Reliability and validity of the Biodex system 3 pro isokinetic dynamometer velocity,torque and position measurements

This study quantitatively assessed the mechanical reliability and validity of position, torque and velocity measurements of the Biodex System 3 isokinetic dynamometer. Trial-to-trial and day-to-day reliability were assessed during three trials on two separate days. To assess instrument validity, measurement of each variable using the Biodex System 3 dynamometer was compared to a criterion measure of position, torque and velocity. Position was assessed at 5° increments across the available range of motion of the dynamometer. Torque measures were assessed isometrically by hanging six different calibrated weights from the lever arm. Velocity was assessed (30°/s to 500°/s) across a 70° arc of motion by manually accelerating the weighted lever arm. With the exception of a systematic decrease in velocity at speeds of 300°/s and higher, the Biodex System 3 performed with acceptable mechanical reliability and validity on all variables tested.DisclosureThe Biodex dynamometer used for this investigation was donated to the laboratory by Biodex Medical Systems. The authors have no commercial or proprietary interest in this device.     

A comparison of gait initiation and termination methods for obtaining plantar foot pressures

The midgait protocol is the most commonly used method to collect pressure platform data. Spatial limitations, however, frequently render this technique unsuitable. Alternative gait protocols have focused on gait initiation procedures in obtaining data. The current study investigated whether a commonly cited two-step gait initiation protocol, or a two-step gait termination protocol produced pressure data more representative of the criterion, midgait method. A pressure platform was used to collect data for 25 asymptomatic subjects using the midgait, two-step gait initiation and two-step gait termination walking protocols. The contact duration, percentage contact duration, peak pressure, peak force, pressure–time integral and force–time integral were calculated for seven sites within the foot. Multivariate analysis of variance with repeated measures identified significant protocol by site interactions for all variables except the force-time integral. The gait initiation protocol, although having minimal effect on peak pressures beneath the forefoot, markedly altered the relative timing parameters of the foot. In contrast, the gait termination protocol had minimal effect on temporal parameters, but resulted in a reduction in pressures beneath the forefoot. Abbreviated gait protocols are often employed in plantar pressure studies. This study suggests that the choice between a gait initiation and termination protocol is largely dependent on the gait parameter of interest.     

Cross-cultural adaptation and validation of the Korean fibromyalgia impact questionnaire in women patients with fibromyalgia for clinical research

Our aim was to translate and cross-culturally adapt the fibromyalgia impact questionnaire into Korean (KFIQ), and then evaluate its reliability and validity. The FIQ was translated into Korean by three translators and then independently translated back into English by three different translators. A total of 62 women patients with fibromyalgia (FM) were studied for the psychometric properties of the KFIQ. The mean age of the patients was 47.1 (25-73) years, and all were female. The mean KFIQ score was 48.3 (17-91), and the mean Korean health assessment questionnaire (KHAQ) score was 0.4 (0-1.7). The test-retest reliability of the KFIQ yielded an intraclass correlation coefficient of 0.85 (0.53-0.96). For the construct validity, the Spearman rank correlations of KFIQ with patient global assessments using visual analog scale (pain, 0.58; morning stiffness, 0.45; fatigue, 0.48; depression, 0.43; anxiety, 0.56; global well-being, 0.46; disease severity, 0.49; impact on life, 0.51), KHAQ (0.44), and tender points (0.60) were high and statistically significant. The KFIQ might be a reliable and valid instrument for measuring health status and physical functioning in Korean women patients with FM, but needs further study.     

