speech error patterns predict different school-age clinical outcomes. Many atypical speech sound errors in preschool may be indicative of weak phonological representations, leading to long-term PA weaknesses. Preschool distortions may be resistant to change over time, leading to persisting speech sound production problems. PMID:23184137

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morley, Steven

The PyForecastTools package provides Python routines for calculating metrics for model validation, forecast verification and model comparison. For continuous predictands the package provides functions for calculating bias (mean error, mean percentage error, median log accuracy, symmetric signed bias), and for calculating accuracy (mean squared error, mean absolute error, mean absolute scaled error, normalized RMSE, median symmetric accuracy). Convenience routines to calculate the component parts (e.g. forecast error, scaled error) of each metric are also provided. To compare models the package provides: generic skill score; percent better. Robust measures of scale including median absolute deviation, robust standard deviation, robust coefficient ofmore » variation and the Sn estimator are all provided by the package. Finally, the package implements Python classes for NxN contingency tables. In the case of a multi-class prediction, accuracy and skill metrics such as proportion correct and the Heidke and Peirce skill scores are provided as object methods. The special case of a 2x2 contingency table inherits from the NxN class and provides many additional metrics for binary classification: probability of detection, probability of false detection, false alarm ration, threat score, equitable threat score, bias. Confidence intervals for many of these quantities can be calculated using either the Wald method or Agresti-Coull intervals.« less

Standard Errors of Estimated Latent Variable Scores with Estimated Structural Parameters

ERIC Educational Resources Information Center

Hoshino, Takahiro; Shigemasu, Kazuo

2008-01-01

The authors propose a concise formula to evaluate the standard error of the estimated latent variable score when the true values of the structural parameters are not known and must be estimated. The formula can be applied to factor scores in factor analysis or ability parameters in item response theory, without bootstrap or Markov chain Monte…

Environmental structure and competitive scoring advantages in team competitions.

PubMed

Merritt, Sears; Clauset, Aaron

2013-10-29

In most professional sports, playing field structure is kept neutral so that scoring imbalances may be attributed to differences in team skill. It thus remains unknown what impact environmental heterogeneities can have on scoring dynamics or competitive advantages. Applying a novel generative model of scoring dynamics to roughly 10 million team competitions drawn from an online game, we quantify the relationship between the structure within a competition and its scoring dynamics, while controlling the impact of chance. Despite wide structural variations, we observe a common three-phase pattern in the tempo of events. Tempo and balance are highly predictable from a competition's structural features alone and teams exploit environmental heterogeneities for sustained competitive advantage. Surprisingly, the most balanced competitions are associated with specific environmental heterogeneities, not from equally skilled teams. These results shed new light on the design principles of balanced competition, and illustrate the potential of online game data for investigating social dynamics and competition.

Environmental structure and competitive scoring advantages in team competitions

NASA Astrophysics Data System (ADS)

Merritt, Sears; Clauset, Aaron

2013-10-01

In most professional sports, playing field structure is kept neutral so that scoring imbalances may be attributed to differences in team skill. It thus remains unknown what impact environmental heterogeneities can have on scoring dynamics or competitive advantages. Applying a novel generative model of scoring dynamics to roughly 10 million team competitions drawn from an online game, we quantify the relationship between the structure within a competition and its scoring dynamics, while controlling the impact of chance. Despite wide structural variations, we observe a common three-phase pattern in the tempo of events. Tempo and balance are highly predictable from a competition's structural features alone and teams exploit environmental heterogeneities for sustained competitive advantage. Surprisingly, the most balanced competitions are associated with specific environmental heterogeneities, not from equally skilled teams. These results shed new light on the design principles of balanced competition, and illustrate the potential of online game data for investigating social dynamics and competition.

Dalfampridine Effects Beyond Walking Speed in Multiple Sclerosis

PubMed Central

Fjeldstad, Cecilie; Suárez, Gustavo; Klingler, Michael; Henney, Herbert R.; Rabinowicz, Adrian L.

2015-01-01

Background: Dalfampridine extended release (ER) improves walking in people with multiple sclerosis (MS), as demonstrated by walking speed improvement. This exploratory study evaluated treatment effects of dalfampridine-ER on gait, balance, and walking through treatment withdrawal and reinitiation. Methods: Dalfampridine-ER responders, based on Timed 25-Foot Walk (T25FW) assessment before study entry, were included in this open-label, three-period, single-center study. Period 1: on-drug evaluations performed at screening and 1 week after screening. Period 2: dalfampridine-ER withdrawal and off-drug evaluations (days 5 and 11). Period 3: dalfampridine-ER reinitiation/final on-drug evaluation (day 15). Primary outcome variables: NeuroCom composite scores for gait and balance; balance was evaluated if gait changes were significant. Secondary variables: individual NeuroCom scores, walking speed (T25FW) and distance (2-Minute Walk Test [2MWT]), and balance (Berg Balance Scale [BBS]). Results: All 20 patients completed the study: mean age, 53.1 years; mean MS duration, 11.3 years; mean time taking dalfampridine-ER, 315.3 days. NeuroCom gait composite scores worsened during period 2 relative to period 1 and improved during period 3; the mean ± SD difference in gait composite scores on drug was 4.03 ± 1.51 points (P = .015). Balance composite scores did not change significantly. Improvements were observed for off-drug versus on-drug for T25FW (0.36 ft/sec, P < .001), 2MWT (25.4 ft, P = .006), and BBS (1.7 points, P = .003). Safety profile was consistent with previous studies. Conclusions: Significant improvements in gait, walking speed, distance, and balance were demonstrated by dalfampridine-ER reinitiation after a 10-day withdrawal period. PMID:26664333

Effects of Uncertainties in Hydrological Modelling. A Case Study of a Mountainous Catchment in Southern Norway

NASA Astrophysics Data System (ADS)

Engeland, Kolbjorn; Steinsland, Ingelin

2016-04-01

The aim of this study is to investigate how the inclusion of uncertainties in inputs and observed streamflow influence the parameter estimation, streamflow predictions and model evaluation. In particular we wanted to answer the following research questions: • What is the effect of including a random error in the precipitation and temperature inputs? • What is the effect of decreased information about precipitation by excluding the nearest precipitation station? • What is the effect of the uncertainty in streamflow observations? • What is the effect of reduced information about the true streamflow by using a rating curve where the measurement of the highest and lowest streamflow is excluded when estimating the rating curve? To answer these questions, we designed a set of calibration experiments and evaluation strategies. We used the elevation distributed HBV model operating on daily time steps combined with a Bayesian formulation and the MCMC routine Dream for parameter inference. The uncertainties in inputs was represented by creating ensembles of precipitation and temperature. The precipitation ensemble were created using a meta-gaussian random field approach. The temperature ensembles were created using a 3D Bayesian kriging with random sampling of the temperature laps rate. The streamflow ensembles were generated by a Bayesian multi-segment rating curve model. Precipitation and temperatures were randomly sampled for every day, whereas the streamflow ensembles were generated from rating curve ensembles, and the same rating curve was always used for the whole time series in a calibration or evaluation run. We chose a catchment with a meteorological station measuring precipitation and temperature, and a rating curve of relatively high quality. This allowed us to investigate and further test the effect of having less information on precipitation and streamflow during model calibration, predictions and evaluation. The results showed that including uncertainty in the precipitation and temperature input has a negligible effect on the posterior distribution of parameters and for the Nash-Sutcliffe (NS) efficiency for the predicted flows, while the reliability and the continuous rank probability score (CRPS) improves. Reduced information in precipitation input resulted in a and a shift in the water balance parameter Pcorr, a model producing smoother streamflow predictions giving poorer NS and CRPS, but higher reliability. The effect of calibrating the hydrological model using wrong rating curves is mainly seen as variability in the water balance parameter Pcorr. When evaluating predictions obtained using a wrong rating curve, the evaluation scores varies depending on the true rating curve. Generally, the best evaluation scores were not achieved for the rating curve used for calibration, but for a rating curves giving low variance in streamflow observations. Reduced information in streamflow influenced the water balance parameter Pcorr, and increased the spread in evaluation scores giving both better and worse scores. This case study shows that estimating the water balance is challenging since both precipitation inputs and streamflow observations have pronounced systematic component in their uncertainties.

The Importance of Relying on the Manual: Scoring Error Variance in the WISC-IV Vocabulary Subtest

ERIC Educational Resources Information Center

Erdodi, Laszlo A.; Richard, David C. S.; Hopwood, Christopher

2009-01-01

Classical test theory assumes that ability level has no effect on measurement error. Newer test theories, however, argue that the precision of a measurement instrument changes as a function of the examinee's true score. Research has shown that administration errors are common in the Wechsler scales and that subtests requiring subjective scoring…

Error Rates in Measuring Teacher and School Performance Based on Student Test Score Gains. NCEE 2010-4004

ERIC Educational Resources Information Center

Schochet, Peter Z.; Chiang, Hanley S.

2010-01-01

This paper addresses likely error rates for measuring teacher and school performance in the upper elementary grades using value-added models applied to student test score gain data. Using realistic performance measurement system schemes based on hypothesis testing, we develop error rate formulas based on OLS and Empirical Bayes estimators.…

The dual task-cost of standing balance affects quality of life in mildly disabled MS people.

PubMed

Castelli, Letizia; De Luca, Francesca; Marchetti, Maria Rita; Sellitto, Giovanni; Fanelli, Fulvia; Prosperini, Luca

2016-05-01

The aim of this study was to explore the correlations between the dual-task cost (DTC) of standing balance and quality of life (QoL) in mildly disabled patients with multiple sclerosis (MS). In this cross-sectional study, patients affected by MS with an expanded disability status scale (EDSS) score of 3.0 or less and without an overt balance impairment were tested by means of static posturography under eyes-opened (single-task condition) and while performing the Stroop word-color test (dual-task condition), to estimate the DTC of standing balance. The self-reported 54-item MS quality of life questionnaire (MSQoL-54) was also administered to obtain a MS-specific assessment of health-related QoL. Among the 120 screened patients, 75 (53 women, 22 men) were tested. Although there was no impact of the DTC of standing balance on the physical and mental composite scores of MSQoL-54, patients who had a greater DTC of standing balance scored worse on role limitations due to physical problems (p = 0.007) and social function (p < 0.001), irrespective of demographic and other clinical characteristics including walking performance and cognitive status. However, the EDSS step and fatigue also contributed to reduced scores in these two QoL domains (p-values < 0.01). In conclusion, the phenomenon of cognitive-motor interference, investigated as DTC of standing balance, may affect specific QoL domains even in mildly disabled patients with MS and in the absence of an overt balance dysfunction.

Neurological tests improve after Olympic-style boxing bouts: a pretournament and post-tournament study in the 2016 Women's World Boxing Championships.

PubMed

Howell, David R; Meehan, William P; Loosemore, Michael P; Cummiskey, Joseph; Grabner von Rosenberg, Jean-Paul; McDonagh, David

2017-09-01

To prospectively examine the neurocognitive, postural, dual-task and visual abilities of female Olympic-style boxers before and after participation in a tournament. Sixty-one females completed the modified Balance Error Scoring System (mBESS), King-Devick test and 3 m timed-up-and-go test in single-task and dual-task conditions. A subset (n=31) completed the CogState computerised neurocognitive test. Initial testing was completed prior to the 2016 Women's World Boxing Championships; each participant repeated the testing protocol within a day of elimination. No participant sustained a concussion. Pretournament and post-tournament performance variables were compared using paired t-tests or Wilcoxon signed-rank tests. Participants completed a mean of 7.5±4.5 rounds of Olympic-style boxing over 2-8 days. Post-tournament scores were significantly lower than pretournament scores for total mBESS (2.2±1.9 errors vs 5.5±2.9 errors, p<0.001, d =1.23) and King-Devick time (14.2±3.9 s vs 18.0±8.3 s, p=0.002, d =0.53). Processing speed was significantly faster after the boxing tournament (maze chase task: 1.39±0.34 correct moves/second vs 1.17±0.44 correct moves/second, p=0.001, d =0.58). No significant changes across time were detected for the other obtained outcome variables. Female boxers demonstrated either improvement or no significant changes in test performance after competing in an Olympic-style boxing tournament, relative to pretournament performance. As many of the test tasks were novel for the boxers, practice effects may have contributed to improved performance. When there is a short time frame between assessments, clinicians should be aware of potential practice effects when using ringside neurological tests. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Detection and Use of Load and Gage Output Repeats of Wind Tunnel Strain-Gage Balance Data

NASA Technical Reports Server (NTRS)

Ulbrich, N.

2017-01-01

Criteria are discussed that may be used for the detection of load and gage output repeats of wind tunnel strain-gage balance data. First, empirical thresholds are introduced that help determine if the loads or electrical outputs of a pair of balance calibration or check load data points match. A threshold of 0.01 percent of the load capacity is suggested for the identification of matching loads. Similarly, a threshold of 0.1 microV/V is recommended for the identification of matching electrical outputs. Two examples for the use of load and output repeats are discussed to illustrate benefits of the implementation of a repeat point detection algorithm in a balance data analysis software package. The first example uses the suggested load threshold to identify repeat data points that may be used to compute pure errors of the balance loads. This type of analysis may reveal hidden data quality issues that could potentially be avoided by making calibration process improvements. The second example uses the electrical output threshold for the identification of balance fouling. Data from the calibration of a six-component force balance is used to illustrate the calculation of the pure error of the balance loads.

Safety culture perceptions of pharmacists in Malaysian hospitals and health clinics: a multicentre assessment using the Safety Attitudes Questionnaire

PubMed Central

Samsuri, Srima Elina; Pei Lin, Lua; Fahrni, Mathumalar Loganathan

2015-01-01

Objective To assess the safety attitudes of pharmacists, provide a profile of their domains of safety attitude and correlate their attitudes with self-reported rates of medication errors. Design A cross-sectional study utilising the Safety Attitudes Questionnaire (SAQ). Setting 3 public hospitals and 27 health clinics. Participants 117 pharmacists. Main outcome measure(s) Safety culture mean scores, variation in scores across working units and between hospitals versus health clinics, predictors of safety culture, and medication errors and their correlation. Results Response rate was 83.6% (117 valid questionnaires returned). Stress recognition (73.0±20.4) and working condition (54.8±17.4) received the highest and lowest mean scores, respectively. Pharmacists exhibited positive attitudes towards: stress recognition (58.1%), job satisfaction (46.2%), teamwork climate (38.5%), safety climate (33.3%), perception of management (29.9%) and working condition (15.4%). With the exception of stress recognition, those who worked in health clinics scored higher than those in hospitals (p<0.05) and higher scores (overall score as well as score for each domain except for stress recognition) correlated negatively with reported number of medication errors. Conversely, those working in hospital (versus health clinic) were 8.9 times more likely (p<0.01) to report a medication error (OR 8.9, CI 3.08 to 25.7). As stress recognition increased, the number of medication errors reported increased (p=0.023). Years of work experience (p=0.017) influenced the number of medication errors reported. For every additional year of work experience, pharmacists were 0.87 times less likely to report a medication error (OR 0.87, CI 0.78 to 0.98). Conclusions A minority (20.5%) of the pharmacists working in hospitals and health clinics was in agreement with the overall SAQ questions and scales. Pharmacists in outpatient and ambulatory units and those in health clinics had better perceptions of safety culture. As perceptions improved, the number of medication errors reported decreased. Group-specific interventions that target specific domains are necessary to improve the safety culture. PMID:26610761

Effect of quadriceps and hamstrings muscle cooling on standing balance in healthy young men.

PubMed

Alghadir, A H; Anwer, S; Zafar, H; Al-Eisa, E S

2017-09-01

The present study compared the effect of quadriceps and hamstring muscle cooling on standing balance in healthy young men. Thirty healthy young men (18-30 years) participated in the study. The participants were randomly assigned to three groups (n=10 each): quadriceps cooling (QC), hamstring cooling (HC), or control group (no cooling). Participants in the QC and HC groups received 20 minutes of cooling using a cold pack (gel pack), placed on the anterior thigh (from the apex of the patella to the mid-thigh) and the posterior thigh (from the base of the popliteal fossa to the mid-thigh), respectively. Balance score including unilateral stance was measured at baseline and immediately after the application of the cold pack. No significant difference in the balance score was noted in any group after the application of the cold pack (p⟩0.05). Similarly, no significant differences in post-test balance score were noted among the three groups (p⟩0.05). Cooling of the quadriceps and hamstring muscles has no immediate effect on standing balance in healthy young men. However, longitudinal studies are warranted to investigate the long-term effects of cooling these muscles on standing balance.

Sex Differences in Balance Among Alpine Ski Racers: Cross-Sectional Age Comparisons.

PubMed

Raschner, Christian; Hildebrandt, Carolin; Mohr, Johanna; Müller, Lisa

2017-12-01

Although balance is a key ability in the strength demands of alpine ski racing, affecting both performance and injury prevention, few studies have examined balance or related sex differences among still-maturing athletes. In this 10-year study, we investigated cross-sectional balance performances at different age periods of a representative sample of over 500 11-18-year-old elite skiers of both genders. Participants performed balance tests using the MFT S3-Check. Left-right and forward-backward movements were used to calculate sensory and symmetry balance scores, which were both incorporated into a stability score. Mann-Whitney U tests assessed gender-specific differences by age-group with a significance level set at p < .05. Results showed gender differences only on forward-backward measurements for 14-16-year-olds, with females showing better stability and sensory (but not symmetry) scores than males. Thus, gender interacted with age and maturation to influence balance ability in these participants. Additionally, these rare 10-year data support coaches in their training and talent development of maturing athletes by providing important sport-, age-, and gender-specific normative comparison data for individual trainees.

Feasibility of a Low-Cost, Interactive Gaming System to Assess Balance in Older Women.

PubMed

Hall, Courtney D; Clevenger, Carolyn K; Wolf, Rachel A; Lin, James S; Johnson, Theodore M; Wolf, Steven L

2016-01-01

The use of low-cost interactive game technology for balance rehabilitation has become more popular recently, with generally good outcomes. Very little research has been undertaken to determine whether this technology is appropriate for balance assessment. The Wii balance board has good reliability and is comparable to a research-grade force plate; however, recent studies examining the relationship between Wii Fit games and measures of balance and mobility demonstrate conflicting findings. This study found that the Wii Fit was feasible for community-dwelling older women to safely use the balance board and quickly learn the Wii Fit games. The Ski Slalom game scores were strongly correlated with several balance and mobility measures, whereas Table Tilt game scores were not. Based on these findings, the Ski Slalom game may have utility in the evaluation of balance problems in community-dwelling older adults.

Emotion perception, non-social cognition and symptoms as predictors of theory of mind in schizophrenia.

PubMed

Vaskinn, Anja; Andersson, Stein; Østefjells, Tiril; Andreassen, Ole A; Sundet, Kjetil

2018-06-05

Theory of mind (ToM) can be divided into cognitive and affective ToM, and a distinction can be made between overmentalizing and undermentalizing errors. Research has shown that ToM in schizophrenia is associated with non-social and social cognition, and with clinical symptoms. In this study, we investigate cognitive and clinical predictors of different ToM processes. Ninety-one individuals with schizophrenia participated. ToM was measured with the Movie for the Assessment of Social Cognition (MASC) yielding six scores (total ToM, cognitive ToM, affective ToM, overmentalizing errors, undermentalizing errors and no mentalizing errors). Neurocognition was indexed by a composite score based on the non-social cognitive tests in the MATRICS Consensus Cognitive Battery (MCCB). Emotion perception was measured with Emotion in Biological Motion (EmoBio), a point-light walker task. Clinical symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). Seventy-one healthy control (HC) participants completed the MASC. Individuals with schizophrenia showed large impairments compared to HC for all MASC scores, except overmentalizing errors. Hierarchical regression analyses with the six different MASC scores as dependent variables revealed that MCCB was a significant predictor of all MASC scores, explaining 8-18% of the variance. EmoBio increased the explained variance significantly, to 17-28%, except for overmentalizing errors. PANSS excited symptoms increased explained variance for total ToM, affective ToM and no mentalizing errors. Both social and non-social cognition were significant predictors of ToM. Overmentalizing was only predicted by non-social cognition. Excited symptoms contributed to overall and affective ToM, and to no mentalizing errors. Copyright © 2018 Elsevier Inc. All rights reserved.

Sustained attention to response task (SART) shows impaired vigilance in a spectrum of disorders of excessive daytime sleepiness.

PubMed

Van Schie, Mojca K M; Thijs, Roland D; Fronczek, Rolf; Middelkoop, Huub A M; Lammers, Gert Jan; Van Dijk, J Gert

2012-08-01

The sustained attention to response task comprises withholding key presses to one in nine of 225 target stimuli; it proved to be a sensitive measure of vigilance in a small group of narcoleptics. We studied sustained attention to response task results in 96 patients from a tertiary narcolepsy referral centre. Diagnoses according to ICSD-2 criteria were narcolepsy with (n=42) and without cataplexy (n=5), idiopathic hypersomnia without long sleep time (n=37), and obstructive sleep apnoea syndrome (n=12). The sustained attention to response task was administered prior to each of five multiple sleep latency test sessions. Analysis concerned error rates, mean reaction time, reaction time variability and post-error slowing, as well as the correlation of sustained attention to response task results with mean latency of the multiple sleep latency test and possible time of day influences. Median sustained attention to response task error scores ranged from 8.4 to 11.1, and mean reaction times from 332 to 366ms. Sustained attention to response task error score and mean reaction time did not differ significantly between patient groups. Sustained attention to response task error score did not correlate with multiple sleep latency test sleep latency. Reaction time was more variable as the error score was higher. Sustained attention to response task error score was highest for the first session. We conclude that a high sustained attention to response task error rate reflects vigilance impairment in excessive daytime sleepiness irrespective of its cause. The sustained attention to response task and the multiple sleep latency test reflect different aspects of sleep/wakefulness and are complementary. © 2011 European Sleep Research Society.

40 CFR 98.123 - Calculating GHG emissions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... mass balance approach to estimate your fluorinated GHG emissions from a process, you must ensure that... relative errors associated with using the mass balance approach on that process using Equations L-1 through... mass-balance approach to estimate emissions from the process if this calculation results in an absolute...

40 CFR 98.123 - Calculating GHG emissions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... mass balance approach to estimate your fluorinated GHG emissions from a process, you must ensure that... relative errors associated with using the mass balance approach on that process using Equations L-1 through... mass-balance approach to estimate emissions from the process if this calculation results in an absolute...

40 CFR 98.123 - Calculating GHG emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... mass balance approach to estimate your fluorinated GHG emissions from a process, you must ensure that... relative errors associated with using the mass balance approach on that process using Equations L-1 through... mass-balance approach to estimate emissions from the process if this calculation results in an absolute...

40 CFR 98.123 - Calculating GHG emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... mass balance approach to estimate your fluorinated GHG emissions from a process, you must ensure that... relative errors associated with using the mass balance approach on that process using Equations L-1 through... mass-balance approach to estimate emissions from the process if this calculation results in an absolute...

Comparison of Objective Measures for Predicting Perceptual Balance and Visual Aesthetic Preference

PubMed Central

Hübner, Ronald; Fillinger, Martin G.

2016-01-01

The aesthetic appreciation of a picture largely depends on the perceptual balance of its elements. The underlying mental mechanisms of this relation, however, are still poorly understood. For investigating these mechanisms, objective measures of balance have been constructed, such as the Assessment of Preference for Balance (APB) score of Wilson and Chatterjee (2005). In the present study we examined the APB measure and compared it to an alternative measure (DCM; Deviation of the Center of “Mass”) that represents the center of perceptual “mass” in a picture and its deviation from the geometric center. Additionally, we applied measures of homogeneity and of mirror symmetry. In a first experiment participants had to rate the balance and symmetry of simple pictures, whereas in a second experiment different participants rated their preference (liking) for these pictures. In a third experiment participants rated the balance as well as the preference of new pictures. Altogether, the results show that DCM scores accounted better for balance ratings than APB scores, whereas the opposite held with respect to preference. Detailed analyses revealed that these results were due to the fact that aesthetic preference does not only depend on balance but also on homogeneity, and that the APB measure takes this feature into account. PMID:27014143

M-071 critical data analysis

NASA Technical Reports Server (NTRS)

Hegsted, D. M.

1975-01-01

A prototype balance study was conducted on earth prior to the balance studies conducted in Skylab itself. Collected were daily dietary intake data of 6 minerals and nitrogen, and fecal and urinary outputs on each of three astronauts. Essential statistical issues show what quantities need to be estimated and establish the scope of inference associated with alternative variance estimates. The procedures for obtaining the final variability due both to errors of measurement and total error (total = measurement and biological variability) are exhibited.

The Impact of Measurement Error on the Accuracy of Individual and Aggregate SGP

ERIC Educational Resources Information Center

McCaffrey, Daniel F.; Castellano, Katherine E.; Lockwood, J. R.

2015-01-01

Student growth percentiles (SGPs) express students' current observed scores as percentile ranks in the distribution of scores among students with the same prior-year scores. A common concern about SGPs at the student level, and mean or median SGPs (MGPs) at the aggregate level, is potential bias due to test measurement error (ME). Shang,…

Beyond the Total Score: A Preliminary Investigation into the Types of Phonological Awareness Errors Made by First Graders

ERIC Educational Resources Information Center

Hayward, Denyse V.; Annable, Caitlin D.; Fung, Jennifer E.; Williamson, Robert D.; Lovell-Johnston, Meridith A.; Phillips, Linda M.

2017-01-01

Current phonological awareness assessment procedures consider only the total score a child achieves. Such an approach may result in children who achieve the same total score receiving the same instruction even though the configuration of their errors represent fundamental knowledge differences. The purpose of this study was to develop a tool for…

Effect of pulmonary rehabilitation on balance in persons with chronic obstructive pulmonary disease.

PubMed

Beauchamp, Marla K; O'Hoski, Sachi; Goldstein, Roger S; Brooks, Dina

2010-09-01

To describe within-subject effects of pulmonary rehabilitation (PR) on balance in persons with chronic obstructive pulmonary disease (COPD) and to determine whether any observed changes in balance were associated with change in exercise tolerance or health-related quality of life. Single-arm longitudinal study. Inpatient PR center. Subjects with COPD (N=29; mean +/- SD age, 69.8+/-10.3y; forced expiratory volume in 1 second, 46.3%+/-22.3% predicted; 59% men [n=17]). A standardized 6-week multidisciplinary PR program (exercise training, breathing exercises, education, and psychologic support). Balance was assessed using the Berg Balance Scale (BBS), Timed Up and Go (TUG) test, and the Activities-Specific Balance Confidence (ABC) scale. Exercise tolerance was determined from the 6-minute walk test (6MWT), and health-related quality of life from the Chronic Respiratory Questionnaire (CRQ). Subjects showed small improvements in BBS (2.8+/-2.8 points; P<.001) and TUG (-1.5+/-2.4s; P=.003) scores, but not in ABC scores (4.8+/-15.4 points; P>.05). There was a weak relationship between change in BBS and change in CRQ scores (r=.40; P=.045) and no relationship with change in 6MWT. PR contributed to minor improvements in balance and had no effect on balance confidence in subjects with COPD. Further work is warranted to determine the optimal intervention for improving balance in this population.

Undergraduate paramedic students cannot do drug calculations

PubMed Central

Eastwood, Kathryn; Boyle, Malcolm J; Williams, Brett

2012-01-01

BACKGROUND: Previous investigation of drug calculation skills of qualified paramedics has highlighted poor mathematical ability with no published studies having been undertaken on undergraduate paramedics. There are three major error classifications. Conceptual errors involve an inability to formulate an equation from information given, arithmetical errors involve an inability to operate a given equation, and finally computation errors are simple errors of addition, subtraction, division and multiplication. The objective of this study was to determine if undergraduate paramedics at a large Australia university could accurately perform common drug calculations and basic mathematical equations normally required in the workplace. METHODS: A cross-sectional study methodology using a paper-based questionnaire was administered to undergraduate paramedic students to collect demographical data, student attitudes regarding their drug calculation performance, and answers to a series of basic mathematical and drug calculation questions. Ethics approval was granted. RESULTS: The mean score of correct answers was 39.5% with one student scoring 100%, 3.3% of students (n=3) scoring greater than 90%, and 63% (n=58) scoring 50% or less, despite 62% (n=57) of the students stating they ‘did not have any drug calculations issues’. On average those who completed a minimum of year 12 Specialist Maths achieved scores over 50%. Conceptual errors made up 48.5%, arithmetical 31.1% and computational 17.4%. CONCLUSIONS: This study suggests undergraduate paramedics have deficiencies in performing accurate calculations, with conceptual errors indicating a fundamental lack of mathematical understanding. The results suggest an unacceptable level of mathematical competence to practice safely in the unpredictable prehospital environment. PMID:25215067

Intra-session test-retest reliability of magnitude and structure of center of pressure from the Nintendo Wii Balance Board™ for a visually impaired and normally sighted population.

PubMed

Jeter, Pamela E; Wang, Jiangxia; Gu, Jialiang; Barry, Michael P; Roach, Crystal; Corson, Marilyn; Yang, Lindsay; Dagnelie, Gislin

2015-02-01

Individuals with visual impairment (VI) have irreparable damage to one of the input streams contributing to postural stability. Here, we evaluated the intra-session test-retest reliability of the Wii Balance Board (WBB) for measuring Center of Pressure (COP) magnitude and structure, i.e. approximate entropy (ApEn) in fourteen legally blind participants and 21 participants with corrected-to-normal vision. Participants completed a validated balance protocol which included four sensory conditions: double-leg standing on a firm surface with eyes open (EO-firm); a firm surface with eyes closed (EC-firm); a foam surface with EO (EO-foam); and a foam surface with EC (EC-foam). Participants performed the full balance protocol twice during the session, separated by a period of 15min, to determine the intraclass correlation coefficient (ICC). Absolute reliability was determined by the standard error of measurement (SEM). The minimal difference (MD) was estimated to determine clinical significance for future studies. COP measures were derived from data sent by the WBB to a laptop via Bluetooth. COP scores increased with the difficulty of sensory condition indicating WBB sensitivity (all p<0.01). ICCs in the VI group ranged from 0.73 to 0.95, indicating high to very high correlations, and the normal group showed moderate to very high ICCs (0.62-0.94). The SEM was comparable between groups regardless of between-subject variability. The reliability of the WBB makes it practical to screen for balance impairment among VI persons. Copyright © 2014 Elsevier B.V. All rights reserved.

Osteoporosis and gait and balance disturbances in older sarcopenic obese New Zealanders.

PubMed

Waters, D L; Hale, L; Grant, A M; Herbison, P; Goulding, A

2010-02-01

Bone, muscle, and fat may affect gait and balance in older adults. Osteoporosis was prevalent in low muscle mass participants and related to gait and balance deficits. Low muscle combined with high fat mass had more functional deficits and poorer bone health, which has implications for falls risk and fractures. Decreasing bone density and muscle mass and increasing fat mass may act synergistically to affect gait and balance in older adults. One hundred eighty-three older adults (age 72.7 +/- 6 years, range 56-93; body mass index 28.2 +/- 4.9, range 16.6-46.0) were recruited from a New Zealand falls prevention intervention trial. Total and appendicular skeletal muscle mass (ASM), percent fat, and bone mineralization were assessed by dual energy X-ray absorptiometry and used to characterize normal lean (NL, n = 51), sarcopenic (SS, n = 18), sarcopenic obese (SO, n = 29), and obese (OO, n = 85) phenotypes. Functional performance was assessed using timed up and go, chair stand, single leg stand, and step test. Regression models were adjusted for age, sex, medications, and physical activity. Femoral neck osteoporosis was present in 22% SS, 17% SO, 12% NL, and 7% OO. Femoral neck osteoporosis with low ASM predicted poor chair stand performance (beta -3.3, standard error 1.6, p = 0.04). SO scored lowest on the chair stand (p = 0.03) and step test (p = 0.03). Higher ASM predicted faster timed up and go performance (p = 0.001). Osteoporosis was prevalent in low ASM groups (SS and SO) and related to gait and balance deficits, particularly in the SO. This has implications for falls risk, fractures, and interventions.

Optimal case-control matching in practice.

PubMed

Cologne, J B; Shibata, Y

1995-05-01

We illustrate modern matching techniques and discuss practical issues in defining the closeness of matching for retrospective case-control designs (in which the pool of subjects already exists when the study commences). We empirically compare matching on a balancing score, analogous to the propensity score for treated/control matching, with matching on a weighted distance measure. Although both methods in principle produce balance between cases and controls in the marginal distributions of the matching covariates, the weighted distance measure provides better balance in practice because the balancing score can be poorly estimated. We emphasize the use of optimal matching based on efficient network algorithms. An illustration is based on the design of a case-control study of hepatitis B virus infection as a possible confounder and/or effect modifier of radiation-related primary liver cancer in atomic bomb survivors.

Graduate Students' Administration and Scoring Errors on the WISC-IV: Reducing Inaccuracies with Training and Experience

ERIC Educational Resources Information Center

Alper, Jaclyn

2012-01-01

A total of 52 Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV) protocols, administered by graduate students were examined to obtain data on the type and frequency of examiner errors, the impact of errors on resultant test scores as well as improvement rate over the course of two years in training. Findings were consistent with…

Tests for detecting overdispersion in models with measurement error in covariates.

PubMed

Yang, Yingsi; Wong, Man Yu

2015-11-30

Measurement error in covariates can affect the accuracy in count data modeling and analysis. In overdispersion identification, the true mean-variance relationship can be obscured under the influence of measurement error in covariates. In this paper, we propose three tests for detecting overdispersion when covariates are measured with error: a modified score test and two score tests based on the proposed approximate likelihood and quasi-likelihood, respectively. The proposed approximate likelihood is derived under the classical measurement error model, and the resulting approximate maximum likelihood estimator is shown to have superior efficiency. Simulation results also show that the score test based on approximate likelihood outperforms the test based on quasi-likelihood and other alternatives in terms of empirical power. By analyzing a real dataset containing the health-related quality-of-life measurements of a particular group of patients, we demonstrate the importance of the proposed methods by showing that the analyses with and without measurement error correction yield significantly different results. Copyright © 2015 John Wiley & Sons, Ltd.

Primary TKA Patients with Quantifiably Balanced Soft-Tissue Achieve Significant Clinical Gains Sooner than Unbalanced Patients

PubMed Central

Gustke, Kenneth A.; Golladay, Gregory J.; Roche, Martin W.; Elson, Leah C.; Anderson, Christopher R.

2014-01-01

Although total knee arthroplasty has a high success rate, poor outcomes and early revision are associated with ligament imbalance. This multicenter evaluation was performed in order to provide 1-year followup of a previously reported group of patients who had sensor-assisted TKA, comparing the clinical outcomes of quantitatively balanced versus unbalanced patients. At 1 year, the balanced cohort scored 179.3 and 10.4 in KSS and WOMAC, respectively; the unbalanced cohort scored 156.1 and 17.9 in KSS and WOMAC (P < 0.001; P = 0.085). The average activity level scores of quantitatively balanced patients were 68.6 (corresponding to tennis, light jogging, and heavy yard work), while the average activity level of unbalanced patients was 46.7 (corresponding to light housework, and limited walking distances) (P = 0.015). Out of all confounding variables, a balanced articulation was the most significant contributing factor to improved postoperative outcomes (P < 0.001). PMID:25210632

How many stakes are required to measure the mass balance of a glacier?

USGS Publications Warehouse

Fountain, A.G.; Vecchia, A.

1999-01-01

Glacier mass balance is estimated for South Cascade Glacier and Maclure Glacier using a one-dimensional regression of mass balance with altitude as an alternative to the traditional approach of contouring mass balance values. One attractive feature of regression is that it can be applied to sparse data sets where contouring is not possible and can provide an objective error of the resulting estimate. Regression methods yielded mass balance values equivalent to contouring methods. The effect of the number of mass balance measurements on the final value for the glacier showed that sample sizes as small as five stakes provided reasonable estimates, although the error estimates were greater than for larger sample sizes. Different spatial patterns of measurement locations showed no appreciable influence on the final value as long as different surface altitudes were intermittently sampled over the altitude range of the glacier. Two different regression equations were examined, a quadratic, and a piecewise linear spline, and comparison of results showed little sensitivity to the type of equation. These results point to the dominant effect of the gradient of mass balance with altitude of alpine glaciers compared to transverse variations. The number of mass balance measurements required to determine the glacier balance appears to be scale invariant for small glaciers and five to ten stakes are sufficient.

EXPLORATION OF SCORE AGREEMENT ON A MODIFIED UPPER QUARTER Y-BALANCE TEST KIT AS COMPARED TO THE UPPER QUARTER Y-BALANCE TEST.

PubMed

Cramer, Josh; Quintero, Miguel; Rhinehart, Alex; Rutherford, Caitlin; Nasypany, Alan; May, James; Baker, Russell T

2017-02-01

Physical performance measures (PPMs) such as The Star Excursion Balance Test (SEBT) and the Y-Balance Test (YBT) are functional movement tests used to assess participants' dynamic balance, which can be a vital component in physical exams to identify predisposing factors for risk of injury. The YBT is a functional assessment tool for the upper and lower body. It evolved from the SEBT, which has been previously used in research as a lower body functional assessment. It is comprised of fewer movement directions, which help limit fatigue. The YBT kit is a commercialized tool, which may pose barriers for clinicians with limited budgets and/or strict approval process for purchasing capital items in their clinics, especially healthcare providers in the secondary school setting. The cost may also pose a barrier for researchers with limited budgets. A less expensive, easy to make kit, may provide clinicians an opportunity to integrate functional testing into their evaluation or research. The purpose of this pilot study was to describe a cost efficient method to gather participant's upper quarter YBT (UQYBT) measurements and examine the inter- and intra-rater score agreement between this method and the commercial YBT measurements. A convenience sample of 20 physically active participants volunteered to participate in a comparison study of the of Upper Quarter Y-Balance Test (UQYBT) using the commercialized kit and the Modified Upper Quarter Y-Balance Test kit (mUQYBT) made with three cloth tape measures, athletic tape, a goniometer and three 2x4x8 wood blocks. A Pearson Product Moment correlation and Bland-Altman analyses were used to examine the relationship between intra-rater scores comparing the UQYBT and mUQYBT. Inter-rater scores were analyzed using intraclass correlation coefficients (ICC) (2,1) and Bland-Altman analyses. All Pearson Product Moment r-values for intra-rater scores were greater than .96 and statistically significant at p<0.05. Coefficients of determination suggest that the mUQYBT scores account for approximately 92% of the UQYBT composite score when analyzing intra-rater comparisons. Bland-Altman plots suggest moderate agreement between the two tests with a potential bias towards higher composite scores in the mUQYBT. Inter-rater ICC scores were all greater than .98, while Bland-Altman plot analyses suggest moderate agreement between the raters. The mUQYBT produced similar results in both inter- and intra-rater measurements when compared to the commercialized YBT kit and offers a cost-effective alternative for assessing upper quarter PPMs for clinicians with limited budgets. 2b.

SIMulation of Medication Error induced by Clinical Trial drug labeling: the SIMME-CT study.

PubMed

Dollinger, Cecile; Schwiertz, Vérane; Sarfati, Laura; Gourc-Berthod, Chloé; Guédat, Marie-Gabrielle; Alloux, Céline; Vantard, Nicolas; Gauthier, Noémie; He, Sophie; Kiouris, Elena; Caffin, Anne-Gaelle; Bernard, Delphine; Ranchon, Florence; Rioufol, Catherine

2016-06-01

To assess the impact of investigational drug labels on the risk of medication error in drug dispensing. A simulation-based learning program focusing on investigational drug dispensing was conducted. The study was undertaken in an Investigational Drugs Dispensing Unit of a University Hospital of Lyon, France. Sixty-three pharmacy workers (pharmacists, residents, technicians or students) were enrolled. Ten risk factors were selected concerning label information or the risk of confusion with another clinical trial. Each risk factor was scored independently out of 5: the higher the score, the greater the risk of error. From 400 labels analyzed, two groups were selected for the dispensing simulation: 27 labels with high risk (score ≥3) and 27 with low risk (score ≤2). Each question in the learning program was displayed as a simulated clinical trial prescription. Medication error was defined as at least one erroneous answer (i.e. error in drug dispensing). For each question, response times were collected. High-risk investigational drug labels correlated with medication error and slower response time. Error rates were significantly 5.5-fold higher for high-risk series. Error frequency was not significantly affected by occupational category or experience in clinical trials. SIMME-CT is the first simulation-based learning tool to focus on investigational drug labels as a risk factor for medication error. SIMME-CT was also used as a training tool for staff involved in clinical research, to develop medication error risk awareness and to validate competence in continuing medical education. © The Author 2016. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.

Simple Forest Canopy Thermal Exitance Model

NASA Technical Reports Server (NTRS)

Smith J. A.; Goltz, S. M.

1999-01-01

We describe a model to calculate brightness temperature and surface energy balance for a forest canopy system. The model is an extension of an earlier vegetation only model by inclusion of a simple soil layer. The root mean square error in brightness temperature for a dense forest canopy was 2.5 C. Surface energy balance predictions were also in good agreement. The corresponding root mean square errors for net radiation, latent, and sensible heat were 38.9, 30.7, and 41.4 W/sq m respectively.

State of balance of the cryosphere

NASA Technical Reports Server (NTRS)

Van Der Veen, C. J.

1991-01-01

Available observations and mass balance estimates of the cryosphere are summarized. Problems discussed include mountain glaciers, the Greenland ice sheet, the Antarctic ice sheet, conventional glacier measurement techniques, and satellite applications in glacier mass balance studies. It is concluded that the interior part of the Greenland ice sheet is thickening or in near equilibrium. Estimates of the mass balance of the Antarctic ice sheet suggest that it is positive, although the error limits allow for a slightly negative balance.

A dual-task home-based rehabilitation programme for improving balance control in patients with acquired brain injury: a single-blind, randomized controlled pilot study.

PubMed

Peirone, Eliana; Goria, Paolo Filiberto; Anselmino, Arianna

2014-04-01

To evaluate the safety, feasibility and effectiveness of a dual-task home-based rehabilitation programme on balance impairments among adult patients with acquired brain injury. Single-blind, randomized controlled pilot study. Single rehabilitation centre. Sixteen participants between 12 and 18 months post-acquired brain injury with balance impairments and a score <10 seconds on the One-Leg Stance Test (eyes open). All participants received 50-minutes individualised traditional physiotherapy sessions three times a week for seven weeks. In addition, the intervention group (N = 8) performed an individualised dual-task home-based programme six days a week for seven weeks. The primary outcome measure was the Balance Evaluation System Test; secondary measures were the Activities-specific Balance Confidence Scale and Goal Attainment Scaling. At the end of the pilot study, the intervention group showed significantly greater improvement in Balance Evaluation System Test scores (17.87, SD 6.05) vs. the control group (5.5, SD 3.53; P = 0.008, r = 0.63). There was no significant difference in improvement in Activities-specific Balance Confidence Scale scores between the intervention group (25.25, SD 25.51) and the control group (7.00, SD 14.73; P = 0.11, r = 0.63). There was no significant improvement in Goal Attainment Scaling scores in the intervention (19.37, SD 9.03) vs. the control group (16.28, SD 6.58; P = 0.093, r = 0.63). This pilot study shows the safety, feasibility and short-term benefit of a dual-task home-based rehabilitation programme to improve balance control in patients with acquired brain injury. A sample size of 26 participants is required for a definitive study.

Awareness of Diagnostic Error among Japanese Residents: a Nationwide Study.

PubMed

Nishizaki, Yuji; Shinozaki, Tomohiro; Kinoshita, Kensuke; Shimizu, Taro; Tokuda, Yasuharu

2018-04-01

Residents' understanding of diagnostic error may differ between countries. We sought to explore the relationship between diagnostic error knowledge and self-study, clinical knowledge, and experience. Our nationwide study involved postgraduate year 1 and 2 (PGY-1 and -2) Japanese residents. The Diagnostic Error Knowledge Assessment Test (D-KAT) and General Medicine In-Training Examination (GM-ITE) were administered at the end of the 2014 academic year. D-KAT scores were compared with the benchmark scores of US residents. Associations between D-KAT score and gender, PGY, emergency department (ED) rotations per month, mean number of inpatients handled at any given time, and mean daily minutes of self-study were also analyzed, both with and without adjusting for GM-ITE scores. Student's t test was used for comparisons with linear mixed models and structural equation models (SEM) to explore associations with D-KAT or GM-ITE scores. The mean D-KAT score among Japanese PGY-2 residents was significantly lower than that of their US PGY-2 counterparts (6.2 vs. 8.3, p < 0.001). GM-ITE scores correlated with ED rotations (≥6 rotations: 2.14; 0.16-4.13; p = 0.03), inpatient caseloads (5-9 patients: 1.79; 0.82-2.76; p < 0.001), and average daily minutes of self-study (≥91 min: 2.05; 0.56-3.53; p = 0.01). SEM revealed that D-KAT scores were directly associated with GM-ITE scores (ß = 0.37, 95% CI: 0.34-0.41) and indirectly associated with ED rotations (ß = 0.06, 95% CI: 0.02-0.10), inpatient caseload (ß = 0.04, 95% CI: 0.003-0.08), and average daily minutes of study (ß = 0.13, 95% CI: 0.09-0.17). Knowledge regarding diagnostic error among Japanese residents was poor compared with that among US residents. D-KAT scores correlated strongly with GM-ITE scores, and the latter scores were positively associated with a greater number of ED rotations, larger caseload (though only up to 15 patients), and more time spent studying.

