Average Limits Of Agreement Research Articles

Validation of a commercially available mobile application for velocity-based resistance training.

Velocity-based training (VBT) is commonly used for programming and autoregulation of resistance training. Velocity may also be measured during resistance training to estimate one repetition maximum and monitor fatigue. This study quantifies the validity of Metric VBT, a mobile application that uses camera-vision for measuring barbell range of motion (RoM) and mean velocity during resistance exercises. Twenty-four participants completed back squat and bench press repetitions across various loads. Five mobile devices were placed at varying angles (0, ±10, and ±20°) perpendicular to the participant. The validity of Metric VBT was assessed in comparison to Vicon motion analysis using precision and recall, Lin's concordance correlation coefficient, and Bland-Altman plots. Proportional bias was assessed using linear regression. Metric VBT accurately detected over 95% of repetitions. It showed moderate to substantial agreement with the Vicon system for measuring RoM in both exercises. The average Limits of Agreement (LoA) for RoM across all camera positions were -5.45 to 4.94 cm for squats and -5.80 to 3.55 cm for bench presses. Metric VBT exhibited poor to moderate agreement with the Vicon system for measuring mean velocity. The average LoA for mean velocity were 0.03 to 0.25 m/s for squats and -5.80 to 3.55 m/s for bench presses. A proportional bias was observed, with bias increasing as repetition velocity increased. Metric VBT's wide LoA for measuring RoM and mean velocity highlights significant accuracy concerns, exceeding acceptable levels for practical use. However, for users prioritizing repetition counts over precise RoM or mean velocity data, the application can still provide useful information for monitoring workout volume.

Validation of an IMU Gait Analysis Algorithm for Gait Monitoring in Daily Life Situations.

Gait is an essential function for humans, and gait patterns in daily life provide meaningful information about a person's cognitive and physical health conditions. Inertial measurement units (IMUs) have emerged as a promising tool for low-cost, unobtrusive gait analysis. However, large varieties of IMU gait analysis algorithms and the lack of consensus for their validation make it difficult for researchers to assess the reliability of the algorithms for specific use cases. In daily life, individuals adapt their gait patterns in response to changes in the environment, making it necessary for IMU gait analysis algorithms to provide accurate measurements despite these gait variations. In this paper, we reviewed common types of IMU gait analysis algorithms and appropriate analysis methods to evaluate the accuracy of gait parameters extracted from IMU measurements. We then evaluated stride lengths and stride times calculated from a comprehensive double integration based IMU gait analysis algorithm using an optoelectric walkway as gold standard. In total, 729 strides from five healthy subjects and three different walking patterns were analyzed. Correlation analyses and Bland-Altman plots showed that this method is accurate and robust against large variations in walking patterns (stride length: correlation coefficient (r) was 0.99, root mean square error (RMSE) was 3% and average limits of agreement (LoA) was 6%; stride time: r was 0.95, RMSE was 4% and average LoA was 7%), making it suitable for gait evaluation in daily life situations. Due to the small sample size, our preliminary findings should be verified in future studies.

MR Pelvimetry for Breech Presentation at Term- Interobserver Reliability, Incidental Findings and Reference Values.

Antepartal MR pelvimetry is used to assess the viability of vaginal breech delivery. We evaluated the reliability of MR pelvimetric measurements as well as incidental findings noted by different clinicians and assessed potential reference values. In this monocentric study, the radiologic database was searched for obstetric MR pelvimetries with singleton breech pregnancies between 1999 and 2016. 99 consecutive MR pelvimetries were included. A structured, independent review was performed by six observers with three clinical experience levels (attending, fellow, junior resident from the departments of radiology and obstetrics). Image analysis entailed the quantitative assessment of conjugata vera (CV) and diameter transversalis (DT), image quality and incidental findings. Obstetric data was retrieved from the obstetric database for reference value assessment. Interobserver agreement was strong throughout (mean intraclass correlation coefficient range: 0.889 - 0.968). The individual measuring biases ranged between 0 - 2 mm, and the average limits of agreement were ± 3 mm. Regarding the mode of delivery, the recommended cesarean section (rCS) group showed significantly smaller CV measurements (CV: 11.37 ± 0.73, p-value < 0.0001) than any other delivery group. No statistical difference in CV between the vaginal delivery and unplanned cesarean section groups was found (p-value 0.902). DT measurements only showed a significant difference between rCS and elective cesarean section (p-value 0.039). 134 incidental findings were noted. Strong interobserver agreement irrespective of the reader's experience level supports MR pelvimetry as a reliable method for identifying women with fetopelvic disproportion in breech presentation. For a comprehensive appraisal of incidental findings, radiologic expertise is vital. · MR pelvimetry is a reliable method irrespective of the reader's experience level.. · Conjugata vera measurements aid in the prepartal viability assessment of vaginal breech delivery.. · Incidental findings are relatively common.. · von Bismarck A, Ertl-Wagner B, Stöcklein S et al. MR Pelvimetry for Breech Presentation at Term- Interobserver Reliability, Incidental Findings and Reference Values. Fortschr Röntgenstr 2019; 191: 424 - 432.