儿童膳食营养知-信-行问卷的编制及信效度评价

目的编制适用于我国儿童的膳食营养知-信-行调查问卷。方法以Pearson相关分析法分析重测信度;采用Cronbach'sα系数评价内部一致性信度;采用单项与总和相关分析评价内容效度;采用因子分析评价结构效度。结果知识、态度、行为各维度和总问卷的重测信度系数分别为0.684、0.792、0.752、0.705,Cronbach'sα系数分别为0.816、0.889、0.981、0.943。内容效度中,除态度2、行为2、行为8、行为10条目外,其他各条目与问卷总分的相关系数均大于0.200;除知识7、行为2、行为8、行为10条目外,其他各条目与所属维度总分的相关系数均大于0.300。因子分析提取了3个公因子,累积方差贡献率为51.21%,56%的条目提取公因子后的共同度超过0.5。结论该问卷具有较好的效度和信度,可为同类研究提供参考。     

Medical errors,incidents, accidents and violations

Atul Gawande: 'The real problem isn't how to stop bad doctors from harming, even killing their patients. It's how to prevent good doctors from doing so.'A. Gawande: When doctors make mistakes. The New Yorker, 1st February 1999; 40-55.Errors are an integral part of human behaviour and performance, and in this respect, medical/ surgical practice is no exception. Undoubtedly medical errors account for substantial patient morbidity and mortality. The subject is complicated due to complex and at times confusing taxonomy and the lack of agreed definitions and classification of medical/ surgical errors. It is not possible to eliminate errors from clinical practice but we can improve the quality of medical care by adopting error-tolerant operating medical systems (E-TOMS) based on progress in cognitive psychology, human factors, and human reliability assessment made during the past 30 years. E-TOMS should enable detection, reporting and targeted reduction of errors, and together with effective team dynamics, good clinical governance incorporating root-cause analysis of adverse events during the delivery of health care should improve the quality of care that we can provide for our patients.     

Is the center of mass (COM) a reliable parameter for the localization of brain function in fMRI?

The center of mass (COM) in functional MRI studies is defined as the center of a cerebral activation cluster. Although the COM is a well-accepted parameter for exactly localizing brain function, the reliability of COMs has not received much attention until now. Our goal was to investigate COM reliability as a function of the thresholding technique, the threshold level, and the type of COM calculation. Therefore 15 subjects were examined repeatedly using simple hand and tongue movement paradigms. Postprocessing was performed with uncorrected, corrected, and proportional thresholding as well as different threshold levels. Geometric and T-weighted COMs of left-hemispheric primary hand and tongue motor clusters were calculated. The COM variation was evaluated within and between repeated sessions depending on the different postprocessing setups. Mean COM variations over three repeated sessions varied between 1.6 mm and 9.8 mm for the hand paradigm and between 7.0 mm and 14.4 mm for the tongue task. Stringent thresholding techniques and high threshold levels were required to assess reliable results, whereas the kind of COM calculation was of lesser relevance. Thus, COM reliability cannot be presupposed; it depends strongly on the individual postprocessing techniques. This should be considered when using COMs for localizing brain function.     

Neck Pain and Disability Scale and the Neck Disability Index: reproducibility of the Dutch Language Versions

The first aim of this study was to translate the Neck Pain and Disability Scale (NPAD) from English into Dutch producing the NPAD–Dutch Language Version (DLV). The second aim was to analyze test–retest reliability and agreement of the NPAD–DLV and the Neck Disability Index (NDI)–DLV. The NPAD was translated according to established guidelines. Thirty-four patients (mean age 37.5 years, 68% female) with chronic neck pain (CNP), within an outpatient rehabilitation setting, participated in this study. The NPAD–DLV and the NDI–DLV were filled out twice with a mean test–retest interval of 18 days. The intraclass correlation coefficient of the NPAD–DLV was 0.76 (95% confidence interval (CI) 0.57–0.87) and of the NDI–DLV 0.84 (95% CI 0.69–0.92). The limits of agreement of the NPAD–DLV and the NDI–DLV were, respectively, ±20.9 (scale 0–100) and ±6.5 (scale 0–50). The reliability of the NPAD–DLV and the NDI–DLV was acceptable for patients with CNP. The variation (‘instability’) in the NPAD–DLV total scores was relatively large and larger than the variation of the NDI–DLV.     

Classification systems for tibial plateau fractures; Does computed tomography scanning improve their reliability?

