A model to differentiate WAD patients and people with abnormal pain behaviour based on biomechanical and self-reported tests.

The prevalence of malingering among individuals presenting whiplash-related symptoms is significant and leads to a huge economic loss due to fraudulent injury claims. Various strategies have been proposed to detect malingering and symptoms exaggeration. However, most of them have been not consistently validated and tested to determine their accuracy in detecting feigned whiplash. This study merges two different approaches to detect whiplash malingering (the mechanical approach and the qualitative analysis of the symptomatology) to obtain a malingering detection model based on a wider range of indices, both biomechanical and self-reported. A sample of 46 malingerers and 59 genuine clinical patients was tested using a kinematic test and a self-report questionnaire asking about the presence of rare and impossible symptoms. The collected measures were used to train and validate a linear discriminant analysis (LDA) classification model. Results showed that malingerers were discriminated from genuine clinical patients based on a greater proportion of rare symptoms vs. possible self-reported symptoms and slower but more repeatable neck motions in the biomechanical test. The fivefold cross-validation of the LDA model yielded an area under the curve (AUC) of 0.84, with a sensitivity of 77.8% and a specificity of 84.7%.

Posturografía estática con pruebas dinámicas. Utilidad de los parámetros biomecánicos en la valoración del paciente vestibular / Static posturography with dynamic tests. Usefulness of biomechanical parameters in assessing vestibular patients

Introducción y objetivos: La posturografía permite evaluar el control postural de un sujeto. En este estudio se presentan aquellos parámetros biomecánicos del sistema de posturografía empleado, que han resultado útiles para valorar funcionalmente los pacientes vestibulares de nuestra muestra. Material y métodos: De un total de 89 participantes, 59 eran sujetos sanos y 30 presentaban un trastorno vestibular periférico. Todos ellos realizaron un estudio posturográfico mediante el sistema NedSVE/IBV que combina pruebas estáticas (Romberg) y dinámicas (límites de estabilidad y control rítmico-direccional). Posteriormente se compararon las medidas halladas en uno y otro grupo. Resultados: Los sujetos normales presentaron menores oscilaciones que los enfermos en los distintos parámetros posturográficos estudiados (excepto en el ángulo de desplazamiento)de forma estadísticamente significativa. En la prueba de los límites de estabilidad, aunque los sujetos normales lograron desplazamientos máximos mayores que los enfermos, las diferencias halladas no fueron significativas. En la prueba de control rítmico y direccional, los sujetos normales presentaron resultados más favorables que los patológicos y las diferencias fueron significativas en 3 de los 4 parámetros estudiados: 1) habilidad anteroposterior, 2) habilidad mediolateral, y 3) control y eficacia anteroposterior. Conclusión: Los parámetros del sistema de posturografía estática empleado y la prueba de control rítmico y direccional resultaron de utilidad para discriminar entre los sujetos normales y patológicos de nuestra muestra (AU)

Introduction and objective: Posturography allows evaluating postural control. This study showed the posturographic parameters that were useful for assessing the functional ability to maintain balance in our sample of vestibular patients. Material and methods: Of a total of 89 patients, 59 were healthy subjects and 30 had a peripheral vestibular disorder. The subjects were studied using the posturographic NedSVE/IBV system, combining static (Romberg) and dynamic (stability limits and rhythmic weight shifts) tests. We then compared the measurements found in the groups. Results: Normal subjects showed significantly lower oscillations than our patients in all of the posturographic parameters studied (except the displacement angle). In testing the limits of stability, although normal subjects achieved maximum displacements greater than the subjects with the disorder, the differences found were not significant. In rhythmic weight shift tests, normal subjects showed more favourable results than did the vestibular patients, with significant differences in 3 of the 4 parameters studied: 1) anteroposterior ability, 2) mediolateral ability, and 3) anteroposterior control and efficiency. Conclusion: Rhythmic weight shift tests and the static posturography test parameters used were useful in discriminating among the normal and pathological subjects in this study (AU)

Static posturography with dynamic tests. Usefulness of biomechanical parameters in assessing vestibular patients.

INTRODUCTION AND OBJECTIVE: Posturography allows evaluating postural control. This study showed the posturographic parameters that were useful for assessing the functional ability to maintain balance in our sample of vestibular patients. MATERIAL AND METHODS: Of a total of 89 patients, 59 were healthy subjects and 30 had a peripheral vestibular disorder. The subjects were studied using the posturographic NedSVE/IBV system, combining static (Romberg) and dynamic (stability limits and rhythmic weight shifts) tests. We then compared the measurements found in the groups. RESULTS: Normal subjects showed significantly lower oscillations than our patients in all of the posturographic parameters studied (except the displacement angle). In testing the limits of stability, although normal subjects achieved maximum displacements greater than the subjects with the disorder, the differences found were not significant. In rhythmic weight shift tests, normal subjects showed more favourable results than did the vestibular patients, with significant differences in 3 of the 4 parameters studied: 1) anteroposterior ability, 2) mediolateral ability, and 3) anteroposterior control and efficiency. CONCLUSION: Rhythmic weight shift tests and the static posturography test parameters used were useful in discriminating among the normal and pathological subjects in this study.

Laboratory evaluation of the pivot-shift phenomenon with use of kinetic analysis: a preliminary study.

BACKGROUND: Currently, a suitable and reliable noninvasive method to evaluate rotational stability in vivo in anterior cruciate ligament-deficient knees, particularly during sports movements, does not exist. We speculated that if there is a rotational instability, the patient would avoid reaching a high pivoting moment during pivoting activities as a defense mechanism, and that the ground reaction moment, as registered by dynamometric platforms, would be reduced. On the basis of this hypothesis, we developed a study using kinetic analysis to evaluate rotational stability under dynamic loading. METHODS: Thirty recreationally active athletes, including fifteen healthy subjects and fifteen with an anterior cruciate ligament-deficient knee, were recruited for this study. Patients performed jumping with pivoting with internal tibial rotation and external tibial rotation on the dynamometric platform with both the healthy and the injured limb. The quantitative results were graphically plotted, and the following parameters were evaluated: loading moment, pivoting moment, torque amplitude, loading slope, pivoting slope, percentage of pivoting with load, loading impulse, pivoting impulse, and maximum body rotation angle. RESULTS: There were no significant differences between the dominant and nondominant knees in the control group during the jumping with pivoting and external tibial rotation test with regard to the pivoting moment (p = 0.805), pivoting slope (p = 0.716), pivoting impulse 2 (p = 0.858), and pivoting impulse 3 (p = 0.873). In patients with a chronic tear of the anterior cruciate ligament, there was a significant decrease of the pivoting moment (p = 0.02), pivoting slope (p = 0.005), pivoting impulse 2 (p = 0.006), and pivoting impulse 3 (p = 0.035) during the jumping with pivoting and external tibial rotation test in the anterior cruciate ligament-deficient knee compared with the healthy, contralateral knee. CONCLUSION: Kinetic analysis with use of a dynamic platform can objectively detect alterations of rotational stability in anterior cruciate ligament-deficient knees, which may allow this to be a useful research tool for evaluating treatment strategies in patients with anterior cruciate ligament injuries.