Validity of an Automated Balance Error Scoring System.

The Balance Error Scoring System (BESS) is a human-scored, field-based balance test used in cases of suspected concussion. Recently developed instrumented alternatives to human scoring carry substantial advantages over traditional testing, but thus far report relatively abstract outcomes which may not be useful to clinicians or coaches. In contrast, the Automated Assessment of Postural Stability (AAPS) is a computerized system that tabulates error events in accordance with the original description of the BESS. This study compared AAPS and human-based BESS scores. Twenty-five healthy adults performed the modified BESS. Tests were scored twice each by human raters (3) and the computerized system. Interrater (between-human) and inter-method (AAPS vs. human) agreement (ICC(2,1)) were calculated alongside Bland-Altman limits of agreement (LOA). Interrater analyses were significant (p<0.005) and demonstrated good to excellent agreement. Inter-method agreement analyses were significant (p<0.005), with agreement ranging from poor to excellent. Computerized scores were equivalent across rating occasions. LOA ranges for AAPS vs. the Human Average exceeded the average LOA ranges between human raters. Coaches and clinicians may consider a system such as AAPS to automate balance testing while maintaining the familiarity of human-based scoring, although scores should not yet be considered interchangeable with those of a human rater.

Reliability of isometric knee extension muscle strength measurements made by a hand-held dynamometer and a belt: a comparison of two types of device.

[Purpose] The purpose of the present study was to compare the reliability of 2 hand-held dynamometers (HHD-1, 2) with different designs, by performing isometric knee muscle extension measurements two times each. [Subjects] The subjects were 40 young healthy adults. [Methods] The reliability of the measurements was examined using Bland-Altman analysis. [Results] Bland-Altman analysis found a fixed bias in measurements made by HHD-1 with an average limits of agreement (LOA) value of −2.1 kgf. For HHD-2, only random errors were detected, and the minimal detectable change (MDC) was 11.4 kgf. Fixed biases were observed between the two devices with an average LOA value of 2.2 kgf. When the bodyweight ratio was used, fixed biases were observed in measurements made by both devices, and the average value of LOA was −0.03 kgf/kg. The comparison of the two devices revealed only random errors, and MDC was 0.22 kgf/kg. [Conclusion] For HHD measurements using these two devices, the appropriate number of measurements is two times, and comparison of measurement values between the two devices should be avoided.

Translation, cross-cultural adaptation and validation of the Danish version of the Oxford hip score

ObjectivesThe Oxford hip score (OHS) is a 12-item questionnaire designed and developed to assess function and pain from the perspective of patients who are undergoing total hip replacement (THR). The OHS has been shown to be consistent, reliable, valid and sensitive to clinical change following THR. It has been translated into different languages, but no adequately translated, adapted and validated Danish language version exists.MethodsThe OHS was translated and cross-culturally adapted into Danish from the original English version, using methods based on best-practice guidelines. The translation was tested for psychometric quality in patients drawn from a cohort from the Danish Hip Arthroplasty Register (DHR).ResultsThe Danish OHS had a response rate of 87.4%, no floor effect and a 19.9% ceiling effect (as expected in post-operative patients). Only 1.2% of patients had too many items missing to calculate a sum score. Construct validity was adequate and 80% of our predefined hypotheses regarding the correlation between scores on the Danish OHS and the other questionnaires were confirmed. The intraclass correlation (ICC) of the different items ranged from 0.80 to 0.95 and the average limits of agreement (LOA) ranged from -0.05 to 0.06. The Danish OHS had a high internal consistency with a Cronbach’s alpha of 0.99 and an average inter-item correlation of 0.88.ConclusionsThis Danish version of the OHS is a valid and reliable patient-reported outcome measurement instrument (PROM) with similar qualities to the original English language version.