Introduction

The purpose of this study was to evaluate the impact of computed tomography scanning on the inter- and intra-observer reliability of the OTA/AO, the Schatzker, and the Hohl classifications in the assessment of tibial plateau fractures.

Methods

Four independent observers classified 45 consecutive fractures of the tibial plateau according to the criteria of the OTA/AO system, the Schatzker classification, and the Hohl classification. Two sessions of readings were compared; first, the use of plain anterior-posterior and lateral X-rays alone was evaluated, then 4 weeks later the combination of plain X-rays and two-dimensional computed tomography scans were evaluated. The readings were repeated 8 weeks later to evaluate intra-observer reliability.

Results

The three classification systems showed “moderate” inter-observer reliability and “good” and “moderate” intra-observer reliability when classified solely on the basis of plain radiographs. After the addition of computed tomography scans inter-observer reliability significantly improved to “good” in all classifications. Likewise, intra-observer reliability improved to “good” in all classifications after the addition of CT-scans. Statistical analysis showed no significant difference regarding inter- and intra-observer agreement between the three classifications.

Conclusions

Computed tomography scanning improved the inter- and intra-observer reliability of the OTA/AO, the Schatzker, and the Hohl classification. Overall, all three classification systems showed “good” inter- and intra-observer reproducibility when classified with CT-scans.     

Pitfalls and Important Issues in Testing Reliability Using Intraclass Correlation Coefficients in Orthopaedic Research

Background

Intra-class correlation coefficients (ICCs) provide a statistical means of testing the reliability. However, their interpretation is not well documented in the orthopedic field. The purpose of this study was to investigate the use of ICCs in the orthopedic literature and to demonstrate pitfalls regarding their use.

Methods

First, orthopedic articles that used ICCs were retrieved from the Pubmed database, and journal demography, ICC models and concurrent statistics used were evaluated. Second, reliability test was performed on three common physical examinations in cerebral palsy, namely, the Thomas test, the Staheli test, and popliteal angle measurement. Thirty patients were assessed by three orthopedic surgeons to explore the statistical methods testing reliability. Third, the factors affecting the ICC values were examined by simulating the data sets based on the physical examination data where the ranges, slopes, and interobserver variability were modified.

Results

Of the 92 orthopedic articles identified, 58 articles (63%) did not clarify the ICC model used, and only 5 articles (5%) described all models, types, and measures. In reliability testing, although the popliteal angle showed a larger mean absolute difference than the Thomas test and the Staheli test, the ICC of popliteal angle was higher, which was believed to be contrary to the context of measurement. In addition, the ICC values were affected by the model, type, and measures used. In simulated data sets, the ICC showed higher values when the range of data sets were larger, the slopes of the data sets were parallel, and the interobserver variability was smaller.

Conclusions

Care should be taken when interpreting the absolute ICC values, i.e., a higher ICC does not necessarily mean less variability because the ICC values can also be affected by various factors. The authors recommend that researchers clarify ICC models used and ICC values are interpreted in the context of measurement.     

Reliability of classification systems for intertrochanteric fractures of the proximal femur in experienced orthopaedic surgeons

INTRODUCTION: The aim of this study was to determine the reliability of currently used classification systems for intertrochanteric fractures of the proximal femur, and to determine the reliability of these systems in experienced orthopaedic surgeons. MATERIALS AND METHODS: Forty intertrochanteric fractures of the proximal femur were classified independently by five experienced observers using the AO, Evans, Kyle, and Boyd classification systems on two separate occasions 3 months apart. The interobserver and intraobserver variation was assessed using kappa statistics. RESULTS: The level of agreement for classification into AO groups was almost perfect or substantial, and higher than other classification systems. When the fractures were further classified using the AO classification with subgroups, reliability became worse. CONCLUSIONS: The current study suggests that the AO classification system with groups can be used more reliably to measure intertrochanteric fractures of the proximal femur than Evans, Kyle, and Boyd classification systems. However, the reliability of the AO classification with subgroups is not satisfactory.