Net Weight Issue LLNL DOE-STD-3013 Containers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilk, P

2008-01-16

The following position paper will describe DOE-STD-3013 container sets No.L000072 and No.L000076, and how they are compliant with DOE-STD-3013-2004. All masses of accountable nuclear materials are measured on LLNL certified balances maintained under an MC&A Program approved by DOE/NNSA LSO. All accountability balances are recalibrated annually and checked to be within calibration on each day that the balance is used for accountability purposes. A statistical analysis of the historical calibration checks from the last seven years indicates that the full-range Limit of Error (LoE, 95% confidence level) for the balance used to measure the mass of the contents of themore » above indicated 3013 containers is 0.185 g. If this error envelope, at the 95% confidence level, were to be used to generate an upper-limit to the measured weight of the containers No.L000072 and No.L000076, the error-envelope would extend beyond the 5.0 kg 3013-standard limit on the package contents by less than 0.3 g. However, this is still well within the intended safety bounds of DOE-STD-3013-2004.« less

Modified bathroom scale and balance assessment: a comparison with clinical tests.

PubMed

Duchêne, Jacques; Hewson, David; Rumeau, Pierre

2016-01-01

Frailty and detection of fall risk are major issues in preventive gerontology. A simple tool frequently used in daily life, a bathroom scale (balance quality tester: BQT), was modified to obtain information on the balance of 84 outpatients consulting at a geriatric clinic. The results computed from the BQT were compared to the values of three geriatric tests that are widely used either to detect a fall risk or frailty (timed get up and go: TUG; 10 m walking speed: WS; walking time: WT; one-leg stand: OS). The BQT calculates four parameters that are then scored and weighted, thus creating an overall indicator of balance quality. Raw data, partial scores and the global score were compared with the results of the three geriatric tests. The WT values had the highest correlation with BQT raw data (r = 0.55), while TUG (r = 0.53) and WS (r = 0.56) had the highest correlation with BQT partial scores. ROC curves for OS cut-off values (4 and 5 s) were produced, with the best results obtained for a 5 s cut-off, both with the partial scores combined using Fisher's combination (specificity 85 %: <0.11, sensitivity 85 %: >0.48), and with the empirical score (specificity 85 %: <7, sensitivity 85 %: >8). A BQT empirical score of less than seven can detect fall risk in a community dwelling population.

Effect of Lower Extremity Stretching Exercises on Balance in Geriatric Population.

PubMed

Reddy, Ravi Shankar; Alahmari, Khalid A

2016-07-01

The purpose of this study was to find "Effect of lower extremity stretching exercises on balance in the geriatric population. 60 subjects (30 male and 30 female) participated in the study. The subjects underwent 10 weeks of lower limb stretching exercise program. Pre and post 10 weeks stretching exercise program, the subjects were assessed for balance, using single limb stance time in seconds and berg balance score. These outcome measures were analyzed. Pre and post lower extremity stretching on balance was analyzed using paired t test. Of 60 subjects 50 subjects completed the stretching exercise program. Paired sample t test analysis showed a significant improvement in single limb stance time (eyes open and eyes closed) (p<0.001) and berg balance score (p<0.001). Lower extremity stretching exercises enhances balance in the geriatric population and thereby reduction in the number of falls.

Modular Battery Charge Controller

NASA Technical Reports Server (NTRS)

Button, Robert; Gonzalez, Marcelo

2009-01-01

A new approach to masterless, distributed, digital-charge control for batteries requiring charge control has been developed and implemented. This approach is required in battery chemistries that need cell-level charge control for safety and is characterized by the use of one controller per cell, resulting in redundant sensors for critical components, such as voltage, temperature, and current. The charge controllers in a given battery interact in a masterless fashion for the purpose of cell balancing, charge control, and state-of-charge estimation. This makes the battery system invariably fault-tolerant. The solution to the single-fault failure, due to the use of a single charge controller (CC), was solved by implementing one CC per cell and linking them via an isolated communication bus [e.g., controller area network (CAN)] in a masterless fashion so that the failure of one or more CCs will not impact the remaining functional CCs. Each micro-controller-based CC digitizes the cell voltage (V(sub cell)), two cell temperatures, and the voltage across the switch (V); the latter variable is used in conjunction with V(sub cell) to estimate the bypass current for a given bypass resistor. Furthermore, CC1 digitizes the battery current (I1) and battery voltage (V(sub batt) and CC5 digitizes a second battery current (I2). As a result, redundant readings are taken for temperature, battery current, and battery voltage through the summation of the individual cell voltages given that each CC knows the voltage of the other cells. For the purpose of cell balancing, each CC periodically and independently transmits its cell voltage and stores the received cell voltage of the other cells in an array. The position in the array depends on the identifier (ID) of the transmitting CC. After eight cell voltage receptions, the array is checked to see if one or more cells did not transmit. If one or more transmissions are missing, the missing cell(s) is (are) eliminated from cell-balancing calculations. The cell-balancing algorithm is based on the error between the cell s voltage and the other cells and is categorized into four zones of operation. The algorithm is executed every second and, if cell balancing is activated, the error variable is set to a negative low value. The largest error between the cell and the other cells is found and the zone of operation determined. If the error is zero or negative, then the cell is at the lowest voltage and no balancing action is needed. If the error is less than a predetermined negative value, a Cell Bad Flag is set. If the error is positive, then cell balancing is needed, but a hysteretic zone is added to prevent the bypass circuit from triggering repeatedly near zero error. This approach keeps the cells within a predetermined voltage range.

Hope Modified the Association between Distress and Incidence of Self-Perceived Medical Errors among Practicing Physicians: Prospective Cohort Study

PubMed Central

Hayashino, Yasuaki; Utsugi-Ozaki, Makiko; Feldman, Mitchell D.; Fukuhara, Shunichi

2012-01-01

The presence of hope has been found to influence an individual's ability to cope with stressful situations. The objective of this study is to evaluate the relationship between medical errors, hope and burnout among practicing physicians using validated metrics. Prospective cohort study was conducted among hospital based physicians practicing in Japan (N = 836). Measures included the validated Burnout Scale, self-assessment of medical errors and Herth Hope Index (HHI). The main outcome measure was the frequency of self-perceived medical errors, and Poisson regression analysis was used to evaluate the association between hope and medical error. A total of 361 errors were reported in 836 physician-years. We observed a significant association between hope and self-report of medical errors. Compared with the lowest tertile category of HHI, incidence rate ratios (IRRs) of self-perceived medical errors of physicians in the highest category were 0.44 (95%CI, 0.34 to 0.58) and 0.54 (95%CI, 0.42 to 0.70) respectively, for the 2nd and 3rd tertile. In stratified analysis by hope score, among physicians with a low hope score, those who experienced higher burnout reported higher incidence of errors; physicians with high hope scores did not report high incidences of errors, even if they experienced high burnout. Self-perceived medical errors showed a strong association with physicians' hope, and hope modified the association between physicians' burnout and self-perceived medical errors. PMID:22530055

Evaluating the Effective Factors for Reporting Medical Errors among Midwives Working at Teaching Hospitals Affiliated to Isfahan University of Medical Sciences.

PubMed

Khorasani, Fahimeh; Beigi, Marjan

2017-01-01

Recently, evaluation and accreditation system of hospitals has had a special emphasis on reporting malpractices and sharing errors or lessons learnt from errors, but still due to lack of promotion of systematic approach for solving problems from the same system, this issue has remained unattended. This study was conducted to determine the effective factors for reporting medical errors among midwives. This project was a descriptive cross-sectional observational study. Data gathering tools were a standard checklist and two researcher-made questionnaires. Sampling for this study was conducted from all the midwives who worked at teaching hospitals affiliated to Isfahan University of Medical Sciences through census method (convenient) and lasted for 3 months. Data were analyzed using descriptive and inferential statistics through SPSS 16. Results showed that 79.1% of the staff reported errors and the highest rate of errors was in the process of patients' tests. In this study, the mean score of midwives' knowledge about the errors was 79.1 and the mean score of their attitude toward reporting errors was 70.4. There was a direct relation between the score of errors' knowledge and attitude in the midwifery staff and reporting errors. Based on the results of this study about the appropriate knowledge and attitude of midwifery staff regarding errors and action toward reporting them, it is recommended to strengthen the system when it comes to errors and hospitals risks.

Introducing a balanced scorecard management system in a university anesthesiology department.

PubMed

Zbinden, Alex M

2002-12-01

The study goal was to show how Balanced Scorecard, a modern management tool based on score numbers, can efficiently be applied to a university anesthesiology department. Nineteen score numbers were established in four perspectives. Meaningful results were obtained with limited resources to support a process of innovation and improvement.

Imbalance: Objective measures versus subjective self-report in clinical practice.

PubMed

Chiarovano, Elodie; Wang, Wei; Reynolds, Pam; MacDougall, Hamish G

2018-01-01

Dizziness and imbalance are very common complaints in clinical practice. One of the challenges is to evaluate the 'real' risk of falls. Two tools are available: the patient's self-report and the measure of the patient's balance. We evaluated the relationship between these methods using the Dizziness Handicap Inventory (DHI) and measures of balance while visual inputs are perturbed with Virtual Reality (VR). 90 consecutive patients underwent the DHI questionnaire and the balance test. The DHI questionnaire was used to measure the subject's perception of handicap associated with dizziness. The balance test measured the postural sway in several visual conditions: eyes open, eyes closed, and with an unpredictable visual perturbation using VR at several amplitudes of movement. No correlation was found between the DHI score and the balance measurement. The visual perturbations allow us to characterize patients into three groups: one group with a high DHI score who did not fall on the balance test (5.5%), one group with a low DHI score who failed eyes closed on a compliant surface (9.0%), and one group of the remaining patients (85.5%). The correlation between the DHI score and the balance performance became significant on the remaining group of patients. Both subjective self-report and objective measure are important to characterize a patient. The use of VR visual perturbations allowed us to define three important groups of patients. VR visual perturbations provided additional information that helps explain the lack of correlation between DHI and objective test results. Copyright © 2017 Elsevier B.V. All rights reserved.

Case report: a balance training program using the Nintendo Wii Fit to reduce fall risk in an older adult with bilateral peripheral neuropathy.

PubMed

Hakim, Renée Marie; Salvo, Charles J; Balent, Anthony; Keyasko, Michael; McGlynn, Deidre

2015-02-01

A recent systematic review supported the use of strength and balance training for older adults at risk for falls, and provided preliminary evidence for those with peripheral neuropathy (PN). However, the role of gaming systems in fall risk reduction was not explored. The purpose of this case report was to describe the use of the Nintendo® Wii™ Fit gaming system to train standing balance in a community-dwelling older adult with PN and a history of recurrent near falls. A 76-year-old patient with bilateral PN participated in 1 h of Nintendo® Wii™ Fit balance training, two times a week for 6 weeks. Examination was conducted using a Computerized Dynamic Posturography system (i.e. Sensory Organization Test (SOT), Limits of Stability (LOS), Adaptation Test (ADT) and Motor Control Test (MCT) and clinical testing with the Berg Balance Scale (BBS), Timed Up and Go (TUG), Activities-specific Balance Confidence (ABC) scale and 30-s Chair Stand. Following training, sensory integration scores on the SOT were unchanged. Maximum excursion abilities improved by a range of 37-86% on the LOS test. MCT scores improved for amplitude with forward translations and ADT scores improved for downward platform rotations. Clinical scores improved on the BBS (28/56-34/56), ABC (57.5-70.6%) and TUG (14.9-10.9 s) which indicated reduced fall risk. Balance training with a gaming system showed promise as a feasible, objective and enjoyable method to improve physical performance and reduce fall risk in an individual with PN.

Can a pilates exercise program be effective on balance, flexibility and muscle endurance? A randomized controlled trial.

PubMed

Kibar, Sibel; Yardimci, Fatma Ö; Evcik, Deniz; Ay, Saime; Alhan, Aslıhan; Manço, Miray; Ergin, Emine S

2016-10-01

This randomized controlled study aims to determine the effect of pilates mat exercises on dynamic and static balance, hamstring flexibility, abdominal muscle activity and endurance in healthy adults. Female healthy volunteer university students randomly assigned into two groups. Group 1 followed a pilates program for an hour two times a week. Group 2 continued daily activities as control group. Dynamic and static balance were evaluated by Sport Kinesthetic Ability Trainer (KAT) 4000 device. Hamstring flexibility and abdominal endurance were determined by sit-and-reach test, curl-up test respectively. Pressure biofeedback unit (PBU) was used to measure transversus abdominis and lumbar muscle activity. The physical activity of the participants was followed by International Physical Activity Questionnaire-Short Form. Twenty-three subjects in pilates group and 24 control subjects completed the study. In pilates group, statistical significant improvements were observed in curl-up, sit-and-reach test, PBU scores at sixth week (P<0.001), and KAT static and dynamic balance scores (P<0.001), waist circumference (P=0.007) at eighth week. In the comparison between two groups, there were significant improvements in pilates group for sit-and-reach test (P=0.01) and PBU scores (P<0.001) at sixth week, additionally curl-up and static KAT scores progressed in eighth week (P<0.001). No correlation was found between flexibility, endurance, trunk muscle activity and balance parameters. An eight-week pilates training program has been found to have beneficial effect on static balance, flexibility, abdominal muscle endurance, abdominal and lumbar muscle activity. These parameters have no effect on balance.

Reliability of System Identification Techniques to Assess Standing Balance in Healthy Elderly

PubMed Central

Maier, Andrea B.; Aarts, Ronald G. K. M.; van Gerven, Joop M. A.; Arendzen, J. Hans; Schouten, Alfred C.; Meskers, Carel G. M.; van der Kooij, Herman

2016-01-01

Objectives System identification techniques have the potential to assess the contribution of the underlying systems involved in standing balance by applying well-known disturbances. We investigated the reliability of standing balance parameters obtained with multivariate closed loop system identification techniques. Methods In twelve healthy elderly balance tests were performed twice a day during three days. Body sway was measured during two minutes of standing with eyes closed and the Balance test Room (BalRoom) was used to apply four disturbances simultaneously: two sensory disturbances, to the proprioceptive and the visual system, and two mechanical disturbances applied at the leg and trunk segment. Using system identification techniques, sensitivity functions of the sensory disturbances and the neuromuscular controller were estimated. Based on the generalizability theory (G theory), systematic errors and sources of variability were assessed using linear mixed models and reliability was assessed by computing indexes of dependability (ID), standard error of measurement (SEM) and minimal detectable change (MDC). Results A systematic error was found between the first and second trial in the sensitivity functions. No systematic error was found in the neuromuscular controller and body sway. The reliability of 15 of 25 parameters and body sway were moderate to excellent when the results of two trials on three days were averaged. To reach an excellent reliability on one day in 7 out of 25 parameters, it was predicted that at least seven trials must be averaged. Conclusion This study shows that system identification techniques are a promising method to assess the underlying systems involved in standing balance in elderly. However, most of the parameters do not appear to be reliable unless a large number of trials are collected across multiple days. To reach an excellent reliability in one third of the parameters, a training session for participants is needed and at least seven trials of two minutes must be performed on one day. PMID:26953694

Model Reduction for Control System Design

NASA Technical Reports Server (NTRS)

Enns, D. F.

1985-01-01

An approach and a technique for effectively obtaining reduced order mathematical models of a given large order model for the purposes of synthesis, analysis and implementation of control systems is developed. This approach involves the use of an error criterion which is the H-infinity norm of a frequency weighted error between the full and reduced order models. The weightings are chosen to take into account the purpose for which the reduced order model is intended. A previously unknown error bound in the H-infinity norm for reduced order models obtained from internally balanced realizations was obtained. This motivated further development of the balancing technique to include the frequency dependent weightings. This resulted in the frequency weighted balanced realization and a new model reduction technique. Two approaches to designing reduced order controllers were developed. The first involves reducing the order of a high order controller with an appropriate weighting. The second involves linear quadratic Gaussian synthesis based on a reduced order model obtained with an appropriate weighting.

The effects of a multi-axis balance board intervention program in an elderly population.

PubMed

Dougherty, John; Kancel, Anne; Ramar, Cassandra; Meacham, Crystal; Derrington, Stephen

2011-01-01

Balance is a major issue facing the geriatric population. Nine participants from a local community center for seniors completed a five-week study to assess improvement in balance. Measures of balance, performance times, and scores on the Berg Balance Scale (BBS) and the Wii Fit Age (WFA) were recorded before and after the entire intervention. An analysis of variance (ANOVA) with repeated measures was used to assess change in BBS and WFA scores. An analysis of covariance with repeated measures was used to asses the impact of possible contributing factors of age, gender, BMI and total balance board training time over the five-week period. The analysis indicated that use of the Indo Balance Board three times a week for ten minutes can significantly improve balance and potentially decrease the risk of falls, as measured by the BBS. Age was the only factor that significantly influenced balance (p = .006). These improvements are postulated to be due to an increase in subjects' core and lower extremity muscle strength and improved proprioception; a result of balance board usage.

Posturography and locomotor tests of dynamic balance after long-duration spaceflight.

PubMed

Cohen, Helen S; Kimball, Kay T; Mulavara, Ajitkumar P; Bloomberg, Jacob J; Paloski, William H

2012-01-01

The currently approved objective clinical measure of standing balance in astronauts after space flight is the Sensory Organization Test battery of computerized dynamic posturography. No tests of walking balance are currently approved for standard clinical testing of astronauts. This study determined the sensitivity and specificity of standing and walking balance tests for astronauts before and after long-duration space flight. Astronauts were tested on an obstacle avoidance test known as the Functional Mobility Test (FMT) and on the Sensory Organization Test using sway-referenced support surface motion with eyes closed (SOT 5) before and six months after (n=15) space flight on the International Space Station. They were tested two to seven days after landing. Scores on SOT tests decreased and scores on FMT increased significantly from pre- to post-flight. In other words, post-flight scores were worse than pre-flight scores. SOT and FMT scores were not significantly related. ROC analyses indicated supra-clinical cut-points for SOT 5 and for FMT. The standard clinical cut-point for SOT 5 had low sensitivity to post-flight astronauts. Higher cut-points increased sensitivity to post-flight astronauts but decreased specificity to pre-flight astronauts. Using an FMT cut-point that was moderately highly sensitive and highly specific plus SOT 5 at the standard clinical cut-point was no more sensitive than SOT 5, alone. FMT plus SOT 5 at higher cut-points was more specific and more sensitive. The total correctly classified was highest for FMT, alone, and for FMT plus SOT 5 at the highest cut-point. These findings indicate that standard clinical comparisons are not useful for identifying problems. Testing both standing and walking balance will be more likely to identify balance deficits.

Reliability of the Balance Evaluation Systems Test (BESTest) and BESTest sections for adults with hemiparesis

PubMed Central

Rodrigues, Letícia C.; Marques, Aline P.; Barros, Paula B.; Michaelsen, Stella M.

2014-01-01

BACKGROUND: The Balance Evaluation Systems Test (BESTest) was recently created to allow the development of treatments according to the specific balance system affected in each patient. The Brazilian version of the BESTest has not been specifically tested after stroke. OBJECTIVE: To evaluate the intra- and inter-rater reliability and concurrent and convergent validity of the total score of the BESTest and BESTest sections for adults with hemiparesis after stroke. METHOD: The study included 16 subjects (61.1±7.5 years) with chronic hemiparesis (54.5±43.5 months after stroke). The BESTest was administered by two raters in the same week and one of the raters repeated the test after a one-week interval. Intraclass correlation coefficient (ICC) was calculated to assess intra- and interrater reliability. Concurrent validity with the Berg Balance Scale (BBS) and convergent validity with the Activities-specific Balance Confidence scale (ABC-Brazil) were assessed using Pearson's correlation coefficient. RESULTS: Both the BESTest total score (ICC=0.98) and the BESTest sections (ICC between 0.85 and 0.96) have excellent intrarater reliability. Interrater reliability for the total score was excellent (ICC=0.93) and, for the sections, it ranged between 0.71 and 0.94. The correlation coefficient between the BESTest and the BBS and ABC-Brazil were 0.78 and 0.59, respectively. CONCLUSIONS: The Brazilian version of the BESTest demonstrated adequate reliability when measured by sections and could identify what balance system was affected in patients after stroke. Concurrent validity was excellent with the BBS total score and good to excellent with the sections. The total scores but not the sections present adequate convergent validity with the ABC-Brazil. However, other psychometric properties should be further investigated. PMID:25003281

Effects of Exergames on Balance, Functional Mobility, and Quality of Life of Geriatrics Versus Home Exercise Programme: Randomized Controlled Study.

PubMed

Karahan, Ali Yavuz; Tok, Fatih; Taşkın, Halil; Kuçuksaraç, Seher; Başaran, Aynur; Yıldırım, Pelin

2015-11-01

To compare the effects of exergames (EGs) using the Xbox Kinect™ device and home exercise (HE) on balance, functional mobility, and quality of life of individuals aged 65 years or older. One hundred participants who met the inclusion criteria were randomized to the EG or HE group. The EG group took part in a 6-week programme using the Xbox360Kinect™ device, and the HE group took part in a 6-week balance exercise programme at home 5 days a week. The Berg Balance Scale (BBS) was used to assess balance, the Timed Up and Go (TUG) test was used to evaluate functional walking, and the Short Form 36 (SF-36) was used to assess quality of life. Forty-eight participants in the EG group and 42 participants in the HE group completed the study. The groups were similar in terms of age, sex, and pretreatment values of BBS, TUG, and SF-36. Although the BBS scores of both groups improved significantly (all p<0.05), the post-treatment scores of the EG group were better than those of the HE group. The TUG scores improved only in the EG group (p<0.05). The increase in the BBS scores and decrease in the TUG test scores were significant only in the EG group (all p<0.05). A significant improvement was also observed in the quality of life parameters of physical functioning, social role functioning, physical role restriction, general health perceptions, and physical component scores in the post-exercise evaluations of the EG group. The participants commented that they found the EG programme very entertaining. The EG can be considered a safe, entertaining and sustainable alternative to HE programmes, and it may have positive effects on balance, functional walking and quality of life in geriatric subjects. Copyright© by the National Institute of Public Health, Prague 2015.

The impact of statistical adjustment on conditional standard errors of measurement in the assessment of physician communication skills.

PubMed

Raymond, Mark R; Clauser, Brian E; Furman, Gail E

2010-10-01

The use of standardized patients to assess communication skills is now an essential part of assessing a physician's readiness for practice. To improve the reliability of communication scores, it has become increasingly common in recent years to use statistical models to adjust ratings provided by standardized patients. This study employed ordinary least squares regression to adjust ratings, and then used generalizability theory to evaluate the impact of these adjustments on score reliability and the overall standard error of measurement. In addition, conditional standard errors of measurement were computed for both observed and adjusted scores to determine whether the improvements in measurement precision were uniform across the score distribution. Results indicated that measurement was generally less precise for communication ratings toward the lower end of the score distribution; and the improvement in measurement precision afforded by statistical modeling varied slightly across the score distribution such that the most improvement occurred in the upper-middle range of the score scale. Possible reasons for these patterns in measurement precision are discussed, as are the limitations of the statistical models used for adjusting performance ratings.

Changes in balance in older adults based on use of physical therapy vs the Wii Fit gaming system: a preliminary study.

PubMed

Bateni, Hamid

2012-09-01

To determine the effectiveness of Wii Fit training on balance control in older adults compared with physical therapy training. Quasi-experimental design. Eight males and nine females aged 53 to 91 years. Participants were divided into three groups: one group received both physical therapy training and Wii Fit training (PW group), one group received Wii Fit training alone (WI group), and one group received physical therapy training alone (PT group). Training consisted of three sessions per week for 4 weeks. Berg Balance Scale (all groups) and Bubble Test (PW and WI groups) scores. Descriptive statistics, medians, interquartile ranges and 95% confidence intervals are reported to identify trends in balance control as a result of different types of training. All subjects showed improvement in the Berg Balance Scale and Bubble Test scores. The PT and PW groups tended to perform better than the WI group on the Berg Balance Scale following treatment. Although the differences in the Bubble Test score were not substantial between the PW and WI groups, the PW group performed slightly better than the WI group on the Berg Balance Scale. Wii Fit training appears to improve balance. However, physical therapy training on its own or in addition to Wii Fit training appears to improve balance to a greater extent than Wii Fit training alone. Copyright © 2011 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Metrics for covariate balance in cohort studies of causal effects.

PubMed

Franklin, Jessica M; Rassen, Jeremy A; Ackermann, Diana; Bartels, Dorothee B; Schneeweiss, Sebastian

2014-05-10

Inferring causation from non-randomized studies of exposure requires that exposure groups can be balanced with respect to prognostic factors for the outcome. Although there is broad agreement in the literature that balance should be checked, there is confusion regarding the appropriate metric. We present a simulation study that compares several balance metrics with respect to the strength of their association with bias in estimation of the effect of a binary exposure on a binary, count, or continuous outcome. The simulations utilize matching on the propensity score with successively decreasing calipers to produce datasets with varying covariate balance. We propose the post-matching C-statistic as a balance metric and found that it had consistently strong associations with estimation bias, even when the propensity score model was misspecified, as long as the propensity score was estimated with sufficient study size. This metric, along with the average standardized difference and the general weighted difference, outperformed all other metrics considered in association with bias, including the unstandardized absolute difference, Kolmogorov-Smirnov and Lévy distances, overlapping coefficient, Mahalanobis balance, and L1 metrics. Of the best-performing metrics, the C-statistic and general weighted difference also have the advantage that they automatically evaluate balance on all covariates simultaneously and can easily incorporate balance on interactions among covariates. Therefore, when combined with the usual practice of comparing individual covariate means and standard deviations across exposure groups, these metrics may provide useful summaries of the observed covariate imbalance. Copyright © 2013 John Wiley & Sons, Ltd.

Comparing mass balance and adjoint methods for inverse modeling of nitrogen dioxide columns for global nitrogen oxide emissions

NASA Astrophysics Data System (ADS)

Cooper, Matthew; Martin, Randall V.; Padmanabhan, Akhila; Henze, Daven K.

2017-04-01

Satellite observations offer information applicable to top-down constraints on emission inventories through inverse modeling. Here we compare two methods of inverse modeling for emissions of nitrogen oxides (NOx) from nitrogen dioxide (NO2) columns using the GEOS-Chem chemical transport model and its adjoint. We treat the adjoint-based 4D-Var modeling approach for estimating top-down emissions as a benchmark against which to evaluate variations on the mass balance method. We use synthetic NO2 columns generated from known NOx emissions to serve as "truth." We find that error in mass balance inversions can be reduced by up to a factor of 2 with an iterative process that uses finite difference calculations of the local sensitivity of NO2 columns to a change in emissions. In a simplified experiment to recover local emission perturbations, horizontal smearing effects due to NOx transport are better resolved by the adjoint approach than by mass balance. For more complex emission changes, or at finer resolution, the iterative finite difference mass balance and adjoint methods produce similar global top-down inventories when inverting hourly synthetic observations, both reducing the a priori error by factors of 3-4. Inversions of simulated satellite observations from low Earth and geostationary orbits also indicate that both the mass balance and adjoint inversions produce similar results, reducing a priori error by a factor of 3. As the iterative finite difference mass balance method provides similar accuracy as the adjoint method, it offers the prospect of accurately estimating top-down NOx emissions using models that do not have an adjoint.

Systematic review of the evidence for Trails B cut-off scores in assessing fitness-to-drive.

PubMed

Roy, Mononita; Molnar, Frank

2013-01-01

Fitness-to-drive guidelines recommend employing the Trail Making B Test (a.k.a. Trails B), but do not provide guidance regarding cut-off scores. There is ongoing debate regarding the optimal cut-off score on the Trails B test. The objective of this study was to address this controversy by systematically reviewing the evidence for specific Trails B cut-off scores (e.g., cut-offs in both time to completion and number of errors) with respect to fitness-to-drive. Systematic review of all prospective cohort, retrospective cohort, case-control, correlation, and cross-sectional studies reporting the ability of the Trails B to predict driving safety that were published in English-language, peer-reviewed journals. Forty-seven articles were reviewed. None of the articles justified sample sizes via formal calculations. Cut-off scores reported based on research include: 90 seconds, 133 seconds, 147 seconds, 180 seconds, and < 3 errors. There is support for the previously published Trails B cut-offs of 3 minutes or 3 errors (the '3 or 3 rule'). Major methodological limitations of this body of research were uncovered including (1) lack of justification of sample size leaving studies open to Type II error (i.e., false negative findings), and (2) excessive focus on associations rather than clinically useful cut-off scores.

Safety culture perceptions of pharmacists in Malaysian hospitals and health clinics: a multicentre assessment using the Safety Attitudes Questionnaire.

PubMed

Samsuri, Srima Elina; Pei Lin, Lua; Fahrni, Mathumalar Loganathan

2015-11-26

To assess the safety attitudes of pharmacists, provide a profile of their domains of safety attitude and correlate their attitudes with self-reported rates of medication errors. A cross-sectional study utilising the Safety Attitudes Questionnaire (SAQ). 3 public hospitals and 27 health clinics. 117 pharmacists. Safety culture mean scores, variation in scores across working units and between hospitals versus health clinics, predictors of safety culture, and medication errors and their correlation. Response rate was 83.6% (117 valid questionnaires returned). Stress recognition (73.0±20.4) and working condition (54.8±17.4) received the highest and lowest mean scores, respectively. Pharmacists exhibited positive attitudes towards: stress recognition (58.1%), job satisfaction (46.2%), teamwork climate (38.5%), safety climate (33.3%), perception of management (29.9%) and working condition (15.4%). With the exception of stress recognition, those who worked in health clinics scored higher than those in hospitals (p<0.05) and higher scores (overall score as well as score for each domain except for stress recognition) correlated negatively with reported number of medication errors. Conversely, those working in hospital (versus health clinic) were 8.9 times more likely (p<0.01) to report a medication error (OR 8.9, CI 3.08 to 25.7). As stress recognition increased, the number of medication errors reported increased (p=0.023). Years of work experience (p=0.017) influenced the number of medication errors reported. For every additional year of work experience, pharmacists were 0.87 times less likely to report a medication error (OR 0.87, CI 0.78 to 0.98). A minority (20.5%) of the pharmacists working in hospitals and health clinics was in agreement with the overall SAQ questions and scales. Pharmacists in outpatient and ambulatory units and those in health clinics had better perceptions of safety culture. As perceptions improved, the number of medication errors reported decreased. Group-specific interventions that target specific domains are necessary to improve the safety culture. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Flexible reserve markets for wind integration

NASA Astrophysics Data System (ADS)

Fernandez, Alisha R.

The increased interconnection of variable generation has motivated the use of improved forecasting to more accurately predict future production with the purpose to lower total system costs for balancing when the expected output exceeds or falls short of the actual output. Forecasts are imperfect, and the forecast errors associated with utility-scale generation from variable generators need new balancing capabilities that cannot be handled by existing ancillary services. Our work focuses on strategies for integrating large amounts of wind generation under the flex reserve market, a market that would called upon for short-term energy services during an under or oversupply of wind generation to maintain electric grid reliability. The flex reserve market would be utilized for time intervals that fall in-between the current ancillary services markets that would be longer than second-to-second energy services for maintaining system frequency and shorter than reserve capacity services that are called upon for several minutes up to an hour during an unexpected contingency on the grid. In our work, the wind operator would access the flex reserve market as an energy service to correct for unanticipated forecast errors, akin to paying the generators participating in the market to increase generation during a shortfall or paying the other generators to decrease generation during an excess of wind generation. Such a market does not currently exist in the Mid-Atlantic United States. The Pennsylvania-New Jersey-Maryland Interconnection (PJM) is the Mid-Atlantic electric grid case study that was used to examine if a flex reserve market can be utilized for integrating large capacities of wind generation in a lowcost manner for those providing, purchasing and dispatching these short-term balancing services. The following work consists of three studies. The first examines the ability of a hydroelectric facility to provide short-term forecast error balancing services via a flex reserve market, identifying the operational constraints that inhibit a multi-purpose dam facility to meet the desired flexible energy demand. The second study transitions from the hydroelectric facility as the decision maker providing flex reserve services to the wind plant as the decision maker purchasing these services. In this second study, methods for allocating the costs of flex reserve services under different wind policy scenarios are explored that aggregate farms into different groupings to identify the least-cost strategy for balancing the costs of hourly day-ahead forecast errors. The least-cost strategy may be different for an individual wind plant and for the system operator, noting that the least-cost strategy is highly sensitive to cost allocation and aggregation schemes. The latter may also cause cross-subsidies in the cost for balancing wind forecast errors among the different wind farms. The third study builds from the second, with the objective to quantify the amount of flex reserves needed for balancing future forecast errors using a probabilistic approach (quantile regression) to estimating future forecast errors. The results further examine the usefulness of separate flexible markets PJM could use for balancing oversupply and undersupply events, similar to the regulation up and down markets used in Europe. These three studies provide the following results and insights to large-scale wind integration using actual PJM wind farm data that describe the markets and generators within PJM. • Chapter 2 provides an in-depth analysis of the valuable, yet highly-constrained, energy services multi-purpose hydroelectric facilities can provide, though the opportunity cost for providing these services can result in large deviations from the reservoir policies with minimal revenue gain in comparison to dedicating the whole of dam capacity to providing day-ahead, baseload generation. • Chapter 3 quantifies the system-wide efficiency gains and the distributive effects of PJM's decision to act as a single balancing authority, which means that it procures ancillary services across its entire footprint simultaneously. This can be contrasted to Midwest Independent System Operator (MISO), which has several balancing authorities operating under its footprint. • Chapter 4 uses probabilistic methods to estimate the uncertainty in the forecast errors and the quantity of energy needed to balance these forecast errors at a certain percentile. Current practice is to use a point forecast that describes the conditional expectation of the dependent variable at each time step. The approach here uses quantile regression to describe the relationship between independent variable and the conditional quantiles (equivalently the percentiles) of the dependent variable. An estimate of the conditional density is performed, which contains information about the covariate relationship of the sign of the forecast errors (negative for too much wind generation and positive for too little wind generation) and the wind power forecast. This additional knowledge may be implemented in the decision process to more accurately schedule day-ahead wind generation bids and provide an example for using separate markets for balancing an oversupply and undersupply of generation. Such methods are currently used for coordinating large footprints of wind generation in Europe.

Performance-oriented mobility assessment (POMA) balance score indicates need for assistive device.

PubMed

Mitchell, Kathryn D; Newton, Roberta A

2006-06-01

To determine (1) if older adults using an assistive device (AD) score lower on the Performance-Oriented Mobility Assessment (POMA) balance subscale (B-subscale) than individuals not using an AD; and (2) if a cut-score of 12 would indicate the need to use an AD. Elderly persons (n = 82, mean age = 82.1 years) were surveyed about AD use, health status, activity level and fall history. A one-time assessment of balance was conducted using the B-subscale. The 'arising task' was repeated to evaluate performance on the sit-to-stand task without using hands. A significant difference in B-subscale scores was observed between the two groups (AD; no AD), (P < 0.001). AD use was associated with lower activity level and health status. A cut-score of 12 points indicated device use (P = 0.000). The repeated 'arising task' demonstrated that 76.8% performed the task without using hands for support. Older adults using an AD will score lower on the B-subscale and report lower activity level and health status. A score of less than 12 on the B-subscale is indicative of AD need. Older adults who use an AD and self-report a falls history will score lower on the B-subscale than individuals using an AD and no reported history of falls.

Evaluating Students' Conceptual Understanding of Balanced Equations and Stoichiometric Ratios Using a Particulate Drawing

ERIC Educational Resources Information Center

Sanger, Michael J.

2005-01-01

A total of 156 students were asked to provide free-response balanced chemical equations for a classic multiple-choice particulate-drawing question first used by Nurrenbern and Pickering. The balanced equations and the number of students providing each equation are reported in this study. The most common student errors included a confusion between…

A Systematic Review of Yoga for Balance in a Healthy Population

PubMed Central

Nkodo, Amélie-Françoise; Moonaz, Steffany Haaz; Dagnelie, Gislin

2014-01-01

Abstract Objective: A systematic review was done of the evidence on yoga for improving balance. Design: Relevant articles and reviews were identified in major databases (PubMed, MEDLINE®, IndMed, Web of Knowledge, EMBASE, EBSCO, Science Direct, and Google Scholar), and their reference lists searched. Key search words were yoga, balance, proprioception, falling, fear of falling, and falls. Included studies were peer-reviewed articles published in English before June 2012, using healthy populations. All yoga styles and study designs were included. Two (2) raters individually rated study quality using the Downs & Black (DB) checklist. Final scores were achieved by consensus. Achievable scores ranged from 0 to 27. Effect size (ES) was calculated where possible. Results: Fifteen (15) of 152 studies (age range 10–93, n=688) met the inclusion criteria: 5 randomized controlled trials (RCTs), 4 quasi-experimental, 2 cross-sectional, and 4 single-group designs. DB scores ranged from 10 to 24 (RCTs), 14–19 (quasi-experimental), 6–12 (cross-sectional), and 11–20 (single group). Studies varied by yoga style, frequency of practice, and duration. Eleven (11) studies found positive results (p<0.05) on at least one balance outcome. ES ranged from −0.765 to 2.71 (for 8 studies) and was not associated with DB score. Conclusions: Yoga may have a beneficial effect on balance, but variable study design and poor reporting quality obscure the results. Balance as an outcome is underutilized, and more probing measures are needed. PMID:24517304

Random Versus Nonrandom Peer Review: A Case for More Meaningful Peer Review.

PubMed

Itri, Jason N; Donithan, Adam; Patel, Sohil H

2018-05-10

Random peer review programs are not optimized to discover cases with diagnostic error and thus have inherent limitations with respect to educational and quality improvement value. Nonrandom peer review offers an alternative approach in which diagnostic error cases are targeted for collection during routine clinical practice. The objective of this study was to compare error cases identified through random and nonrandom peer review approaches at an academic center. During the 1-year study period, the number of discrepancy cases and score of discrepancy were determined from each approach. The nonrandom peer review process collected 190 cases, of which 60 were scored as 2 (minor discrepancy), 94 as 3 (significant discrepancy), and 36 as 4 (major discrepancy). In the random peer review process, 1,690 cases were reviewed, of which 1,646 were scored as 1 (no discrepancy), 44 were scored as 2 (minor discrepancy), and none were scored as 3 or 4. Several teaching lessons and quality improvement measures were developed as a result of analysis of error cases collected through the nonrandom peer review process. Our experience supports the implementation of nonrandom peer review as a replacement to random peer review, with nonrandom peer review serving as a more effective method for collecting diagnostic error cases with educational and quality improvement value. Copyright © 2018 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Constructing better classifier ensemble based on weighted accuracy and diversity measure.

PubMed

Zeng, Xiaodong; Wong, Derek F; Chao, Lidia S

2014-01-01

A weighted accuracy and diversity (WAD) method is presented, a novel measure used to evaluate the quality of the classifier ensemble, assisting in the ensemble selection task. The proposed measure is motivated by a commonly accepted hypothesis; that is, a robust classifier ensemble should not only be accurate but also different from every other member. In fact, accuracy and diversity are mutual restraint factors; that is, an ensemble with high accuracy may have low diversity, and an overly diverse ensemble may negatively affect accuracy. This study proposes a method to find the balance between accuracy and diversity that enhances the predictive ability of an ensemble for unknown data. The quality assessment for an ensemble is performed such that the final score is achieved by computing the harmonic mean of accuracy and diversity, where two weight parameters are used to balance them. The measure is compared to two representative measures, Kappa-Error and GenDiv, and two threshold measures that consider only accuracy or diversity, with two heuristic search algorithms, genetic algorithm, and forward hill-climbing algorithm, in ensemble selection tasks performed on 15 UCI benchmark datasets. The empirical results demonstrate that the WAD measure is superior to others in most cases.

Constructing Better Classifier Ensemble Based on Weighted Accuracy and Diversity Measure

PubMed Central

Chao, Lidia S.

2014-01-01

A weighted accuracy and diversity (WAD) method is presented, a novel measure used to evaluate the quality of the classifier ensemble, assisting in the ensemble selection task. The proposed measure is motivated by a commonly accepted hypothesis; that is, a robust classifier ensemble should not only be accurate but also different from every other member. In fact, accuracy and diversity are mutual restraint factors; that is, an ensemble with high accuracy may have low diversity, and an overly diverse ensemble may negatively affect accuracy. This study proposes a method to find the balance between accuracy and diversity that enhances the predictive ability of an ensemble for unknown data. The quality assessment for an ensemble is performed such that the final score is achieved by computing the harmonic mean of accuracy and diversity, where two weight parameters are used to balance them. The measure is compared to two representative measures, Kappa-Error and GenDiv, and two threshold measures that consider only accuracy or diversity, with two heuristic search algorithms, genetic algorithm, and forward hill-climbing algorithm, in ensemble selection tasks performed on 15 UCI benchmark datasets. The empirical results demonstrate that the WAD measure is superior to others in most cases. PMID:24672402

Competition-Level Differences on the Lower Quarter Y-Balance Test in Baseball Players

PubMed Central

Butler, Robert J.; Bullock, Garrett; Arnold, Todd; Plisky, Phillip; Queen, Robin

2016-01-01

Context: Decreased performance in dynamic balance has previously been associated with a history of ulnar collateral ligament injury in baseball players. Previous research on dynamic balance in soccer players has shown that test performance depends on competition level. However, dynamic balance has yet to be examined in baseball players. Objective: To understand normative values and determine differences in dynamic balance, as measured by the Lower Quarter Y-Balance Test, across competition levels in baseball players. Design: Cross-sectional study. Setting: Preseason physical examinations. Patients or Other Participants: Dynamic balance was measured in 88 high school (HS), 78 collegiate (COL), and 90 professional (PRO) baseball players. Main Outcome Measure(s): All participants completed the Lower Quarter Y-Balance Test using the standard protocol. In unilateral stance, they reached with 1 foot in the anterior, posteromedial, and posterolateral directions. We calculated 1-way analyses of variance to compare performance, composite score, and reach asymmetry for each direction as well as the sum of the asymmetry values (P < .05). Composite score was calculated by averaging the maximum normalized reach scores. Reach asymmetry was determined by calculating bilateral differences in reach ability. Results: In comparison with the HS and COL groups, the PRO players exhibited greater posteromedial (P < .01; effect size index [ESI]HS = 1.06, ESICOL = 0.95) and posterolateral reach (P < .01; ESIHS = 0.82, ESICOL = 0.84) as well as a greater composite score (P < .01; ESIHS = 0.60, ESICOL = 0.87). In contrast, HS baseball players exhibited increased anterior reach (P < .01; ESICOL = 0.60, ESIPRO = 0.39) compared with the COL and PRO cohorts. No significant differences in reach asymmetry were observed among groups. Conclusions: Lower extremity dynamic balance performance differed based on the baseball players' competition level. These baseline data may be helpful in identifying low-performing athletes who might benefit from neuromuscular interventions. PMID:27849388

Competition-Level Differences on the Lower Quarter Y-Balance Test in Baseball Players.

PubMed

Butler, Robert J; Bullock, Garrett; Arnold, Todd; Plisky, Phillip; Queen, Robin

2016-12-01

Decreased performance in dynamic balance has previously been associated with a history of ulnar collateral ligament injury in baseball players. Previous research on dynamic balance in soccer players has shown that test performance depends on competition level. However, dynamic balance has yet to be examined in baseball players. To understand normative values and determine differences in dynamic balance, as measured by the Lower Quarter Y-Balance Test, across competition levels in baseball players. Cross-sectional study. Preseason physical examinations. Dynamic balance was measured in 88 high school (HS), 78 collegiate (COL), and 90 professional (PRO) baseball players. All participants completed the Lower Quarter Y-Balance Test using the standard protocol. In unilateral stance, they reached with 1 foot in the anterior, posteromedial, and posterolateral directions. We calculated 1-way analyses of variance to compare performance, composite score, and reach asymmetry for each direction as well as the sum of the asymmetry values (P < .05). Composite score was calculated by averaging the maximum normalized reach scores. Reach asymmetry was determined by calculating bilateral differences in reach ability. In comparison with the HS and COL groups, the PRO players exhibited greater posteromedial (P < .01; effect size index [ESI] HS = 1.06, ESI COL = 0.95) and posterolateral reach (P < .01; ESI HS = 0.82, ESI COL = 0.84) as well as a greater composite score (P < .01; ESI HS = 0.60, ESI COL = 0.87). In contrast, HS baseball players exhibited increased anterior reach (P < .01; ESI COL = 0.60, ESI PRO = 0.39) compared with the COL and PRO cohorts. No significant differences in reach asymmetry were observed among groups. Lower extremity dynamic balance performance differed based on the baseball players' competition level. These baseline data may be helpful in identifying low-performing athletes who might benefit from neuromuscular interventions.

Sensitivity and Specificity of the Coma Recovery Scale--Revised Total Score in Detection of Conscious Awareness.

PubMed

Bodien, Yelena G; Carlowicz, Cecilia A; Chatelle, Camille; Giacino, Joseph T

2016-03-01

To describe the sensitivity and specificity of Coma Recovery Scale-Revised (CRS-R) total scores in detecting conscious awareness. Data were retrospectively extracted from the medical records of patients enrolled in a specialized disorders of consciousness (DOC) program. Sensitivity and specificity analyses were completed using CRS-R-derived diagnoses of minimally conscious state (MCS) or emerged from minimally conscious state (EMCS) as the reference standard for conscious awareness and the total CRS-R score as the test criterion. A receiver operating characteristic curve was constructed to demonstrate the optimal CRS-R total cutoff score for maximizing sensitivity and specificity. Specialized DOC program. Patients enrolled in the DOC program (N=252, 157 men; mean age, 49y; mean time from injury, 48d; traumatic etiology, n=127; nontraumatic etiology, n=125; diagnosis of coma or vegetative state, n=70; diagnosis of MCS or EMCS, n=182). Not applicable. Sensitivity and specificity of CRS-R total scores in detecting conscious awareness. A CRS-R total score of 10 or higher yielded a sensitivity of .78 for correct identification of patients in MCS or EMCS, and a specificity of 1.00 for correct identification of patients who did not meet criteria for either of these diagnoses (ie, were diagnosed with vegetative state or coma). The area under the curve in the receiver operating characteristic curve analysis is .98. A total CRS-R score of 10 or higher provides strong evidence of conscious awareness but resulted in a false-negative diagnostic error in 22% of patients who demonstrated conscious awareness based on CRS-R diagnostic criteria. A cutoff score of 8 provides the best balance between sensitivity and specificity, accurately classifying 93% of cases. The optimal total score cutoff will vary depending on the user's objective. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Does Field Reliability for Static-99 Scores Decrease as Scores Increase?

PubMed Central

Rice, Amanda K.; Boccaccini, Marcus T.; Harris, Paige B.; Hawes, Samuel W.

2015-01-01

This study examined the field reliability of Static-99 (Hanson & Thornton, 2000) scores among 21,983 sex offenders and focused on whether rater agreement decreased as scores increased. As expected, agreement was lowest for high-scoring offenders. Initial and most recent Static-99 scores were identical for only about 40% of offenders who had been assigned a score of 6 during their initial evaluations, but for more than 60% of offenders who had been assigned a score of 2 or lower. In addition, the size of the difference between scores increased as scores increased, with pairs of scores differing by 2 or more points for about 30% of offenders scoring in the high-risk range. Because evaluators and systems use high Static-99 scores to identify sexual offenders who may require intensive supervision or even postrelease civil commitment, it is important to recognize that there may be more measurement error for high scores than low scores and to consider adopting procedures for minimizing or accounting for measurement error. PMID:24932647

Energy expenditure in obesity associated with craniopharyngioma

PubMed Central

Shah, Rachana; Tershakovec, Andy M.; Zemel, Babette S.; Sutton, Leslie N.; Grimberg, Adda; Moshang, Thomas

2010-01-01

Background and purpose Obesity is a common yet incompletely understood complication of childhood craniopharyngioma. We hypothesized that craniopharyngioma is associated with specific defects in energy balance compared to obese control children. Methods Eleven craniopharyngioma patients were recruited for a study on body composition and energy balance. Eight subjects were obese. The obese craniopharyngioma patients had a mean age (±SD) of 11.2±1.7 years. The average body mass index z score was 2.33 (±0.32). A previously studied group of obese children (BMI z score 2.46±0.46) served as controls. Resting energy expenditure (REE) was determined by indirect calorimetry and body composition by dual energy X-ray absorptiometry in all children. Results Obese craniopharyngioma patient subjects had increased mean (±standard error) fat-free mass compared to obese controls (57%±0.88 % vs 50.0%±0.87%, p=0.02). The obese craniopharyngioma patients had a 17% lower REE compared to values expected from the World Health Organization equation (1,541±112.6 vs 1,809±151.8 kcal; p=0.01). In contrast, the obese control children had measured REE within 1% of predicted (1,647±33.2 vs. 1,652±40.2; p=0.8). In a linear regression model, REE remained significantly lower than predicted after controlling for FFM. Conclusions Lower REE may be a factor contributing to obesity in children with craniopharyngioma. Further study is needed into the mechanisms for reduced energy expenditure in patients with craniopharyngioma. PMID:20107994

Low-level hydrogen sulfide and central nervous system dysfunction.

PubMed

Kilburn, Kaye H; Thrasher, Jack D; Gray, Michael R

2010-08-01

Forty-nine adults living in Lovington, Tatum, and Artesia, the sour gas/oil sector of Southeastern New Mexico, were tested for neurobehavioral impairment. Contributing hydrogen sulfide were (1) an anaerobic sewage plant; (2) two oil refineries; (3) natural gas/oil wells and (4) a cheese-manufacturing plant and its waste lagoons. Comparisons were to unexposed Wickenburg, Arizona, adults. Neurobehavioral functions were measured in 26 Lovington adults including 23 people from Tatum and Artesia, New Mexico, and 42 unexposed Arizona people. Participants completed questionnaires including chemical exposures, symptom frequencies and the Profile of Mood States. Measurements included balance, reaction time, color discrimination, blink reflex, visual fields, grip strength, hearing, vibration, problem solving, verbal recall, long-term memory, peg placement, trail making and fingertip number writing errors (FTNWE). Average numbers of abnormalities and test scores were adjusted for age, gender, educational level, height and weight, expressed as percent predicted (% pred) and compared by analysis of variance (ANOVA). Ages and educational attainment of the three groups were not statistically significantly different (ssd). Mean values of Lovington residents were ssd from the unexposed Arizona people for simple and choice reaction times, balance with eyes open and closed, visual field score, hearing and grip strength. Culture Fair, digit symbol substitution, vocabulary, verbal recall, peg placement, trail making A and B, FTNWE, information, picture completion and similarities were also ssd. The Lovington adults who averaged 11.8 abnormalities were ssd from, Tatum-Artesia adults who had 3.6 and from unexposed subjects with 2.0. Multiple source community hydrogen sulfide exposures impaired neurobehavioral functions.

Validation of mid-infrared spectrometry in milk for predicting body energy status in Holstein-Friesian cows.

PubMed

McParland, S; Banos, G; McCarthy, B; Lewis, E; Coffey, M P; O'Neill, B; O'Donovan, M; Wall, E; Berry, D P

2012-12-01

Cow energy balance is known to be associated with cow health and fertility; therefore, routine access to data on energy balance can be useful in both management and breeding decisions to improve cow performance. The objective of this study was to determine if individual cow milk mid-infrared spectra (MIR) could be useful to predict cow energy balance across contrasting production systems. Direct energy balance was calculated as the differential between energy intake and energy output in milk and maintenance (maintenance was predicted using body weight). Body energy content was calculated from (change in) body weight and body condition score. Following editing, 2,992 morning, 2,742 midday, and 2,989 evening milk MIR records from 564 lactations on 337 Scottish cows, managed in a confinement system on 1 of 2 diets, were available. An additional 844 morning and 820 evening milk spectral records from 338 lactations on 244 Irish cows offered a predominantly grazed grass diet were also available. Equations were developed to predict body energy status using the milk spectral data and milk yield as predictor variables. Several different approaches were used to test the robustness of the equations calibrated in one data set and validated in another. The analyses clearly showed that the variation in the validation data set must be represented in the calibration data set. The accuracy (i.e., square root of the coefficient of multiple determinations) of predicting, from MIR, direct energy balance, body energy content, and energy intake was 0.47 to 0.69, 0.51 to 0.56, and 0.76 to 0.80, respectively. This highlights the ability of milk MIR to predict body energy balance, energy content, and energy intake with reasonable accuracy. Very high accuracy, however, was not expected, given the likely random errors in the calculation of these energy status traits using field data. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Hypothesis Testing Using Factor Score Regression

PubMed Central

Devlieger, Ines; Mayer, Axel; Rosseel, Yves

2015-01-01

In this article, an overview is given of four methods to perform factor score regression (FSR), namely regression FSR, Bartlett FSR, the bias avoiding method of Skrondal and Laake, and the bias correcting method of Croon. The bias correcting method is extended to include a reliable standard error. The four methods are compared with each other and with structural equation modeling (SEM) by using analytic calculations and two Monte Carlo simulation studies to examine their finite sample characteristics. Several performance criteria are used, such as the bias using the unstandardized and standardized parameterization, efficiency, mean square error, standard error bias, type I error rate, and power. The results show that the bias correcting method, with the newly developed standard error, is the only suitable alternative for SEM. While it has a higher standard error bias than SEM, it has a comparable bias, efficiency, mean square error, power, and type I error rate. PMID:29795886

Precision diet formulation to improve performance and profitability across various climates: Modeling the implications of increasing the formulation frequency of dairy cattle diets.

PubMed

White, Robin R; Capper, Judith L

2014-03-01

The objective of this study was to use a precision nutrition model to simulate the relationship between diet formulation frequency and dairy cattle performance across various climates. Agricultural Modeling and Training Systems (AMTS) CattlePro diet-balancing software (Cornell Research Foundation, Ithaca, NY) was used to compare 3 diet formulation frequencies (weekly, monthly, or seasonal) and 3 levels of climate variability (hot, cold, or variable). Predicted daily milk yield (MY), metabolizable energy (ME) balance, and dry matter intake (DMI) were recorded for each frequency-variability combination. Economic analysis was conducted to calculate the predicted revenue over feed and labor costs. Diet formulation frequency affected ME balance and MY but did not affect DMI. Climate variability affected ME balance and DMI but not MY. The interaction between climate variability and formulation frequency did not affect ME balance, MY, or DMI. Formulating diets more frequently increased MY, DMI, and ME balance. Economic analysis showed that formulating diets weekly rather than seasonally could improve returns over variable costs by $25,000 per year for a moderate-sized (300-cow) operation. To achieve this increase in returns, an entire feeding system margin of error of <1% was required. Formulating monthly, rather than seasonally, may be a more feasible alternative as this requires a margin of error of only 2.5% for the entire feeding system. Feeding systems with a low margin of error must be developed to better take advantage of the benefits of precision nutrition. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Validation of Scores on the Marlowe-Crowne Social Desirability Scale and the Balanced Inventory of Desirable Responding

ERIC Educational Resources Information Center

Leite, Walter L.; Beretvas, S. Natasha

2005-01-01

The Marlowe-Crowne Social Desirability Scale (MCSDS), the most commonly used social desirability bias (SDB) assessment, conceptualizes SDB as an individual's need for approval. The Balanced Inventory of Desirable Responding (BIDR) measures SDB as two separate constructs: impression management and self-deception. Scores on SDB scales are commonly…

Stabilizing Conditional Standard Errors of Measurement in Scale Score Transformations

ERIC Educational Resources Information Center

Moses, Tim; Kim, YoungKoung

2017-01-01

The focus of this article is on scale score transformations that can be used to stabilize conditional standard errors of measurement (CSEMs). Three transformations for stabilizing the estimated CSEMs are reviewed, including the traditional arcsine transformation, a recently developed general variance stabilization transformation, and a new method…

Alternative Matching Scores to Control Type I Error of the Mantel-Haenszel Procedure for DIF in Dichotomously Scored Items Conforming to 3PL IRT and Nonparametric 4PBCB Models

ERIC Educational Resources Information Center

Monahan, Patrick O.; Ankenmann, Robert D.

2010-01-01

When the matching score is either less than perfectly reliable or not a sufficient statistic for determining latent proficiency in data conforming to item response theory (IRT) models, Type I error (TIE) inflation may occur for the Mantel-Haenszel (MH) procedure or any differential item functioning (DIF) procedure that matches on summed-item…

Driving error and anxiety related to iPod mp3 player use in a simulated driving experience.

PubMed

Harvey, Ashley R; Carden, Randy L

2009-08-01

Driver distraction due to cellular phone usage has repeatedly been shown to increase the risk of vehicular accidents; however, the literature regarding the use of other personal electronic devices while driving is relatively sparse. It was hypothesized that the usage of an mp3 player would result in an increase in not only driving error while operating a driving simulator, but driver anxiety scores as well. It was also hypothesized that anxiety scores would be positively related to driving errors when using an mp3 player. 32 participants drove through a set course in a driving simulator twice, once with and once without an iPod mp3 player, with the order counterbalanced. Number of driving errors per course, such as leaving the road, impacts with stationary objects, loss of vehicular control, etc., and anxiety were significantly higher when an iPod was in use. Anxiety scores were unrelated to number of driving errors.

Influence of Forecast Accuracy of Photovoltaic Power Output on Capacity Optimization of Microgrid Composition under 30 min Power Balancing Control

NASA Astrophysics Data System (ADS)

Sone, Akihito; Kato, Takeyoshi; Shimakage, Toyonari; Suzuoki, Yasuo

A microgrid (MG) is one of the measures for enhancing the high penetration of renewable energy (RE)-based distributed generators (DGs). If a number of MGs are controlled to maintain the predetermined electricity demand including RE-based DGs as negative demand, they would contribute to supply-demand balancing of whole electric power system. For constructing a MG economically, the capacity optimization of controllable DGs against RE-based DGs is essential. By using a numerical simulation model developed based on a demonstrative study on a MG using PAFC and NaS battery as controllable DGs and photovoltaic power generation system (PVS) as a RE-based DG, this study discusses the influence of forecast accuracy of PVS output on the capacity optimization. Three forecast cases with different accuracy are compared. The main results are as follows. Even with no forecast error during every 30 min. as the ideal forecast method, the required capacity of NaS battery reaches about 40% of PVS capacity for mitigating the instantaneous forecast error within 30 min. The required capacity to compensate for the forecast error is doubled with the actual forecast method. The influence of forecast error can be reduced by adjusting the scheduled power output of controllable DGs according to the weather forecast. Besides, the required capacity can be reduced significantly if the error of balancing control in a MG is acceptable for a few percentages of periods, because the total periods of large forecast error is not so often.

Evaluation of the validity of the Psychology Experiment Building Language tests of vigilance, auditory memory, and decision making.

PubMed

Piper, Brian; Mueller, Shane T; Talebzadeh, Sara; Ki, Min Jung

2016-01-01

Background. The Psychology Experimental Building Language (PEBL) test battery (http://pebl.sourceforge.net/) is a popular application for neurobehavioral investigations. This study evaluated the correspondence between the PEBL and the non-PEBL versions of four executive function tests. Methods. In one cohort, young-adults (N = 44) completed both the Conner's Continuous Performance Test (CCPT) and the PEBL CPT (PCPT) with the order counter-balanced. In a second cohort, participants (N = 47) completed a non-computerized (Wechsler) and a computerized (PEBL) Digit Span (WDS or PDS) both Forward and Backward. Participants also completed the Psychological Assessment Resources or the PEBL versions of the Iowa Gambling Task (PARIGT or PEBLIGT). Results. The between-test correlations were moderately high (reaction time r = 0.78, omission errors r = 0.65, commission errors r = 0.66) on the CPT. DS Forward was significantly greater than DS Backward on the WDS (p < .0005) and the PDS (p < .0005). The total WDS score was moderately correlated with the PDS (r = 0.56). The PARIGT and the PEBLIGTs showed a very similar pattern for response times across blocks, development of preference for Advantageous over Disadvantageous Decks, and Deck selections. However, the amount of money earned (score-loan) was significantly higher in the PEBLIGT during the last Block. Conclusions. These findings are broadly supportive of the criterion validity of the PEBL measures of sustained attention, short-term memory, and decision making. Select differences between workalike versions of the same test highlight how detailed aspects of implementation may have more important consequences for computerized testing than has been previously acknowledged.

Detailed comparison of the geodetic and direct glaciological mass balances on an annual time scale at Hintereisferner, Austria

NASA Astrophysics Data System (ADS)

Klug, Christoph; Bollmann, Erik; Galos, Stephan; Kaser, Georg; Prinz, Rainer; Rieg, Lorenzo; Sailer, Rudolf

2016-04-01

The quantification of glacier mass changes is fundamental for glacier monitoring and provides important information for climate change assessments, hydrological applications and sea-level changes. On Alpine glaciers two methods of measuring glacier mass changes are widely applied: the direct glaciological method and the geodetic method. Over the last decades several studies compared the mass balance estimates obtained by both methods to identify and correct stochastic and systematic errors. In almost all of these studies, the time span for comparison between the two methods is about one decade or longer. On Hintereisferner (HEF; Ötztal Alps, Austria) mass balance measurements were initiated in the glaciological year 1952/53, resulting in a consistent mass balance data set with an estimated accuracy of ±0.2 m w.e. a-1. Furthermore, 11 airborne laser scanning (ALS) campaigns were conducted between 2001 and 2011 at HEF, all consistent in accuracy as well as in precision (± 0.04 to 0.10 m for slopes ≤ 50°). This is a world-wide unique ALS dataset of a glacierized alpine catchment. Flight campaigns were performed close to the end of the hydrological year (30th September). Resulting data provide high quality topographic information to derive glacier mass changes by applying the geodetic method. On sub-decadal time-scales such method comparisons are rare, or reveal unexplainable large discrepancies between both mass balance methods. In this study we estimate stochastic and systematic uncertainties of the ALS data for processing volume changes, and quantify methodological differences, such as density assumptions, unequal measurement dates, crevasses and glacier dynamics. Hence, we present a method to compare direct glaciological and geodetic mass balances on an annual basis. In a first step, we calculate the annual geodetic mass balance of HEF between 2001 and 2011, resulting in a thickness change map of the glacier. In a second step, the snow cover, which has eventually built up before the ALS acquisition, is corrected. As snow cover biases are particular uncertain, a statistical approach has been applied to assess combined DTM errors by using the population of DTM differences over stable terrain. This method incorporates all known and unknown error sources from the surface difference in stable areas and uses its median thickness for correction in all altitudinal belts. In addition, intensity data of the ALS surveys are used to classify the optical surface properties into ice and firn zones. The resulting grids with according conversion factors (900 and 700 kg/m³ for ice and firn, respectively) are combined to calculate mass changes. In a last step, the survey dates are adjusted, using numerous field observations. On an annual time scale, the geodetic mass balances of HEF corrected using this approach, correlate well with the results from the homogenized direct glaciological method. Significant deviations occur in years with few measurements in the uppermost areas applying the direct glaciological method, due to strong melt in areas not equipped with ablation stakes (cf. Figure 2 for 2002/03) or inaccessibility due to weather conditions. On the basis of these results, the conventional error risk (e.g. confidence levels), was adopted in order to test the null hypothesis and to check if unexplained discrepancies suggest reanalyses of glaciological mass balances. Regarding the cumulative mass balance, the deviations between the two methods tend to become smaller the longer the period of comparison extends. Averaged between 2001 and 2011 the largest sources of differences are snow cover and density assumptions having high uncertainties in their estimates and/or leading to higher error ranges in the geodetic mass balances. Some errors were found to have a minor impact and are not treated explicitly, such as uncertainties in different glacier outlines used in both methods or the influence of snow covered and snow free crevasses in successive years on the geodetic mass balance.

Balance outcomes following a tap dance program for a child with congenital myotonic muscular dystrophy.

PubMed

Biricocchi, Charlanne; Drake, JaimeLynn; Svien, Lana

2014-01-01

This case report describes the effects of a 6-week progressive tap dance program on static and dynamic balance for a child with type 1 congenital myotonic muscular dystrophy (congenital MMD1). A 6-year-old girl with congenital MMD1 participated in a 1-hour progressive tap dance program. Classes were held once a week for 6 consecutive weeks and included 3 children with adaptive needs and 1 peer with typical development. The Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2) balance subsection and the Pediatric Balance Scale were completed at the beginning of the first class and the sixth class. The participant's BOT-2 score improved from 3 to 14. Her Pediatric Balance Scale score did not change. Participation in a progressive tap dance class by a child with congenital MMD1 may facilitate improvements in static and dynamic balance.

Effect of revised high-heeled shoes on foot pressure and static balance during standing.

PubMed

Bae, Young-Hyeon; Ko, Mansoo; Park, Young-Soul; Lee, Suk-Min

2015-04-01

[Purpose] The purpose of this study was to investigate the effects of revised high-heeled shoes on the foot pressure ratio and static balance during standing. [Subjects and Methods] A single-subject design was used, 15 healthy women wearing revised high-heeled shoes and general high-heeled shoes in a random order. The foot pressure ratio and static balance scores during standing were measured using a SpaceBalance 3D system. [Results] Forefoot and rearfoot pressures were significantly different between the 2 types of high-heeled shoes. Under the 3 conditions tested, the static balance score was higher for the revised high-heeled shoes than for the general high-heeled shoes, but this difference was not statistically significant. [Conclusion] Revised high-heeled shoes are preferable to general high-heeled shoes, as they result in normalization of normalized foot pressure and a positive effect on static balance.

Effect of revised high-heeled shoes on foot pressure and static balance during standing

PubMed Central

Bae, Young-Hyeon; Ko, Mansoo; Park, Young-Soul; Lee, Suk-Min

2015-01-01

[Purpose] The purpose of this study was to investigate the effects of revised high-heeled shoes on the foot pressure ratio and static balance during standing. [Subjects and Methods] A single-subject design was used, 15 healthy women wearing revised high-heeled shoes and general high-heeled shoes in a random order. The foot pressure ratio and static balance scores during standing were measured using a SpaceBalance 3D system. [Results] Forefoot and rearfoot pressures were significantly different between the 2 types of high-heeled shoes. Under the 3 conditions tested, the static balance score was higher for the revised high-heeled shoes than for the general high-heeled shoes, but this difference was not statistically significant. [Conclusion] Revised high-heeled shoes are preferable to general high-heeled shoes, as they result in normalization of normalized foot pressure and a positive effect on static balance. PMID:25995572

Reliability and Validity of the Sport Concussion Assessment Tool-3 (SCAT3) in High School and Collegiate Athletes.

PubMed

Chin, Esther Y; Nelson, Lindsay D; Barr, William B; McCrory, Paul; McCrea, Michael A

2016-09-01

The Sport Concussion Assessment Tool-3 (SCAT3) facilitates sideline clinical assessments of concussed athletes. Yet, there is little published research on clinically relevant metrics for the SCAT3 as a whole. We documented the psychometric properties of the major SCAT3 components (symptoms, cognition, balance) and derived clinical decision criteria (ie, reliable change score cutoffs and normative conversation tables) for clinicians to apply to cases with and without available preinjury baseline data. Cohort study (diagnosis); Level of evidence, 2. High school and collegiate athletes (N = 2018) completed preseason baseline evaluations including the SCAT3. Re-evaluations of 166 injured athletes and 164 noninjured controls were performed within 24 hours of injury and at 8, 15, and 45 days after injury. Analyses focused on predictors of baseline performance, test-retest reliability, and sensitivity and specificity of the SCAT3 using either single postinjury cutoffs or reliable change index (RCI) criteria derived from this sample. Athlete sex, level of competition, attention-deficit/hyperactivity disorder (ADHD), learning disability (LD), and estimated verbal intellectual ability (but not concussion history) were associated with baseline scores on ≥1 SCAT3 components (small to moderate effect sizes). Female sex, high school level of competition (vs college), and ADHD were associated with higher baseline symptom ratings (d = 0.25-0.32). Male sex, ADHD, and LD were associated with lower baseline Standardized Assessment of Concussion (SAC) scores (d = 0.28-0.68). Male sex, high school level of competition, ADHD, and LD were associated with poorer baseline Balance Error Scoring System (BESS) performance (d = 0.14-0.26). After injury, the symptom checklist manifested the largest effect size at the 24-hour assessment (d = 1.52), with group differences diminished but statistically significant at day 8 (d = 0.39) and nonsignificant at day 15. Effect sizes for the SAC and BESS were small to moderate at 24 hours (SAC: d = -0.36; modified BESS: d = 0.46; full BESS: d = 0.51) and became nonsignificant at day 8 (SAC) and day 15 (BESS). Receiver operating characteristic curve analyses demonstrated a stronger discrimination for symptoms (area under the curve [AUC] = 0.86) than cognitive and balance measures (AUCs = 0.58 and 0.62, respectively), with comparable discrimination of each SCAT3 component using postinjury scores alone versus baseline-adjusted scores (P = .71-.90). Normative conversion tables and RCI criteria were created to facilitate the use of the SCAT3 both with and without baseline test results. Individual predictors should be taken into account when interpreting the SCAT3. The normative conversion tables and RCIs presented can be used to help interpret concussed athletes' performance both with and without baseline data, given the comparability of the 2 interpretative approaches. © 2016 The Author(s).

Clinical Risk Score for Persistent Postconcussion Symptoms Among Children With Acute Concussion in the ED.

PubMed

Zemek, Roger; Barrowman, Nick; Freedman, Stephen B; Gravel, Jocelyn; Gagnon, Isabelle; McGahern, Candice; Aglipay, Mary; Sangha, Gurinder; Boutis, Kathy; Beer, Darcy; Craig, William; Burns, Emma; Farion, Ken J; Mikrogianakis, Angelo; Barlow, Karen; Dubrovsky, Alexander S; Meeuwisse, Willem; Gioia, Gerard; Meehan, William P; Beauchamp, Miriam H; Kamil, Yael; Grool, Anne M; Hoshizaki, Blaine; Anderson, Peter; Brooks, Brian L; Yeates, Keith Owen; Vassilyadi, Michael; Klassen, Terry; Keightley, Michelle; Richer, Lawrence; DeMatteo, Carol; Osmond, Martin H

2016-03-08

Approximately one-third of children experiencing acute concussion experience ongoing somatic, cognitive, and psychological or behavioral symptoms, referred to as persistent postconcussion symptoms (PPCS). However, validated and pragmatic tools enabling clinicians to identify patients at risk for PPCS do not exist. To derive and validate a clinical risk score for PPCS among children presenting to the emergency department. Prospective, multicenter cohort study (Predicting and Preventing Postconcussive Problems in Pediatrics [5P]) enrolled young patients (aged 5-<18 years) who presented within 48 hours of an acute head injury at 1 of 9 pediatric emergency departments within the Pediatric Emergency Research Canada (PERC) network from August 2013 through September 2014 (derivation cohort) and from October 2014 through June 2015 (validation cohort). Participants completed follow-up 28 days after the injury. All eligible patients had concussions consistent with the Zurich consensus diagnostic criteria. The primary outcome was PPCS risk score at 28 days, which was defined as 3 or more new or worsening symptoms using the patient-reported Postconcussion Symptom Inventory compared with recalled state of being prior to the injury. In total, 3063 patients (median age, 12.0 years [interquartile range, 9.2-14.6 years]; 1205 [39.3%] girls) were enrolled (n = 2006 in the derivation cohort; n = 1057 in the validation cohort) and 2584 of whom (n = 1701 [85%] in the derivation cohort; n = 883 [84%] in the validation cohort) completed follow-up at 28 days after the injury. Persistent postconcussion symptoms were present in 801 patients (31.0%) (n = 510 [30.0%] in the derivation cohort and n = 291 [33.0%] in the validation cohort). The 12-point PPCS risk score model for the derivation cohort included the variables of female sex, age of 13 years or older, physician-diagnosed migraine history, prior concussion with symptoms lasting longer than 1 week, headache, sensitivity to noise, fatigue, answering questions slowly, and 4 or more errors on the Balance Error Scoring System tandem stance. The area under the curve was 0.71 (95% CI, 0.69-0.74) for the derivation cohort and 0.68 (95% CI, 0.65-0.72) for the validation cohort. A clinical risk score developed among children presenting to the emergency department with concussion and head injury within the previous 48 hours had modest discrimination to stratify PPCS risk at 28 days. Before this score is adopted in clinical practice, further research is needed for external validation, assessment of accuracy in an office setting, and determination of clinical utility.

The association between frequency of self-reported medical errors and anesthesia trainee supervision: a survey of United States anesthesiology residents-in-training.

PubMed

De Oliveira, Gildasio S; Rahmani, Rod; Fitzgerald, Paul C; Chang, Ray; McCarthy, Robert J

2013-04-01

Poor supervision of physician trainees can be detrimental not only to resident education but also to patient care and safety. Inadequate supervision has been associated with more frequent deaths of patients under the care of junior residents. We hypothesized that residents reporting more medical errors would also report lower quality of supervision scores than the ones with lower reported medical errors. The primary objective of this study was to evaluate the association between the frequency of medical errors reported by residents and their perceived quality of faculty supervision. A cross-sectional nationwide survey was sent to 1000 residents randomly selected from anesthesiology training departments across the United States. Residents from 122 residency programs were invited to participate, the median (interquartile range) per institution was 7 (4-11). Participants were asked to complete a survey assessing demography, perceived quality of faculty supervision, and perceived causes of inadequate perceived supervision. Responses to the statements "I perform procedures for which I am not properly trained," "I make mistakes that have negative consequences for the patient," and "I have made a medication error (drug or incorrect dose) in the last year" were used to assess error rates. Average supervision scores were determined using the De Oliveira Filho et al. scale and compared among the frequency of self-reported error categories using the Kruskal-Wallis test. Six hundred four residents responded to the survey (60.4%). Forty-five (7.5%) of the respondents reported performing procedures for which they were not properly trained, 24 (4%) reported having made mistakes with negative consequences to patients, and 16 (3%) reported medication errors in the last year having occurred multiple times or often. Supervision scores were inversely correlated with the frequency of reported errors for all 3 questions evaluating errors. At a cutoff value of 3, supervision scores demonstrated an overall accuracy (area under the curve) (99% confidence interval) of 0.81 (0.73-0.86), 0.89 (0.77-0.95), and 0.93 (0.77-0.98) for predicting a response of multiple times or often to the question of performing procedures for which they were not properly trained, reported mistakes with negative consequences to patients, and reported medication errors in the last year, respectively. Anesthesiology trainees who reported a greater incidence of medical errors with negative consequences to patients and drug errors also reported lower scores for supervision by faculty. Our findings suggest that further studies of the association between supervision and patient safety are warranted. (Anesth Analg 2013;116:892-7).

The Effects of Comprehensive Warm-Up Programs on Proprioception, Static and Dynamic Balance on Male Soccer Players

PubMed Central

Daneshjoo, Abdolhamid; Mokhtar, Abdul Halim; Rahnama, Nader; Yusof, Ashril

2012-01-01

Purpose The study investigated the effects of FIFA 11+ and HarmoKnee, both being popular warm-up programs, on proprioception, and on the static and dynamic balance of professional male soccer players. Methods Under 21 year-old soccer players (n = 36) were divided randomly into 11+, HarmoKnee and control groups. The programs were performed for 2 months (24 sessions). Proprioception was measured bilaterally at 30°, 45° and 60° knee flexion using the Biodex Isokinetic Dynamometer. Static and dynamic balances were evaluated using the stork stand test and Star Excursion Balance Test (SEBT), respectively. Results The proprioception error of dominant leg significantly decreased from pre- to post-test by 2.8% and 1.7% in the 11+ group at 45° and 60° knee flexion, compared to 3% and 2.1% in the HarmoKnee group. The largest joint positioning error was in the non-dominant leg at 30° knee flexion (mean error value = 5.047), (p<0.05). The static balance with the eyes opened increased in the 11+ by 10.9% and in the HarmoKnee by 6.1% (p<0.05). The static balance with eyes closed significantly increased in the 11+ by 12.4% and in the HarmoKnee by 17.6%. The results indicated that static balance was significantly higher in eyes opened compared to eyes closed (p = 0.000). Significant improvements in SEBT in the 11+ (12.4%) and HarmoKnee (17.6%) groups were also found. Conclusion Both the 11+ and HarmoKnee programs were proven to be useful warm-up protocols in improving proprioception at 45° and 60° knee flexion as well as static and dynamic balance in professional male soccer players. Data from this research may be helpful in encouraging coaches or trainers to implement the two warm-up programs in their soccer teams. PMID:23251579

Minimally important change, measurement error, and responsiveness for the Self-Reported Foot and Ankle Score

PubMed Central

Cöster, Maria C; Nilsdotter, Anna; Brudin, Lars; Bremander, Ann

2017-01-01

Background and purpose Patient-reported outcome measures (PROMs) are increasingly used to evaluate results in orthopedic surgery. To enhance good responsiveness with a PROM, the minimally important change (MIC) should be established. MIC reflects the smallest measured change in score that is perceived as being relevant by the patients. We assessed MIC for the Self-reported Foot and Ankle Score (SEFAS) used in Swedish national registries. Patients and methods Patients with forefoot disorders (n = 83) or hindfoot/ankle disorders (n = 80) completed the SEFAS before surgery and 6 months after surgery. At 6 months also, a patient global assessment (PGA) scale—as external criterion—was completed. Measurement error was expressed as the standard error of a single determination. MIC was calculated by (1) median change scores in improved patients on the PGA scale, and (2) the best cutoff point (BCP) and area under the curve (AUC) using analysis of receiver operating characteristic curves (ROCs). Results The change in mean summary score was the same, 9 (SD 9), in patients with forefoot disorders and in patients with hindfoot/ankle disorders. MIC for SEFAS in the total sample was 5 score points (IQR: 2–8) and the measurement error was 2.4. BCP was 5 and AUC was 0.8 (95% CI: 0.7–0.9). Interpretation As previously shown, SEFAS has good responsiveness. The score change in SEFAS 6 months after surgery should exceed 5 score points in both forefoot patients and hindfoot/ankle patients to be considered as being clinically relevant. PMID:28464751

Hypoxia-induced changes in standing balance.

PubMed

Wagner, Linsey S; Oakley, Sarah R; Vang, Pao; Noble, Brie N; Cevette, Michael J; Stepanek, Jan P

2011-05-01

A few studies in the literature have reported postural changes with hypoxia, but none have quantified the magnitude of change. Further understanding of this condition could have implications for patients at risk for falls, individuals undergoing acute altitude exposure, and pilots and commercial passengers. The objective of this study was to evaluate the effect of different levels of hypoxia (oxygen nitrogen mixtures) on postural standing balance using the computerized dynamic posturography (CDP) system. This improves upon previous protocols by manipulating vision and standing balance with a sway-referenced visual field and/or platform. Additionally, normative data were available for comparison with the cumulative test scores and scores for each condition. Altitude hypoxia was simulated by use of admixing nitrogen to the breathing gas to achieve equivalent altitudes of 1524 m, 2438 m, and 3048 m. Subjects were evaluated using the CDP system. Subjects showed an overall trend toward decreased performance at higher simulated altitudes consistent with the initial hypothesis. Composite standing balance sway scores for the sensory organization subtest of CDP were decreased compared to baseline for simulated altitudes as low as 2438 m (mean sway scores: 81.92 at baseline; 81.85 at 1524 m; 79.15 at 2438 m; 79.15 at 3048 m). Reaction times to unexpected movements in the support surface for the motor control subtest (MCT) increased compared to baseline (mean composite scores: 133.3 at baseline; 135.9 ms at 1524 m; 138.0 ms at 2438 m; 140.9 ms at 3048 m). The CDP testing provided a reliable objective measurement of degradation of balance under hypoxic conditions.

Effects of exercise continued until anaerobic threshold on balance performance in male basketball players.

PubMed

Erkmen, Nurtekin; Suveren, Sibel; Göktepe, Ahmet Salim

2012-06-01

The objective of the present study was to determine the effects of exercise continued until the anaerobic threshold on balance performance in basketball players. Twelve male basketball players (age = 20.92 ± 2.81 years, body height = 192.72 ± 7.61 cm, body mass = 88.09 ± 8.41 kg, training experience = 7.17 ± 3.10 years) volunteered to participate in this study. A Kinesthetic Ability Trainer (KAT 2000 stabilometer) was used to measure the balance performance. Balance tests consisted of static tests on dominant, nondominant and double leg stance. The Bruce Protocol was performed by means of a treadmill. The exercise protocol was terminated when the subject passed the anaerobic threshold. After the exercise protocol, balance measurements were immediately repeated. Statistical differences between pre and post-exercise for dominant, nondominant and double leg stance were determined by the paired samples t-test according to the results of the test of normality. The post-exercise balance score on the dominant leg was significantly higher than pre-exercise (t = -2.758, p < 0.05). No differences existed between pre- and post-exercise in the balance scores of the nondominant leg after the exercise protocol (t = 0.428, p > 0.05). A significant difference was found between pre and post-exercise balance scores in the double leg stance (t = -2.354, p < 0.05). The main finding of this study was that an incremental exercise continued until the anaerobic threshold decreased balance performance on the dominant leg in basketball players, but did not alter it in the nondominant leg.

Internal and External Validity of Scores on the Balanced Inventory of Desirable Responding and the Paulhus Deception Scales

ERIC Educational Resources Information Center

Lanyon, Richard I.; Carle, Adam C.

2007-01-01

The internal and external validity of scores on the two-scale Balanced Inventory of Desirable Responding (BIDR) and its recent revision, the Paulhus Deception Scales (PDS), developed to measure two facets of social desirability, were studied with three groups of forensic clients and two groups of college undergraduates (total N = 519). The two…

Measuring occupational balance and its relationship to perceived stress and health: Mesurer l'équilibre occupationnel et sa relation avec le stress perçus et la santé.

PubMed

Yu, Yu; Manku, Mandeep; Backman, Catherine L

2018-04-01

There is an assumption that occupational balance is integrally related to health and well-being. This study aimed to investigate test-retest reliability of the English-translated Occupational Balance Questionnaire (OBQ), its relationship to measures of health (Short Form Health Survey-36 Version 2.0 [SF-36v2]) and stress (Perceived Stress Scale-10; PSS-10), and demographic differences in OBQ scores in Canadian adults. Test-retest reliability (2 weeks) was assessed using intraclass correlation (ICC) coefficients. Online surveys from 86 adults were analyzed using descriptive, correlational, and t test statistics. OBQ test-retest reliability was ICC = 0.74 (95% CI [0.34, 0.90]; p = .003) when excluding an influential case ( n = 20). OBQ correlations with PSS-10 were r = -.72; with SF-36v2 Mental Component Score, r = .65; and with Physical Component Score, r = .31; all p < .001. Age and gender had no impact on OBQ scores. Findings help elucidate relationships among health, stress, and occupational balance; however, further psychometric testing is warranted before using OBQ for clinical purposes.

Measurement instruments to assess posture, gait, and balance in Parkinson's disease: Critique and recommendations.

PubMed

Bloem, Bastiaan R; Marinus, Johan; Almeida, Quincy; Dibble, Lee; Nieuwboer, Alice; Post, Bart; Ruzicka, Evzen; Goetz, Christopher; Stebbins, Glenn; Martinez-Martin, Pablo; Schrag, Anette

2016-09-01

Disorders of posture, gait, and balance in Parkinson's disease (PD) are common and debilitating. This MDS-commissioned task force assessed clinimetric properties of existing rating scales, questionnaires, and timed tests that assess these features in PD. A literature review was conducted. Identified instruments were evaluated systematically and classified as "recommended," "suggested," or "listed." Inclusion of rating scales was restricted to those that could be used readily in clinical research and practice. One rating scale was classified as "recommended" (UPDRS-derived Postural Instability and Gait Difficulty score) and 2 as "suggested" (Tinetti Balance Scale, Rating Scale for Gait Evaluation). Three scales requiring equipment (Berg Balance Scale, Mini-BESTest, Dynamic Gait Index) also fulfilled criteria for "recommended" and 2 for "suggested" (FOG score, Gait and Balance Scale). Four questionnaires were "recommended" (Freezing of Gait Questionnaire, Activities-specific Balance Confidence Scale, Falls Efficacy Scale, Survey of Activities, and Fear of Falling in the Elderly-Modified). Four tests were classified as "recommended" (6-minute and 10-m walk tests, Timed Up-and-Go, Functional Reach). We identified several questionnaires that adequately assess freezing of gait and balance confidence in PD and a number of useful clinical tests. However, most clinical rating scales for gait, balance, and posture perform suboptimally or have been evaluated insufficiently. No instrument comprehensively and separately evaluates all relevant PD-specific gait characteristics with good clinimetric properties, and none provides separate balance and gait scores with adequate content validity for PD. We therefore recommend the development of such a PD-specific, easily administered, comprehensive gait and balance scale that separately assesses all relevant constructs. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

STATIC BALANCE MEASUREMENTS IN STABLE AND UNSTABLE CONDITIONS DO NOT DISCRIMINATE GROUPS OF YOUNG ADULTS ASSESSED BY THE FUNCTIONAL MOVEMENT SCREEN™ (FMS™).

PubMed

Trindade, Matheus A; de Toledo, Aline Martins; Cardoso, Jefferson Rosa; Souza, Igor Eduardo; Dos Santos Mendes, Felipe Augusto; Santana, Luisiane A; Carregaro, Rodrigo Luiz

2017-11-01

The Functional Movement Screen™ (FMS™) has been the focus of recent research related to movement profiling and injury prediction. However, there is a paucity of studies examining the associations between physical performance tasks such as balance and the FMS™ screening system. The purpose of this study was to compare measures of static balance in stable and unstable conditions between different groups divided by FMS™ scores. A secondary purpose was to discern if balance indices discriminate the groups divided by FMS™ scores. Cross-sectional study. Fifty-seven physically active subjects (25 men and 32 women; mean age of 22.9 ± 3.1 yrs) participated. The outcome was unilateral stance balance indices, composed by: Anteroposterior Index; Medial-lateral Index, and Overall Balance Index in stable and unstable conditions, as provided by the Biodex balance platform. Subjects were dichotomized into two groups, according to a FMS™ cut-off score of 14: FMS1 (score > 14) and FMS2 (score ≤ 14). The independent Students t-test was used to verify differences in balance indices between FMS1 and FMS2 groups. A discriminant analysis was applied in order to identify which of the balance indices would adequately discriminate the FMS™ groups. Comparisons between FMS1 and FMS2 groups in the stable and unstable conditions demonstrated a higher unstable Anteroposterior index for FMS2 (p=0.017). No significant differences were found for other comparisons (p>0.05). The indices did not discriminate the FMS™ groups ( p  > 0.05). The balance indices adopted in this study were not useful as a parameter for identification and discrimination of healthy subjects assessed by the FMS™. 2c.

Differential sensitivity between a virtual reality (VR) balance module and clinically used concussion balance modalities

PubMed Central

Teel, Elizabeth F; Gay, Michael R; Arnett, Peter A; Slobounov, Semyon M

2015-01-01

Objective Balance assessments are part of the recommended clinical concussion evaluation, along with computerized neuropsychological testing and self-reported symptoms checklists. New technology has allowed for the creation of virtual reality (VR) balance assessments to be used in concussion care, but there is little information on the sensitivity and specificity of these evaluations. The purpose of this study is to establish the sensitivity and specificity of a VR balance module for detecting lingering balance deficits clinical concussion care. Design Retrospective, case-control study Setting Institutional research laboratory Participants Normal controls (n=94) and concussed participants (n=27) Interventions All participants completed a VR balance assessment paradigm. Concussed participants were diagnosed by a Certified Athletic Trainer or physician (with 48 hours post-injury) and tested in the lab between 7-10 days post-injury. ROC curves were performed in order to establish the VR module’s sensitivity and specificity for detecting lingering balance deficits. Main Outcome Measures Final balance score Results For the VR balance module, a cutoff score of 8.25 was established to maximize sensitivity at 85.7% and specificity at 87.8%. Conclusions The VR balance module has high sensitivity and specificity for detecting sub-acute balance deficits after concussive injury. PMID:26505696

Systematic review of the evidence for Trails B cut-off scores in assessing fitness-to-drive

PubMed Central

Roy, Mononita; Molnar, Frank

2013-01-01

Background Fitness-to-drive guidelines recommend employing the Trail Making B Test (a.k.a. Trails B), but do not provide guidance regarding cut-off scores. There is ongoing debate regarding the optimal cut-off score on the Trails B test. The objective of this study was to address this controversy by systematically reviewing the evidence for specific Trails B cut-off scores (e.g., cut-offs in both time to completion and number of errors) with respect to fitness-to-drive. Methods Systematic review of all prospective cohort, retrospective cohort, case-control, correlation, and cross-sectional studies reporting the ability of the Trails B to predict driving safety that were published in English-language, peer-reviewed journals. Results Forty-seven articles were reviewed. None of the articles justified sample sizes via formal calculations. Cut-off scores reported based on research include: 90 seconds, 133 seconds, 147 seconds, 180 seconds, and < 3 errors. Conclusions There is support for the previously published Trails B cut-offs of 3 minutes or 3 errors (the ‘3 or 3 rule’). Major methodological limitations of this body of research were uncovered including (1) lack of justification of sample size leaving studies open to Type II error (i.e., false negative findings), and (2) excessive focus on associations rather than clinically useful cut-off scores. PMID:23983828

Comment on 3PL IRT Adjustment for Guessing

ERIC Educational Resources Information Center

Chiu, Ting-Wei; Camilli, Gregory

2013-01-01

Guessing behavior is an issue discussed widely with regard to multiple choice tests. Its primary effect is on number-correct scores for examinees at lower levels of proficiency. This is a systematic error or bias, which increases observed test scores. Guessing also can inflate random error variance. Correction or adjustment for guessing formulas…

An Effectiveness Index and Profile for Instructional Media.

ERIC Educational Resources Information Center

Bond, Jack H.

A scale was developed for judging the relative value of various media in teaching children. Posttest scores were partitioned into several components: error, prior knowledge, guessing, and gain from the learning exercise. By estimating the amounts of prior knowledge, guessing, and error, and then subtracting these from the total score, an index of…

Nonparametric Item Response Curve Estimation with Correction for Measurement Error

ERIC Educational Resources Information Center

Guo, Hongwen; Sinharay, Sandip

2011-01-01

Nonparametric or kernel regression estimation of item response curves (IRCs) is often used in item analysis in testing programs. These estimates are biased when the observed scores are used as the regressor because the observed scores are contaminated by measurement error. Accuracy of this estimation is a concern theoretically and operationally.…

Constrained binary classification using ensemble learning: an application to cost-efficient targeted PrEP strategies.

PubMed

Zheng, Wenjing; Balzer, Laura; van der Laan, Mark; Petersen, Maya

2018-01-30

Binary classification problems are ubiquitous in health and social sciences. In many cases, one wishes to balance two competing optimality considerations for a binary classifier. For instance, in resource-limited settings, an human immunodeficiency virus prevention program based on offering pre-exposure prophylaxis (PrEP) to select high-risk individuals must balance the sensitivity of the binary classifier in detecting future seroconverters (and hence offering them PrEP regimens) with the total number of PrEP regimens that is financially and logistically feasible for the program. In this article, we consider a general class of constrained binary classification problems wherein the objective function and the constraint are both monotonic with respect to a threshold. These include the minimization of the rate of positive predictions subject to a minimum sensitivity, the maximization of sensitivity subject to a maximum rate of positive predictions, and the Neyman-Pearson paradigm, which minimizes the type II error subject to an upper bound on the type I error. We propose an ensemble approach to these binary classification problems based on the Super Learner methodology. This approach linearly combines a user-supplied library of scoring algorithms, with combination weights and a discriminating threshold chosen to minimize the constrained optimality criterion. We then illustrate the application of the proposed classifier to develop an individualized PrEP targeting strategy in a resource-limited setting, with the goal of minimizing the number of PrEP offerings while achieving a minimum required sensitivity. This proof of concept data analysis uses baseline data from the ongoing Sustainable East Africa Research in Community Health study. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Basecalling with LifeTrace

PubMed Central

Walther, Dirk; Bartha, Gábor; Morris, Macdonald

2001-01-01

A pivotal step in electrophoresis sequencing is the conversion of the raw, continuous chromatogram data into the actual sequence of discrete nucleotides, a process referred to as basecalling. We describe a novel algorithm for basecalling implemented in the program LifeTrace. Like Phred, currently the most widely used basecalling software program, LifeTrace takes processed trace data as input. It was designed to be tolerant to variable peak spacing by means of an improved peak-detection algorithm that emphasizes local chromatogram information over global properties. LifeTrace is shown to generate high-quality basecalls and reliable quality scores. It proved particularly effective when applied to MegaBACE capillary sequencing machines. In a benchmark test of 8372 dye-primer MegaBACE chromatograms, LifeTrace generated 17% fewer substitution errors, 16% fewer insertion/deletion errors, and 2.4% more aligned bases to the finished sequence than did Phred. For two sets totaling 6624 dye-terminator chromatograms, the performance improvement was 15% fewer substitution errors, 10% fewer insertion/deletion errors, and 2.1% more aligned bases. The processing time required by LifeTrace is comparable to that of Phred. The predicted quality scores were in line with observed quality scores, permitting direct use for quality clipping and in silico single nucleotide polymorphism (SNP) detection. Furthermore, we introduce a new type of quality score associated with every basecall: the gap-quality. It estimates the probability of a deletion error between the current and the following basecall. This additional quality score improves detection of single basepair deletions when used for locating potential basecalling errors during the alignment. We also describe a new protocol for benchmarking that we believe better discerns basecaller performance differences than methods previously published. PMID:11337481

WE-H-BRC-09: Simulated Errors in Mock Radiotherapy Plans to Quantify the Effectiveness of the Physics Plan Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gopan, O; Kalet, A; Smith, W

2016-06-15

Purpose: A standard tool for ensuring the quality of radiation therapy treatments is the initial physics plan review. However, little is known about its performance in practice. The goal of this study is to measure the effectiveness of physics plan review by introducing simulated errors into “mock” treatment plans and measuring the performance of plan review by physicists. Methods: We generated six mock treatment plans containing multiple errors. These errors were based on incident learning system data both within the department and internationally (SAFRON). These errors were scored for severity and frequency. Those with the highest scores were included inmore » the simulations (13 errors total). Observer bias was minimized using a multiple co-correlated distractor approach. Eight physicists reviewed these plans for errors, with each physicist reviewing, on average, 3/6 plans. The confidence interval for the proportion of errors detected was computed using the Wilson score interval. Results: Simulated errors were detected in 65% of reviews [51–75%] (95% confidence interval [CI] in brackets). The following error scenarios had the highest detection rates: incorrect isocenter in DRRs/CBCT (91% [73–98%]) and a planned dose different from the prescribed dose (100% [61–100%]). Errors with low detection rates involved incorrect field parameters in record and verify system (38%, [18–61%]) and incorrect isocenter localization in planning system (29% [8–64%]). Though pre-treatment QA failure was reliably identified (100%), less than 20% of participants reported the error that caused the failure. Conclusion: This is one of the first quantitative studies of error detection. Although physics plan review is a key safety measure and can identify some errors with high fidelity, others errors are more challenging to detect. This data will guide future work on standardization and automation. Creating new checks or improving existing ones (i.e., via automation) will help in detecting those errors with low detection rates.« less

Global carbon - nitrogen - phosphorus cycle interactions: A key to solving the atmospheric CO2 balance problem?

NASA Technical Reports Server (NTRS)

Peterson, B. J.; Mellillo, J. M.

1984-01-01

If all biotic sinks of atmospheric CO2 reported were added a value of about 0.4 Gt C/yr would be found. For each category, a very high (non-conservative) estimate was used. This still does not provide a sufficient basis for achieving a balance between the sources and sinks of atmospheric CO2. The bulk of the discrepancy lies in a combination of errors in the major terms, the greatest being in a combination of errors in the major terms, the greatest being in the net biotic release and ocean uptake segments, but smaller errors or biases may exist in calculations of the rate of atmospheric CO2 increase and total fossil fuel use as well. The reason why biotic sinks are not capable of balancing the CO2 increase via nutrient-matching in the short-term is apparent from a comparison of the stoichiometry of the sources and sinks. The burning of fossil fuels and forest biomass releases much more CO2-carbon than is sequestered as organic carbon.

Uncertainty Propagation in OMFIT

NASA Astrophysics Data System (ADS)

Smith, Sterling; Meneghini, Orso; Sung, Choongki

2017-10-01

A rigorous comparison of power balance fluxes and turbulent model fluxes requires the propagation of uncertainties in the kinetic profiles and their derivatives. Making extensive use of the python uncertainties package, the OMFIT framework has been used to propagate covariant uncertainties to provide an uncertainty in the power balance calculation from the ONETWO code, as well as through the turbulent fluxes calculated by the TGLF code. The covariant uncertainties arise from fitting 1D (constant on flux surface) density and temperature profiles and associated random errors with parameterized functions such as a modified tanh. The power balance and model fluxes can then be compared with quantification of the uncertainties. No effort is made at propagating systematic errors. A case study will be shown for the effects of resonant magnetic perturbations on the kinetic profiles and fluxes at the top of the pedestal. A separate attempt at modeling the random errors with Monte Carlo sampling will be compared to the method of propagating the fitting function parameter covariant uncertainties. Work supported by US DOE under DE-FC02-04ER54698, DE-FG2-95ER-54309, DE-SC 0012656.

Skylab water balance analysis

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1977-01-01

The water balance of the Skylab crew was analyzed. Evaporative water loss using a whole body input/output balance equation, water, body tissue, and energy balance was analyzed. The approach utilizes the results of several major Skylab medical experiments. Subsystems were designed for the use of the software necessary for the analysis. A partitional water balance that graphically depicts the changes due to water intake is presented. The energy balance analysis determines the net available energy to the individual crewman during any period. The balances produce a visual description of the total change of a particular body component during the course of the mission. The information is salvaged from metabolic balance data if certain techniques are used to reduce errors inherent in the balance method.

Syntactic error modeling and scoring normalization in speech recognition

NASA Technical Reports Server (NTRS)

Olorenshaw, Lex

1991-01-01

The objective was to develop the speech recognition system to be able to detect speech which is pronounced incorrectly, given that the text of the spoken speech is known to the recognizer. Research was performed in the following areas: (1) syntactic error modeling; (2) score normalization; and (3) phoneme error modeling. The study into the types of errors that a reader makes will provide the basis for creating tests which will approximate the use of the system in the real world. NASA-Johnson will develop this technology into a 'Literacy Tutor' in order to bring innovative concepts to the task of teaching adults to read.

Feasibility of early functional rehabilitation in acute stroke survivors using the Balance-Bed—a technology that emulates microgravity

PubMed Central

Oddsson, Lars I. E.; Finkelstein, Marsha J.; Meissner, Sarah

2015-01-01

Evidence-based guidelines recommend early functional rehabilitation of stroke patients when risk of patient harm can be managed. Current tools do not allow balance training under load conditions sufficiently low for acute stroke patients. This single-arm pilot study tested feasibility and safety for acute stroke survivors to use “Balance-Bed”, a technology for balance exercises in supine initially developed to emulate microgravity effects on balance. Nine acute stroke patients (50–79 years) participated in 3–10 sessions over 16–46 days as part of their rehabilitation in a hospital inpatient setting. Standard inpatient measures of outcome were monitored where lack of progress from admission to discharge might indicate possible harm. Total FIM scores at admission (median 40, range 22–53) changed to (74, 50–96), Motor FIM scores from (23, 13–32) to (50, 32–68) and Berg Balance scores from (3, 0–6) to (19, 7–43) at discharge. Changes reached Minimal Clinical Important Difference for a sufficient proportion (>0.6) of the patients to indicate no harm to the patients. In addition, therapists reported the technology was safe, provided a positive experience for the patient and fit within the rehabilitation program. They reported the device should be easier to set up and exit. We conclude acute stroke patients tolerated Balance-Bed exercises such as standing on one or two legs, squats, stepping in place as well as balance perturbations provided by the therapist. We believe this is the first time it has been demonstrated that acute stroke patients can safely perform whole body balance training including balance perturbations as part of their rehabilitation program. Future studies should include a control group and compare outcomes from best practices to interventions using the Balance-Bed. In addition, the technology is relevant for countermeasure development for spaceflight and as a test-bed of balance function under microgravity-like conditions. PMID:26074789

An examination of the interrater reliability between practitioners and researchers on the static-99.

PubMed

Quesada, Stephen P; Calkins, Cynthia; Jeglic, Elizabeth L

2014-11-01

Many studies have validated the psychometric properties of the Static-99, the most widely used measure of sexual offender recidivism risk. However much of this research relied on instrument coding completed by well-trained researchers. This study is the first to examine the interrater reliability (IRR) of the Static-99 between practitioners in the field and researchers. Using archival data from a sample of 1,973 formerly incarcerated sex offenders, field raters' scores on the Static-99 were compared with those of researchers. Overall, clinicians and researchers had excellent IRR on Static-99 total scores, with IRR coefficients ranging from "substantial" to "outstanding" for the individual 10 items of the scale. The most common causes of discrepancies were coding manual errors, followed by item subjectivity, inaccurate item scoring, and calculation errors. These results offer important data with regard to the frequency and perceived nature of scoring errors. © The Author(s) 2013.

Verbal Serial List Learning in Mild Cognitive Impairment: A Profile Analysis of Interference, Forgetting, and Errors

PubMed Central

Libon, David J.; Bondi, Mark W.; Price, Catherine C.; Lamar, Melissa; Eppig, Joel; Wambach, Denene M.; Nieves, Christine; Delano-Wood, Lisa; Giovannetti, Tania; Lippa, Carol; Kabasakalian, Anahid; Cosentino, Stephanie; Swenson, Rod; Penney, Dana L.

2012-01-01

Using cluster analysis Libon et al. (2010) found three verbal serial list-learning profiles involving delay memory test performance in patients with mild cognitive impairment (MCI). Amnesic MCI (aMCI) patients presented with low scores on delay free recall and recognition tests; mixed MCI (mxMCI) patients scored higher on recognition compared to delay free recall tests; and dysexecutive MCI (dMCI) patients generated relatively intact scores on both delay test conditions. The aim of the current research was to further characterize memory impairment in MCI by examining forgetting/savings, interference from a competing word list, intrusion errors/perseverations, intrusion word frequency, and recognition foils in these three statistically determined MCI groups compared to normal control (NC) participants. The aMCI patients exhibited little savings, generated more highly prototypic intrusion errors, and displayed indiscriminate responding to delayed recognition foils. The mxMCI patients exhibited higher saving scores, fewer and less prototypic intrusion errors, and selectively endorsed recognition foils from the interference list. dMCI patients also selectively endorsed recognition foils from the interference list but performed similarly compared to NC participants. These data suggest the existence of distinct memory impairments in MCI and caution against the routine use of a single memory test score to operationally define MCI. PMID:21880171

Evaluation of seasonal and spatial variations of lumped water balance model sensitivity to precipitation data errors

NASA Astrophysics Data System (ADS)

Xu, Chong-yu; Tunemar, Liselotte; Chen, Yongqin David; Singh, V. P.

2006-06-01

Sensitivity of hydrological models to input data errors have been reported in the literature for particular models on a single or a few catchments. A more important issue, i.e. how model's response to input data error changes as the catchment conditions change has not been addressed previously. This study investigates the seasonal and spatial effects of precipitation data errors on the performance of conceptual hydrological models. For this study, a monthly conceptual water balance model, NOPEX-6, was applied to 26 catchments in the Mälaren basin in Central Sweden. Both systematic and random errors were considered. For the systematic errors, 5-15% of mean monthly precipitation values were added to the original precipitation to form the corrupted input scenarios. Random values were generated by Monte Carlo simulation and were assumed to be (1) independent between months, and (2) distributed according to a Gaussian law of zero mean and constant standard deviation that were taken as 5, 10, 15, 20, and 25% of the mean monthly standard deviation of precipitation. The results show that the response of the model parameters and model performance depends, among others, on the type of the error, the magnitude of the error, physical characteristics of the catchment, and the season of the year. In particular, the model appears less sensitive to the random error than to the systematic error. The catchments with smaller values of runoff coefficients were more influenced by input data errors than were the catchments with higher values. Dry months were more sensitive to precipitation errors than were wet months. Recalibration of the model with erroneous data compensated in part for the data errors by altering the model parameters.

A simple scoring system for predicting early major complications in spine surgery: the cumulative effect of age and size of surgery.

PubMed

Brasil, Albert Vincent Berthier; Teles, Alisson R; Roxo, Marcelo Ricardo; Schuster, Marcelo Neutzling; Zauk, Eduardo Ballverdu; Barcellos, Gabriel da Costa; Costa, Pablo Ramon Fruett da; Ferreira, Nelson Pires; Kraemer, Jorge Luiz; Ferreira, Marcelo Paglioli; Gobbato, Pedro Luis; Worm, Paulo Valdeci

2016-10-01

To analyze the cumulative effect of risk factors associated with early major complications in postoperative spine surgery. Retrospective analysis of 583 surgically-treated patients. Early "major" complications were defined as those that may lead to permanent detrimental effects or require further significant intervention. A balanced risk score was built using multiple logistic regression. Ninety-two early major complications occurred in 76 patients (13%). Age > 60 years and surgery of three or more levels proved to be significant independent risk factors in the multivariate analysis. The balanced scoring system was defined as: 0 points (no risk factor), 2 points (1 factor) or 4 points (2 factors). The incidence of early major complications in each category was 7% (0 points), 15% (2 points) and 29% (4 points) respectively. This balanced scoring system, based on two risk factors, represents an important tool for both surgical indication and for patient counseling before surgery.

The community balance and mobility scale alleviates the ceiling effects observed in the currently used gait and balance assessments for the community-dwelling older adults.

PubMed

Balasubramanian, Chitralakshmi K

2015-01-01

Currently used balance assessments show a ceiling effect and lack activities essential for community mobility in higher-functioning older adults. The aim of this study was to investigate the reliability and validity of the Community Balance and Mobility (CB&M) Scale in a high-functioning community-dwelling older adult population since the CB&M Scale includes assessment of several challenging tasks and may alleviate the ceiling effects observed in commonly used gait and balance assessments for this cohort. A convenience sample of 40 older adults (73.4 ± 6.9 years) participated in this cross-sectional study. Previously standardized balance and mobility assessments measuring similar constructs as the CB&M were used for validation. Outcomes included Timed Up and Go Test, Berg Balance Scale (BBS), Dynamic Gait Index (DGI), Functional Reach Test (FRT), Short Physical Performance Battery (SPPB), 6-Minute Walk Test (6MWT), Activities Specific Balance Confidence scale (ABC), gait speed, and intraindividual gait variability. A falls questionnaire documented the history of falls. Rater reliability (ICC > 0.95) and internal consistency (α= .97) of the CB&M scale were high. CB&M scores demonstrated strong correlations with DGI, BBS, SPPB, and 6MWT (ρ= 0.70-0.87; P < .01); moderate correlations with falls history, TUG, ABC, and gait speed (ρ= 0.44-0.65; P < .01); and low correlations with FRT, swing and stance time variability (ρ= 0.34-0.37; P < .05). Dynamic Gait Index, BBS, SPPB, and ABC assessments demonstrated ceiling effects (7.5%-32.5%), while no floor or ceiling effects were noted on the CB&M. Logistic regression model showed that the CB&M scores significantly predicted falls history (χ(2) = 6.66, odds ratio = 0.92; P < .01). Area under the curve for the CB&M scale was 0.80 (95% CI: 0.65-0.95). A score of CB&M ≤ 39 was the optimal trade-off between sensitivity and specificity (sensitivity = 79%, specificity = 76%) and a score of CB&M ≤ 45 maximized sensitivity (sensitivity = 93%, specificity = 60%) to discriminate persons with 2 or more falls from those with fewer than 2 falls in the past year. CB&M scale is reliable and valid to evaluate gait, balance, and mobility in community-dwelling older adults. Unlike some currently used balance and mobility assessments for the community-dwelling older adults, the CB&M scale did not show a ceiling in detection of balance and mobility deficits. In addition, cutoff scores have been proposed that might serve as criteria to discriminate older adults with balance and mobility deficits. The CB&M scale might enable assessment of balance and mobility limitations masked by other assessments and help design interventions to improve community mobility and sustain independence in the higher-functioning community-dwelling older adult.

ReQON: a Bioconductor package for recalibrating quality scores from next-generation sequencing data

PubMed Central

2012-01-01

Background Next-generation sequencing technologies have become important tools for genome-wide studies. However, the quality scores that are assigned to each base have been shown to be inaccurate. If the quality scores are used in downstream analyses, these inaccuracies can have a significant impact on the results. Results Here we present ReQON, a tool that recalibrates the base quality scores from an input BAM file of aligned sequencing data using logistic regression. ReQON also generates diagnostic plots showing the effectiveness of the recalibration. We show that ReQON produces quality scores that are both more accurate, in the sense that they more closely correspond to the probability of a sequencing error, and do a better job of discriminating between sequencing errors and non-errors than the original quality scores. We also compare ReQON to other available recalibration tools and show that ReQON is less biased and performs favorably in terms of quality score accuracy. Conclusion ReQON is an open source software package, written in R and available through Bioconductor, for recalibrating base quality scores for next-generation sequencing data. ReQON produces a new BAM file with more accurate quality scores, which can improve the results of downstream analysis, and produces several diagnostic plots showing the effectiveness of the recalibration. PMID:22946927

Comparing continuous and dichotomous scoring of the balanced inventory of desirable responding.

PubMed

Stöber, Joachim; Dette, Dorothea E; Musch, Jochen

2002-04-01

The Balanced Inventory of Desirable Responding (BIDR; Paulhus, 1994) is a widely used instrument to measure the 2 components of social desirability: self-deceptive enhancement and impression management. With respect to scoring of the BIDR, Paulhus (1994) authorized 2 methods, namely continuous scoring (all answers on the continuous answer scale are counted) and dichotomous scoring (only extreme answers are counted). In this article, we report 3 studies with student samples, and continuous and dichotomous scoring of BIDR subscales are compared with respect to reliability, convergent validity, sensitivity to instructional variations, and correlations with personality. Across studies, the scores from continuous scoring (continuous scores) showed higher Cronbach's alphas than those from dichotomous scoring (dichotomous scores). Moreover, continuous scores showed higher convergent correlations with other measures of social desirability and more consistent effects with self-presentation instructions (fake-good vs. fake-bad instructions). Finally, continuous self-deceptive enhancement scores showed higher correlations with those traits of the Five-factor model for which substantial correlations were expected (i.e., Neuroticism, Extraversion, and Conscientiousness). Consequently, these findings indicate that continuous scoring may be preferable to dichotomous scoring when assessing socially desirable responding with the BIDR.

Contributions to lateral balance control in ambulatory older adults.

PubMed

Sparto, Patrick J; Newman, A B; Simonsick, E M; Caserotti, P; Strotmeyer, E S; Kritchevsky, S B; Yaffe, K; Rosano, C

2018-06-01

In older adults, impaired control of standing balance in the lateral direction is associated with the increased risk of falling. Assessing the factors that contribute to impaired standing balance control may identify areas to address to reduce falls risk. To investigate the contributions of physiological factors to standing lateral balance control. Two hundred twenty-two participants from the Pittsburgh site of the Health, Aging and Body Composition Study had lateral balance control assessed using a clinical sensory integration balance test (standing on level and foam surface with eyes open and closed) and a lateral center of pressure tracking test using visual feedback. The center of pressure was recorded from a force platform. Multiple linear regression models examined contributors of lateral control of balance performance, including concurrently measured tests of lower extremity sensation, knee extensor strength, executive function, and clinical balance tests. Models were adjusted for age, body mass index, and sex. Larger lateral sway during the sensory integration test performed on foam was associated with longer repeated chair stands time. During the lateral center of pressure tracking task, the error in tracking increased at higher frequencies; greater error was associated with worse executive function. The relationship between sway performance and physical and cognitive function differed between women and men. Contributors to control of lateral balance were task-dependent. Lateral standing performance on an unstable surface may be more dependent upon general lower extremity strength, whereas visual tracking performance may be more dependent upon cognitive factors. Lateral balance control in ambulatory older adults is associated with deficits in strength and executive function.

Asymptotic Standard Errors for Item Response Theory True Score Equating of Polytomous Items

ERIC Educational Resources Information Center

Cher Wong, Cheow

2015-01-01

Building on previous works by Lord and Ogasawara for dichotomous items, this article proposes an approach to derive the asymptotic standard errors of item response theory true score equating involving polytomous items, for equivalent and nonequivalent groups of examinees. This analytical approach could be used in place of empirical methods like…

Some Results on Mean Square Error for Factor Score Prediction

ERIC Educational Resources Information Center

Krijnen, Wim P.

2006-01-01

For the confirmatory factor model a series of inequalities is given with respect to the mean square error (MSE) of three main factor score predictors. The eigenvalues of these MSE matrices are a monotonic function of the eigenvalues of the matrix gamma[subscript rho] = theta[superscript 1/2] lambda[subscript rho] 'psi[subscript rho] [superscript…

Standard Error Estimation of 3PL IRT True Score Equating with an MCMC Method

ERIC Educational Resources Information Center

Liu, Yuming; Schulz, E. Matthew; Yu, Lei

2008-01-01

A Markov chain Monte Carlo (MCMC) method and a bootstrap method were compared in the estimation of standard errors of item response theory (IRT) true score equating. Three test form relationships were examined: parallel, tau-equivalent, and congeneric. Data were simulated based on Reading Comprehension and Vocabulary tests of the Iowa Tests of…

Standard Error of Linear Observed-Score Equating for the NEAT Design with Nonnormally Distributed Data

ERIC Educational Resources Information Center

Zu, Jiyun; Yuan, Ke-Hai

2012-01-01

In the nonequivalent groups with anchor test (NEAT) design, the standard error of linear observed-score equating is commonly estimated by an estimator derived assuming multivariate normality. However, real data are seldom normally distributed, causing this normal estimator to be inconsistent. A general estimator, which does not rely on the…

Measurement Error in Nonparametric Item Response Curve Estimation. Research Report. ETS RR-11-28

ERIC Educational Resources Information Center

Guo, Hongwen; Sinharay, Sandip

2011-01-01

Nonparametric, or kernel, estimation of item response curve (IRC) is a concern theoretically and operationally. Accuracy of this estimation, often used in item analysis in testing programs, is biased when the observed scores are used as the regressor because the observed scores are contaminated by measurement error. In this study, we investigate…

Does Wechsler Intelligence Scale administration and scoring proficiency improve during assessment training?

PubMed

Platt, Tyson L; Zachar, Peter; Ray, Glen E; Lobello, Steven G; Underhill, Andrea T

2007-04-01

Studies have found that Wechsler scale administration and scoring proficiency is not easily attained during graduate training. These findings may be related to methodological issues. Using a single-group repeated measures design, this study documents statistically significant, though modest, error reduction on the WAIS-III and WISC-III during a graduate course in assessment. The study design does not permit the isolation of training factors related to error reduction, or assessment of whether error reduction is a function of mere practice. However, the results do indicate that previous study findings of no or inconsistent improvement in scoring proficiency may have been the result of methodological factors. Implications for teaching individual intelligence testing and further research are discussed.

Rank score and permutation testing alternatives for regression quantile estimates

USGS Publications Warehouse

Cade, B.S.; Richards, J.D.; Mielke, P.W.

2006-01-01

Performance of quantile rank score tests used for hypothesis testing and constructing confidence intervals for linear quantile regression estimates (0 ≤ τ ≤ 1) were evaluated by simulation for models with p = 2 and 6 predictors, moderate collinearity among predictors, homogeneous and hetero-geneous errors, small to moderate samples (n = 20–300), and central to upper quantiles (0.50–0.99). Test statistics evaluated were the conventional quantile rank score T statistic distributed as χ2 random variable with q degrees of freedom (where q parameters are constrained by H 0:) and an F statistic with its sampling distribution approximated by permutation. The permutation F-test maintained better Type I errors than the T-test for homogeneous error models with smaller n and more extreme quantiles τ. An F distributional approximation of the F statistic provided some improvements in Type I errors over the T-test for models with > 2 parameters, smaller n, and more extreme quantiles but not as much improvement as the permutation approximation. Both rank score tests required weighting to maintain correct Type I errors when heterogeneity under the alternative model increased to 5 standard deviations across the domain of X. A double permutation procedure was developed to provide valid Type I errors for the permutation F-test when null models were forced through the origin. Power was similar for conditions where both T- and F-tests maintained correct Type I errors but the F-test provided some power at smaller n and extreme quantiles when the T-test had no power because of excessively conservative Type I errors. When the double permutation scheme was required for the permutation F-test to maintain valid Type I errors, power was less than for the T-test with decreasing sample size and increasing quantiles. Confidence intervals on parameters and tolerance intervals for future predictions were constructed based on test inversion for an example application relating trout densities to stream channel width:depth.

Discriminant analysis for predictor of falls in stroke patients by using the Berg Balance Scale.

PubMed

Maeda, Noriaki; Urabe, Yukio; Murakami, Masahito; Itotani, Keisuke; Kato, Junichi

2015-05-01

An observational study was carried out to estimate the strength of the relationships among balance, mobility and falls in hemiplegic stroke inpatients. The objective was to examine factors that may aid in the prediction of the likelihood of falls in stroke patients. A total of 53 stroke patients (30 male, 23 female) aged 67.0 ± 11.1 years were interviewed regarding their fall history. Physical performance was assessed using the Berg Balance Scale (BBS) and the Functional Independence Measure (FIM) scale. Variables that differed between fallers and non-fallers were identified, and a discriminant function analysis was carried out to determine the combination of variables that effectively predicted fall status. Of the 53 stroke patients, 19 were fallers. Compared with the non-fallers, the fallers scored low on the FIM, and differed with respect to age, time from stroke onset, length of hospital stay, Brunnstrom recovery stage and admission BBS score. Discriminant analysis for predicting falls in stroke patients showed that admission BBS score was significantly related to the likelihood of falls. Moreover, discriminant analysis showed that the use of a significant BBS score to classify fallers and non-fallers had an accuracy of 81.1%. The discriminating criterion between the two groups was a score of 31 points on the BBS. The results of this study suggest that BBS score is a strong predictor of falls in stroke patients. As balance is closely related to the risk of falls in hospitalised stroke patients, BBS might be useful in the prediction of falls.

Balance, Falls Risk, and Related Disability in Untreated Vestibular Schwannoma Patients

PubMed Central

Saman, Yougan; Bamiou, Doris-Eva; Murdin, Louisa; Tsioulos, K.; Davies, Rosalyn; Dutia, Mayank B.; Obholzer, Rupert; Gleeson, Michael

2014-01-01

Background Many vestibular schwannoma (VS) patients complain of balance dysfunction; however, validated standardized assessments are lacking. The relative contribution of imbalance and factors like anxiety to disability is unknown. Because imbalance significantly affects quality of life in this group and vestibular rehabilitation may improve outcomes, determining the severity of balance dysfunction is important to understand long-term rehabilitation needs. Aim To assess functional balance (Vertigo Symptom Scale-Vertigo [VSS-VER] and Functional Gait Assessment [FGA]) and the relative contribution of symptom severity (VSS-VER), ambulant posture (FGA), and anxiety symptoms (Vertigo Symptom Scale-Anxiety [VSS-SA]) to disability in untreated patients. Methods Patients not exposed to surgery completed the VSS, Vertigo Handicap Questionnaire (VHQ), and FGA. VSS scores were compared with migrainous vertigo (MV) patients, a mixed neuro-otological group, and healthy controls. Results A correlation was found between decreased FGA and increasing age (r = − 0.35; p < 0.01), female sex (r = 0.42; p = 0.001), increasing handicap (r = − 0.55; p < 0.001), and symptom severity (r = − 0.52; p < 0.001). In 12 of 21 patients (57%) > 60 years of age the FGA score was ≤ 22 suggesting increased falls risk. VSS-VER scores were higher than in healthy controls (p < 0.001) but lower than MV (p < 0.001) and mixed neuro-otology controls (p < 0.001). VSS-SA scores in VS patients with balance symptoms were higher than normal controls (p < 0.05) and correlated with handicap (r = 0.59; p < 0.001) and symptom severity (r = 0.74; p < 0.001). After controlling for age and sex, the VSS-VER, VSS-SA, and FGA explained 47% of the variation in VHQ scores. Conclusion Older VS patients are at significant risk of falls. Balance symptoms are more severe than in healthy controls but less than other neuro-otological patients. Balance symptom severity, anxiety symptoms, and ambulant posture were significant contributors to disability and should be the focus of vestibular rehabilitation strategies. PMID:25276598

Pollen flow in the wildservice tree, Sorbus torminalis (L.) Crantz. I. Evaluating the paternity analysis procedure in continuous populations.

PubMed

Oddou-Muratorio, S; Houot, M-L; Demesure-Musch, B; Austerlitz, F

2003-12-01

The joint development of polymorphic molecular markers and paternity analysis methods provides new approaches to investigate ongoing patterns of pollen flow in natural plant populations. However, paternity studies are hindered by false paternity assignment and the nondetection of true fathers. To gauge the risk of these two types of errors, we performed a simulation study to investigate the impact on paternity analysis of: (i) the assumed values for the size of the breeding male population (NBMP), and (ii) the rate of scoring error in genotype assessment. Our simulations were based on microsatellite data obtained from a natural population of the entomophilous wild service tree, Sorbus torminalis (L.) Crantz. We show that an accurate estimate of NBMP is required to minimize both types of errors, and we assess the reliability of a technique used to estimate NBMP based on parent-offspring genetic data. We then show that scoring errors in genotype assessment only slightly affect the assessment of paternity relationships, and conclude that it is generally better to neglect the scoring error rate in paternity analyses within a nonisolated population.

Predictors of chronic ankle instability: Analysis of peroneal reaction time, dynamic balance and isokinetic strength.

PubMed

Sierra-Guzmán, Rafael; Jiménez, Fernando; Abián-Vicén, Javier

2018-05-01

Previous studies have reported the factors contributing to chronic ankle instability, which could lead to more effective treatments. However, factors such as the reflex response and ankle muscle strength have not been taken into account in previous investigations. Fifty recreational athletes with chronic ankle instability and 55 healthy controls were recruited. Peroneal reaction time in response to sudden inversion, isokinetic evertor muscle strength and dynamic balance with the Star Excursion Balance Test and the Biodex Stability System were measured. The relationship between the Cumberland Ankle Instability Tool score and performance on each test was assessed and a backward multiple linear regression analysis was conducted. Participants with chronic ankle instability showed prolonged peroneal reaction time, poor performance in the Biodex Stability System and decreased reach distance in the Star Excursion Balance Test. No significant differences were found in eversion and inversion peak torque. Moderate correlations were found between the Cumberland Ankle Instability Tool score and the peroneal reaction time and performance on the Star Excursion Balance Test. Peroneus brevis reaction time and the posteromedial and lateral directions of the Star Excursion Balance Test accounted for 36% of the variance in the Cumberland Ankle Instability Tool. Dynamic balance deficits and delayed peroneal reaction time are present in participants with chronic ankle instability. Peroneus brevis reaction time and the posteromedial and lateral directions of the Star Excursion Balance Test were the main contributing factors to the Cumberland Ankle Instability Tool score. No clear strength impairments were reported in unstable ankles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of Tai Chi Exercise on Glucose Control, Neuropathy Scores, Balance, and Quality of Life in Patients with Type 2 Diabetes and Neuropathy

PubMed Central

Ahn, Sukhee

2012-01-01

Abstract Purpose The aim of this study was to determine the effects of Tai Chi exercise on glucose control, neuropathy scores, balance, and quality of life in patients with type 2 diabetes and neuropathy. Methods A pretest–posttest design with a nonequivalent control group was utilized to recruit 59 diabetic patients with neuropathy from an outpatient clinic of a university hospital. A standardized Tai Chi for diabetes program was provided, which comprised 1 hour of Tai Chi per session, twice a week for 12 weeks. Outcome variables were fasting blood glucose and glycosylated hemoglobin for glucose control, the Semmes-Weinstein 10-g monofilament examination scores and total symptom scores for neuropathy, single leg stance for balance, and the Korean version of the SF-36v2 for quality of life. Thirty-nine patients completed the posttest measures after the 12-week Tai Chi intervention, giving a 34% dropout rate. Results The mean age of the participants was 64 years, and they had been diagnosed with type 2 diabetes for more than 12 years. The status was significantly better for the participants in the Tai Chi group (n=20) than for their control (i.e., nonintervention) counterparts (n=19) in terms of total symptom scores, glucose control, balance, and quality of life. Conclusion Tai Chi improved glucose control, balance, neuropathic symptoms, and some dimensions of quality of life in diabetic patients with neuropathy. Further studies with larger samples and long-term follow-up are needed to confirm the effects of Tai Chi on the management of diabetic neuropathy, which may have an impact on fall prevention in this population. PMID:22985218

Is balance exercise training as effective as aerobic exercise training in fibromyalgia syndrome?

PubMed

Duruturk, Neslihan; Tuzun, Emine Handan; Culhaoglu, Belde

2015-05-01

The aim was to compare the effect of aerobic and balance exercises on pain severity, myalgic score, quality of life, exercise capacity and balance in fibromyalgia syndrome (FMS). A total of 33 females diagnosed with FMS by the American College of Rheumatology criteria were recruited in this randomised controlled study and allocated to aerobic exercise (AE) or balance exercise (BE) groups. Exercises were performed three times a week, for 6 weeks on a treadmill or with a Tetrax interactive balance system (TIBS). Outcome measures were characterised by myalgic score, visual analogue scale, Fibromyalgia Impact Questionnaire (FIQ), exercise testing, Timed Up-Go (TUG) and TIBS measurements. Comparisons from baseline to 6 weeks were evaluated using Wilcoxon test. Mann-Whitney U test was used to compare differences between groups. Effect sizes were also calculated. Improvements in pain, myalgic score and FIQ were found in both groups (p < 0.05). While comparing groups, myalgic score was significant (p = 0.02, d = -1.77), the value was higher in AE. Exercise duration, Borg scale, resting blood pressures (RBP) and maximal heart rate were significant in AE. In BE, Borg scale, exercise duration was significant (p < 0.05). While comparing groups, diastolic RBP (p = 0.04, d = -0.92), exercise duration (p = 0.00, d = -1.64) were significant, with higher values in AE. TUG significantly changed in groups (p < 0.05, d ≥ -1.22). Stability scores, eyes open while standing on elastic pads (p = 0.00, d = -0.98) and head back (p = 0.03, d = -0.74), were significant, with higher values in BE. This study showed that BE provided some improvements in FMS, but AE training led to greater gains. BE training should be included in comprehensive programs.

The impact of falls on motor and cognitive recovery after discharge from in-patient stroke rehabilitation

PubMed Central

Wong, Jennifer S.; Brooks, Dina; Inness, Elizabeth L.; Mansfield, Avril

2016-01-01

Background Falls are common among community-dwelling stroke survivors. The aim of this study was to (1) compare motor and cognitive outcomes between individuals who fell in the six months post-discharge from in-patient stroke rehabilitation and those who did not fall, and (2) explore potential mechanisms underlying the relationship between falls and recovery of motor and cognitive function. Methods Secondary analysis of a prospective cohort study of individuals discharged home from in-patient rehabilitation was conducted. Participants were recruited at discharge and completed a six-month falls monitoring period using postcards with follow-up. Non-fallers and fallers were compared at the six-month follow-up assessment on the Berg Balance Scale (BBS), Chedoke-McMaster Stroke Assessment (CMSA), gait speed, and Montreal Cognitive Assessment (MoCA). Measures of balance confidence and physical activity were also assessed. Results 23 fallers were matched to 23 non-fallers on age and functional balance scores at discharge. A total of 43 falls were reported during the study period (8 participants fell more than once). At follow-up, BBS scores (p=0.0066) and CMSA foot scores (p=0.0033) were significantly lower for fallers than non-fallers. The two groups did not differ on CMSA leg scores (p=0.049), gait speed (p=0.47) or MoCA (p=0.23). There was no significant association between change in balance confidence scores and change in physical activity levels among all participants from the first and third questionnaire (r=0.27, p=0.08). Conclusions Performance in balance and motor recovery of the foot were compromised in fallers when compared to non-fallers at six months post-discharge from in-patient stroke rehabilitation. PMID:27062418

Quantitative analysis of the radiation error for aerial coiled-fiber-optic distributed temperature sensing deployments using reinforcing fabric as support structure

NASA Astrophysics Data System (ADS)

Sigmund, Armin; Pfister, Lena; Sayde, Chadi; Thomas, Christoph K.

2017-06-01

In recent years, the spatial resolution of fiber-optic distributed temperature sensing (DTS) has been enhanced in various studies by helically coiling the fiber around a support structure. While solid polyvinyl chloride tubes are an appropriate support structure under water, they can produce considerable errors in aerial deployments due to the radiative heating or cooling. We used meshed reinforcing fabric as a novel support structure to measure high-resolution vertical temperature profiles with a height of several meters above a meadow and within and above a small lake. This study aimed at quantifying the radiation error for the coiled DTS system and the contribution caused by the novel support structure via heat conduction. A quantitative and comprehensive energy balance model is proposed and tested, which includes the shortwave radiative, longwave radiative, convective, and conductive heat transfers and allows for modeling fiber temperatures as well as quantifying the radiation error. The sensitivity of the energy balance model to the conduction error caused by the reinforcing fabric is discussed in terms of its albedo, emissivity, and thermal conductivity. Modeled radiation errors amounted to -1.0 and 1.3 K at 2 m height but ranged up to 2.8 K for very high incoming shortwave radiation (1000 J s-1 m-2) and very weak winds (0.1 m s-1). After correcting for the radiation error by means of the presented energy balance, the root mean square error between DTS and reference air temperatures from an aspirated resistance thermometer or an ultrasonic anemometer was 0.42 and 0.26 K above the meadow and the lake, respectively. Conduction between reinforcing fabric and fiber cable had a small effect on fiber temperatures (< 0.18 K). Only for locations where the plastic rings that supported the reinforcing fabric touched the fiber-optic cable were significant temperature artifacts of up to 2.5 K observed. Overall, the reinforcing fabric offers several advantages over conventional support structures published to date in the literature as it minimizes both radiation and conduction errors.

Persistent Symptoms and Objectively Measured Balance Performance Among OEF/OIF Veterans With Remote Mild Traumatic Brain Injury.

PubMed

Hebert, Jeffrey R; Forster, Jeri E; Stearns-Yoder, Kelly A; Penzenik, Molly E; Brenner, Lisa A

2018-01-30

To investigate linear relationships between dizziness, fatigue, and depression and posttraumatic stress disorder (PTSD) and objectively measured balance performance in Veterans with remote mild traumatic brain injury (mTBI). Academic laboratory; Veterans Affairs Medical Center. Thirty Veterans (28 men) who served in Iraq/Afghanistan and whose most recent mTBI was sustained more than 6 months prior to enrollment. Cross-sectional, observational trial. The Computerized Dynamic Posturography-Sensory Organization Test (CDP-SOT) and the Community Balance and Mobility (CB&M) scale measured balance. Dizziness (Dizziness Handicap Inventory), fatigue (Modified Fatigue Impact Scale), depression-related symptoms (Beck Depression Inventory-II), and PTSD-related symptoms (PTSD Checklist 5) were also measured. Objectively measured balance, CDP-SOT composite, was impaired (mean score of 67.9). CDP-SOT scores correlated with dizziness (r = -0.53; P = .002), fatigue (r = -0.38; P = .03), depression (r = -0.55; P = .001), and PTSD symptoms (r = -0.53; P = .002). Dizziness, time since most recent mTBI, and PTSD symptoms and depression combined explained significant variability in CDP-SOT scores (R = 0.46; P = .003), as did fatigue depression and PTSD symptoms (R = 0.33; P = .01). Impaired balance was identified among the cohort. Findings suggest that dizziness, fatigue, depression and PTSD, and time since most recent mTBI may influence balance performance. Additional research is needed to identify the potentially interrelated natural histories of these co-occurring symptoms.

Community Delivery of a Comprehensive Fall-Prevention Program in People with Multiple Sclerosis

PubMed Central

Frankel, Debra; Tompkins, Sara A.; Cameron, Michelle

2016-01-01

Background: People with multiple sclerosis (MS) fall frequently. In 2011, the National Multiple Sclerosis Society launched a multifactorial fall-prevention group exercise and education program, Free From Falls (FFF), to prevent falls in MS. The objective of this study was to assess the impact of participation in the FFF program on balance, mobility, and falls in people with MS. Methods: This was a retrospective evaluation of assessments from community delivery of FFF. Changes in Activities-specific Balance Confidence scale scores, Berg Balance Scale scores, 8-foot Timed Up and Go performance, and falls were assessed. Results: A total of 134 participants completed the measures at the first and last FFF sessions, and 109 completed a 6-month follow-up assessment. Group mean scores on the Activities-specific Balance Confidence scale (F1,66 = 17.14, P < .05, η2 = 0.21), Berg Balance Scale (F1,68 = 23.39, P < .05, η2 = 0.26), and 8-foot Timed Up and Go (F1,79 = 4.83, P < .05, η2 = 0.06) all improved significantly from the first to the last session. At the 6-month follow-up, fewer falls were reported (χ2 [4, N = 239] = 10.56, P < .05, Phi = 0.21). Conclusions: These observational data suggest that the FFF group education and exercise program improves balance confidence, balance performance, and functional mobility and reduces falls in people with MS. PMID:26917997

Functional status mediates the association between peripheral neuropathy and health-related quality of life in individuals with diabetes.

PubMed

Riandini, Tessa; Wee, Hwee Lin; Khoo, Eric Y H; Tai, Bee Choo; Wang, Wilson; Koh, Gerald C H; Tai, E Shyong; Tavintharan, Subramaniam; Chandran, Kurumbian; Hwang, Siew Wai; Venkataraman, Kavita

2018-02-01

To examine differences in health-related quality of life (HRQoL) between patients with and without diabetic peripheral neuropathy (DPN), and whether these differences can be explained by functional deficits. This was a cross-sectional study of 160 patients with type 2 diabetes mellitus, 80 with DPN and 80 without. Assessments included HRQoL (health utility score derived from EQ-5D-5L), functional status measurements [muscle strength, timed up and go (TUG), five times sit-to-stand (FTSTS), functional reach, body sway velocity] and self-reported balance confidence [Activities-specific Balance Confidence (ABC) scale]. Mean utility scores were 0.67 ± 0.14 and 0.77 ± 0.16 in patients with and without DPN, respectively (p < 0.001). Patients with DPN had lower great toe extensor strength (6.4 ± 1.8 vs 7.6 ± 2.8 lbs, p = 0.001), greater body sway velocity (2.40 ± 1.31 vs 1.90 ± 0.52 mm/s, p = 0.002), slower TUG (12.1 ± 4.6 vs 10.1 ± 2.3 s, p < 0.001) and FTSTS (15.8 ± 5.8 vs 13.9 ± 5.4 s, p = 0.03) scores, and lower ABC score (73.4 ± 21.3 vs 82.6 ± 16.9, p = 0.003), compared to those without DPN. On stepwise multiple regression, DPN status, FTSTS, body sway velocity, BMI, diabetes duration, pain, and gender explained 38% of HRQoL variance. Addition of ABC score into the model explained 45% of variance. Results from structural equation modelling showed that DPN had direct effects on HRQoL and indirect effects through FTSTS, body sway velocity, and ABC score, with χ 2  = 8.075 (p = 0.044), root mean square error of approximation = 0.103 (lower bound 0.015, upper bound 0.191), Comparative Fit Index = 0.966, Tucker-Lewis Index = 0.887, and Standardized Root Mean Square Residual = 0.053. Patients with DPN have worse HRQoL compared to patients without DPN, partly mediated by functional status parameters. Effective interventions targeting functional status may be beneficial in improving HRQoL in these patients.

Measuring Health System Strengthening: Application of the Balanced Scorecard Approach to Rank the Baseline Performance of Three Rural Districts in Zambia

PubMed Central

Mutale, Wilbroad; Godfrey-Fausset, Peter; Mwanamwenge, Margaret Tembo; Kasese, Nkatya; Chintu, Namwinga; Balabanova, Dina; Spicer, Neil; Ayles, Helen

2013-01-01

Introduction There is growing interest in health system performance and recently WHO launched a report on health systems strengthening emphasising the need for close monitoring using system-wide approaches. One recent method is the balanced scorecard system. There is limited application of this method in middle- and low-income countries. This paper applies the concept of balanced scorecard to describe the baseline status of three intervention districts in Zambia. Methodology The Better Health Outcome through Mentoring and Assessment (BHOMA) project is a randomised step-wedged community intervention that aims to strengthen the health system in three districts in the Republic of Zambia. To assess the baseline status of the participating districts we used a modified balanced scorecard approach following the domains highlighted in the MOH 2011 Strategic Plan. Results Differences in performance were noted by district and residence. Finance and service delivery domains performed poorly in all study districts. The proportion of the health workers receiving training in the past 12 months was lowest in Kafue (58%) and highest in Luangwa district (77%). Under service capacity, basic equipment and laboratory capacity scores showed major variation, with Kafue and Luangwa having lower scores when compared to Chongwe. The finance domain showed that Kafue and Chongwe had lower scores (44% and 47% respectively). Regression model showed that children's clinical observation scores were negatively correlated with drug availability (coeff −0.40, p = 0.02). Adult clinical observation scores were positively association with adult service satisfaction score (coeff 0.82, p = 0.04) and service readiness (coeff 0.54, p = 0.03). Conclusion The study applied the balanced scorecard to describe the baseline status of 42 health facilities in three districts of Zambia. Differences in performance were noted by district and residence in most domains with finance and service delivery performing poorly in all study districts. This tool could be valuable in monitoring and evaluation of health systems. PMID:23555590

Measuring health system strengthening: application of the balanced scorecard approach to rank the baseline performance of three rural districts in Zambia.

PubMed

Mutale, Wilbroad; Godfrey-Fausset, Peter; Mwanamwenge, Margaret Tembo; Kasese, Nkatya; Chintu, Namwinga; Balabanova, Dina; Spicer, Neil; Ayles, Helen

2013-01-01

There is growing interest in health system performance and recently WHO launched a report on health systems strengthening emphasising the need for close monitoring using system-wide approaches. One recent method is the balanced scorecard system. There is limited application of this method in middle- and low-income countries. This paper applies the concept of balanced scorecard to describe the baseline status of three intervention districts in Zambia. The Better Health Outcome through Mentoring and Assessment (BHOMA) project is a randomised step-wedged community intervention that aims to strengthen the health system in three districts in the Republic of Zambia. To assess the baseline status of the participating districts we used a modified balanced scorecard approach following the domains highlighted in the MOH 2011 Strategic Plan. Differences in performance were noted by district and residence. Finance and service delivery domains performed poorly in all study districts. The proportion of the health workers receiving training in the past 12 months was lowest in Kafue (58%) and highest in Luangwa district (77%). Under service capacity, basic equipment and laboratory capacity scores showed major variation, with Kafue and Luangwa having lower scores when compared to Chongwe. The finance domain showed that Kafue and Chongwe had lower scores (44% and 47% respectively). Regression model showed that children's clinical observation scores were negatively correlated with drug availability (coeff -0.40, p = 0.02). Adult clinical observation scores were positively association with adult service satisfaction score (coeff 0.82, p = 0.04) and service readiness (coeff 0.54, p = 0.03). The study applied the balanced scorecard to describe the baseline status of 42 health facilities in three districts of Zambia. Differences in performance were noted by district and residence in most domains with finance and service delivery performing poorly in all study districts. This tool could be valuable in monitoring and evaluation of health systems.

Regression away from the mean: Theory and examples.

PubMed

Schwarz, Wolf; Reike, Dennis

2018-02-01

Using a standard repeated measures model with arbitrary true score distribution and normal error variables, we present some fundamental closed-form results which explicitly indicate the conditions under which regression effects towards (RTM) and away from the mean are expected. Specifically, we show that for skewed and bimodal distributions many or even most cases will show a regression effect that is in expectation away from the mean, or that is not just towards but actually beyond the mean. We illustrate our results in quantitative detail with typical examples from experimental and biometric applications, which exhibit a clear regression away from the mean ('egression from the mean') signature. We aim not to repeal cautionary advice against potential RTM effects, but to present a balanced view of regression effects, based on a clear identification of the conditions governing the form that regression effects take in repeated measures designs. © 2017 The British Psychological Society.

A structural equation model of the relationship between muscle strength, balance performance, walking endurance and community integration in stroke survivors

PubMed Central

2017-01-01

Purpose To use structural equation modelling (SEM) to determine (1) the direct and indirect associations of strength of paretic lower limb muscles with the level of community integration, and (2) the direct association of walking endurance and balance performance with the level of community integration in community-dwelling stroke survivors. Materials and methods In this cross-sectional study of 105 stroke survivors, the Subjective Index of Physical and Social Outcome (SIPSO) was used to measure the level of community integration. Lower-limb strength measures included isometric paretic ankle strength and isokinetic paretic knee peak torque. The Berg Balance Scale (BBS) and the 6-minute walk test (6MWT) were used to evaluate balance performance and walking endurance, respectively. Results SEM revealed that the distance walked on the 6MWT had the strongest direct association with the SIPSO score (β = 0.41, p <0.001). An increase of one standard deviation in the 6MWT distance resulted in an increase of 0.41 standard deviations in the SIPSO score. Moreover, dorsiflexion strength (β = 0.18, p = 0.044) and the BBS score (β = 0.21, p = 0.021) had direct associations with the SIPSO score. Conclusions The results of the proposed model suggest that rehabilitation training of community-dwelling stroke survivors could focus on walking endurance, balance performance and dorsiflexor muscle strengthening if the aim is to augment the level of community integration. PMID:29049293

Abnormal Error Monitoring in Math-Anxious Individuals: Evidence from Error-Related Brain Potentials

PubMed Central

Suárez-Pellicioni, Macarena; Núñez-Peña, María Isabel; Colomé, Àngels

2013-01-01

This study used event-related brain potentials to investigate whether math anxiety is related to abnormal error monitoring processing. Seventeen high math-anxious (HMA) and seventeen low math-anxious (LMA) individuals were presented with a numerical and a classical Stroop task. Groups did not differ in terms of trait or state anxiety. We found enhanced error-related negativity (ERN) in the HMA group when subjects committed an error on the numerical Stroop task, but not on the classical Stroop task. Groups did not differ in terms of the correct-related negativity component (CRN), the error positivity component (Pe), classical behavioral measures or post-error measures. The amplitude of the ERN was negatively related to participants’ math anxiety scores, showing a more negative amplitude as the score increased. Moreover, using standardized low resolution electromagnetic tomography (sLORETA) we found greater activation of the insula in errors on a numerical task as compared to errors in a non-numerical task only for the HMA group. The results were interpreted according to the motivational significance theory of the ERN. PMID:24236212

Differences in dynamic balance scores in one sport versus multiple sport high school athletes.

PubMed

Gorman, Paul P; Butler, Robert J; Rauh, Mitchell J; Kiesel, Kyle; Plisky, Phillip J

2012-04-01

Researchers have previously reported on the importance of dynamic balance in assessing an individual's risk for injury during sport. However, to date there is no research on whether multiple sport participation affects dynamic balance ability. Therefore, the purpose of this study was to determine if there was a difference in dynamic balance scores in high school athletes that competed in one sport only as compared athletes who competed in multiple sports, as tested by the Lower Quarter Y Balance Test (YBT-LQ). Ninety-two high school athletes who participated in one sport were matched, by age, gender and sport played, to athletes who participated in the same sport as well as additional sports. All individuals were assessed using the YBT-LQ to examine differences in composite reach score and reach direction asymmetry between single sport and multiple sport athletes. The greatest reach distance of three trials in each reach direction for right and left lower-extremities was normalized by limb length and used for analysis. A two-way ANOVA (gender x number of sports played) was used to statistically analyze the variables in the study. No significant interactions or main effects related to number of sports played were observed for any YBT-LQ score (p>0.05). Male athletes exhibited significantly greater normalized reach values for the posteromedial, posterolateral, and composite reach while also exhibiting a larger anterior reach difference when compared to the females. Athletes who participated in multiple sports had similar performances on the YBT-LQ when compared to athletes who participated in a single sport. The findings of this study suggest that the number of sports played by a high school athlete does not need to be controlled for when evaluating dynamic balance with the YBT-LQ.

Performance scores and standings during the 43rd Artistic Gymnastics World Championships, 2011.

PubMed

Massidda, Myosotis; Calò, Carla M

2012-01-01

Scores in artistic gymnastics are subject to changes in the rules that occur each Olympic cycle as outlined in the Code of Points, because rules influence the composition of routines and therefore performance. The aim of this study was to identify the most important routine apparatus for success in a World competition. The data were the official results for the 478 gymnasts (262 men, 216 women) who competed in the 43rd Artistic Gymnastic World Championships in 2011 in Tokyo, Japan. The factors least influenced by the technical standard of competitors were performance scores on uneven bars and balance beam for women, and those on pommel horse for men. For uneven bars, balance beam, and pommel horse, scores were consistently good predictors of final standing. Our results suggest that high scores on these apparatus have a greater influence on overall performance than scores on the other apparatus, regardless of the competitors' standard.

Effects of visual feedback balance training on the balance and ankle instability in adult men with functional ankle instability.

PubMed

Nam, Seung-Min; Kim, Kyoung; Lee, Do Youn

2018-01-01

[Purpose] This study examined the effects of visual feedback balance training on the balance and ankle instability in adult men with functional ankle instability. [Subjects and Methods] Twenty eight adults with functional ankle instability, divided randomly into an experimental group, which performed visual feedback balance training for 20 minutes and ankle joint exercises for 10 minutes, and a control group, which performed ankle joint exercise for 30 minutes. Exercises were completed three times a week for 8 weeks. Bio rescue was used for balance ability. It measured limit of stability at one minute. For ankle instability was measured using Cumberland ankle instability tool (CAIT). This measure was performed before and after the experiments in each group. [Results] The experimental group had significant increase in the Limit of Stability and CAIT score. The control group had significant increase in CAIT score. While the Limit of Stability increased without significance. [Conclusion] In conclusion, visual feedback balance training can be recommended as a treatment method for patients with functional ankle instability.

Virtual reality rehabilitation of balance: assessment of the usability of the Nintendo Wii(®) Fit Plus.

PubMed

Meldrum, Dara; Glennon, Aine; Herdman, Susan; Murray, Deirdre; McConn-Walsh, Rory

2012-05-01

The aim of this study was to investigate the usability of the Nintendo Wii Fit Plus(®) (NWFP) in the treatment of balance impairment in vestibular and other neurological disease. This was a cross-sectional, quasi-experimental study. Participants (n = 26; mean age 43 ± 14, M13:F13) with quantified balance impairment took part in a 30-minute session on the NWFP using exercises and games that challenge balance. Outcomes included the System Usability Scale (SUS), a numerical rating scale of enjoyment and a post treatment questionnaire. The mean SUS score was high (mean 82 ± 18%) with only two participants rating below 50%. There was a negative correlation of age with SUS scores (r = -0.54; p = 0.004). Mean numerical rating scale score (/10) for enjoyment of the NWFP session was 8.4 ± 3. Of the participants, 88.5% said that they would like to use the NWFP in future treatment. Seventy-three percent reported more enjoyment and motivation than usual physiotherapy. No falls occurred during testing. This study has quantified the usability of the NWFP as a treatment for balance impairment showing high levels of usability and enjoyment with no serious adverse effects. The results of this study may assist physiotherapists in devising novel balance rehabilitation programmes. [Box: see text].

Executive function predicts risk of falls in older adults without balance impairment

PubMed Central

2011-01-01

Background Executive dysfunction has previously been found to be a risk factor for falls. The aim of this study is to investigate the association between executive dysfunction and risk of falling and to determine if this association is independent of balance. Methods Participants were 188 community-dwelling individuals aged 65 and older. All participants underwent baseline and annual evaluations with review of health history, standardized neurologic examination, neuropsychological testing, and qualitative and quantitative assessment of motor function. Falls were recorded prospectively using weekly online health forms. Results During 13 months of follow-up, there were 65 of 188 participants (34.6%) who reported at least one fall. Univariate analysis showed that fallers were more likely to have lower baseline scores in executive function than non-fallers (p = 0.03). Among participants without balance impairment we found that higher executive function z-scores were associated with lower fall counts (p = 0.03) after adjustment for age, sex, health status and prior history of falls using negative binomial regression models. This relationship was not present among participants with poor balance. Conclusions Lower scores on executive function tests are a risk factor for falls in participants with minimal balance impairment. However, this effect is attenuated in individuals with poor balance where physical or more direct motor systems factors may play a greater role in fall risk. PMID:22070602

An evaluation of exact matching and propensity score methods as applied in a comparative effectiveness study of inhaled corticosteroids in asthma.

PubMed

Burden, Anne; Roche, Nicolas; Miglio, Cristiana; Hillyer, Elizabeth V; Postma, Dirkje S; Herings, Ron Mc; Overbeek, Jetty A; Khalid, Javaria Mona; van Eickels, Daniela; Price, David B

2017-01-01

Cohort matching and regression modeling are used in observational studies to control for confounding factors when estimating treatment effects. Our objective was to evaluate exact matching and propensity score methods by applying them in a 1-year pre-post historical database study to investigate asthma-related outcomes by treatment. We drew on longitudinal medical record data in the PHARMO database for asthma patients prescribed the treatments to be compared (ciclesonide and fine-particle inhaled corticosteroid [ICS]). Propensity score methods that we evaluated were propensity score matching (PSM) using two different algorithms, the inverse probability of treatment weighting (IPTW), covariate adjustment using the propensity score, and propensity score stratification. We defined balance, using standardized differences, as differences of <10% between cohorts. Of 4064 eligible patients, 1382 (34%) were prescribed ciclesonide and 2682 (66%) fine-particle ICS. The IPTW and propensity score-based methods retained more patients (96%-100%) than exact matching (90%); exact matching selected less severe patients. Standardized differences were >10% for four variables in the exact-matched dataset and <10% for both PSM algorithms and the weighted pseudo-dataset used in the IPTW method. With all methods, ciclesonide was associated with better 1-year asthma-related outcomes, at one-third the prescribed dose, than fine-particle ICS; results varied slightly by method, but direction and statistical significance remained the same. We found that each method has its particular strengths, and we recommend at least two methods be applied for each matched cohort study to evaluate the robustness of the findings. Balance diagnostics should be applied with all methods to check the balance of confounders between treatment cohorts. If exact matching is used, the calculation of a propensity score could be useful to identify variables that require balancing, thereby informing the choice of matching criteria together with clinical considerations.

An evaluation of exact matching and propensity score methods as applied in a comparative effectiveness study of inhaled corticosteroids in asthma

PubMed Central

Burden, Anne; Roche, Nicolas; Miglio, Cristiana; Hillyer, Elizabeth V; Postma, Dirkje S; Herings, Ron MC; Overbeek, Jetty A; Khalid, Javaria Mona; van Eickels, Daniela; Price, David B

2017-01-01

Background Cohort matching and regression modeling are used in observational studies to control for confounding factors when estimating treatment effects. Our objective was to evaluate exact matching and propensity score methods by applying them in a 1-year pre–post historical database study to investigate asthma-related outcomes by treatment. Methods We drew on longitudinal medical record data in the PHARMO database for asthma patients prescribed the treatments to be compared (ciclesonide and fine-particle inhaled corticosteroid [ICS]). Propensity score methods that we evaluated were propensity score matching (PSM) using two different algorithms, the inverse probability of treatment weighting (IPTW), covariate adjustment using the propensity score, and propensity score stratification. We defined balance, using standardized differences, as differences of <10% between cohorts. Results Of 4064 eligible patients, 1382 (34%) were prescribed ciclesonide and 2682 (66%) fine-particle ICS. The IPTW and propensity score-based methods retained more patients (96%–100%) than exact matching (90%); exact matching selected less severe patients. Standardized differences were >10% for four variables in the exact-matched dataset and <10% for both PSM algorithms and the weighted pseudo-dataset used in the IPTW method. With all methods, ciclesonide was associated with better 1-year asthma-related outcomes, at one-third the prescribed dose, than fine-particle ICS; results varied slightly by method, but direction and statistical significance remained the same. Conclusion We found that each method has its particular strengths, and we recommend at least two methods be applied for each matched cohort study to evaluate the robustness of the findings. Balance diagnostics should be applied with all methods to check the balance of confounders between treatment cohorts. If exact matching is used, the calculation of a propensity score could be useful to identify variables that require balancing, thereby informing the choice of matching criteria together with clinical considerations. PMID:28356782

Automated Quantification of the Landing Error Scoring System With a Markerless Motion-Capture System.

PubMed

Mauntel, Timothy C; Padua, Darin A; Stanley, Laura E; Frank, Barnett S; DiStefano, Lindsay J; Peck, Karen Y; Cameron, Kenneth L; Marshall, Stephen W

2017-11-01

  The Landing Error Scoring System (LESS) can be used to identify individuals with an elevated risk of lower extremity injury. The limitation of the LESS is that raters identify movement errors from video replay, which is time-consuming and, therefore, may limit its use by clinicians. A markerless motion-capture system may be capable of automating LESS scoring, thereby removing this obstacle.   To determine the reliability of an automated markerless motion-capture system for scoring the LESS.   Cross-sectional study.   United States Military Academy.   A total of 57 healthy, physically active individuals (47 men, 10 women; age = 18.6 ± 0.6 years, height = 174.5 ± 6.7 cm, mass = 75.9 ± 9.2 kg).   Participants completed 3 jump-landing trials that were recorded by standard video cameras and a depth camera. Their movement quality was evaluated by expert LESS raters (standard video recording) using the LESS rubric and by software that automates LESS scoring (depth-camera data). We recorded an error for a LESS item if it was present on at least 2 of 3 jump-landing trials. We calculated κ statistics, prevalence- and bias-adjusted κ (PABAK) statistics, and percentage agreement for each LESS item. Interrater reliability was evaluated between the 2 expert rater scores and between a consensus expert score and the markerless motion-capture system score.   We observed reliability between the 2 expert LESS raters (average κ = 0.45 ± 0.35, average PABAK = 0.67 ± 0.34; percentage agreement = 0.83 ± 0.17). The markerless motion-capture system had similar reliability with consensus expert scores (average κ = 0.48 ± 0.40, average PABAK = 0.71 ± 0.27; percentage agreement = 0.85 ± 0.14). However, reliability was poor for 5 LESS items in both LESS score comparisons.   A markerless motion-capture system had the same level of reliability as expert LESS raters, suggesting that an automated system can accurately assess movement. Therefore, clinicians can use the markerless motion-capture system to reliably score the LESS without being limited by the time requirements of manual LESS scoring.

Sympathetic nervous system activity measured by skin conductance quantifies the challenge of walking adaptability tasks after stroke

PubMed Central

Clark, David J.; Chatterjee, Sudeshna A.; McGuirk, Theresa E.; Porges, Eric C.; Fox, Emily J.; Balasubramanian, Chitralakshmi K.

2018-01-01

Background Walking adaptability tasks are challenging for people with motor impairments. The construct of perceived challenge is typically measured by self-report assessments, which are susceptible to subjective measurement error. The development of an objective physiologically-based measure of challenge may help to improve the ability to assess this important aspect of mobility function. The objective of this study to investigate the use of sympathetic nervous system (SNS) activity measured by skin conductance to gauge the physiological stress response to challenging walking adaptability tasks in people post-stroke. Methods Thirty adults with chronic post-stroke hemiparesis performed a battery of seventeen walking adaptability tasks. SNS activity was measured by skin conductance from the palmar surface of each hand. The primary outcome variable was the percent change in skin conductance level (ΔSCL) between the baseline resting and walking phases of each task. Task difficulty was measured by performance speed and by physical therapist grading of performance. Walking function and balance confidence were measured by preferred walking speed and the Activities Specific Balance Confidence Scale, respectively. Results There was a statistically significant negative association between ΔSCL and task performance speed and between ΔSCL and clinical score, indicating that tasks with greater SNS activity had slower performance speed and poorer clinical scores. ΔSCL was significantly greater for low functioning participants versus high functioning participants, particularly during the most challenging walking adaptability tasks. Conclusion This study supports the use of SNS activity measured by skin conductance as a valuable approach for objectively quantifying the perceived challenge of walking adaptability tasks in people post-stroke. PMID:29216598

Analysis of Covariance: Is It the Appropriate Model to Study Change?

ERIC Educational Resources Information Center

Marston, Paul T., Borich, Gary D.

The four main approaches to measuring treatment effects in schools; raw gain, residual gain, covariance, and true scores; were compared. A simulation study showed true score analysis produced a large number of Type-I errors. When corrected for this error, this method showed the least power of the four. This outcome was clearly the result of the…

A Guide for Setting the Cut-Scores to Minimize Weighted Classification Errors in Test Batteries

ERIC Educational Resources Information Center

Grabovsky, Irina; Wainer, Howard

2017-01-01

In this article, we extend the methodology of the Cut-Score Operating Function that we introduced previously and apply it to a testing scenario with multiple independent components and different testing policies. We derive analytically the overall classification error rate for a test battery under the policy when several retakes are allowed for…

How Achievement Error Patterns of Students with Mild Intellectual Disability Differ from Low IQ and Low Achievement Students without Diagnoses

ERIC Educational Resources Information Center

Root, Melissa M.; Marchis, Lavinia; White, Erica; Courville, Troy; Choi, Dowon; Bray, Melissa A.; Pan, Xingyu; Wayte, Jessica

2017-01-01

This study investigated the differences in error factor scores on the Kaufman Test of Educational Achievement-Third Edition between individuals with mild intellectual disabilities (Mild IDs), those with low achievement scores but average intelligence, and those with low intelligence but without a Mild ID diagnosis. The two control groups were…

Evaluation of Two Methods for Modeling Measurement Errors When Testing Interaction Effects with Observed Composite Scores

ERIC Educational Resources Information Center

Hsiao, Yu-Yu; Kwok, Oi-Man; Lai, Mark H. C.

2018-01-01

Path models with observed composites based on multiple items (e.g., mean or sum score of the items) are commonly used to test interaction effects. Under this practice, researchers generally assume that the observed composites are measured without errors. In this study, we reviewed and evaluated two alternative methods within the structural…

Relationships between evidence-based practice, quality improvement and clinical error experience of nurses in Korean hospitals.

PubMed

Hwang, Jee-In; Park, Hyeoun-Ae

2015-07-01

This study investigated individual and work-related factors associated with nurses' perceptions of evidence-based practice (EBP) and quality improvement (QI), and the relationships between evidence-based practice, quality improvement and clinical errors. Understanding the factors affecting evidence-based practice and quality improvement activities and their relationships with clinical errors is important for designing strategies to promote evidence-based practice, quality improvement and patient safety. A cross-sectional survey was conducted with 594 nurses in two Korean teaching hospitals using the evidence-based practice Questionnaire and quality improvement scale developed in this study. Four hundred and forty-three nurses (74.6%) returned the completed survey. Nurses' ages and educational levels were significantly associated with evidence-based practice scores whereas age and job position were associated with quality improvement scores. There were positive, moderate correlations between evidence-based practice and quality improvement scores. Nurses who had not made any clinical errors during the past 12 months had significantly higher quality improvement skills scores than those who had. The findings indicated the necessity of educational support regarding evidence-based practice and quality improvement for younger staff nurses who have no master degrees. Enhancing quality improvement skills may reduce clinical errors. Nurse managers should consider the characteristics of their staff when implementing educational and clinical strategies for evidence-based practice and quality improvement. © 2013 John Wiley & Sons Ltd.

Validation of the Kp Geomagnetic Index Forecast at CCMC

NASA Astrophysics Data System (ADS)

Frechette, B. P.; Mays, M. L.

2017-12-01

The Community Coordinated Modeling Center (CCMC) Space Weather Research Center (SWRC) sub-team provides space weather services to NASA robotic mission operators and science campaigns and prototypes new models, forecasting techniques, and procedures. The Kp index is a measure of geomagnetic disturbances for space weather in the magnetosphere such as geomagnetic storms and substorms. In this study, we performed validation on the Newell et al. (2007) Kp prediction equation from December 2010 to July 2017. The purpose of this research is to understand the Kp forecast performance because it's critical for NASA missions to have confidence in the space weather forecast. This research was done by computing the Kp error for each forecast (average, minimum, maximum) and each synoptic period. Then to quantify forecast performance we computed the mean error, mean absolute error, root mean square error, multiplicative bias and correlation coefficient. A contingency table was made for each forecast and skill scores were computed. The results are compared to the perfect score and reference forecast skill score. In conclusion, the skill score and error results show that the minimum of the predicted Kp over each synoptic period from the Newell et al. (2007) Kp prediction equation performed better than the maximum or average of the prediction. However, persistence (reference forecast) outperformed all of the Kp forecasts (minimum, maximum, and average). Overall, the Newell Kp prediction still predicts within a range of 1, even though persistence beats it.

Correction

NASA Astrophysics Data System (ADS)

2014-09-01

An error was made in the spelling of the name of Mark Abbott, who was quoted in the news article "Earth observation plan looks toward balancing U.S. federal priorities," published in the 19 August 2014 issue of Eos (95(33), 295-296, doi:10.1002/2014EO330003). Eos regrets the error.

Effective reinforcement learning following cerebellar damage requires a balance between exploration and motor noise.

PubMed

Therrien, Amanda S; Wolpert, Daniel M; Bastian, Amy J

2016-01-01

Reinforcement and error-based processes are essential for motor learning, with the cerebellum thought to be required only for the error-based mechanism. Here we examined learning and retention of a reaching skill under both processes. Control subjects learned similarly from reinforcement and error-based feedback, but showed much better retention under reinforcement. To apply reinforcement to cerebellar patients, we developed a closed-loop reinforcement schedule in which task difficulty was controlled based on recent performance. This schedule produced substantial learning in cerebellar patients and controls. Cerebellar patients varied in their learning under reinforcement but fully retained what was learned. In contrast, they showed complete lack of retention in error-based learning. We developed a mechanistic model of the reinforcement task and found that learning depended on a balance between exploration variability and motor noise. While the cerebellar and control groups had similar exploration variability, the patients had greater motor noise and hence learned less. Our results suggest that cerebellar damage indirectly impairs reinforcement learning by increasing motor noise, but does not interfere with the reinforcement mechanism itself. Therefore, reinforcement can be used to learn and retain novel skills, but optimal reinforcement learning requires a balance between exploration variability and motor noise. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain.

Effective reinforcement learning following cerebellar damage requires a balance between exploration and motor noise

PubMed Central

Therrien, Amanda S.; Wolpert, Daniel M.

2016-01-01

Abstract See Miall and Galea (doi: 10.1093/awv343 ) for a scientific commentary on this article. Reinforcement and error-based processes are essential for motor learning, with the cerebellum thought to be required only for the error-based mechanism. Here we examined learning and retention of a reaching skill under both processes. Control subjects learned similarly from reinforcement and error-based feedback, but showed much better retention under reinforcement. To apply reinforcement to cerebellar patients, we developed a closed-loop reinforcement schedule in which task difficulty was controlled based on recent performance. This schedule produced substantial learning in cerebellar patients and controls. Cerebellar patients varied in their learning under reinforcement but fully retained what was learned. In contrast, they showed complete lack of retention in error-based learning. We developed a mechanistic model of the reinforcement task and found that learning depended on a balance between exploration variability and motor noise. While the cerebellar and control groups had similar exploration variability, the patients had greater motor noise and hence learned less. Our results suggest that cerebellar damage indirectly impairs reinforcement learning by increasing motor noise, but does not interfere with the reinforcement mechanism itself. Therefore, reinforcement can be used to learn and retain novel skills, but optimal reinforcement learning requires a balance between exploration variability and motor noise. PMID:26626368

Matching weights to simultaneously compare three treatment groups: Comparison to three-way matching

PubMed Central

Yoshida, Kazuki; Hernández-Díaz, Sonia; Solomon, Daniel H.; Jackson, John W.; Gagne, Joshua J.; Glynn, Robert J.; Franklin, Jessica M.

2017-01-01

BACKGROUND Propensity score matching is a commonly used tool. However, its use in settings with more than two treatment groups has been less frequent. We examined the performance of a recently developed propensity score weighting method in the three treatment group setting. METHODS The matching weight method is an extension of inverse probability of treatment weighting (IPTW) that reweights both exposed and unexposed groups to emulate a propensity score matched population. Matching weights can generalize to multiple treatment groups. The performance of matching weights in the three-group setting was compared via simulation to three-way 1:1:1 propensity score matching and IPTW. We also applied these methods to an empirical example that compared the safety of three analgesics. RESULTS Matching weights had similar bias, but better mean squared error (MSE) compared to three-way matching in all scenarios. The benefits were more pronounced in scenarios with a rare outcome, unequally sized treatment groups, or poor covariate overlap. IPTW’s performance was highly dependent on covariate overlap. In the empirical example, matching weights achieved the best balance for 24 out of 35 covariates. Hazard ratios were numerically similar to matching. However, the confidence intervals were narrower for matching weights. CONCLUSIONS Matching weights demonstrated improved performance over three-way matching in terms of MSE, particularly in simulation scenarios where finding matched subjects was difficult. Given its natural extension to settings with even more than three groups, we recommend matching weights for comparing outcomes across multiple treatment groups, particularly in settings with rare outcomes or unequal exposure distributions. PMID:28151746

30 Years Trend of Competitive Balance in Turkish Football Super League

ERIC Educational Resources Information Center

Inan, Tugbay

2018-01-01

We must point out that the results of football games affect the competitive balance degree. In other words, the calculations we made in the score table at the end of the season give us a degree of competitive balance. The degree on which the concept of competitiveness is based is cited as competitive balance in football. Sports economics can be…

Improving the quality of cognitive screening assessments: ACEmobile, an iPad-based version of the Addenbrooke's Cognitive Examination-III.

PubMed

Newman, Craig G J; Bevins, Adam D; Zajicek, John P; Hodges, John R; Vuillermoz, Emil; Dickenson, Jennifer M; Kelly, Denise S; Brown, Simona; Noad, Rupert F

2018-01-01

Ensuring reliable administration and reporting of cognitive screening tests are fundamental in establishing good clinical practice and research. This study captured the rate and type of errors in clinical practice, using the Addenbrooke's Cognitive Examination-III (ACE-III), and then the reduction in error rate using a computerized alternative, the ACEmobile app. In study 1, we evaluated ACE-III assessments completed in National Health Service (NHS) clinics ( n  = 87) for administrator error. In study 2, ACEmobile and ACE-III were then evaluated for their ability to capture accurate measurement. In study 1, 78% of clinically administered ACE-IIIs were either scored incorrectly or had arithmetical errors. In study 2, error rates seen in the ACE-III were reduced by 85%-93% using ACEmobile. Error rates are ubiquitous in routine clinical use of cognitive screening tests and the ACE-III. ACEmobile provides a framework for supporting reduced administration, scoring, and arithmetical error during cognitive screening.

Sensitivity to Change and Responsiveness of Four Balance Measures for Community-Dwelling Older Adults

PubMed Central

Latham, Nancy K.; Jette, Alan M.; Wagenaar, Robert C.; Ni, Pengsheng; Slavin, Mary D.; Bean, Jonathan F.

2012-01-01

Background Impaired balance has a significant negative impact on mobility, functional independence, and fall risk in older adults. Although several, well-respected balance measures are currently in use, there is limited evidence regarding the most appropriate measure to assess change in community-dwelling older adults. Objective The aim of this study was to compare floor and ceiling effects, sensitivity to change, and responsiveness across the following balance measures in community-dwelling elderly people with functional limitations: Berg Balance Scale (BBS), Performance-Oriented Mobility Assessment total scale (POMA-T), POMA balance subscale (POMA-B), and Dynamic Gait Index (DGI). Design Retrospective data from a 16-week exercise trial were used. Secondary analyses were conducted on the total sample and by subgroups of baseline functional limitation or baseline balance scores. Methods Participants were 111 community-dwelling older adults 65 years of age or older, with functional limitations. Sensitivity to change was assessed using effect size, standardized response mean, and paired t tests. Responsiveness was assessed using minimally important difference (MID) estimates. Results No floor effects were noted. Ceiling effects were observed on all measures, including in people with moderate to severe functional limitations. The POMA-T, POMA-B, and DGI showed significantly larger ceiling effects compared with the BBS. All measures had low sensitivity to change in total sample analyses. Subgroup analyses revealed significantly better sensitivity to change in people with lower compared with higher baseline balance scores. Although both the total sample and lower baseline balance subgroups showed statistically significant improvement from baseline to 16 weeks on all measures, only the lower balance subgroup showed change scores that consistently exceeded corresponding MID estimates. Limitations This study was limited to comparing 4 measures of balance, and anchor-based methods for assessing MID could not be reported. Conclusions Important limitations, including ceiling effects and relatively low sensitivity to change and responsiveness, were noted across all balance measures, highlighting their limited utility across the full spectrum of the community-dwelling elderly population. New, more challenging measures are needed for better discrimination of balance ability in community-dwelling elderly people at higher functional levels. PMID:22114200

12 CFR 205.15 - Electronic fund transfer of government benefits.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) Account balance. The means by which the consumer may obtain information concerning the account balance... history or other account information, under paragraph (c) of this section, in which the error is first... consumer for use in initiating an electronic fund transfer of government benefits from an account, other...

Feasibility of Self-Reflection as a Tool to Balance Clinical Reasoning Strategies

ERIC Educational Resources Information Center

Sibbald, Matthew; de Bruin, Anique B. H.

2012-01-01

Clinicians are believed to use two predominant reasoning strategies: system 1 based pattern recognition, and system 2 based analytical reasoning. Balancing these cognitive reasoning strategies is widely believed to reduce diagnostic error. However, clinicians approach different problems with different reasoning strategies. This study explores…

Use of the SMART Balance Master to quantify the effects of osteopathic manipulative treatment in patients with dizziness.

PubMed

Fraix, Marcel; Gordon, Ashlynn; Graham, Victoria; Hurwitz, Eric; Seffinger, Michael A

2013-05-01

Dizziness is the third most common complaint among outpatients and the most common complaint in patients aged 75 years or older. It can be incapacitating for patients, affecting both productivity and quality of life. To evaluate the effect of osteopathic manipulative treatment (OMT) for spinal somatic dysfunction in patients with dizziness lasting longer than 3 months. A prospective clinical cohort study that took place in 2011. Department of Physical Therapy laboratory at the Western University of Health Sciences College of Osteopathic Medicine in Pomona, California. Sixteen participants (2 male, 14 female; mean [range] age, 49 [13-75] years) with dizziness lasting at least 3 months (mean duration of symptoms, 84 months) and spinal somatic dysfunction, but no history of known stroke or brain disease, were recruited from the local community and evaluated for postural balance control before, immediately after, and 1 week after OMT. Four osteopathic physicians board certified in neuromusculoskeletal medicine/osteopathic manipulative medicine provided OMT, including muscle energy; high-velocity, low-amplitude; counterstrain; myofascial release; balanced ligamentous release; and cranial OMT techniques. Outcomes were assessed with the SMART Balance Master (NeuroCom), a validated instrument that provides graphic and quantitative analyses of sway and balance, and the Dizziness Handicap Inventory (DHI), a self-assessment inventory designed to assess precipitating physical factors associated with dizziness and functional and emotional consequences of vestibular disease. Paired t tests, performed to assess changes in mean composite scores for all challenge tests, revealed that balance was significantly improved both immediately and 1 week after OMT (both P<.001), with no significant difference between immediate and 1-week post-OMT scores (P=.20). The DHI scores, both total and subscale, improved significantly after OMT (P<.001), and changes in composite and DHI scores were correlated with each other (P=.047). Osteopathic manipulative treatment for spinal somatic dysfunction improved balance in patients with dizziness lasting at least 3 months.

Effect of Wii-intervention on balance of children with poor motor performance.

PubMed

Mombarg, Remo; Jelsma, Dorothee; Hartman, Esther

2013-09-01

The purpose of this study was to investigate the effects of training with the Wii-balance board on balance and balance-related skills of children with poor motor performance. Twenty-nine children (23 boys, 6 girls; aged 7-12 years) participated in this study and were randomly assigned to an experimental and control group. All children scored below the 16th percentile on a standardized test of motor ability and balance skills (Movement Assessment Battery for children (M-ABC-2)). Before and after a six-week Wii-intervention (M=8h, 22 min, SD=53 min), the balance skills of the experimental group and control group were measured with the M-ABC-2 and the Bruininks-Oseretsky test of motor proficiency (BOT-2). Both groups improved on all tests. The M-ABC-2 and the BOT-2 total balance-scores of the experimental group improved significantly from pre to post intervention, whereas those of the control group showed no significant progress. This resulted in significant interaction-effects, favoring the experimental children. No transfer-effects of the intervention on balance-related skills were demonstrated. Our findings showed that the Wii-balance board is an effective intervention for children with poor balance control. Further development and investigation of the intervention could be directed toward the implementation of the newly acquired balance-skills in daily life. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of age, sex, technique, and exercise program on movement patterns after an anterior cruciate ligament injury prevention program in youth soccer players.

PubMed

DiStefano, Lindsay J; Padua, Darin A; DiStefano, Michael J; Marshall, Stephen W

2009-03-01

Anterior cruciate ligament (ACL) injury prevention programs show promising results with changing movement; however, little information exists regarding whether a program designed for an individual's movements may be effective or how baseline movements may affect outcomes. A program designed to change specific movements would be more effective than a "one-size-fits-all" program. Greatest improvement would be observed among individuals with the most baseline error. Subjects of different ages and sexes respond similarly. Randomized controlled trial; Level of evidence, 1. One hundred seventy-three youth soccer players from 27 teams were randomly assigned to a generalized or stratified program. Subjects were videotaped during jump-landing trials before and after the program and were assessed using the Landing Error Scoring System (LESS), which is a valid clinical movement analysis tool. A high LESS score indicates more errors. Generalized players performed the same exercises, while the stratified players performed exercises to correct their initial movement errors. Change scores were compared between groups of varying baseline errors, ages, sexes, and programs. Subjects with the highest baseline LESS score improved the most (95% CI, -3.4 to -2.0). High school subjects (95% CI, -1.7 to -0.98) improved their technique more than pre-high school subjects (95% CI, -1.0 to -0.4). There was no difference between the programs or sexes. Players with the greatest amount of movement errors experienced the most improvement. A program's effectiveness may be enhanced if this population is targeted.

King-Devick Test reference values and associations with balance measures in high school American football players.

PubMed

Alsalaheen, B; Haines, J; Yorke, A; Diebold, J

2016-02-01

The King-Devick test appears to be a promising tool in screening for concussions. However, limited evidence exists on the baseline associations between the K-D test and age and baseline screening tools used after concussion. Additionally, there are no published reference values for the K-D test in high school football players. The K-D test, the Balance Error Scoring System, and the Limits of Stability (LOS) test were administered to 157 high school football players. Additionally, a subsample of 62 participants completed the test twice to examine the reliability of K-D test. There was no relationship between the K-D test and the BESS, or the reaction time and directional control of LOS test. Students aged between 16 and 18 years demonstrated faster K-D test performance compared to students between 13 and 15 years of age. However, there was no association between K-D test and history of concussion. The reliability of the K-D test was (ICC2,1 = 0.89), and the minimal detectable change was 6.10 s. Normative reference values for high school football players are presented in this study. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Virtual reality-based therapy for the treatment of balance deficits in patients receiving inpatient rehabilitation for traumatic brain injury.

PubMed

Cuthbert, Jeffrey P; Staniszewski, Kristi; Hays, Kaitlin; Gerber, Don; Natale, Audrey; O'Dell, Denise

2014-01-01

To evaluate the feasibility and safety of utilizing a commercially available virtual reality gaming system as a treatment intervention for balance training. A randomized controlled trial in which assessment and analysis were blinded. An inpatient rehabilitation facility. Interventions included balance-based physical therapy using a Nintendo Wii, as monitored by a physical therapist, and receipt of one-on-one balance-based physical therapy using standard physical therapy modalities available for use in the therapy gym. Participants in the standard physical therapy group were found to have slightly higher enjoyment at mid-intervention, while those receiving the virtual reality-based balance intervention were found to have higher enjoyment at study completion. Both groups demonstrated improved static and dynamic balance over the course of the study, with no significant differences between groups. Correlational analyses suggest a relationship exists between Wii balance board game scores and BBS scores for measures taken beyond the baseline assessment. This study provides a modest level of evidence to support using commercially available VR gaming systems for the treatment of balance deficits in patients with a primary diagnosis of TBI receiving inpatient rehabilitation. Additional research of these types of interventions for the treatment of balance deficits is warranted.

Errors and Understanding: The Effects of Error-Management Training on Creative Problem-Solving

ERIC Educational Resources Information Center

Robledo, Issac C.; Hester, Kimberly S.; Peterson, David R.; Barrett, Jamie D.; Day, Eric A.; Hougen, Dean P.; Mumford, Michael D.

2012-01-01

People make errors in their creative problem-solving efforts. The intent of this article was to assess whether error-management training would improve performance on creative problem-solving tasks. Undergraduates were asked to solve an educational leadership problem known to call for creative thought where problem solutions were scored for…

Linear and nonlinear response of a rotating tokamak plasma to a resonant error-field

NASA Astrophysics Data System (ADS)

Fitzpatrick, Richard

2014-09-01

An in-depth investigation of the effect of a resonant error-field on a rotating, quasi-cylindrical, tokamak plasma is preformed within the context of constant-ψ, resistive-magnetohydrodynamical theory. General expressions for the response of the plasma at the rational surface to the error-field are derived in both the linear and nonlinear regimes, and the extents of these regimes mapped out in parameter space. Torque-balance equations are also obtained in both regimes. These equations are used to determine the steady-state plasma rotation at the rational surface in the presence of the error-field. It is found that, provided the intrinsic plasma rotation is sufficiently large, the torque-balance equations possess dynamically stable low-rotation and high-rotation solution branches, separated by a forbidden band of dynamically unstable solutions. Moreover, bifurcations between the two stable solution branches are triggered as the amplitude of the error-field is varied. A low- to high-rotation bifurcation is invariably associated with a significant reduction in the width of the magnetic island chain driven at the rational surface, and vice versa. General expressions for the bifurcation thresholds are derived and their domains of validity mapped out in parameter space.

Detailed Uncertainty Analysis for Ares I Ascent Aerodynamics Wind Tunnel Database

NASA Technical Reports Server (NTRS)

Hemsch, Michael J.; Hanke, Jeremy L.; Walker, Eric L.; Houlden, Heather P.

2008-01-01

A detailed uncertainty analysis for the Ares I ascent aero 6-DOF wind tunnel database is described. While the database itself is determined using only the test results for the latest configuration, the data used for the uncertainty analysis comes from four tests on two different configurations at the Boeing Polysonic Wind Tunnel in St. Louis and the Unitary Plan Wind Tunnel at NASA Langley Research Center. Four major error sources are considered: (1) systematic errors from the balance calibration curve fits and model + balance installation, (2) run-to-run repeatability, (3) boundary-layer transition fixing, and (4) tunnel-to-tunnel reproducibility.

THE DYNAMIC LEAP AND BALANCE TEST (DLBT): A TEST-RETEST RELIABILITY STUDY

PubMed Central

Newman, Thomas M.; Smith, Brent I.; John Miller, Sayers

2017-01-01

Background There is a need for new clinical assessment tools to test dynamic balance during typical functional movements. Common methods for assessing dynamic balance, such as the Star Excursion Balance Test, which requires controlled movement of body segments over an unchanged base of support, may not be an adequate measure for testing typical functional movements that involve controlled movement of body segments along with a change in base of support. Purpose/hypothesis The purpose of this study was to determine the reliability of the Dynamic Leap and Balance Test (DLBT) by assessing its test-retest reliability. It was hypothesized that there would be no statistically significant differences between testing days in time taken to complete the test. Study Design Reliability study Methods Thirty healthy college aged individuals participated in this study. Participants performed a series of leaps in a prescribed sequence, unique to the DLBT test. Time required by the participants to complete the 20-leap task was the dependent variable. Subjects leaped back and forth from peripheral to central targets alternating weight bearing from one leg to the other. Participants landed on the central target with the tested limb and were required to stabilize for two seconds before leaping to the next target. Stability was based upon qualitative measures similar to Balance Error Scoring System. Each assessment was comprised of three trials and performed on two days with a separation of at least six days. Results Two-way mixed ANOVA was used to analyze the differences in time to complete the sequence between the three trial averages of the two testing sessions. Intraclass Correlation Coefficient (ICC3,1) was used to establish between session test-retest reliability of the test trial averages. Significance was set a priori at p ≤ 0.05. No significant differences (p > 0.05) were detected between the two testing sessions. The ICC was 0.93 with a 95% confidence interval from 0.84 to 0.96. Conclusion This test is a cost-effective, easy to administer and clinically relevant novel measure for assessing dynamic balance that has excellent test-retest reliability. Clinical relevance As a new measure of dynamic balance, the DLBT has the potential to be a cost-effective, challenging and functional tool for clinicians. Level of Evidence 2b PMID:28900556

The Relationship between Mean Square Differences and Standard Error of Measurement: Comment on Barchard (2012)

ERIC Educational Resources Information Center

Pan, Tianshu; Yin, Yue

2012-01-01

In the discussion of mean square difference (MSD) and standard error of measurement (SEM), Barchard (2012) concluded that the MSD between 2 sets of test scores is greater than 2(SEM)[superscript 2] and SEM underestimates the score difference between 2 tests when the 2 tests are not parallel. This conclusion has limitations for 2 reasons. First,…

A Brief Look at: Test Scores and the Standard Error of Measurement. E&R Report No. 10.13

ERIC Educational Resources Information Center

Holdzkom, David; Sumner, Brian; McMillen, Brad

2010-01-01

In the context of standardized testing, the standard error of measurement (SEM) is a measure of the factors other than the student's actual knowledge of the tested material that may affect the student's test score. Such factors may include distractions in the testing environment, fatigue, hunger, or even luck. This means that a student's observed…

Malingering in Toxic Exposure. Classification Accuracy of Reliable Digit Span and WAIS-III Digit Span Scaled Scores

ERIC Educational Resources Information Center

Greve, Kevin W.; Springer, Steven; Bianchini, Kevin J.; Black, F. William; Heinly, Matthew T.; Love, Jeffrey M.; Swift, Douglas A.; Ciota, Megan A.

2007-01-01

This study examined the sensitivity and false-positive error rate of reliable digit span (RDS) and the WAIS-III Digit Span (DS) scaled score in persons alleging toxic exposure and determined whether error rates differed from published rates in traumatic brain injury (TBI) and chronic pain (CP). Data were obtained from the files of 123 persons…

Static balance function in children with a history of preterm birth

PubMed Central

Eshaghi, Zahra; Jafari, Zahra; Jalaie, Shohreh

2015-01-01

Background: The incomplete maturation of brain in preterm children results in long-term neurodevelopmental impairment. This study aimed to investigate the static balance function in children with a history of preterm birth. Methods: Participants were 31 preterm children including 21 moderately preterm (MPT), 10 very preterm (VPT), and 20 term children aged 5.5 and 6.5 years. The cervical vestibular-evoked myogenic potential (cVEMP) test and four static balance subscales of BOT-2 were performed. Results: The VPT children showed a significant increase in P1 and N1 wave latencies in cVEMP test compared to those in the term children (p= 0.041). Mean scores in the four static balance subscales of BOT-2 were significantly lower in the preterm children compared to those in the term children (p= 0.025). The P1 wave latency (p= 0.003) and mean score of standing on a balance beam with open eyes (p= 0.039) were significantly lower in the VPT children compared to those in the MPT children. A significant correlation was observed between the mean score in exercise 4 (standing on one leg on a balance beam with closed eyes) of static balance subscales of BOT-2 and P1 (r= -0.267, p= 0.036) and N1 (r= -0.304, p= 0.016) wave latencies of cVEMP. Conclusion: The longer latency of cVEMP waves along with a poor performance of children with a history of preterm birth suggests a possible defect in central vestibular pathway. PMID:26913273

Mind the Mode: Differences in Paper vs. Web-Based Survey Modes Among Women With Cancer.

PubMed

Hagan, Teresa L; Belcher, Sarah M; Donovan, Heidi S

2017-09-01

Researchers administering surveys seek to balance data quality, sources of error, and practical concerns when selecting an administration mode. Rarely are decisions about survey administration based on the background of study participants, although socio-demographic characteristics like age, education, and race may contribute to participants' (non)responses. In this study, we describe differences in paper- and web-based surveys administered in a national cancer survivor study of women with a history of cancer to compare the ability of each survey administrative mode to provide quality, generalizable data. We compared paper- and web-based survey data by socio-demographic characteristics of respondents, missing data rates, scores on primary outcome measure, and administrative costs and time using descriptive statistics, tests of mean group differences, and linear regression. Our findings indicate that more potentially vulnerable patients preferred paper questionnaires and that data quality, responses, and costs significantly varied by mode and participants' demographic information. We provide targeted suggestions for researchers conducting survey research to reduce survey error and increase generalizability of study results to the patient population of interest. Researchers must carefully weigh the pros and cons of survey administration modes to ensure a representative sample and high-quality data. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Clinical use of Nintendo Wii bowling simulation to decrease fall risk in an elderly resident of a nursing home: a case report.

PubMed

Clark, Robert; Kraemer, Theresa

2009-01-01

Of the estimated 1.7 million residents of nursing homes in the United States, approximately half fall annually; and 11% of these sustain injury. This is twice the rate for persons dwelling in the community. By addressing fall risk, physical therapists have an opportunity to reduce falls which are the leading cause of injury deaths, as well as the most common cause of nonfatal injuries for older adults in the United States. This case report examines the effect of a novel interactive video game intervention to address balance dysfunction in an elderly resident of a nursing home who was at risk for falls. The patient is an 89-year-old resident diagnosed with an unspecified balance disorder and a history of multiple falls. Self reports of gait abnormalities, scores on several clinical measures, and her fall history classified her as having substantial risk for future falls. A nontraditional approach to balance training, employing the Nintendo Wii bowling simulation, was used as intervention for this patient's balance disorder. After 6 one-hour treatment sessions, the patient's Berg Balance Score improved from 48 to 53. On the Dynamic Gait Index, the patient improved her score from 19 to 21. The patient's Timed Up and Go Test improved from 14.9 to 10.5 seconds, all suggesting a reduced risk of falling. The patient's ABC Score improved from 88 to 90%. Physical therapy intervention, using the Nintendo Wii bowling simulation, may have decreased fall risk for this individual.

Improvement of the Mair scoring system using structural equations modeling for classifying the diagnostic adequacy of cytology material from thyroid lesions.

PubMed

Kulkarni, H R; Kamal, M M; Arjune, D G

1999-12-01

The scoring system developed by Mair et al. (Acta Cytol 1989;33:809-813) is frequently used to grade the quality of cytology smears. Using a one-factor analytic structural equations model, we demonstrate that the errors in measurement of the parameters used in the Mair scoring system are highly and significantly correlated. We recommend the use of either a multiplicative scoring system, using linear scores, or an additive scoring system, using exponential scores, to correct for the correlated errors. We suggest that the 0, 1, and 2 points used in the Mair scoring system be replaced by 1, 2, and 4, respectively. Using data on fine-needle biopsies of 200 thyroid lesions by both fine-needle aspiration (FNA) and fine-needle capillary sampling (FNC), we demonstrate that our modification of the Mair scoring system is more sensitive and more consistent with the structural equations model. Therefore, we recommend that the modified Mair scoring system be used for classifying the diagnostic adequacy of cytology smears. Diagn. Cytopathol. 1999;21:387-393. Copyright 1999 Wiley-Liss, Inc.

Balance impairment in individuals with Wolfram syndrome

PubMed Central

Pickett, Kristen A.; Duncan, Ryan P.; Paciorkowski, Alex R.; Permutt, Alan; Marshall, Bess; Hershey, Tamara; Earhart, Gammon M.

2012-01-01

AIM Wolfram syndrome (WFS), a rare neurodegenerative disorder, is characterized by early onset insulin-dependent diabetes mellitus, optic atrophy, deafness, diabetes insipidus, and neurological abnormalities. Although previously unreported, we hypothesized that neurological complications may be detectable in relatively early stages of the disease. As the cerebellum and brainstem seem particularly vulnerable in WFS, we focused on balance functions critically dependent on these regions. The primary goal of this investigation was to compare balance in young individuals with WFS, in relatively early stages of the disease, to an age-matched cohort using a clinically applicable test. METHOD Balance was assessed via the mini-BESTest in 13 children, adolescents and young adults with WFS and 30 typically developing age-matched individuals. RESULTS A significant difference was observed between groups in balance as well as in three of four subcomponents of the mini-BESTest and in two timed tasks related to balance. Mini-BESTest scores were correlated with age (p < 0.001, rs = 0.59) among typically developing individuals. In the WFS group, mini-BESTest scores were related to overall motor dysfunction, but not age. INTERPRETATION Impairments in balance in WFS may occur earlier in the disease process than previously recognized and appear to be related to overall neurological progression rather than chronological age. Recognizing balance impairments and understanding which balance systems contribute to balance deficits in those with WFS may allow for development of effective patient-centered treatment paradigms. PMID:22771154

Comparing Propensity Score Methods in Balancing Covariates and Recovering Impact in Small Sample Educational Program Evaluations

ERIC Educational Resources Information Center

Stone, Clement A.; Tang, Yun

2013-01-01

Propensity score applications are often used to evaluate educational program impact. However, various options are available to estimate both propensity scores and construct comparison groups. This study used a student achievement dataset with commonly available covariates to compare different propensity scoring estimation methods (logistic…

Performance Assessment of IT Governance with Balanced Score Card and COBIT 4.1 of Universitas Pendidikan Indonesia

NASA Astrophysics Data System (ADS)

Wijayanti, N. Y.; Setiawan, W.; Sukamto, R. A.

2017-02-01

Information technology’s application has become an important daily support for all sectors. Educational institutions, including Universitas Pendidikan Indonesia (UPI), enable information technology as the main asset to increase its qualities and global’s competitive power. By the importances of using information technology for almost every scope, measurement is needed to identify how optimal the IT governance is. Based on these facts, the purposes of this reaseacrh are identify the IT governance’s performance assessment indicators, discover the scores based on the indicators, and analyse IT governance’s performance in UPI. This research is using the combination of Balanced Score Card (BSC) and COBIT 4.1 as the framework to establish assessment indicators in questionnaire’s form. By combining both methods, the final scores of IT governance’s performance will represent UPI’s business goals and objectives in all sectors. This research used 26 COBIT’s processes as assessment indicator of IT performance from the maping 15 IT and business goals of COBIT, and 17 UPI’s strategic plans. The final score are 3.80 for financial perspective, 3.63 for customer perspective, 3.62 for internal business process perspective, and 3.72 for learning and growth perspective. With these scores, then the final result is each perspectives of Balanced Score Card’s current maturity levels are at level 4, which is IT process criticality is regularly defined with full support and agreement from the relevant business process owners.

Simulated Driving Assessment (SDA) for Teen Drivers: Results from a Validation Study

PubMed Central

McDonald, Catherine C.; Kandadai, Venk; Loeb, Helen; Seacrist, Thomas S.; Lee, Yi-Ching; Winston, Zachary; Winston, Flaura K.

2015-01-01

Background Driver error and inadequate skill are common critical reasons for novice teen driver crashes, yet few validated, standardized assessments of teen driving skills exist. The purpose of this study was to evaluate the construct and criterion validity of a newly developed Simulated Driving Assessment (SDA) for novice teen drivers. Methods The SDA's 35-minute simulated drive incorporates 22 variations of the most common teen driver crash configurations. Driving performance was compared for 21 inexperienced teens (age 16–17 years, provisional license ≤90 days) and 17 experienced adults (age 25–50 years, license ≥5 years, drove ≥100 miles per week, no collisions or moving violations ≤3 years). SDA driving performance (Error Score) was based on driving safety measures derived from simulator and eye-tracking data. Negative driving outcomes included simulated collisions or run-off-the-road incidents. A professional driving evaluator/instructor reviewed videos of SDA performance (DEI Score). Results The SDA demonstrated construct validity: 1.) Teens had a higher Error Score than adults (30 vs. 13, p=0.02); 2.) For each additional error committed, the relative risk of a participant's propensity for a simulated negative driving outcome increased by 8% (95% CI: 1.05–1.10, p<0.01). The SDA demonstrated criterion validity: Error Score was correlated with DEI Score (r=−0.66, p<0.001). Conclusions This study supports the concept of validated simulated driving tests like the SDA to assess novice driver skill in complex and hazardous driving scenarios. The SDA, as a standard protocol to evaluate teen driver performance, has the potential to facilitate screening and assessment of teen driving readiness and could be used to guide targeted skill training. PMID:25740939

Balance Velocities of the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Joughin, Ian; Fahnestock, Mark; Ekholm, Simon; Kwok, Ron

1997-01-01

We present a map of balance velocities for the Greenland ice sheet. The resolution of the underlying DEM, which was derived primarily from radar altimetry data, yields far greater detail than earlier balance velocity estimates for Greenland. The velocity contours reveal in striking detail the location of an ice stream in northeastern Greenland, which was only recently discovered using satellite imagery. Enhanced flow associated with all of the major outlets is clearly visible, although small errors in the source data result in less accurate estimates of the absolute flow speeds. Nevertheless, the balance map is useful for ice-sheet modelling, mass balance studies, and field planning.

Limitations of the paraxial Debye approximation.

PubMed

Sheppard, Colin J R

2013-04-01

In the paraxial form of the Debye integral for focusing, higher order defocus terms are ignored, which can result in errors in dealing with aberrations, even for low numerical aperture. These errors can be avoided by using a different integration variable. The aberrations of a glass slab, such as a coverslip, are expanded in terms of the new variable, and expressed in terms of Zernike polynomials to assist with aberration balancing. Tube length error is also discussed.

Evaluation of Nintendo Wii Balance Board as a Tool for Measuring Postural Stability After Sport-Related Concussion.

PubMed

Merchant-Borna, Kian; Jones, Courtney Marie Cora; Janigro, Mattia; Wasserman, Erin B; Clark, Ross A; Bazarian, Jeffrey J

2017-03-01

Recent changes to postconcussion guidelines indicate that postural-stability assessment may augment traditional neurocognitive testing when making return-to-participation decisions. The Balance Error Scoring System (BESS) has been proposed as 1 measure of balance assessment. A new, freely available software program to accompany the Nintendo Wii Balance Board (WBB) system has recently been developed but has not been tested in concussed patients. To evaluate the feasibility of using the WBB to assess postural stability across 3 time points (baseline and postconcussion days 3 and 7) and to assess concurrent and convergent validity of the WBB with other traditional measures (BESS and Immediate Post-Concussion Assessment and Cognitive Test [ImPACT] battery) of assessing concussion recovery. Cohort study. Athletic training room and collegiate sports arena. We collected preseason baseline data from 403 National Collegiate Athletic Association Division I and III student-athletes participating in contact sports and studied 19 participants (age = 19.2 ± 1.2 years, height = 177.7 ± 8.0 cm, mass = 75.3 ± 16.6 kg, time from baseline to day 3 postconcussion = 27.1 ± 36.6 weeks) who sustained concussions. We assessed balance using single-legged and double-legged stances for both the BESS and WBB, focusing on the double-legged, eyes-closed stance for the WBB, and used ImPACT to assess neurocognition at 3 time points. Descriptive statistics were used to characterize the sample. Mean differences and Spearman rank correlation coefficients were used to determine differences within and between metrics over the 3 time points. Individual-level changes over time were also assessed graphically. The WBB demonstrated mean changes between baseline and day 3 postconcussion and between days 3 and 7 postconcussion. It was correlated with the BESS and ImPACT for several measures and identified 2 cases of abnormal balance postconcussion that would not have been identified via the BESS. When accompanied by the appropriate analytic software, the WBB may be an alternative for assessing postural stability in concussed student-athletes and may provide additional information to that obtained via the BESS and ImPACT. However, verification among independent samples is required.

Violating Conventional Wisdom in Multiple Choice Test Construction

ERIC Educational Resources Information Center

Taylor, Annette Kujawski

2005-01-01

This research examined 2 elements of multiple-choice test construction, balancing the key and optimal number of options. In Experiment 1 the 3 conditions included a balanced key, overrepresentation of a and b responses, and overrepresentation of c and d responses. The results showed that error-patterns were independent of the key, reflecting…

Accuracy and Efficiency of Recording Pediatric Early Warning Scores Using an Electronic Physiological Surveillance System Compared With Traditional Paper-Based Documentation.

PubMed

Sefton, Gerri; Lane, Steven; Killen, Roger; Black, Stuart; Lyon, Max; Ampah, Pearl; Sproule, Cathryn; Loren-Gosling, Dominic; Richards, Caitlin; Spinty, Jean; Holloway, Colette; Davies, Coral; Wilson, April; Chean, Chung Shen; Carter, Bernie; Carrol, E D

2017-05-01

Pediatric Early Warning Scores are advocated to assist health professionals to identify early signs of serious illness or deterioration in hospitalized children. Scores are derived from the weighting applied to recorded vital signs and clinical observations reflecting deviation from a predetermined "norm." Higher aggregate scores trigger an escalation in care aimed at preventing critical deterioration. Process errors made while recording these data, including plotting or calculation errors, have the potential to impede the reliability of the score. To test this hypothesis, we conducted a controlled study of documentation using five clinical vignettes. We measured the accuracy of vital sign recording, score calculation, and time taken to complete documentation using a handheld electronic physiological surveillance system, VitalPAC Pediatric, compared with traditional paper-based charts. We explored the user acceptability of both methods using a Web-based survey. Twenty-three staff participated in the controlled study. The electronic physiological surveillance system improved the accuracy of vital sign recording, 98.5% versus 85.6%, P < .02, Pediatric Early Warning Score calculation, 94.6% versus 55.7%, P < .02, and saved time, 68 versus 98 seconds, compared with paper-based documentation, P < .002. Twenty-nine staff completed the Web-based survey. They perceived that the electronic physiological surveillance system offered safety benefits by reducing human error while providing instant visibility of recorded data to the entire clinical team.

The impact of a balanced science pedagogical approach to scores on the Texas Assessment of Knowledge and Skills

NASA Astrophysics Data System (ADS)

Murray, Judith L.

This applied dissertation was designed to investigate whether a science curriculum using a balance between inquiry methodologies and vocabulary instruction would increase student achievement as measured by the Texas Assessment of Knowledge and Skills test. Fifth grade students' science test scores were analyzed from two successive school years. The first year, an inquiry only methodology was used in the study. The second year, a balanced curriculum approach, where inquiry methods were balanced with vocabulary instruction, was implemented in the classrooms. Results were analyzed for the total population, as well as the subpopulations of Hispanic, low socioeconomic, and gender. Analysis of the data revealed statistically significant gains for the total population of students and female students. However, these same gains did not occur in the Hispanic and low socioeconomic student populations.

Comparative Effects of Different Balance-Training-Progression Styles on Postural Control and Ankle Force Production: A Randomized Controlled Trial.

PubMed

Cuğ, Mutlu; Duncan, Ashley; Wikstrom, Erik

2016-02-01

Despite the effectiveness of balance training, the exact parameters needed to maximize the benefits of such programs remain unknown. One such factor is how individuals should progress to higher levels of task difficulty within a balance-training program. Yet no investigators have directly compared different balance-training-progression styles. To compare an error-based progression (ie, advance when proficient at a task) with a repetition-based progression (ie, advance after a set amount of repetitions) style during a balance-training program in healthy individuals. Randomized controlled trial. Research laboratory. A total of 28 (16 women, 12 men) physically healthy young adults (age = 21.57 ± 3.95 years, height = 171.60 ± 11.03 cm, weight = 72.96 ± 16.18 kg, body mass index = 24.53 ± 3.7). All participants completed 12 supervised balance-training sessions over 4 weeks. Each session consisted of a combination of dynamic unstable-surface tasks that incorporated a BOSU ball and lasted about 30 minutes. Static balance from an instrumented force plate, dynamic balance as measured via the Star Excursion Balance Test, and ankle force production in all 4 cardinal planes of motion as measured with a handheld dynamometer before and after the intervention. Selected static postural-control outcomes, dynamic postural control, and ankle force production in all planes of motion improved (P < .05). However, no differences between the progression styles were observed (P > .05) for any of the outcome measures. A 4-week balance-training program consisting of dynamic unstable-surface exercises on a BOSU ball improved dynamic postural control and ankle force production in healthy young adults. These results suggest that an error-based balance-training program is comparable with but not superior to a repetition-based balance-training program in improving postural control and ankle force production in healthy young adults.

Comparison of Uninjured and Concussed Adolecent Athletes on the Concussion Balance Test (COBALT).

PubMed

Massingale, Shelly; Alexander, Amy; Erickson, Steven; McQueary, Elizabeth; Gerkin, Richard; Kisana, Haroon; Silvestri, Briana; Schodrof, Sarah; Nalepa, Bryce; Pardini, Jamie

2018-06-01

Dizziness and balance problems are common symptoms following sports-related concussion (SRC). Most sports require high-level balance skills that integrate the sensory inputs used for balance. Thus, a comprehensive assessment of postural control following SRC is recommended as an integral part of evaluation and management of the injury. The purpose of this exploratory study was to examine performance differences between uninjured and concussed athletes on the Concussion Balance Test (COBALT), as well as complete preliminary analyses of criterion-related validity and reliability of COBALT. COBALT is an 8 condition test developed for both preseason and postinjury assessment using force plate technology to measure sway velocity under dynamic postural conditions that challenge the vestibular system. Retrospective COBALT data obtained through chart review for 132 uninjured athletes and 106 concussed age-matched athletes were compared. All uninjured athletes were able to complete the assessment, compared with only 55% of concussed athletes. Concussed athletes committed significantly more errors than uninjured athletes. Sway velocity for concussed athletes was higher (worse) than that for uninjured athletes on 2 conditions in COBALT. By examining an athlete's ability to complete the protocol, error rate, and sway velocity on COBALT postinjury, the clinician can identify balance function impairment, which may help the medical team develop a more targeted treatment plan, and provide objective input regarding recovery of balance function following SRC.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A204).

Measuring Error Identification and Recovery Skills in Surgical Residents.

PubMed

Sternbach, Joel M; Wang, Kevin; El Khoury, Rym; Teitelbaum, Ezra N; Meyerson, Shari L

2017-02-01

Although error identification and recovery skills are essential for the safe practice of surgery, they have not traditionally been taught or evaluated in residency training. This study validates a method for assessing error identification and recovery skills in surgical residents using a thoracoscopic lobectomy simulator. We developed a 5-station, simulator-based examination containing the most commonly encountered cognitive and technical errors occurring during division of the superior pulmonary vein for left upper lobectomy. Successful completion of each station requires identification and correction of these errors. Examinations were video recorded and scored in a blinded fashion using an examination-specific rating instrument evaluating task performance as well as error identification and recovery skills. Evidence of validity was collected in the categories of content, response process, internal structure, and relationship to other variables. Fifteen general surgical residents (9 interns and 6 third-year residents) completed the examination. Interrater reliability was high, with an intraclass correlation coefficient of 0.78 between 4 trained raters. Station scores ranged from 64% to 84% correct. All stations adequately discriminated between high- and low-performing residents, with discrimination ranging from 0.35 to 0.65. The overall examination score was significantly higher for intermediate residents than for interns (mean, 74 versus 64 of 90 possible; p = 0.03). The described simulator-based examination with embedded errors and its accompanying assessment tool can be used to measure error identification and recovery skills in surgical residents. This examination provides a valid method for comparing teaching strategies designed to improve error recognition and recovery to enhance patient safety. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Do Pilates-based exercises following total knee arthroplasty improve postural control and quality of life?

PubMed

Karaman, Aysenur; Yuksel, Inci; Kinikli, Gizem Irem; Caglar, Omur

2017-04-01

The aim of this prospective, randomized, controlled study was to investigate the effects of the addition of Pilates-based exercises to standard exercise programs performed after total knee arthroplasty on quality of life and balance. Forty-six volunteers were divided into two groups. The control group (n = 17) was assigned a standard exercise program after discharge; the study group (n = 17) was assigned Pilates-based exercises along with the standard exercise program. We carried out clinical evaluations of all patients on the day of discharge and after the completion of the 6-week exercise program. We also recorded sociodemographic data, Berg Balance test scores, and Short Form-36 (SF-36) health-related quality of life measurements. When we compared the differences between pre- and post-treatment balance scores of the groups, we found a significant change in favor of the Pilates-based exercise group (13.64 ± 1.45; p < 0.01). The changes in the pre- and post-treatment SF-36 scores of the Pilates-based exercises group were found to be significant in terms of physical function (p = 0.001), physical role restriction (p = 0.01), and physical component score (p = 0.001). Pilates-based exercises performed along with standard exercise programs were more effective for improving balance and quality of life than standard exercise programs alone.

Higher mental workload is associated with poorer laparoscopic performance as measured by the NASA-TLX tool.

PubMed

Yurko, Yuliya Y; Scerbo, Mark W; Prabhu, Ajita S; Acker, Christina E; Stefanidis, Dimitrios

2010-10-01

Increased workload during task performance may increase fatigue and facilitate errors. The National Aeronautics and Space Administration-Task Load Index (NASA-TLX) is a previously validated tool for workload self-assessment. We assessed the relationship of workload and performance during simulator training on a complex laparoscopic task. NASA-TLX workload data from three separate trials were analyzed. All participants were novices (n = 28), followed the same curriculum on the fundamentals of laparoscopic surgery suturing model, and were tested in the animal operating room (OR) on a Nissen fundoplication model after training. Performance and workload scores were recorded at baseline, after proficiency achievement, and during the test. Performance, NASA-TLX scores, and inadvertent injuries during the test were analyzed and compared. Workload scores declined during training and mirrored performance changes. NASA-TLX scores correlated significantly with performance scores (r = -0.5, P < 0.001). Participants with higher workload scores caused more inadvertent injuries to adjacent structures in the OR (r = 0.38, P < 0.05). Increased mental and physical workload scores at baseline correlated with higher workload scores in the OR (r = 0.52-0.82; P < 0.05) and more inadvertent injuries (r = 0.52, P < 0.01). Increased workload is associated with inferior task performance and higher likelihood of errors. The NASA-TLX questionnaire accurately reflects workload changes during simulator training and may identify individuals more likely to experience high workload and more prone to errors during skill transfer to the clinical environment.

Validation of scores of use of inhalation devices: valoration of errors *

PubMed Central

Zambelli-Simões, Letícia; Martins, Maria Cleusa; Possari, Juliana Carneiro da Cunha; Carvalho, Greice Borges; Coelho, Ana Carla Carvalho; Cipriano, Sonia Lucena; de Carvalho-Pinto, Regina Maria; Cukier, Alberto; Stelmach, Rafael

2015-01-01

Abstract Objective: To validate two scores quantifying the ability of patients to use metered dose inhalers (MDIs) or dry powder inhalers (DPIs); to identify the most common errors made during their use; and to identify the patients in need of an educational program for the use of these devices. Methods: This study was conducted in three phases: validation of the reliability of the inhaler technique scores; validation of the contents of the two scores using a convenience sample; and testing for criterion validation and discriminant validation of these instruments in patients who met the inclusion criteria. Results: The convenience sample comprised 16 patients. Interobserver disagreement was found in 19% and 25% of the DPI and MDI scores, respectively. After expert analysis on the subject, the scores were modified and were applied in 72 patients. The most relevant difficulty encountered during the use of both types of devices was the maintenance of total lung capacity after a deep inhalation. The degree of correlation of the scores by observer was 0.97 (p < 0.0001). There was good interobserver agreement in the classification of patients as able/not able to use a DPI (50%/50% and 52%/58%; p < 0.01) and an MDI (49%/51% and 54%/46%; p < 0.05). Conclusions: The validated scores allow the identification and correction of inhaler technique errors during consultations and, as a result, improvement in the management of inhalation devices. PMID:26398751

Exercise and health-related quality of life during the first year following acute stroke. A randomized controlled trial.

PubMed

Langhammer, Birgitta; Stanghelle, Johan K; Lindmark, Birgitta

2008-02-01

To evaluate the impact of two different physiotherapy exercise regimes in patients after acute stroke on health-related quality of life (HRQoL) and to investigate how the degree of motor and balance function, gait capacity, activities of daily living and instrumental activities of daily living influenced HRQoL. A longitudinal randomized controlled stratified trial of two interventions: the intensive exercise groups with scheduled intensive training during four periods of the first year after stroke and the regular exercise group with self-initiated training. There was a tendency of better HRQoL in the regular exercise group on NHP total score (p = 0.05). Patients with low scores in activities of daily living, balance and motor function and inability to perform 6-minute walk test on admission, scored lower on self-perceived health than patients with high scores and ability to perform the walking test. At 1 year post-stroke, total scores on NHP were moderately associated with motor function (r = -0.63), balance (r = -0.56), gait (r = -0.57), activities of daily living (r = -0.57) and instrumental activities of daily living (r = -0.49-0.58). The physical mobility sub-scale of NHP had the strongest association ranging from r = -0.47-0.82. The regular exercise group with self-initiated training seemed to enhance HRQoL more than the intensive exercise group with scheduled intensive training. The degree of motor function, balance, walking capacity and independence in activities of daily living is of importance for perceived HRQoL.

Centre of pressure correlates with pyramid performance in acrobatic gymnastics.

PubMed

Floría, Pablo; Gómez-Landero, Luis Arturo; Harrison, Andrew J

2015-01-01

Acrobatic gymnasts need excellent balance control to execute pyramids where one gymnast is supported by another. The objectives of this study were: (1) to describe balance performance by assessing the centre of pressure displacement in a group of acrobatic gymnasts executing pyramids; (2) to determine the relationship between the parameters describing the centre of pressure oscillations and pyramid score; and (3) to examine the role of each foot in providing a solid base of support to maintain the balance of the pyramid. Sixteen acrobatic gymnasts grouped in pairs performed a Half pyramid and a Straddle pyramid held for 7 s on two force platforms. Path length, variance, range trajectory, and surface area of the centre of pressure of each foot were examined to analyse the balance of the pyramid. The path length was correlated with the pyramid score (Straddle: p = 0.692 [large]; Half: p = 0.407 [moderate]). There were differences in the functions of each leg to maintain balance, with the non-preferred leg supporting a higher weight of the pyramid while the preferred leg performed control movements to maintain balance. The results suggested that quantitative analysis of balance can provide important information on pyramid performance.

Effect of footwear on standing balance in healthy young adult males.

PubMed

Alghadir, Ahmad H; Zafar, Hamayun; Anwer, Shahnawaz

2018-03-01

The present study aimed to evaluate the effect of footwear on standing balance in healthy young adult males. Thirty healthy male participants aged 20-30 years were tested for standing balance on the Balance Master on three occasions, including wearing a sandal, standard shoe, or no footwear (barefoot). The tests of postural stability include; "Modified Clinical Test of Sensory Interaction on Balance" (mCTSIB), "Unilateral Stance" (US), and the "Limits of Stability" (LOS). The balance scores (mCTSIB, US, and LOS) was analyzed. There was a significant effect between footwear conditions for mCTIB with eye closed on a firm surface (p=0.002). There was a significant effect between footwear conditions for the US with eye open and closed (p⟨0.05). There was a significant effect between footwear conditions for LOS reaction time during forward movement (p=0.02). Similarly, there was a significant effect between footwear conditions for LOS reaction time during left side movement (p=0.01). Wearing sandals compared to bare feet significantly increased postural sway and reduced stability in healthy young adult males. However, wearing a standard shoe compared to bare feet did not significantly affect balance scores in standing.

Propensity score models in observational comparative effectiveness studies: cornerstone of design or statistical afterthought?

PubMed

Robinson, John W

2012-03-01

Propensity score models are increasingly used in observational comparative effectiveness studies to reduce confounding by covariates that are associated with both a study outcome and treatment choice. Any such potentially confounding covariate will bias estimation of the effect of treatment on the outcome, unless the distribution of that covariate is well-balanced between treatment and control groups. Constructing a subsample of treated and control subjects who are matched on estimated propensity scores is a means of achieving such balance for covariates that are included in the propensity score model. If, during study design, investigators assemble a comprehensive inventory of known and suspected potentially confounding covariates, examination of how well this inventory is covered by the chosen dataset yields an assessment of the extent of bias reduction that is possible by matching on estimated propensity scores. These considerations are explored by examining the designs of three recently published comparative effectiveness studies.

Research developing closed loop roll control for magnetic balance systems

NASA Technical Reports Server (NTRS)

Covert, E. E.; Haldeman, C. W.

1981-01-01

Computer inputs were interfaced to the magnetic balance outputs to provide computer position control and data acquisition. The use of parameter identification of a means of determining dynamic characteristics was investigated. The thyraton and motor generator power supplies for the pitch and yaw degrees of freedom were repaired. Topics covered include: choice of a method for handling dynamic system data; applications to the magnetic balance; the computer interface; and wind tunnel tests, results, and error analysis.

78 FR 11705 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing of Proposed Rule Change...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-19

... losses and reduce the corresponding large wind-falls. However, to maintain the appropriate balance, the... help market participants better manage their risk by addressing the situation where, under current... review. Certain more substantial errors may fall under the category of a catastrophic error, for which a...

Visuomotor adaptability in older adults with mild cognitive decline.

PubMed

Schaffert, Jeffrey; Lee, Chi-Mei; Neill, Rebecca; Bo, Jin

2017-02-01

The current study examined the augmentation of error feedback on visuomotor adaptability in older adults with varying degrees of cognitive decline (assessed by the Montreal Cognitive Assessment; MoCA). Twenty-three participants performed a center-out computerized visuomotor adaptation task when the visual feedback of their hand movement error was presented in a regular (ratio=1:1) or enhanced (ratio=1:2) error feedback schedule. Results showed that older adults with lower scores on the MoCA had less adaptability than those with higher MoCA scores during the regular feedback schedule. However, participants demonstrated similar adaptability during the enhanced feedback schedule, regardless of their cognitive ability. Furthermore, individuals with lower MoCA scores showed larger after-effects in spatial control during the enhanced schedule compared to the regular schedule, whereas individuals with higher MoCA scores displayed the opposite pattern. Additional neuro-cognitive assessments revealed that spatial working memory and processing speed were positively related to motor adaptability during the regular scheduled but negatively related to adaptability during the enhanced schedule. We argue that individuals with mild cognitive decline employed different adaptation strategies when encountering enhanced visual feedback, suggesting older adults with mild cognitive impairment (MCI) may benefit from enhanced visual error feedback during sensorimotor adaptation. Copyright © 2016 Elsevier B.V. All rights reserved.

The balanced mind: the variability of task-unrelated thoughts predicts error monitoring

PubMed Central

Allen, Micah; Smallwood, Jonathan; Christensen, Joanna; Gramm, Daniel; Rasmussen, Beinta; Jensen, Christian Gaden; Roepstorff, Andreas; Lutz, Antoine

2013-01-01

Self-generated thoughts unrelated to ongoing activities, also known as “mind-wandering,” make up a substantial portion of our daily lives. Reports of such task-unrelated thoughts (TUTs) predict both poor performance on demanding cognitive tasks and blood-oxygen-level-dependent (BOLD) activity in the default mode network (DMN). However, recent findings suggest that TUTs and the DMN can also facilitate metacognitive abilities and related behaviors. To further understand these relationships, we examined the influence of subjective intensity, ruminative quality, and variability of mind-wandering on response inhibition and monitoring, using the Error Awareness Task (EAT). We expected to replicate links between TUT and reduced inhibition, and explored whether variance in TUT would predict improved error monitoring, reflecting a capacity to balance between internal and external cognition. By analyzing BOLD responses to subjective probes and the EAT, we dissociated contributions of the DMN, executive, and salience networks to task performance. While both response inhibition and online TUT ratings modulated BOLD activity in the medial prefrontal cortex (mPFC) of the DMN, the former recruited a more dorsal area implying functional segregation. We further found that individual differences in mean TUTs strongly predicted EAT stop accuracy, while TUT variability specifically predicted levels of error awareness. Interestingly, we also observed co-activation of salience and default mode regions during error awareness, supporting a link between monitoring and TUTs. Altogether our results suggest that although TUT is detrimental to task performance, fluctuations in attention between self-generated and external task-related thought is a characteristic of individuals with greater metacognitive monitoring capacity. Achieving a balance between internally and externally oriented thought may thus aid individuals in optimizing their task performance. PMID:24223545

Effect of bilateral lower limb strengthening exercise on balance and walking in hemiparetic patients after stroke: a randomized controlled trial.

PubMed

Jeon, Hye Joo; Hwang, Byong Yong

2018-02-01

[Purpose] To evaluate the effect of bilateral lower limb strengthening designed to improve balance and walking in stroke patients. [Subjects and Methods] Twenty hemiparetic stroke patients were divided into two groups: a unilateral therapy group (UTG) (n=10) and a bilateral therapy group (BTG) (n=10). The UTG completed strength training only in the paretic lower limb. The BTG completed strength training in the paretic and non-paretic lower limbs. Assessment tools included the functional reach test (FRT), the Berg balance scale (BBS), the timed up and go (TUG) test, and a 10-meter walk test (10MWT). [Results] In both groups, the lower limb strengthening exercise for balance and walking significantly improved the FRT, BBS, TUG, and 10MWT scores. Compared with UTG, the BTG attained significantly improved FRT and BBS scores. [Conclusion] Bilateral therapy using this lower limb strengthening exercise effectively promotes balance in hemiparetic stroke patients.

Gait and balance of transfemoral amputees using passive mechanical and microprocessor-controlled prosthetic knees.

PubMed

Kaufman, K R; Levine, J A; Brey, R H; Iverson, B K; McCrady, S K; Padgett, D J; Joyner, M J

2007-10-01

Microprocessor-controlled knee joints appeared on the market a decade ago. These joints are more sophisticated and more expensive than mechanical ones. The literature is contradictory regarding changes in gait and balance when using these sophisticated devices. This study employed a crossover design to assess the comparative performance of a passive mechanical knee prosthesis compared to a microprocessor-controlled knee joint in 15 subjects with an above-knee amputation. Objective measurements of gait and balance were obtained. Subjects demonstrated significantly improved gait characteristics after receiving the microprocessor-controlled prosthetic knee joint (p<0.01). Improvements in gait were a transition from a hyperextended knee to a flexed knee during loading response which resulted in a change from an internal knee flexor moment to a knee extensor moment. The participants' balance also improved (p<0.01). All conditions of the Sensory Organization Test (SOT) demonstrated improvements in equilibrium score. The composite score also increased. Transfemoral amputees using a microprocessor-controlled knee have significant improvements in gait and balance.

The Affordable Care Act Medicaid Expansions and Personal Finance.

PubMed

Caswell, Kyle J; Waidmann, Timothy A

2017-09-01

Using a novel data set from a major credit bureau, we examine the early effects of the Affordable Care Act Medicaid expansions on personal finance. We analyze less common events such as personal bankruptcy, and more common occurrences such as medical collection balances, and change in credit scores. We estimate triple-difference models that compare individual outcomes across counties that expanded Medicaid versus counties that did not, and across expansion counties that had more uninsured residents versus those with fewer. Results demonstrate financial improvements in states that expanded their Medicaid programs as measured by improved credit scores, reduced balances past due as a percent of total debt, reduced probability of a medical collection balance of $1,000 or more, reduced probability of having one or more recent medical bills go to collections, reduction in the probability of experiencing a new derogatory balance of any type, reduced probability of incurring a new derogatory balance equal to $1,000 or more, and a reduction in the probability of a new bankruptcy filing.

Effect of bilateral lower limb strengthening exercise on balance and walking in hemiparetic patients after stroke: a randomized controlled trial

PubMed Central

Jeon, Hye Joo; Hwang, Byong Yong

2018-01-01

[Purpose] To evaluate the effect of bilateral lower limb strengthening designed to improve balance and walking in stroke patients. [Subjects and Methods] Twenty hemiparetic stroke patients were divided into two groups: a unilateral therapy group (UTG) (n=10) and a bilateral therapy group (BTG) (n=10). The UTG completed strength training only in the paretic lower limb. The BTG completed strength training in the paretic and non-paretic lower limbs. Assessment tools included the functional reach test (FRT), the Berg balance scale (BBS), the timed up and go (TUG) test, and a 10-meter walk test (10MWT). [Results] In both groups, the lower limb strengthening exercise for balance and walking significantly improved the FRT, BBS, TUG, and 10MWT scores. Compared with UTG, the BTG attained significantly improved FRT and BBS scores. [Conclusion] Bilateral therapy using this lower limb strengthening exercise effectively promotes balance in hemiparetic stroke patients. PMID:29545693

The relationship between somatic and cognitive-affective depression symptoms and error-related ERP’s

PubMed Central

Bridwell, David A.; Steele, Vaughn R.; Maurer, J. Michael; Kiehl, Kent A.; Calhoun, Vince D.

2014-01-01

Background The symptoms that contribute to the clinical diagnosis of depression likely emerge from, or are related to, underlying cognitive deficits. To understand this relationship further, we examined the relationship between self-reported somatic and cognitive-affective Beck’s Depression Inventory-II (BDI-II) symptoms and aspects of cognitive control reflected in error event-related potential (ERP) responses. Methods Task and assessment data were analyzed within 51 individuals. The group contained a broad distribution of depressive symptoms, as assessed by BDI-II scores. ERP’s were collected following error responses within a go/no-go task. Individual error ERP amplitudes were estimated by conducting group independent component analysis (ICA) on the electroencephalographic (EEG) time series and analyzing the individual reconstructed source epochs. Source error amplitudes were correlated with the subset of BDI-II scores representing somatic and cognitive-affective symptoms. Results We demonstrate a negative relationship between somatic depression symptoms (i.e. fatigue or loss of energy) (after regressing out cognitive-affective scores, age and IQ) and the central-parietal ERP response that peaks at 359 ms. The peak amplitudes within this ERP response were not significantly related to cognitive-affective symptom severity (after regressing out the somatic symptom scores, age, and IQ). Limitations These findings were obtained within a population of female adults from a maximum-security correctional facility. Thus, additional research is required to verify that they generalize to the broad population. Conclusions These results suggest that individuals with greater somatic depression symptoms demonstrate a reduced awareness of behavioral errors, and help clarify the relationship between clinical measures of self-reported depression symptoms and cognitive control. PMID:25451400

The relationship between somatic and cognitive-affective depression symptoms and error-related ERPs.

PubMed

Bridwell, David A; Steele, Vaughn R; Maurer, J Michael; Kiehl, Kent A; Calhoun, Vince D

2015-02-01

The symptoms that contribute to the clinical diagnosis of depression likely emerge from, or are related to, underlying cognitive deficits. To understand this relationship further, we examined the relationship between self-reported somatic and cognitive-affective Beck'sDepression Inventory-II (BDI-II) symptoms and aspects of cognitive control reflected in error event-related potential (ERP) responses. Task and assessment data were analyzed within 51 individuals. The group contained a broad distribution of depressive symptoms, as assessed by BDI-II scores. ERPs were collected following error responses within a go/no-go task. Individual error ERP amplitudes were estimated by conducting group independent component analysis (ICA) on the electroencephalographic (EEG) time series and analyzing the individual reconstructed source epochs. Source error amplitudes were correlated with the subset of BDI-II scores representing somatic and cognitive-affective symptoms. We demonstrate a negative relationship between somatic depression symptoms (i.e. fatigue or loss of energy) (after regressing out cognitive-affective scores, age and IQ) and the central-parietal ERP response that peaks at 359 ms. The peak amplitudes within this ERP response were not significantly related to cognitive-affective symptom severity (after regressing out the somatic symptom scores, age, and IQ). These findings were obtained within a population of female adults from a maximum-security correctional facility. Thus, additional research is required to verify that they generalize to the broad population. These results suggest that individuals with greater somatic depression symptoms demonstrate a reduced awareness of behavioral errors, and help clarify the relationship between clinical measures of self-reported depression symptoms and cognitive control. Copyright © 2014 Elsevier B.V. All rights reserved.

Basic psychometric properties of the transfer assessment instrument (version 3.0).

PubMed

Tsai, Chung-Ying; Rice, Laura A; Hoelmer, Claire; Boninger, Michael L; Koontz, Alicia M

2013-12-01

To refine the Transfer Assessment Instrument (TAI 2.0), develop a training program for the TAI, and analyze the basic psychometric properties of the TAI 3.0, including reliability, standard error of measurement (SEM), minimal detectable change (MDC), and construct validity. Repeated measures. A winter sports clinic for disabled veterans. Wheelchair users (N=41) who perform sitting-pivot or standing-pivot transfers. Not applicable. TAI version 3.0, intraclass correlation coefficients, SEMs, and MDCs for reliable measurement of raters' responses. Spearman correlation coefficient, 1-way analysis of variance, and independent t tests to evaluate construct validity. TAI 3.0 had acceptable to high levels of reliability (range, .74-.88). The SEMs for part 1, part 2, and final scores ranged from .45 to .75. The MDC was 1.5 points on the 10-point scale for the final score. There were weak correlations (ρ range, -.13 to .25; P>.11) between TAI final scores and subjects' characteristics (eg, sex, body mass index, age, type of disability, length of wheelchair use, grip and elbow strength, sitting balance). With comprehensive training, the refined TAI 3.0 yields high reliability among raters of different clinical backgrounds and experience. TAI 3.0 was unbiased toward certain physical characteristics that may influence transfer. TAI fills a void in the field by providing a quantitative measurement of transfers and a tool that can be used to detect problems and guide transfer training. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The effects of balance and postural stability exercises on spa based rehabilitation programme in patients with ankylosing spondylitis.

PubMed

Gunay, Selim M; Keser, Ilke; Bicer, Zemzem T

2018-01-01

Ankylosing spondylitis (AS) can cause severe functional disorders that lead to loss of balance. The aim of this study was to investigate the effects of balance and postural stability exercises on spa based rehabilitation programme in AS subjects. Twenty-one participants were randomized to the study (n= 11) and control groups (n= 10). Patients balance and stability were assessed with the Berg Balance Scale (BBS), Timed Up and Go (TUG) Test, Single Leg Stance Test (SLST) and Functional Reach Test (FRT). AS spesicied measures were used for assessing to other parameters. The treatment plan for both groups consisted of conventional transcutaneous electrical nerve stimulation (TENS), spa and land-based exercises 5 days per week for 3 weeks. The study group performed exercises based on postural stability and balance with routine physiotherapy practice in thermal water and in exercise room. The TUG, SLST and FUT scores were significantly increased in the study group. In both groups, the BASMI, BASFI, BASDAI and ASQoL scores decreased significantly by the end of the treatment period (p< 0.05). In AS rehabilitation, performing balance and stability exercises in addition to spa based routine approaches can increase the duration of maintaining balance and can improve the benefits of physiotherapy.

Examination of the perceived agility and balance during a reactive agility task.

PubMed

Stirling, Leia; Eke, Chika; Cain, Stephen M

2018-01-01

In vehicle dynamics, it is commonly understood that there is an inverse relationship between stability and maneuverability. However, animal studies have found that stability and maneuverability can coincide. In this study, we examine humans running a reactive agility obstacle and consider the relationship between observational perceived agility and balance, as well as the relationship between quantified surrogates of agility and balance. Recreational athletes (n = 18) completed the agility task while wearing inertial measurement units (IMUs) on their body. The task was also video-recorded. An observational study was completed by a separate group of adults (n = 33) that were asked to view the videos and score each athlete on a Likert scale for balance and for agility. The data from the body-worn IMUs were used to estimate quantified surrogate measures for agility and balance, and to assess if the relationship between the quantified agility and balance was in the same direction as the perceived relationship from the Likert scale responses. Results indicate that athletes that were given a higher Likert agility score were also given a higher balance score (rs = 0.75,p < 0.001). Quantitative surrogates of agility and balance also showed this same relationship. Additional insights on technique for this reactive agility task were informed by the quantitative surrogates. We observed the importance of stepping technique in achieving the faster completion times. The fast performing athletes spent a greater proportion of the task in double support and lower overall time in single support indicating increased periods of static stability. The fast performing athletes did not have a higher body speed, but performed the task with a more efficient technique, using foot placement to enable heading changes, and thus may have had a more efficient path. Similar to animal studies, people use technique to enable agile strategies while also enabling increased balance across the task.

Technical Note: Introduction of variance component analysis to setup error analysis in radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuo, Yukinori, E-mail: ymatsuo@kuhp.kyoto-u.ac.

Purpose: The purpose of this technical note is to introduce variance component analysis to the estimation of systematic and random components in setup error of radiotherapy. Methods: Balanced data according to the one-factor random effect model were assumed. Results: Analysis-of-variance (ANOVA)-based computation was applied to estimate the values and their confidence intervals (CIs) for systematic and random errors and the population mean of setup errors. The conventional method overestimates systematic error, especially in hypofractionated settings. The CI for systematic error becomes much wider than that for random error. The ANOVA-based estimation can be extended to a multifactor model considering multiplemore » causes of setup errors (e.g., interpatient, interfraction, and intrafraction). Conclusions: Variance component analysis may lead to novel applications to setup error analysis in radiotherapy.« less

Outlier removal, sum scores, and the inflation of the Type I error rate in independent samples t tests: the power of alternatives and recommendations.

PubMed

Bakker, Marjan; Wicherts, Jelte M

2014-09-01

In psychology, outliers are often excluded before running an independent samples t test, and data are often nonnormal because of the use of sum scores based on tests and questionnaires. This article concerns the handling of outliers in the context of independent samples t tests applied to nonnormal sum scores. After reviewing common practice, we present results of simulations of artificial and actual psychological data, which show that the removal of outliers based on commonly used Z value thresholds severely increases the Type I error rate. We found Type I error rates of above 20% after removing outliers with a threshold value of Z = 2 in a short and difficult test. Inflations of Type I error rates are particularly severe when researchers are given the freedom to alter threshold values of Z after having seen the effects thereof on outcomes. We recommend the use of nonparametric Mann-Whitney-Wilcoxon tests or robust Yuen-Welch tests without removing outliers. These alternatives to independent samples t tests are found to have nominal Type I error rates with a minimal loss of power when no outliers are present in the data and to have nominal Type I error rates and good power when outliers are present. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Global modeling of land water and energy balances. Part I: The land dynamics (LaD) model

USGS Publications Warehouse

Milly, P.C.D.; Shmakin, A.B.

2002-01-01

A simple model of large-scale land (continental) water and energy balances is presented. The model is an extension of an earlier scheme with a record of successful application in climate modeling. The most important changes from the original model include 1) introduction of non-water-stressed stomatal control of transpiration, in order to correct a tendency toward excessive evaporation: 2) conversion from globally constant parameters (with the exception of vegetation-dependent snow-free surface albedo) to more complete vegetation and soil dependence of all parameters, in order to provide more realistic representation of geographic variations in water and energy balances and to enable model-based investigations of land-cover change; 3) introduction of soil sensible heat storage and transport, in order to move toward realistic diurnal-cycle modeling; 4) a groundwater (saturated-zone) storage reservoir, in order to provide more realistic temporal variability of runoff; and 5) a rudimentary runoff-routing scheme for delivery of runoff to the ocean, in order to provide realistic freshwater forcing of the ocean general circulation model component of a global climate model. The new model is tested with forcing from the International Satellite Land Surface Climatology Project Initiative I global dataset and a recently produced observation-based water-balance dataset for major river basins of the world. Model performance is evaluated by comparing computed and observed runoff ratios from many major river basins of the world. Special attention is given to distinguishing between two components of the apparent runoff ratio error: the part due to intrinsic model error and the part due to errors in the assumed precipitation forcing. The pattern of discrepancies between modeled and observed runoff ratios is consistent with results from a companion study of precipitation estimation errors. The new model is tuned by adjustment of a globally constant scale factor for non-water-stressed stomatal resistance. After tuning, significant overestimation of runoff is found in environments where an overall arid climate includes a brief but intense wet season. It is shown that this error may be explained by the neglect of upward soil water diffusion from below the root zone during the dry season. With the exception of such basins, and in the absence of precipitation errors. It is estimated that annual runoff ratios simulated by the model would have a root-mean-square error of about 0.05. The new model matches observations better than its predecessor, which has a negative runoff bias and greater scatter.

Error and Error Mitigation in Low-Coverage Genome Assemblies

PubMed Central

Hubisz, Melissa J.; Lin, Michael F.; Kellis, Manolis; Siepel, Adam

2011-01-01

The recent release of twenty-two new genome sequences has dramatically increased the data available for mammalian comparative genomics, but twenty of these new sequences are currently limited to ∼2× coverage. Here we examine the extent of sequencing error in these 2× assemblies, and its potential impact in downstream analyses. By comparing 2× assemblies with high-quality sequences from the ENCODE regions, we estimate the rate of sequencing error to be 1–4 errors per kilobase. While this error rate is fairly modest, sequencing error can still have surprising effects. For example, an apparent lineage-specific insertion in a coding region is more likely to reflect sequencing error than a true biological event, and the length distribution of coding indels is strongly distorted by error. We find that most errors are contributed by a small fraction of bases with low quality scores, in particular, by the ends of reads in regions of single-read coverage in the assembly. We explore several approaches for automatic sequencing error mitigation (SEM), making use of the localized nature of sequencing error, the fact that it is well predicted by quality scores, and information about errors that comes from comparisons across species. Our automatic methods for error mitigation cannot replace the need for additional sequencing, but they do allow substantial fractions of errors to be masked or eliminated at the cost of modest amounts of over-correction, and they can reduce the impact of error in downstream phylogenomic analyses. Our error-mitigated alignments are available for download. PMID:21340033

Medication errors: definitions and classification

PubMed Central

Aronson, Jeffrey K

2009-01-01

To understand medication errors and to identify preventive strategies, we need to classify them and define the terms that describe them. The four main approaches to defining technical terms consider etymology, usage, previous definitions, and the Ramsey–Lewis method (based on an understanding of theory and practice). A medication error is ‘a failure in the treatment process that leads to, or has the potential to lead to, harm to the patient’. Prescribing faults, a subset of medication errors, should be distinguished from prescription errors. A prescribing fault is ‘a failure in the prescribing [decision-making] process that leads to, or has the potential to lead to, harm to the patient’. The converse of this, ‘balanced prescribing’ is ‘the use of a medicine that is appropriate to the patient's condition and, within the limits created by the uncertainty that attends therapeutic decisions, in a dosage regimen that optimizes the balance of benefit to harm’. This excludes all forms of prescribing faults, such as irrational, inappropriate, and ineffective prescribing, underprescribing and overprescribing. A prescription error is ‘a failure in the prescription writing process that results in a wrong instruction about one or more of the normal features of a prescription’. The ‘normal features’ include the identity of the recipient, the identity of the drug, the formulation, dose, route, timing, frequency, and duration of administration. Medication errors can be classified, invoking psychological theory, as knowledge-based mistakes, rule-based mistakes, action-based slips, and memory-based lapses. This classification informs preventive strategies. PMID:19594526

Interobserver Reliability of the Total Body Score System for Quantifying Human Decomposition.

PubMed

Dabbs, Gretchen R; Connor, Melissa; Bytheway, Joan A

2016-03-01

Several authors have tested the accuracy of the Total Body Score (TBS) method for quantifying decomposition, but none have examined the reliability of the method as a scoring system by testing interobserver error rates. Sixteen participants used the TBS system to score 59 observation packets including photographs and written descriptions of 13 human cadavers in different stages of decomposition (postmortem interval: 2-186 days). Data analysis used a two-way random model intraclass correlation in SPSS (v. 17.0). The TBS method showed "almost perfect" agreement between observers, with average absolute correlation coefficients of 0.990 and average consistency correlation coefficients of 0.991. While the TBS method may have sources of error, scoring reliability is not one of them. Individual component scores were examined, and the influences of education and experience levels were investigated. Overall, the trunk component scores were the least concordant. Suggestions are made to improve the reliability of the TBS method. © 2016 American Academy of Forensic Sciences.

Upper limb contributions to frontal plane balance control in rollator-assisted walking.

PubMed

Tung, James Y; Gage, William H; Poupart, Pascal; McIlroy, William E

2014-01-01

While assisting with balance is a primary reason for rollator use, few studies have examined how the upper limbs are used for balance. This study examines upper limb contributions to balance control during rollator-assisted walking. We hypothesized that there would be an increased upper limb contribution, measured by mean vertical loading (Fz) and variation in frontal plane center-of-pressure (COPhigh), when walking balance is challenged/impaired. Experiment 1 compared straight-line and beam-walking in young adults (n = 11). As hypothesized, Fz and COPhighincreased in beam-walking compared to baseline (mean Fz: 13.7 vs. 9.1% body weight (BW), p < 0.001, RMS COPhigh: 1.35 vs. 1.07 cm, p < 0.001). Experiment 2 compared older adults who regularly use rollators (RU, n = 10) to older adult controls (CTL, n = 10). The predicted higher upper limb contribution in the RU group was not supported. However, when individuals were grouped by balance impairment, those with the lowest Berg Balance scores (< 45) demonstrated greater speed-adjusted COPhigh than those with higher scores (p = 0.013). Furthermore, greater COPhigh and Fz were correlated to greater reduction in step width, supporting the role of upper limb contributions to frontal plane balance. This work will guide studies assessing reliance on rollators by providing a basis for measurement of upper limb balance contributions.

Responsiveness of performance-based outcome measures for mobility, balance, muscle strength and manual dexterity in adults with myotonic dystrophy type 1.

PubMed

Kierkegaard, Marie; Petitclerc, Émilie; Hébert, Luc J; Mathieu, Jean; Gagnon, Cynthia

2018-02-28

To assess changes and responsiveness in outcome measures of mobility, balance, muscle strength and manual dexterity in adults with myotonic dystrophy type 1. A 9-year longitudinal study conducted with 113 patients. The responsiveness of the Timed Up and Go test, Berg Balance Scale, quantitative muscle testing, grip and pinch-grip strength, and Purdue Pegboard Test was assessed using criterion and construct approaches. Patient-reported perceived changes (worse/stable) in balance, walking, lower-limb weakness, stair-climbing and hand weakness were used as criteria. Predefined hypotheses about expected area under the receiver operating characteristic curves (criterion approach) and correlations between relative changes (construct approach) were explored. The direction and magnitude of median changes in outcome measures corresponded with patient-reported changes. Median changes in the Timed Up and Go test, grip strength, pinch-grip strength and Purdue Pegboard Test did not, in general, exceed known measurement errors. Most criterion (72%) and construct (70%) approach hypotheses were supported. Promising responsiveness was found for outcome measures of mobility, balance and muscle strength. Grip strength and manual dexterity measures showed poorer responsiveness. The performance-based outcome measures captured changes over the 9-year period and responsiveness was promising. Knowledge of measurement errors is needed to interpret the meaning of these longitudinal changes.

Recruitment into diabetes prevention programs: what is the impact of errors in self-reported measures of obesity?

PubMed

Hernan, Andrea; Philpot, Benjamin; Janus, Edward D; Dunbar, James A

2012-07-08

Error in self-reported measures of obesity has been frequently described, but the effect of self-reported error on recruitment into diabetes prevention programs is not well established. The aim of this study was to examine the effect of using self-reported obesity data from the Finnish diabetes risk score (FINDRISC) on recruitment into the Greater Green Triangle Diabetes Prevention Project (GGT DPP). The GGT DPP was a structured group-based lifestyle modification program delivered in primary health care settings in South-Eastern Australia. Between 2004-05, 850 FINDRISC forms were collected during recruitment for the GGT DPP. Eligible individuals, at moderate to high risk of developing diabetes, were invited to undertake baseline tests, including anthropometric measurements performed by specially trained nurses. In addition to errors in calculating total risk scores, accuracy of self-reported data (height, weight, waist circumference (WC) and Body Mass Index (BMI)) from FINDRISCs was compared with baseline data, with impact on participation eligibility presented. Overall, calculation errors impacted on eligibility in 18 cases (2.1%). Of n = 279 GGT DPP participants with measured data, errors (total score calculation, BMI or WC) in self-report were found in n = 90 (32.3%). These errors were equally likely to result in under- or over-reported risk. Under-reporting was more common in those reporting lower risk scores (Spearman-rho = -0.226, p-value < 0.001). However, underestimation resulted in only 6% of individuals at high risk of diabetes being incorrectly categorised as moderate or low risk of diabetes. Overall FINDRISC was found to be an effective tool to screen and recruit participants at moderate to high risk of diabetes, accurately categorising levels of overweight and obesity using self-report data. The results could be generalisable to other diabetes prevention programs using screening tools which include self-reported levels of obesity.

Dynamic balance performance and noncontact lower extremity injury in college football players: an initial study.

PubMed

Butler, Robert J; Lehr, Michael E; Fink, Michael L; Kiesel, Kyle B; Plisky, Phillip J

2013-09-01

Field expedient screening tools that can identify individuals at an elevated risk for injury are needed to minimize time loss in American football players. Previous research has suggested that poor dynamic balance may be associated with an elevated risk for injury in athletes; however, this has yet to be examined in college football players. To determine if dynamic balance deficits are associated with an elevated risk of injury in collegiate football players. It was hypothesized that football players with lower performance and increased asymmetry in dynamic balance would be at an elevated risk for sustaining a noncontact lower extremity injury. Prospective cohort study. Fifty-nine collegiate American football players volunteered for this study. Demographic information, injury history, and dynamic balance testing performance were collected, and noncontact lower extremity injuries were recorded over the course of the season. Receiver operator characteristic curves were calculated based on performance on the Star Excursion Balance Test (SEBT), including composite score and asymmetry, to determine the population-specific risk cut-off point. Relative risk was then calculated based on these variables, as well as previous injury. A cut-off point of 89.6% composite score on the SEBT optimized the sensitivity (100%) and specificity (71.7%). A college football player who scored below 89.6% was 3.5 times more likely to get injured. Poor performance on the SEBT may be related to an increased risk for sustaining a noncontact lower extremity injury over the course of a competitive American football season. College football players should be screened preseason using the SEBT to identify those at an elevated risk for injury based upon dynamic balance performance to implement injury mitigation strategies to this specific subgroup of athletes.

The Association of Glaucomatous Visual Field Loss and Balance

PubMed Central

de Luna, Regina A.; Mihailovic, Aleksandra; Nguyen, Angeline M.; Friedman, David S.; Gitlin, Laura N.; Ramulu, Pradeep Y.

2017-01-01

Purpose To relate balance measures to visual field (VF) damage from glaucoma. Methods The OPAL kinematic system measured balance, as root mean square (RMS) sway, on 236 patients with suspect/diagnosed glaucoma. Balance was measured with feet shoulder width apart while standing on a firm/foam surface with eyes opened/closed (Instrumental Clinical Test of Sensory Integration and Balance [ICTSIB] conditions), and eyes open on a firm surface under feet together, semi-tandem, or tandem positions (standing balance conditions). Integrated VF (IVF) sensitivities were calculated by merging right and left eye 24-2 VF data. Results Mean age was 71 years (range, 57–93) and mean IVF sensitivity was 27.1 dB (normal = 31 dB). Lower IVF sensitivity was associated with greater RMS sway during eyes-open foam-surface testing (β = 0.23 z-score units/5 dB IVF sensitivity decrement, P = 0.001), but not during other ICTSIB conditions. Lower IVF sensitivity also was associated with greater RMS sway during feet together standing balance testing (0.10 z-score units/5 dB IVF sensitivity decrement, P = 0.049), but not during other standing balance conditions. Visual dependence of balance was lower in patients with worse IVF sensitivity (β = −21%/5 dB IVF sensitivity decrement, P < 0.001). Neither superior nor inferior IVF sensitivity consistently predicted balance measures better than measures of overall VF sensitivity. Conclusions Balance was worse in glaucoma patients with greater VF damage under foam surface testing (designed to inhibit proprioceptive contributions to balance) as well as feet-together firm-surface conditions when somatosensory inputs were available. Translational Relevance Good balance is essential to avoid unnecessary falls and patients with VF loss from glaucoma may be at higher risk of falls because of poor balance. PMID:28553562

Quantification of the sit-to-stand movement for monitoring age-related motor deterioration using the Nintendo Wii Balance Board.

PubMed

Yamako, Go; Chosa, Etsuo; Totoribe, Koji; Fukao, Yuu; Deng, Gang

2017-01-01

Simple methods for quantitative evaluations of individual motor performance are crucial for the early detection of motor deterioration. Sit-to-stand movement from a chair is a mechanically demanding component of activities of daily living. Here, we developed a novel method using the ground reaction force and center of pressure measured from the Nintendo Wii Balance Board to quantify sit-to-stand movement (sit-to-stand score) and investigated the age-related change in the sit-to-stand score as a method to evaluate reduction in motor performance. The study enrolled 503 participants (mean age ± standard deviation, 51.0 ± 19.7 years; range, 20-88 years; male/female ratio, 226/277) without any known musculoskeletal conditions that limit sit-to-stand movement, which were divided into seven 10-year age groups. The participants were instructed to stand up as quickly as possible, and the sit-to-stand score was calculated as the combination of the speed and balance indices, which have a tradeoff relationship. We also performed the timed up and go test, a well-known clinical test used to evaluate an individual's mobility. There were significant differences in the sit-to-stand score and timed up and go time among age groups. The mean sit-to-stand score for 60s, 70s, and 80s were 77%, 68%, and 53% of that for the 20s, respectively. The timed up and go test confirmed the age-related decrease in mobility of the participants. In addition, the sit-to-stand score measured using the Wii Balance Board was compared with that from a laboratory-graded force plate using the Bland-Altman plot (bias = -3.1 [ms]-1, 95% limit of agreement: -11.0 to 3.9 [ms]-1). The sit-to-stand score has good inter-device reliability (intraclass correlation coefficient = 0.87). Furthermore, the test-retest reliability is substantial (intraclass correlation coefficient = 0.64). Thus, the proposed STS score will be useful to detect the early deterioration of motor performance.

Quantification of the sit-to-stand movement for monitoring age-related motor deterioration using the Nintendo Wii Balance Board

PubMed Central

Chosa, Etsuo; Totoribe, Koji; Fukao, Yuu; Deng, Gang

2017-01-01

Simple methods for quantitative evaluations of individual motor performance are crucial for the early detection of motor deterioration. Sit-to-stand movement from a chair is a mechanically demanding component of activities of daily living. Here, we developed a novel method using the ground reaction force and center of pressure measured from the Nintendo Wii Balance Board to quantify sit-to-stand movement (sit-to-stand score) and investigated the age-related change in the sit-to-stand score as a method to evaluate reduction in motor performance. The study enrolled 503 participants (mean age ± standard deviation, 51.0 ± 19.7 years; range, 20–88 years; male/female ratio, 226/277) without any known musculoskeletal conditions that limit sit-to-stand movement, which were divided into seven 10-year age groups. The participants were instructed to stand up as quickly as possible, and the sit-to-stand score was calculated as the combination of the speed and balance indices, which have a tradeoff relationship. We also performed the timed up and go test, a well-known clinical test used to evaluate an individual’s mobility. There were significant differences in the sit-to-stand score and timed up and go time among age groups. The mean sit-to-stand score for 60s, 70s, and 80s were 77%, 68%, and 53% of that for the 20s, respectively. The timed up and go test confirmed the age-related decrease in mobility of the participants. In addition, the sit-to-stand score measured using the Wii Balance Board was compared with that from a laboratory-graded force plate using the Bland–Altman plot (bias = −3.1 [ms]-1, 95% limit of agreement: −11.0 to 3.9 [ms]-1). The sit-to-stand score has good inter-device reliability (intraclass correlation coefficient = 0.87). Furthermore, the test–retest reliability is substantial (intraclass correlation coefficient = 0.64). Thus, the proposed STS score will be useful to detect the early deterioration of motor performance. PMID:29136031

Type I and Type II error concerns in fMRI research: re-balancing the scale

PubMed Central

Cunningham, William A.

2009-01-01

Statistical thresholding (i.e. P-values) in fMRI research has become increasingly conservative over the past decade in an attempt to diminish Type I errors (i.e. false alarms) to a level traditionally allowed in behavioral science research. In this article, we examine the unintended negative consequences of this single-minded devotion to Type I errors: increased Type II errors (i.e. missing true effects), a bias toward studying large rather than small effects, a bias toward observing sensory and motor processes rather than complex cognitive and affective processes and deficient meta-analyses. Power analyses indicate that the reductions in acceptable P-values over time are producing dramatic increases in the Type II error rate. Moreover, the push for a mapwide false discovery rate (FDR) of 0.05 is based on the assumption that this is the FDR in most behavioral research; however, this is an inaccurate assessment of the conventions in actual behavioral research. We report simulations demonstrating that combined intensity and cluster size thresholds such as P < 0.005 with a 10 voxel extent produce a desirable balance between Types I and II error rates. This joint threshold produces high but acceptable Type II error rates and produces a FDR that is comparable to the effective FDR in typical behavioral science articles (while a 20 voxel extent threshold produces an actual FDR of 0.05 with relatively common imaging parameters). We recommend a greater focus on replication and meta-analysis rather than emphasizing single studies as the unit of analysis for establishing scientific truth. From this perspective, Type I errors are self-erasing because they will not replicate, thus allowing for more lenient thresholding to avoid Type II errors. PMID:20035017

Influence of Altered Auditory Feedback on Oral-Nasal Balance in Speech

ERIC Educational Resources Information Center

de Boer, Gillian; Bressmann, Tim

2017-01-01

Purpose: This study explored the role of auditory feedback in the regulation of oral-nasal balance in speech. Method: Twenty typical female speakers wore a Nasometer 6450 (KayPentax) headset and headphones while continuously repeating a sentence with oral and nasal sounds. Oral-nasal balance was quantified with nasalance scores. The signals from 2…

Double-adjustment in propensity score matching analysis: choosing a threshold for considering residual imbalance.

PubMed

Nguyen, Tri-Long; Collins, Gary S; Spence, Jessica; Daurès, Jean-Pierre; Devereaux, P J; Landais, Paul; Le Manach, Yannick

2017-04-28

Double-adjustment can be used to remove confounding if imbalance exists after propensity score (PS) matching. However, it is not always possible to include all covariates in adjustment. We aimed to find the optimal imbalance threshold for entering covariates into regression. We conducted a series of Monte Carlo simulations on virtual populations of 5,000 subjects. We performed PS 1:1 nearest-neighbor matching on each sample. We calculated standardized mean differences across groups to detect any remaining imbalance in the matched samples. We examined 25 thresholds (from 0.01 to 0.25, stepwise 0.01) for considering residual imbalance. The treatment effect was estimated using logistic regression that contained only those covariates considered to be unbalanced by these thresholds. We showed that regression adjustment could dramatically remove residual confounding bias when it included all of the covariates with a standardized difference greater than 0.10. The additional benefit was negligible when we also adjusted for covariates with less imbalance. We found that the mean squared error of the estimates was minimized under the same conditions. If covariate balance is not achieved, we recommend reiterating PS modeling until standardized differences below 0.10 are achieved on most covariates. In case of remaining imbalance, a double adjustment might be worth considering.

Sarcopenia and sarcopenic obesity in Spanish community-dwelling middle-aged and older women: Association with balance confidence, fear of falling and fall risk.

PubMed

Aibar-Almazán, Agustín; Martínez-Amat, Antonio; Cruz-Díaz, David; Jiménez-García, José D; Achalandabaso, Alexander; Sánchez-Montesinos, Indalecio; de la Torre-Cruz, Manuel; Hita-Contreras, Fidel

2018-01-01

To analyze the association of sarcopenia, obesity, and sarcopenic obesity (SO) with fear of falling (FoF) and balance confidence in a Spanish sample of middle-aged and older community-dwelling women. A total of 235 women (69.21±7.56 years) participated in this study. Body composition (bioelectrical impedance analysis), hand-grip strength, and physical performance (gait speed) were evaluated for the diagnosis of sarcopenia, obesity, and SO. Anxiety and depression were measured using the Hospital Anxiety and Depression Scale. The Activities-Specific Balance Confidence Scale (ABC) and the Falls Efficacy Scale-International (FES-I) were employed to assess FoF and balance confidence, respectively. Scores of >26 on the FES-I and <67% on the ABC were used to identify women at risk of falling. The independent associations of sarcopenia, obesity and SO with FoF, balance confidence, and fall risk were evaluated by multivariate linear and logistic regressions, adjusting for potential confounding variables. 27.23% and 18.72% of women presented with sarcopenia and SO, respectively. Gait speed, body mass index (BMI), and fall history were independently associated with ABC score (adjusted-R 2 =0.152) and fall risk (ABC) (adjusted-R 2 =0.115). FES-I score was independently associated (adjusted-R 2 =0.193) with fall history, gait speed, BMI, and depression, which, together with obesity (BMI) and SO, remained independent factors for fall risk measured as FES-I score (adjusted-R 2 =0.243). In community-dwelling middle-aged and older Spanish women, BMI, gait speed, and fall history were independently associated with FoF, balance confidence, and fall risk. Depression was related only to FoF, and, together with obesity (BMI) and SO, was an independent predictor of fall risk as assessed by the FES-I. Copyright © 2017 Elsevier B.V. All rights reserved.

The Truth about Scores Children Achieve on Tests.

ERIC Educational Resources Information Center

Brown, Jonathan R.

1989-01-01

The importance of using the standard error of measurement (SEm) in determining reliability in test scores is emphasized. The SEm is compared to the hypothetical true score for standardized tests, and procedures for calculation of the SEm are explained. (JDD)

Correcting Severe Varus Deformity Using Trial Components During Total Knee Arthroplasty.

PubMed

Kim, Man S; Koh, In J; Choi, Young J; Kim, Yong D; In, Yong

2017-05-01

Extensive medial soft tissue release may be necessary to correct severe varus deformity during total knee arthroplasty (TKA). However, this procedure may result in instability. Here, we describe a novel soft tissue balancing technique, which can minimize medial release in severe varus deformity during TKA. Fifty knees (40 patients) with hip-knee-ankle angle of more than 20° of varus were corrected using this technique (group 1). After achieving flexion gap balancing by needle puncturing and spreading of the superficial medial collateral ligament, extension gap balancing was obtained by gradual extension with the trial components in place. After group 1 was set, a one-to-one patient-matched control group who had mild varus deformity was selected by propensity score matching (50 knees, 48 patients, group 2). At postoperative 1 year, mediolateral laxity was compared between the 2 groups using the stress radiographs. Clinical outcomes were also compared using the Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index score. There were no differences in mean medial and lateral laxities between groups 1 and 2 at 1 year after the operation (medial laxity: 2.3° ± 1.4° and 2.7° ± 1.3°, respectively, P = .310) (lateral laxity: 3.6° ± 1.7° and 3.2° ± 2.0°, respectively, P = .459). There were no significant differences in postoperative clinical scores and knee alignment. Our technique of obtaining extension gap balancing using trial components led to safe and effective balancing by avoiding unnecessary extensive release in severe varus deformity during TKA. Copyright © 2016 Elsevier Inc. All rights reserved.

The search for causal inferences: using propensity scores post hoc to reduce estimation error with nonexperimental research.

PubMed

Tumlinson, Samuel E; Sass, Daniel A; Cano, Stephanie M

2014-03-01

While experimental designs are regarded as the gold standard for establishing causal relationships, such designs are usually impractical owing to common methodological limitations. The objective of this article is to illustrate how propensity score matching (PSM) and using propensity scores (PS) as a covariate are viable alternatives to reduce estimation error when experimental designs cannot be implemented. To mimic common pediatric research practices, data from 140 simulated participants were used to resemble an experimental and nonexperimental design that assessed the effect of treatment status on participant weight loss for diabetes. Pretreatment participant characteristics (age, gender, physical activity, etc.) were then used to generate PS for use in the various statistical approaches. Results demonstrate how PSM and using the PS as a covariate can be used to reduce estimation error and improve statistical inferences. References for issues related to the implementation of these procedures are provided to assist researchers.

Smoothing of the bivariate LOD score for non-normal quantitative traits.

PubMed

Buil, Alfonso; Dyer, Thomas D; Almasy, Laura; Blangero, John

2005-12-30

Variance component analysis provides an efficient method for performing linkage analysis for quantitative traits. However, type I error of variance components-based likelihood ratio testing may be affected when phenotypic data are non-normally distributed (especially with high values of kurtosis). This results in inflated LOD scores when the normality assumption does not hold. Even though different solutions have been proposed to deal with this problem with univariate phenotypes, little work has been done in the multivariate case. We present an empirical approach to adjust the inflated LOD scores obtained from a bivariate phenotype that violates the assumption of normality. Using the Collaborative Study on the Genetics of Alcoholism data available for the Genetic Analysis Workshop 14, we show how bivariate linkage analysis with leptokurtotic traits gives an inflated type I error. We perform a novel correction that achieves acceptable levels of type I error.

The Effects of the Gaelic Athletic Association 15 Training Program on Neuromuscular Outcomes in Gaelic Football and Hurling Players: A Randomized Cluster Trial.

PubMed

OʼMalley, Edwenia; Murphy, John C; McCarthy Persson, Ulrik; Gissane, Conor; Blake, Catherine

2017-08-01

O'Malley, E, Murphy, JC, McCarthy Persson, U, Gissane, C, and Blake, C. The effects of the Gaelic Athletic Association 15 training program on neuromuscular outcomes in Gaelic football and hurling players: A randomized cluster trial. J Strength Cond Res 31(8): 2119-2130, 2017-Team-based neuromuscular training programs for injury prevention have been tested primarily in female and adolescent athletes in soccer, handball, and basketball with limited research in adult male field sports. This study explored whether the GAA 15, a multifaceted 8-week neuromuscular training program developed by the Gaelic Athletic Association (GAA), could improve risk factors for lower limb injury in male Gaelic footballers and hurlers. Four Gaelic sports collegiate teams were randomized into intervention or control groups. Two teams (n = 41), one football and one hurling, were allocated to the intervention, undertaking a 15 minutes program of neuromuscular training exercises at the start of team training sessions, twice weekly for 8 weeks. Two matched teams (n = 37) acted as controls, participating in usual team training. Lower extremity stability (Y-Balance test [YBT]) and jump-landing technique using the Landing Error Scoring System (LESS) were assessed preintervention and postintervention. There were moderate effect sizes in favor of the intervention for right (d = 0.59) and left (d = 0.69) composite YBT scores, with adjusted mean differences between intervention and control of 3.85 ± 0.91% and 4.34 ± 0.92% for right and left legs, respectively (p < 0.001). There was a greater reduction in the mean LESS score in favor of the intervention group after exercise training (Cohen's d = 0.72, adjusted mean difference 2.49 ± 0.54, p < 0.001). Clinically and statistically significant improvements in dynamic balance and jump-landing technique occurred in collegiate level Gaelic football and hurling players who adopted the GAA 15, when compared with usual training. These findings support application and evaluation of the GAA 15 in other player groups within the Gaelic games playing population.

Sport and team differences on baseline measures of sport-related concussion.

PubMed

Zimmer, Adam; Piecora, Kyle; Schuster, Danielle; Webbe, Frank

2013-01-01

With the advent of the National Collegiate Athletic Association's (NCAA's) mandating the presence and practice of concussion-management plans in collegiate athletic programs, institutions will consider potential approaches for concussion management, including both baseline and normative comparison approaches. To examine sport and team differences in baseline performance on a computer-based neurocognitive measure and 2 standard sideline measures of cognition and balance and to determine the potential effect of premorbid factors sex and height on baseline performance. Cross-sectional study. University laboratory. A total of 437 NCAA Division II student-athletes (males = 273, females = 164; age = 19.61 ± 1.64 years, height = 69.89 ± 4.04 inches [177.52 ± 10.26 cm]) were recruited during mandatory preseason testing conducted in a concussion-management program. The computerized Concussion Resolution Index (CRI), the Standardized Assessment of Concussion (Form A; SAC), and the Balance Error Scoring System (BESS). Players on the men's basketball team tended to perform worse on the baseline measures, whereas soccer players tended to perform better. We found a difference in total BESS scores between these sports (P = .002). We saw a difference between sports on the hard-surface portion of the BESS (F6,347 = 3.33, P = .003, ηp(2) = 0.05). No sport, team, or sex differences were found with SAC scores (P > .05). We noted differences between sports and teams in the CRI indices, with basketball, particularly the men's team, performing worse than soccer (P < .001) and softball/baseball (P = .03). When sex and height were considered as possible sources of variation in BESS and CRI team or sport differences, height was a covariate for the team (F1,385 = 5.109, P = .02, ηp(2) = 0.013) and sport (F1,326 = 11.212, P = .001, ηp(2) = 0.033) analyses, but the interaction of sex and sport on CRI indices was not significant in any test (P > .05). Given that differences in neurocognitive functioning and performance among sports and teams exist, the comparison of posttraumatic and baseline assessment may lead to more accurate diagnoses of concussion and safer return-to-participation decision making than the use of normative comparisons.

Reliability and fall experience discrimination of Cross Step Moving on Four Spots Test in the elderly.

PubMed

Yamaji, Shunsuke; Demura, Shinichi

2013-07-01

To examine the reliability and fall experience discrimination of the Cross Step Moving on Four Spots Test (CSFT) and the relationship between CSFT and fall-related physical function. The reliability of the CSFT was examined in a test-retest format with the same tester. Fall history, fall risk, fear of falling, activities of daily living (ADL), and various physical parameters were measured for all participants. A community center and university medical school. Elderly community-dwelling subjects (N=533; 62 men, 471 women) aged 65 to 94 years living independently. Not applicable. Time to complete all the CSFT steps required, fall risk score, ADL score, and fall-related physical function (isometric muscle strength: toe grip, plantar flexion, knee extension, hip flexion, hand grip; balance: 1-leg standing time with eyes open, functional reach test using an elastic stick; and gait: 10-m maximal walking speed). The trial-to-trial reliability test indicated good reliability of the CSFT in both sexes (intraclass correlation coefficient =.833 in men, .825 in women). However, trial-to-trial errors increased with an increase in the CSFT values in both sexes. Significant correlations were observed between the CSFT values and scores for most fall-related physical function tests in both sexes. However, the correlation coefficient for all significant correlations was <0.5. Two-way analysis of variance (sex × fall experience) revealed that the fall experience is a significant factor affecting CSFT values; values in fallers were significantly lower than those in nonfallers. The odds ratios in logistic regression analysis were significant in both sexes (men, 1.35; women, 1.48). As determined by the Youden index, the optimal cutoff value for identifying fall experience was 7.32 seconds, with an area under the curve of .676. The CSFT can detect fall experience and is useful in the evaluation of different fall-related physical functions including muscle strength, balance, and mobility. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Lower Quarter Y-Balance Test Scores and Lower Extremity Injury in NCAA Division I Athletes.

PubMed

Lai, Wilson C; Wang, Dean; Chen, James B; Vail, Jeremy; Rugg, Caitlin M; Hame, Sharon L

2017-08-01

Functional movement tests that are predictive of injury risk in National Collegiate Athletic Association (NCAA) athletes are useful tools for sports medicine professionals. The Lower Quarter Y-Balance Test (YBT-LQ) measures single-leg balance and reach distances in 3 directions. To assess whether the YBT-LQ predicts the laterality and risk of sports-related lower extremity (LE) injury in NCAA athletes. Case-control study; Level of evidence, 3. The YBT-LQ was administered to 294 NCAA Division I athletes from 21 sports during preparticipation physical examinations at a single institution. Athletes were followed prospectively over the course of the corresponding season. Correlation analysis was performed between the laterality of reach asymmetry and composite scores (CS) versus the laterality of injury. Receiver operating characteristic (ROC) analysis was used to determine the optimal asymmetry cutoff score for YBT-LQ. A multivariate regression analysis adjusting for sex, sport type, body mass index, and history of prior LE surgery was performed to assess predictors of earlier and higher rates of injury. Neither the laterality of reach asymmetry nor the CS correlated with the laterality of injury. ROC analysis found optimal cutoff scores of 2, 9, and 3 cm for anterior, posteromedial, and posterolateral reach, respectively. All of these potential cutoff scores, along with a cutoff score of 4 cm used in the majority of prior studies, were associated with poor sensitivity and specificity. Furthermore, none of the asymmetric cutoff scores were associated with earlier or increased rate of injury in the multivariate analyses. YBT-LQ scores alone do not predict LE injury in this collegiate athlete population. Sports medicine professionals should be cautioned against using the YBT-LQ alone to screen for injury risk in collegiate athletes.

Boundary overlap for medical image segmentation evaluation

NASA Astrophysics Data System (ADS)

Yeghiazaryan, Varduhi; Voiculescu, Irina

2017-03-01

All medical image segmentation algorithms need to be validated and compared, and yet no evaluation framework is widely accepted within the imaging community. Collections of segmentation results often need to be compared and ranked by their effectiveness. Evaluation measures which are popular in the literature are based on region overlap or boundary distance. None of these are consistent in the way they rank segmentation results: they tend to be sensitive to one or another type of segmentation error (size, location, shape) but no single measure covers all error types. We introduce a new family of measures, with hybrid characteristics. These measures quantify similarity/difference of segmented regions by considering their overlap around the region boundaries. This family is more sensitive than other measures in the literature to combinations of segmentation error types. We compare measure performance on collections of segmentation results sourced from carefully compiled 2D synthetic data, and also on 3D medical image volumes. We show that our new measure: (1) penalises errors successfully, especially those around region boundaries; (2) gives a low similarity score when existing measures disagree, thus avoiding overly inflated scores; and (3) scores segmentation results over a wider range of values. We consider a representative measure from this family and the effect of its only free parameter on error sensitivity, typical value range, and running time.

Scoring Methods in the International Land Benchmarking (ILAMB) Package

NASA Astrophysics Data System (ADS)

Collier, N.; Hoffman, F. M.; Keppel-Aleks, G.; Lawrence, D. M.; Mu, M.; Riley, W. J.; Randerson, J. T.

2017-12-01

The International Land Model Benchmarking (ILAMB) project is a model-data intercomparison and integration project designed to improve the performance of the land component of Earth system models. This effort is disseminated in the form of a python package which is openly developed (https://bitbucket.org/ncollier/ilamb). ILAMB is more than a workflow system that automates the generation of common scalars and plot comparisons to observational data. We aim to provide scientists and model developers with a tool to gain insight into model behavior. Thus, a salient feature of the ILAMB package is our synthesis methodology, which provides users with a high-level understanding of model performance. Within ILAMB, we calculate a non-dimensional score of a model's performance in a given dimension of the physics, chemistry, or biology with respect to an observational dataset. For example, we compare the Fluxnet-MTE Gross Primary Productivity (GPP) product against model output in the corresponding historical period. We compute common statistics such as the bias, root mean squared error, phase shift, and spatial distribution. We take these measures and find relative errors by normalizing the values, and then use the exponential to map this relative error to the unit interval. This allows for the scores to be combined into an overall score representing multiple aspects of model performance. In this presentation we give details of this process as well as a proposal for tuning the exponential mapping to make scores more cross comparable. However, as many models are calibrated using these scalar measures with respect to observational datasets, we also score the relationships among relevant variables in the model. For example, in the case of GPP, we also consider its relationship to precipitation, evapotranspiration, and temperature. We do this by creating a mean response curve and a two-dimensional distribution based on the observational data and model results. The response curves are then scored using a relative measure of the root mean squared error and the exponential as before. The distributions are scored using the so-called Hellinger distance, a statistical measure for how well one distribution is represented by another, and included in the model's overall score.

Estimating predictive hydrological uncertainty by dressing deterministic and ensemble forecasts; a comparison, with application to Meuse and Rhine

NASA Astrophysics Data System (ADS)

Verkade, J. S.; Brown, J. D.; Davids, F.; Reggiani, P.; Weerts, A. H.

2017-12-01

Two statistical post-processing approaches for estimation of predictive hydrological uncertainty are compared: (i) 'dressing' of a deterministic forecast by adding a single, combined estimate of both hydrological and meteorological uncertainty and (ii) 'dressing' of an ensemble streamflow forecast by adding an estimate of hydrological uncertainty to each individual streamflow ensemble member. Both approaches aim to produce an estimate of the 'total uncertainty' that captures both the meteorological and hydrological uncertainties. They differ in the degree to which they make use of statistical post-processing techniques. In the 'lumped' approach, both sources of uncertainty are lumped by post-processing deterministic forecasts using their verifying observations. In the 'source-specific' approach, the meteorological uncertainties are estimated by an ensemble of weather forecasts. These ensemble members are routed through a hydrological model and a realization of the probability distribution of hydrological uncertainties (only) is then added to each ensemble member to arrive at an estimate of the total uncertainty. The techniques are applied to one location in the Meuse basin and three locations in the Rhine basin. Resulting forecasts are assessed for their reliability and sharpness, as well as compared in terms of multiple verification scores including the relative mean error, Brier Skill Score, Mean Continuous Ranked Probability Skill Score, Relative Operating Characteristic Score and Relative Economic Value. The dressed deterministic forecasts are generally more reliable than the dressed ensemble forecasts, but the latter are sharper. On balance, however, they show similar quality across a range of verification metrics, with the dressed ensembles coming out slightly better. Some additional analyses are suggested. Notably, these include statistical post-processing of the meteorological forecasts in order to increase their reliability, thus increasing the reliability of the streamflow forecasts produced with ensemble meteorological forcings.

Towards a balanced social psychology: causes, consequences, and cures for the problem-seeking approach to social behavior and cognition.

PubMed

Krueger, Joachim I; Funder, David C

2004-06-01

Mainstream social psychology focuses on how people characteristically violate norms of action through social misbehaviors such as conformity with false majority judgments, destructive obedience, and failures to help those in need. Likewise, they are seen to violate norms of reasoning through cognitive errors such as misuse of social information, self-enhancement, and an over-readiness to attribute dispositional characteristics. The causes of this negative research emphasis include the apparent informativeness of norm violation, the status of good behavior and judgment as unconfirmable null hypotheses, and the allure of counter-intuitive findings. The shortcomings of this orientation include frequently erroneous imputations of error, findings of mutually contradictory errors, incoherent interpretations of error, an inability to explain the sources of behavioral or cognitive achievement, and the inhibition of generalized theory. Possible remedies include increased attention to the complete range of behavior and judgmental accomplishment, analytic reforms emphasizing effect sizes and Bayesian inference, and a theoretical paradigm able to account for both the sources of accomplishment and of error. A more balanced social psychology would yield not only a more positive view of human nature, but also an improved understanding of the bases of good behavior and accurate judgment, coherent explanations of occasional lapses, and theoretically grounded suggestions for improvement.

Linear and Nonlinear Response of a Rotating Tokamak Plasma to a Resonant Error-Field

NASA Astrophysics Data System (ADS)

Fitzpatrick, Richard

2014-10-01

An in-depth investigation of the effect of a resonant error-field on a rotating, quasi-cylindrical, tokamak plasma is preformed within the context of resistive-MHD theory. General expressions for the response of the plasma at the rational surface to the error-field are derived in both the linear and nonlinear regimes, and the extents of these regimes mapped out in parameter space. Torque-balance equations are also obtained in both regimes. These equations are used to determine the steady-state plasma rotation at the rational surface in the presence of the error-field. It is found that, provided the intrinsic plasma rotation is sufficiently large, the torque-balance equations possess dynamically stable low-rotation and high-rotation solution branches, separated by a forbidden band of dynamically unstable solutions. Moreover, bifurcations between the two stable solution branches are triggered as the amplitude of the error-field is varied. A low- to high-rotation bifurcation is invariably associated with a significant reduction in the width of the magnetic island chain driven at the rational surface, and vice versa. General expressions for the bifurcation thresholds are derived, and their domains of validity mapped out in parameter space. This research was funded by the U.S. Department of Energy under Contract DE-FG02-04ER-54742.

The Iatroref study: medical errors are associated with symptoms of depression in ICU staff but not burnout or safety culture.

PubMed

Garrouste-Orgeas, Maité; Perrin, Marion; Soufir, Lilia; Vesin, Aurélien; Blot, François; Maxime, Virginie; Beuret, Pascal; Troché, Gilles; Klouche, Kada; Argaud, Laurent; Azoulay, Elie; Timsit, Jean-François

2015-02-01

Staff behaviours to optimise patient safety may be influenced by burnout, depression and strength of the safety culture. We evaluated whether burnout, symptoms of depression and safety culture affected the frequency of medical errors and adverse events (selected using Delphi techniques) in ICUs. Prospective, observational, multicentre (31 ICUs) study from August 2009 to December 2011. Burnout, depression symptoms and safety culture were evaluated using the Maslach Burnout Inventory (MBI), CES-Depression scale and Safety Attitudes Questionnaire, respectively. Of 1,988 staff members, 1,534 (77.2 %) participated. Frequencies of medical errors and adverse events were 804.5/1,000 and 167.4/1,000 patient-days, respectively. Burnout prevalence was 3 or 40 % depending on the definition (severe emotional exhaustion, depersonalisation and low personal accomplishment; or MBI score greater than -9). Depression symptoms were identified in 62/330 (18.8 %) physicians and 188/1,204 (15.6 %) nurses/nursing assistants. Median safety culture score was 60.7/100 [56.8-64.7] in physicians and 57.5/100 [52.4-61.9] in nurses/nursing assistants. Depression symptoms were an independent risk factor for medical errors. Burnout was not associated with medical errors. The safety culture score had a limited influence on medical errors. Other independent risk factors for medical errors or adverse events were related to ICU organisation (40 % of ICU staff off work on the previous day), staff (specific safety training) and patients (workload). One-on-one training of junior physicians during duties and existence of a hospital risk-management unit were associated with lower risks. The frequency of selected medical errors in ICUs was high and was increased when staff members had symptoms of depression.

Predictors of driving safety in early Alzheimer disease.

PubMed

Dawson, J D; Anderson, S W; Uc, E Y; Dastrup, E; Rizzo, M

2009-02-10

To measure the association of cognition, visual perception, and motor function with driving safety in Alzheimer disease (AD). Forty drivers with probable early AD (mean Mini-Mental State Examination score 26.5) and 115 elderly drivers without neurologic disease underwent a battery of cognitive, visual, and motor tests, and drove a standardized 35-mile route in urban and rural settings in an instrumented vehicle. A composite cognitive score (COGSTAT) was calculated for each subject based on eight neuropsychological tests. Driving safety errors were noted and classified by a driving expert based on video review. Drivers with AD committed an average of 42.0 safety errors/drive (SD = 12.8), compared to an average of 33.2 (SD = 12.2) for drivers without AD (p < 0.0001); the most common errors were lane violations. Increased age was predictive of errors, with a mean of 2.3 more errors per drive observed for each 5-year age increment. After adjustment for age and gender, COGSTAT was a significant predictor of safety errors in subjects with AD, with a 4.1 increase in safety errors observed for a 1 SD decrease in cognitive function. Significant increases in safety errors were also found in subjects with AD with poorer scores on Benton Visual Retention Test, Complex Figure Test-Copy, Trail Making Subtest-A, and the Functional Reach Test. Drivers with Alzheimer disease (AD) exhibit a range of performance on tests of cognition, vision, and motor skills. Since these tests provide additional predictive value of driving performance beyond diagnosis alone, clinicians may use these tests to help predict whether a patient with AD can safely operate a motor vehicle.

Assessing the learning curve for the acquisition of laparoscopic skills on a virtual reality simulator.

PubMed

Sherman, V; Feldman, L S; Stanbridge, D; Kazmi, R; Fried, G M

2005-05-01

The aim of this study was to develop summary metrics and assess the construct validity for a virtual reality laparoscopic simulator (LapSim) by comparing the learning curves of three groups with different levels of laparoscopic expertise. Three groups of subjects ('expert', 'junior', and 'naïve') underwent repeated trials on three LapSim tasks. Formulas were developed to calculate scores for efficiency ('time-error') and economy of 'motion' ('motion') using metrics generated by the software after each drill. Data (mean +/- SD) were evaluated by analysis of variance (ANOVA). Significance was set at p < 0.05. All three groups improved significantly from baseline to final for both 'time-error' and 'motion' scores. There were significant differences between groups in time error performances at baseline and final, due to higher scores in the 'expert' group. A significant difference in 'motion' scores was seen only at baseline. We have developed summary metrics for the LapSim that differentiate among levels of laparoscopic experience. This study also provides evidence of construct validity for the LapSim.

Eye Accommodation, Personality, and Autonomic Balance.

DTIC Science & Technology

1979-11-01

Wenger and Ellington, 1943, and by a technique introduced by Porges, 1976), refractive error (measured by dark focus, near and far points using a...focus, near and far points using a polarized vernier optometer), and introversion - extraversion (Eysenck Personality Inventory introversion...Porges, 1976), refractive error (measured by dark focus, near and far points using a polarized vernier optometer), and introversion - extraversion

Balancing Treatment and Control Groups in Quasi-Experiments: An Introduction to Propensity Scoring

ERIC Educational Resources Information Center

Connelly, Brian S.; Sackett, Paul R.; Waters, Shonna D.

2013-01-01

Organizational and applied sciences have long struggled with improving causal inference in quasi-experiments. We introduce organizational researchers to propensity scoring, a statistical technique that has become popular in other applied sciences as a means for improving internal validity. Propensity scoring statistically models how individuals in…

Accuracy and Efficiency of Recording Pediatric Early Warning Scores Using an Electronic Physiological Surveillance System Compared With Traditional Paper-Based Documentation

PubMed Central

Sefton, Gerri; Lane, Steven; Killen, Roger; Black, Stuart; Lyon, Max; Ampah, Pearl; Sproule, Cathryn; Loren-Gosling, Dominic; Richards, Caitlin; Spinty, Jean; Holloway, Colette; Davies, Coral; Wilson, April; Chean, Chung Shen; Carter, Bernie; Carrol, E.D.

2017-01-01

Pediatric Early Warning Scores are advocated to assist health professionals to identify early signs of serious illness or deterioration in hospitalized children. Scores are derived from the weighting applied to recorded vital signs and clinical observations reflecting deviation from a predetermined “norm.” Higher aggregate scores trigger an escalation in care aimed at preventing critical deterioration. Process errors made while recording these data, including plotting or calculation errors, have the potential to impede the reliability of the score. To test this hypothesis, we conducted a controlled study of documentation using five clinical vignettes. We measured the accuracy of vital sign recording, score calculation, and time taken to complete documentation using a handheld electronic physiological surveillance system, VitalPAC Pediatric, compared with traditional paper-based charts. We explored the user acceptability of both methods using a Web-based survey. Twenty-three staff participated in the controlled study. The electronic physiological surveillance system improved the accuracy of vital sign recording, 98.5% versus 85.6%, P < .02, Pediatric Early Warning Score calculation, 94.6% versus 55.7%, P < .02, and saved time, 68 versus 98 seconds, compared with paper-based documentation, P < .002. Twenty-nine staff completed the Web-based survey. They perceived that the electronic physiological surveillance system offered safety benefits by reducing human error while providing instant visibility of recorded data to the entire clinical team. PMID:27832032

Functional Mobility Performance and Balance Confidence in Older Adults after Sensorimotor Adaptation Training

NASA Technical Reports Server (NTRS)

Buccello-Stout, Regina R.; Cromwell, Ronita L.; Bloomberg, Jacob J.; Weaver, G. D.

2010-01-01

Research indicates a main contributor of injury in older adults is from falling. The decline in sensory systems limits information needed to successfully maneuver through the environment. The objective of this study was to determine if prolonged exposure to the realignment of perceptual-motor systems increases adaptability of balance, and if balance confidence improves after training. A total of 16 older adults between ages 65-85 were randomized to a control group (walking on a treadmill while viewing a static visual scene) and an experimental group (walking on a treadmill while viewing a rotating visual scene). Prior to visual exposure, participants completed six trials of walking through a soft foamed obstacle course. Participants came in twice a week for 4 weeks to complete training of walking on a treadmill and viewing the visual scene for 20 minutes each session. Participants completed the obstacle course after training and four weeks later. Average time, penalty, and Activity Balance Confidence Scale scores were computed for both groups across testing times. The older adults who trained, significantly improved their time through the obstacle course F (2, 28) = 9.41, p < 0.05, as well as reduced their penalty scores F (2, 28) = 21.03, p < 0.05, compared to those who did not train. There was no difference in balance confidence scores between groups across testing times F (2, 28) = 0.503, p > 0.05. Although the training group improved mobility through the obstacle course, there were no differences between the groups in balance confidence.

Assessment of balance and risk for falls in a sample of community-dwelling adults aged 65 and older

PubMed Central

Hawk, Cheryl; Hyland, John K; Rupert, Ronald; Colonvega, Makasha; Hall, Stephanie

2006-01-01

Background Falls are a major health concern for older adults and their impact is a significant public health problem. The chief modifiable risk factors for falls in community-dwellers are psychotropic drugs, polypharmacy, environmental hazards, poor vision, lower extremity impairments, and balance impairments. This study focused on balance impairments. Its purpose was to assess the feasibility of recruiting older adults with possible balance problems for research conducted at a chiropractic research center, and to explore the utility of several widely used balance instruments for future studies of the effect of chiropractic care on balance in older adults. Methods This descriptive study was conducted from September through December 2004. Participants were recruited through a variety of outreach methods, and all were provided with an educational intervention. Data were collected at each of two visits through questionnaires, interviews, and physical examinations. Balance was assessed on both visits using the Activities-specific Balance Confidence Scale (ABCS), the Berg Balance Scale (BBS), and the One Leg Standing Test (OLST). Results A total of 101 participants enrolled in the study. Advertising in the local senior newspaper was the most effective method of recruitment (46%). The majority of our participants were white (86%) females (67%). About one third (32%) of participants had a baseline BBS score below 46, the cut-off point for predicting risk of falling. A mean improvement in BBS scores of 1.7 points was observed on the second visit. For the subgroup with baseline scores below 46, the mean change was 4.5 points, but the group mean remained below 46 (42.5). Conclusion Recruitment of community-dwelling seniors for fall-related research conducted at a chiropractic research center appears feasible, and the most successful recruitment strategies for this center appeared to be a combination of targeted newspaper ads and personal contact through senior centers. The BBS and OLST appear to be promising screening and assessment instruments, which might have utility in future investigations of the possible effects of chiropractic care on balance. PMID:16441893

Assessment of balance and risk for falls in a sample of community-dwelling adults aged 65 and older.

PubMed

Hawk, Cheryl; Hyland, John K; Rupert, Ronald; Colonvega, Makasha; Hall, Stephanie

2006-01-27

Falls are a major health concern for older adults and their impact is a significant public health problem. The chief modifiable risk factors for falls in community-dwellers are psychotropic drugs, polypharmacy, environmental hazards, poor vision, lower extremity impairments, and balance impairments. This study focused on balance impairments. Its purpose was to assess the feasibility of recruiting older adults with possible balance problems for research conducted at a chiropractic research center, and to explore the utility of several widely used balance instruments for future studies of the effect of chiropractic care on balance in older adults. This descriptive study was conducted from September through December 2004. Participants were recruited through a variety of outreach methods, and all were provided with an educational intervention. Data were collected at each of two visits through questionnaires, interviews, and physical examinations. Balance was assessed on both visits using the Activities-specific Balance Confidence Scale (ABCS), the Berg Balance Scale (BBS), and the One Leg Standing Test (OLST). A total of 101 participants enrolled in the study. Advertising in the local senior newspaper was the most effective method of recruitment (46%). The majority of our participants were white (86%) females (67%). About one third (32%) of participants had a baseline BBS score below 46, the cut-off point for predicting risk of falling. A mean improvement in BBS scores of 1.7 points was observed on the second visit. For the subgroup with baseline scores below 46, the mean change was 4.5 points, but the group mean remained below 46 (42.5). Recruitment of community-dwelling seniors for fall-related research conducted at a chiropractic research center appears feasible, and the most successful recruitment strategies for this center appeared to be a combination of targeted newspaper ads and personal contact through senior centers. The BBS and OLST appear to be promising screening and assessment instruments, which might have utility in future investigations of the possible effects of chiropractic care on balance.

Event-Related-Potential (ERP) Correlates of Performance Monitoring in Adults With Attention-Deficit Hyperactivity Disorder (ADHD)

PubMed Central

Marquardt, Lynn; Eichele, Heike; Lundervold, Astri J.; Haavik, Jan; Eichele, Tom

2018-01-01

Introduction: Attention-deficit hyperactivity disorder (ADHD) is one of the most frequent neurodevelopmental disorders in children and tends to persist into adulthood. Evidence from neuropsychological, neuroimaging, and electrophysiological studies indicates that alterations of error processing are core symptoms in children and adolescents with ADHD. To test whether adults with ADHD show persisting deficits and compensatory processes, we investigated performance monitoring during stimulus-evaluation and response-selection, with a focus on errors, as well as within-group correlations with symptom scores. Methods: Fifty-five participants (27 ADHD and 28 controls) aged 19–55 years performed a modified flanker task during EEG recording with 64 electrodes, and the ADHD and control groups were compared on measures of behavioral task performance, event-related potentials of performance monitoring (N2, P3), and error processing (ERN, Pe). Adult ADHD Self-Report Scale (ASRS) was used to assess ADHD symptom load. Results: Adults with ADHD showed higher error rates in incompatible trials, and these error rates correlated positively with the ASRS scores. Also, we observed lower P3 amplitudes in incompatible trials, which were inversely correlated with symptom load in the ADHD group. Adults with ADHD also displayed reduced error-related ERN and Pe amplitudes. There were no significant differences in reaction time (RT) and RT variability between the two groups. Conclusion: Our findings show deviations of electrophysiological measures, suggesting reduced effortful engagement of attentional and error-monitoring processes in adults with ADHD. Associations between ADHD symptom scores, event-related potential amplitudes, and poorer task performance in the ADHD group further support this notion. PMID:29706908

Assessment of a model for achieving competency in administration and scoring of the WAIS-IV in post-graduate psychology students.

PubMed

Roberts, Rachel M; Davis, Melissa C

2015-01-01

There is a need for an evidence-based approach to training professional psychologists in the administration and scoring of standardized tests such as the Wechsler Adult Intelligence Scale (WAIS) due to substantial evidence that these tasks are associated with numerous errors that have the potential to significantly impact clients' lives. Twenty three post-graduate psychology students underwent training in using the WAIS-IV according to a best-practice teaching model that involved didactic teaching, independent study of the test manual, and in-class practice with teacher supervision and feedback. Video recordings and test protocols from a role-played test administration were analyzed for errors according to a comprehensive checklist with self, peer, and faculty member reviews. 91.3% of students were rated as having demonstrated competency in administration and scoring. All students were found to make errors, with substantially more errors being detected by the faculty member than by self or peers. Across all subtests, the most frequent errors related to failure to deliver standardized instructions verbatim from the manual. The failure of peer and self-reviews to detect the majority of the errors suggests that novice feedback (self or peers) may be ineffective to eliminate errors and the use of more senior peers may be preferable. It is suggested that involving senior trainees, recent graduates and/or experienced practitioners in the training of post-graduate students may have benefits for both parties, promoting a peer-learning and continuous professional development approach to the development and maintenance of skills in psychological assessment.

Commentary on Values and Standards in Performance Assessment.

ERIC Educational Resources Information Center

Guion, Robert M.

1995-01-01

This commentary discusses three essential themes in performance assessment and its scoring. First, scores should mean something. Second, performance scores should permit fair and meaningful comparisons. Third, validity-reducing errors should be minimal. Increased attention to performance assessment may overcome these problems. (SLD)

Monitoring glacier albedo as a proxy to derive summer and annual surface mass balances from optical remote-sensing data

NASA Astrophysics Data System (ADS)

Davaze, Lucas; Rabatel, Antoine; Arnaud, Yves; Sirguey, Pascal; Six, Delphine; Letreguilly, Anne; Dumont, Marie

2018-01-01

Less than 0.25 % of the 250 000 glaciers inventoried in the Randolph Glacier Inventory (RGI V.5) are currently monitored with in situ measurements of surface mass balance. Increasing this archive is very challenging, especially using time-consuming methods based on in situ measurements, and complementary methods are required to quantify the surface mass balance of unmonitored glaciers. The current study relies on the so-called albedo method, based on the analysis of albedo maps retrieved from optical satellite imagery acquired since 2000 by the MODIS sensor, on board the TERRA satellite. Recent studies revealed substantial relationships between summer minimum glacier-wide surface albedo and annual surface mass balance, because this minimum surface albedo is directly related to the accumulation-area ratio and the equilibrium-line altitude. On the basis of 30 glaciers located in the French Alps where annual surface mass balance data are available, our study conducted on the period 2000-2015 confirms the robustness and reliability of the relationship between the summer minimum surface albedo and the annual surface mass balance. For the ablation season, the integrated summer surface albedo is significantly correlated with the summer surface mass balance of the six glaciers seasonally monitored. These results are promising to monitor both annual and summer glacier-wide surface mass balances of individual glaciers at a regional scale using optical satellite images. A sensitivity study on the computed cloud masks revealed a high confidence in the retrieved albedo maps, restricting the number of omission errors. Albedo retrieval artifacts have been detected for topographically incised glaciers, highlighting limitations in the shadow correction algorithm, although inter-annual comparisons are not affected by systematic errors.

Deficits in vision and visual attention associated with motor performance of very preterm/very low birth weight children.

PubMed

Geldof, Christiaan J A; van Hus, Janeline W P; Jeukens-Visser, Martine; Nollet, Frans; Kok, Joke H; Oosterlaan, Jaap; van Wassenaer-Leemhuis, Aleid G

2016-01-01

To extend understanding of impaired motor functioning of very preterm (VP)/very low birth weight (VLBW) children by investigating its relationship with visual attention, visual and visual-motor functioning. Motor functioning (Movement Assessment Battery for Children, MABC-2; Manual Dexterity, Aiming & Catching, and Balance component), as well as visual attention (attention network and visual search tests), vision (oculomotor, visual sensory and perceptive functioning), visual-motor integration (Beery Visual Motor Integration), and neurological status (Touwen examination) were comprehensively assessed in a sample of 106 5.5-year-old VP/VLBW children. Stepwise linear regression analyses were conducted to investigate multivariate associations between deficits in visual attention, oculomotor, visual sensory, perceptive and visual-motor integration functioning, abnormal neurological status, neonatal risk factors, and MABC-2 scores. Abnormal MABC-2 Total or component scores occurred in 23-36% of VP/VLBW children. Visual and visual-motor functioning accounted for 9-11% of variance in MABC-2 Total, Manual Dexterity and Balance scores. Visual perceptive deficits only were associated with Aiming & Catching. Abnormal neurological status accounted for an additional 19-30% of variance in MABC-2 Total, Manual Dexterity and Balance scores, and 5% of variance in Aiming & Catching, and neonatal risk factors for 3-6% of variance in MABC-2 Total, Manual Dexterity and Balance scores. Motor functioning is weakly associated with visual and visual-motor integration deficits and moderately associated with abnormal neurological status, indicating that motor performance reflects long term vulnerability following very preterm birth, and that visual deficits are of minor importance in understanding motor functioning of VP/VLBW children. Copyright © 2016 Elsevier Ltd. All rights reserved.

The characteristics of patients with uncertain/mild cognitive impairment on the Alzheimer disease assessment scale-cognitive subscale.

PubMed

Pyo, Geunyeong; Elble, Rodger J; Ala, Thomas; Markwell, Stephen J

2006-01-01

The performances of the uncertain/mild cognitive impairment (MCI) patients on the Alzheimer Disease Assessment Scale-Cognitive (ADAS-Cog) subscale were compared with those of normal controls, Alzheimer disease patients with CDR 0.5, and Alzheimer disease patients with CDR 1.0. The Uncertain/MCI group was significantly different from normal controls and Alzheimer disease CDR 0.5 or 1.0 groups on the ADAS-Cog except on a few non-memory subtests. Age was significantly correlated with total error score in the normal group, but there was no significant correlation between age and ADAS-Cog scores in the patient groups. Education was not significantly correlated with the ADAS-Cog scores in any group. Regardless of age and educational level, there were clear differences between the normal group and the Uncertain/MCI group, especially on the total error scores. We found that the total error score of the ADAS-Cog was the most reliable variable in detecting patients with mild cognitive impairment. The present study demonstrated that the ADAS-Cog is a promising tool for detecting and studying patients with mild cognitive impairment. The results also indicated that demographic variables such as age and education do not play a significant role in the diagnosis of mild cognitive impaired patients based on the ADAS-Cog scores.

Validity and reliability of the Nintendo Wii Balance Board to assess standing balance and sensory integration in highly functional older adults.

PubMed

Scaglioni-Solano, Pietro; Aragón-Vargas, Luis F

2014-06-01

Standing balance is an important motor task. Postural instability associated with age typically arises from deterioration of peripheral sensory systems. The modified Clinical Test of Sensory Integration for Balance and the Tandem test have been used to screen for balance. Timed tests present some limitations, whereas quantification of the motions of the center of pressure (CoP) with portable and inexpensive equipment may help to improve the sensitivity of these tests and give the possibility of widespread use. This study determines the validity and reliability of the Wii Balance Board (Wii BB) to quantify CoP motions during the mentioned tests. Thirty-seven older adults completed three repetitions of five balance conditions: eyes open, eyes closed, eyes open on a compliant surface, eyes closed on a compliant surface, and tandem stance, all performed on a force plate and a Wii BB simultaneously. Twenty participants repeated the trials for reliability purposes. CoP displacement was the main outcome measure. Regression analysis indicated that the Wii BB has excellent concurrent validity, and Bland-Altman plots showed good agreement between devices with small mean differences and no relationship between the difference and the mean. Intraclass correlation coefficients (ICCs) indicated modest-to-excellent test-retest reliability (ICC=0.64-0.85). Standard error of measurement and minimal detectable change were similar for both devices, except the 'eyes closed' condition, with greater standard error of measurement for the Wii BB. In conclusion, the Wii BB is shown to be a valid and reliable method to quantify CoP displacement in older adults.

Syntactic error modeling and scoring normalization in speech recognition: Error modeling and scoring normalization in the speech recognition task for adult literacy training

NASA Technical Reports Server (NTRS)

Olorenshaw, Lex; Trawick, David

1991-01-01

The purpose was to develop a speech recognition system to be able to detect speech which is pronounced incorrectly, given that the text of the spoken speech is known to the recognizer. Better mechanisms are provided for using speech recognition in a literacy tutor application. Using a combination of scoring normalization techniques and cheater-mode decoding, a reasonable acceptance/rejection threshold was provided. In continuous speech, the system was tested to be able to provide above 80 pct. correct acceptance of words, while correctly rejecting over 80 pct. of incorrectly pronounced words.

Impact of a virtual reality-based intervention on motor performance and balance of a child with cerebral palsy: a case study

PubMed Central

Pavão, Silvia Leticia; Arnoni, Joice Luiza Bruno; de Oliveira, Alyne Kalyane Câmara; Rocha, Nelci Adriana Cicuto Ferreira

2014-01-01

OBJECTIVE: To verify the effect of an intervention protocol using virtual reality (VR) on the motor performance and balance of a child with cerebral palsy (CP). CASE DESCRIPTION: To comply with the proposed objectives, a 7-year old child with spastic hemiplegic cerebral palsy (CP), GMFCS level I, was submitted to a physiotherapy intervention protocol of 12 45-minute sessions, twice a week, using virtual reality-based therapy. The protocol used a commercially-available console (XBOX(r)360 Kinect(r)) able to track and reproduce body movements on a screen. Prior to the intervention protocol, the child was evaluated using the Motor Development Scale (MDS) and the Pediatric Balance Scale (PBS) in order to assess motor development and balance, respectively. Two baseline assessments with a 2-week interval between each other were carried out for each tool. Then, the child was re-evaluated after the twelfth session. The results showed no changes in the two baseline scores. After the intervention protocol, the child improved his scores in both tools used: the PBS score increased by 3 points, reaching the maximal score, and the MDS increased from a much inferior motor performance to just an inferior motor performance. COMMENTS: The evidence presented in this case supports the use of virtual reality as a promising tool to be incorporated into the rehabilitation process of patients with neuromotor dysfunction. PMID:25511004

Analysis of operator splitting errors for near-limit flame simulations

NASA Astrophysics Data System (ADS)

Lu, Zhen; Zhou, Hua; Li, Shan; Ren, Zhuyin; Lu, Tianfeng; Law, Chung K.

2017-04-01

High-fidelity simulations of ignition, extinction and oscillatory combustion processes are of practical interest in a broad range of combustion applications. Splitting schemes, widely employed in reactive flow simulations, could fail for stiff reaction-diffusion systems exhibiting near-limit flame phenomena. The present work first employs a model perfectly stirred reactor (PSR) problem with an Arrhenius reaction term and a linear mixing term to study the effects of splitting errors on the near-limit combustion phenomena. Analysis shows that the errors induced by decoupling of the fractional steps may result in unphysical extinction or ignition. The analysis is then extended to the prediction of ignition, extinction and oscillatory combustion in unsteady PSRs of various fuel/air mixtures with a 9-species detailed mechanism for hydrogen oxidation and an 88-species skeletal mechanism for n-heptane oxidation, together with a Jacobian-based analysis for the time scales. The tested schemes include the Strang splitting, the balanced splitting, and a newly developed semi-implicit midpoint method. Results show that the semi-implicit midpoint method can accurately reproduce the dynamics of the near-limit flame phenomena and it is second-order accurate over a wide range of time step size. For the extinction and ignition processes, both the balanced splitting and midpoint method can yield accurate predictions, whereas the Strang splitting can lead to significant shifts on the ignition/extinction processes or even unphysical results. With an enriched H radical source in the inflow stream, a delay of the ignition process and the deviation on the equilibrium temperature are observed for the Strang splitting. On the contrary, the midpoint method that solves reaction and diffusion together matches the fully implicit accurate solution. The balanced splitting predicts the temperature rise correctly but with an over-predicted peak. For the sustainable and decaying oscillatory combustion from cool flames, both the Strang splitting and the midpoint method can successfully capture the dynamic behavior, whereas the balanced splitting scheme results in significant errors.

Analysis of operator splitting errors for near-limit flame simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Zhen; Zhou, Hua; Li, Shan

High-fidelity simulations of ignition, extinction and oscillatory combustion processes are of practical interest in a broad range of combustion applications. Splitting schemes, widely employed in reactive flow simulations, could fail for stiff reaction–diffusion systems exhibiting near-limit flame phenomena. The present work first employs a model perfectly stirred reactor (PSR) problem with an Arrhenius reaction term and a linear mixing term to study the effects of splitting errors on the near-limit combustion phenomena. Analysis shows that the errors induced by decoupling of the fractional steps may result in unphysical extinction or ignition. The analysis is then extended to the prediction ofmore » ignition, extinction and oscillatory combustion in unsteady PSRs of various fuel/air mixtures with a 9-species detailed mechanism for hydrogen oxidation and an 88-species skeletal mechanism for n-heptane oxidation, together with a Jacobian-based analysis for the time scales. The tested schemes include the Strang splitting, the balanced splitting, and a newly developed semi-implicit midpoint method. Results show that the semi-implicit midpoint method can accurately reproduce the dynamics of the near-limit flame phenomena and it is second-order accurate over a wide range of time step size. For the extinction and ignition processes, both the balanced splitting and midpoint method can yield accurate predictions, whereas the Strang splitting can lead to significant shifts on the ignition/extinction processes or even unphysical results. With an enriched H radical source in the inflow stream, a delay of the ignition process and the deviation on the equilibrium temperature are observed for the Strang splitting. On the contrary, the midpoint method that solves reaction and diffusion together matches the fully implicit accurate solution. The balanced splitting predicts the temperature rise correctly but with an over-predicted peak. For the sustainable and decaying oscillatory combustion from cool flames, both the Strang splitting and the midpoint method can successfully capture the dynamic behavior, whereas the balanced splitting scheme results in significant errors.« less

Examining the Relationship Between the Functional Movement Screen and the Landing Error Scoring System in an Active, Male Collegiate Population.

PubMed

Everard, Eoin M; Harrison, Andrew J; Lyons, Mark

2017-05-01

Everard, EM, Harrison, AJ, and Lyons, M. Examining the relationship between the functional movement screen and the landing error scoring system in an active, male collegiate population. J Strength Cond Res 31(5): 1265-1272, 2017-In recent years, there has been an increasing focus on movement screening as the principal aspect of preparticipation testing. Two of the most common movement screening tools are the Functional Movement Screen (FMS) and the Landing Error Scoring System (LESS). Several studies have examined the reliability and validity of these tools, but so far, there have been no studies comparing the results of these 2 screening tools against each other. Therefore, the purpose of this study was to determine the relationship between FMS scores and LESS scores. Ninety-eight male college athletes actively competing in sport (Gaelic games, soccer, athletics, boxing/mixed martial arts, Olympic weightlifting) participated in the study and performed the FMS and LESS screens. Both the 21-point and 100-point scoring systems were used to score the FMS. Spearman's correlation coefficients were used to determine the relationship between the 2 screening scores. The results showed a significant moderate correlation between FMS and LESS scores (rho 100 and 21 point = -0.528; -0.487; p < 0.001). In addition, r values of 0.26 and 0.23 indicate a poor shared variance between the 2 screens. The results indicate that performing well in one of the screens does not necessarily equate to performing well in the other. This has practical implications as it highlights that both screens may assess different movement patterns and should not be used as a substitute for each other.

Association of myelopathy scores with cervical sagittal balance and normalized spinal cord volume: analysis of 56 preoperative cases from the AOSpine North America Myelopathy study.

PubMed

Smith, Justin S; Lafage, Virginie; Ryan, Devon J; Shaffrey, Christopher I; Schwab, Frank J; Patel, Alpesh A; Brodke, Darrel S; Arnold, Paul M; Riew, K Daniel; Traynelis, Vincent C; Radcliff, Kris; Vaccaro, Alexander R; Fehlings, Michael G; Ames, Christopher P

2013-10-15

Post hoc analysis of prospectively collected data. Development of methods to determine in vivo spinal cord dimensions and application to correlate preoperative alignment, myelopathy, and health-related quality-of-life scores in patients with cervical spondylotic myelopathy (CSM). CSM is the leading cause of spinal cord dysfunction. The association between cervical alignment, sagittal balance, and myelopathy has not been well characterized. This was a post hoc analysis of the prospective, multicenter AOSpine North America CSM study. Inclusion criteria for this study required preoperative cervical magnetic resonance imaging (MRI) and neutral sagittal cervical radiography. Techniques for MRI assessment of spinal cord dimensions were developed. Correlations between imaging and health-related quality-of-life scores were assessed. Fifty-six patients met inclusion criteria (mean age = 55.4 yr). The modified Japanese Orthopedic Association (mJOA) scores correlated with C2-C7 sagittal vertical axis (SVA) (r = -0.282, P = 0.035). Spinal cord volume correlated with cord length (r = 0.472, P < 0.001) and cord average cross-sectional area (r = 0.957, P < 0.001). For all patients, no correlations were found between MRI measurements of spinal cord length, volume, mean cross-sectional area or surface area, and outcomes. For patients with cervical lordosis, mJOA scores correlated positively with cord volume (r = 0.366, P = 0.022), external cord area (r = 0.399, P = 0.012), and mean cross-sectional cord area (r = 0.345, P = 0.031). In contrast, for patients with cervical kyphosis, mJOA scores correlated negatively with cord volume (r = -0.496, P = 0.043) and mean cross-sectional cord area (r = -0.535, P = 0.027). This study is the first to correlate cervical sagittal balance (C2-C7 SVA) to myelopathy severity. We found a moderate negative correlation in kyphotic patients of cord volume and cross-sectional area to mJOA scores. The opposite (positive correlation) was found for lordotic patients, suggesting a relationship of cord volume to myelopathy that differs on the basis of sagittal alignment. It is interesting to note that sagittal balance but not kyphosis is tied to myelopathy score. Future work will correlate alignment changes to cord morphology changes and myelopathy outcomes. SUMMARY STATEMENTS: This is the first study to correlate sagittal balance (C2-C7 SVA) to myelopathy severity. We found a moderate negative correlation in kyphotic patients of cord volume and cross-sectional area to mJOA scores. The opposite (positive correlation) was found for lordotic patients, suggesting a relationship of cord volume to myelopathy that differs on the basis of sagittal alignment.

Effects of mirror therapy integrated with task-oriented exercise on the balance function of patients with poststroke hemiparesis: a randomized-controlled pilot trial.

PubMed

Cha, Hyun-Gyu; Oh, Duck-Won

2016-03-01

This study aimed to explore the effects of mirror therapy integrated with task-oriented exercise on balance function in poststroke hemiparesis. Twenty patients with poststroke hemiparesis were assigned randomly to an experimental group (EG) and a control group (CG), with 10 individuals each. Participants of the EG and CG received a task-oriented exercise program with a focus on the strengthening of the lower limb and the practice of balance-related functional tasks. An additional option for the EG was front and side wall mirrors to provide visual feedback for their own movements while performing the exercise. The program was performed for 30 min, twice a day, five times per week for 4 weeks. Outcome measures included the Berg balance scale, the timed up-and-go test, and quantitative data (balance index and dynamic limits of stability). In the EG and CG, all variables showed significant differences between pretest and post-test (P<0.05), and post-test values of all variables appeared to be significantly different between two groups (P<0.05). Furthermore, in the EG, the change values between pretest and post-test values of Berg balance scale (13.00±3.20 vs. 6.60±4.55 scores), and timed up-and-go test (6.45±3.00 vs. 3.61±1.84 s), balance index (2.29±0.51 vs. 0.96±0.65 scores), dynamic limits of stability (7.70±3.83 vs. 3.70±4.60 scores) were significantly higher than those of the CG (P<0.05). The findings suggest that a mirror therapy may be used as a beneficial therapeutic option to facilitate the effects of a task-oriented exercise on balance function of patients with poststroke hemiparesis.

The effect of information provision on reduction of errors in intravenous drug preparation and administration by nurses in ICU and surgical wards.

PubMed

Abbasinazari, Mohammad; Zareh-Toranposhti, Samaneh; Hassani, Abdollah; Sistanizad, Mohammad; Azizian, Homa; Panahi, Yunes

2012-01-01

Malpractice in preparation and administration of intravenous (IV) medications has been reported frequently. Inadequate knowledge of nurses has been reported as a cause of such errors. We aimed to evaluate the role of nurses' education via installation of wall posters and giving informative pamphlets in reducing the errors in preparation and administration of intravenous drugs in 2 wards (ICU and surgery) of a teaching hospital in Tehran, Iran. A trained observer stationed in 2 wards in different work shifts. He recorded the nurses' practice regarding the preparation and administration of IV drugs and scored them before and after the education process. 400 observations were evaluated. Of them, 200 were related to before education and 200 were related to after education. On a 0-10 quality scale, mean ± SD scores of before and after education were determined. Mean ± SD scores of before and after education at the 2 wards were 4.51 (± 1.24) and 6.15 (± 1.23) respectively. There was a significant difference between the scores before and after intervention in ICU (P<0.001), surgery (P<0.001), and total two wards (P<0.001). Nurses' education by using wall poster and informative pamphlets regarding the correct preparation and administration of IV drugs can reduce the number of errors.

Study on the Effectiveness of Virtual Reality Game-Based Training on Balance and Functional Performance in Individuals with Paraplegia

PubMed Central

Khurana, Meetika; Walia, Shefali

2017-01-01

Objective: To determine whether there is any difference between virtual reality game–based balance training and real-world task-specific balance training in improving sitting balance and functional performance in individuals with paraplegia. Methods: The study was a pre test–post test experimental design. There were 30 participants (28 males, 2 females) with traumatic spinal cord injury randomly assigned to 2 groups (group A and B). The levels of spinal injury of the participants were between T6 and T12. The virtual reality game–based balance training and real-world task-specific balance training were used as interventions in groups A and B, respectively. The total duration of the intervention was 4 weeks, with a frequency of 5 times a week; each training session lasted 45 minutes. The outcome measures were modified Functional Reach Test (mFRT), t-shirt test, and the self-care component of the Spinal Cord Independence Measure–III (SCIM-III). Results: There was a significant difference for time (p = .001) and Time × Group effect (p = .001) in mFRT scores, group effect (p = .05) in t-shirt test scores, and time effect (p = .001) in the self-care component of SCIM-III. Conclusions: Virtual reality game–based training is better in improving balance and functional performance in individuals with paraplegia than real-world task-specific balance training. PMID:29339902

Study on the Effectiveness of Virtual Reality Game-Based Training on Balance and Functional Performance in Individuals with Paraplegia.

PubMed

Khurana, Meetika; Walia, Shefali; Noohu, Majumi M

2017-01-01

Objective: To determine whether there is any difference between virtual reality game-based balance training and real-world task-specific balance training in improving sitting balance and functional performance in individuals with paraplegia. Methods: The study was a pre test-post test experimental design. There were 30 participants (28 males, 2 females) with traumatic spinal cord injury randomly assigned to 2 groups (group A and B). The levels of spinal injury of the participants were between T6 and T12. The virtual reality game-based balance training and real-world task-specific balance training were used as interventions in groups A and B, respectively. The total duration of the intervention was 4 weeks, with a frequency of 5 times a week; each training session lasted 45 minutes. The outcome measures were modified Functional Reach Test (mFRT), t-shirt test, and the self-care component of the Spinal Cord Independence Measure-III (SCIM-III). Results: There was a significant difference for time ( p = .001) and Time × Group effect ( p = .001) in mFRT scores, group effect ( p = .05) in t-shirt test scores, and time effect ( p = .001) in the self-care component of SCIM-III. Conclusions: Virtual reality game-based training is better in improving balance and functional performance in individuals with paraplegia than real-world task-specific balance training.

Using a dry electrode EEG device during balance tasks in healthy young-adult males: Test-retest reliability analysis.

PubMed

Collado-Mateo, Daniel; Adsuar, Jose C; Olivares, Pedro R; Cano-Plasencia, Ricardo; Gusi, Narcis

2015-01-01

The analysis of brain activity during balance is an important topic in different fields of science. Given that all measurements involve an error that is caused by different agents, like the instrument, the researcher, or the natural human variability, a test-retest reliability evaluation of the electroencephalographic assessment is a needed starting point. However, there is a lack of information about the reliability of electroencephalographic measurements, especially in a new wireless device with dry electrodes. The current study aims to analyze the reliability of electroencephalographic measurements from a wireless device using dry electrodes during two different balance tests. Seventeen healthy male volunteers performed two different static balance tasks on a Biodex Balance Platform: (a) with two feet on the platform and (b) with one foot on the platform. Electroencephalographic data was recorded using Enobio (Neuroelectrics). The mean power spectrum of the alpha band of the central and frontal channels was calculated. Relative and absolute indices of reliability were also calculated. In general terms, the intraclass correlation coefficient (ICC) values of all the assessed channels can be classified as excellent (>0.90). The percentage standard error of measurement oscillated from 0.54% to 1.02% and the percentage smallest real difference ranged from 1.50% to 2.82%. Electroencephalographic assessment through an Enobio device during balance tasks has an excellent reliability. However, its utility was not demonstrated because responsiveness was not assessed.

A Practical Method for Identifying Significant Change Scores

ERIC Educational Resources Information Center

Cascio, Wayne F.; Kurtines, William M.

1977-01-01

A test of significance for identifying individuals who are most influenced by an experimental treatment as measured by pre-post test change score is presented. The technique requires true difference scores, the reliability of obtained differences, and their standard error of measurement. (Author/JKS)

Gender nonconformity, intelligence, and sexual orientation.

PubMed

Rahman, Qazi; Bhanot, Suraj; Emrith-Small, Hanna; Ghafoor, Shilan; Roberts, Steven

2012-06-01

The present study explored whether there were relationships among gender nonconformity, intelligence, and sexual orientation. A total of 106 heterosexual men, 115 heterosexual women, and 103 gay men completed measures of demographic variables, recalled childhood gender nonconformity (CGN), and the National Adult Reading Test (NART). NART error scores were used to estimate Wechsler Adult Intelligence Scale (WAIS) Full-Scale IQ (FSIQ) and Verbal IQ (VIQ) scores. Gay men had significantly fewer NART errors than heterosexual men and women (controlling for years of education). In heterosexual men, correlational analysis revealed significant associations between CGN, NART, and FSIQ scores (elevated boyhood femininity correlated with higher IQ scores). In heterosexual women, the direction of the correlations between CGN and all IQ scores was reversed (elevated girlhood femininity correlating with lower IQ scores). There were no significant correlations among these variables in gay men. These data may indicate a "sexuality-specific" effect on general cognitive ability but with limitations. They also support growing evidence that quantitative measures of sex-atypicality are useful in the study of trait sexual orientation.