Postural indices and limits of stability in subjects having chronic low back pain versus healthy control: A cross-sectional comparative study

Introduction: Balance and postural performance measures are quite variable. These measures could be influenced by chronic musculoskeletal problems. Literature contains contradicting results regarding the affection of postural stability indices and limits of stability measures in subjects having chronic low back pain. Additionally, the available work in this topic is still scarce.

Vibration of the Whole Foot Soles Surface Using an Inexpensive Portable Device to Investigate Age-Related Alterations of Postural Control

Background: Standing on a foam surface is used to investigate how aging affect the ability to keep balance when somatosensory inputs from feet soles become unreliable. However, since standing on foam also affects the efficacy of postural adjustments, the respective contributions of sensory and motor components are impossible to separate. This study tested the hypothesis that these components can be untangled by comparing changes of center of pressure (CoP) parameters induced by standing on a foam pad vs. a novel vibration (VIB) platform developed by our team and targeting feet soles’ mechanoreceptors.Methods: Bipedal postural control of young (n = 20) and healthy elders (n = 20) was assessed while standing barefoot on a force platform through 3 randomized conditions: (1) Baseline (BL); (2) VIB; and (3) Foam. CoP Amplitude and Velocity in the antero-posterior/medio-lateral (AP/ML) directions and COP Surface were compared between conditions and groups.Findings: Both VIB and Foam increased CoP parameters compared to BL, but Foam had a significantly greater impact than VIB for both groups. Young and Old participants significantly differed for all three Conditions. However, when correcting for BL levels of postural performance, VIB-related increase of COP parameters was no longer different between groups, conversely to Foam.Interpretation: Although both VIB and Foam highlighted age-related differences of postural control, their combined use revealed that “motor” and “sensory” components are differently affected by aging, the latter being relatively unaltered, at least in healthy/active elders. The combined used of these methods could provide relevant knowledge to better understand and manage postural impairments in the aging population.

Assessment of Postural Stability During an Upper Extremity Rapid, Bimanual Motor Task After Sport-Related Concussion

Context Sport-related concussion (SRC) often presents with multidimensional and subtle neurologic deficits that are difficult to detect with standard clinical tests. New assessment approaches that efficiently quantify deficits across multiple neurologic domains are needed. Objective To quantify impairments in postural movements during an assessment of rapid, bimanual motor ability in athletes within 10 days of experiencing an SRC and evaluate relationships between impairments in upper extremity and postural performance. Design Cohort study. Setting Sports medicine clinic. Patients or Other Participants Initial baseline assessments were completed for 711 athletes. Seventy-five athletes (age = 15.8 ± 3.3 years at baseline) sustained SRCs and were reassessed within 10 days. Seventy-eight athletes (age = 15.5 ± 2.0 years) completed 2 assessments in a healthy state. Main Outcome Measure(s) Athletes stood on force plates and performed a rapid, bimanual motor task, termed the object-hit task, delivered using a Kinesiological Instrument for Normal and Altered Reaching Movements endpoint robot. Measures of postural stability that quantified center-of-pressure movements and measures of upper extremity performance were used to characterize task performance. Results Performance changes across assessments were converted to reliable change indices. We observed a difference in reliable change indices values between athletes with SRC and healthy control athletes on the combined postural measures (P = .01). Using measures to evaluate the change in postural movements from the early, easier portion of the task to the later, more difficult portion, we identified the highest levels of impairment (19%–25% of the sample impaired). We also noted a difference between individuals with concussion and healthy individuals on the combined upper extremity measures (P = .003), but these impairments were largely unrelated to those identified in the postural movements. Conclusions Measurement of postural movements during the object-hit task revealed impairments in postural stability that were not related to impairments in upper extremity performance. The findings demonstrated the benefits of using assessments that simultaneously evaluate multiple domains of neurologic function (eg, upper extremity and postural control) after SRC.

Validation of Different Filters for Center of Pressure Measurements by a Cross-Section Study

The measurement of the center of pressure (CoP) is one of the most frequently used quantitative methods for quantifying postural performance. Due to the complexity and the high biological variability of the postural control loop, a large number of different methods and parameters have been established to describe the CoP process. Furthermore, the methodological conditions such as the foot position, visual condition, sampling duration, and the data processing also have a relevant influence on the measurement results. In addition, there are various methods for recording the pressure curve, which differ in particular with regard to the filters used, the frequencies, and measurement times. The aim of the present study was the methodical comparison between different digital filters, measurement frequencies and times, and their effects on the CoP process based on a healthy reference group. The data acquisition was done with LabVIEW and the data storage was organized in a subject oriented data structure. Based on the presented results it could be seen that with a different dominant frequency in the spectrum of the group of test persons, certain filter types are required for the processing of CoP data. In the sampling range from 300 Hz to 1 kHz in the bipedal stand and 600 Hz to 1 kHz in the monopedal stand, the choice of measurement frequency had no influence on the filter result.

Validación del sensor Kinect como herramienta de captura para la realización de estudios de desempeño postural.

Assessing the degree of a person’s postural performance constitutes a high-value clinical and therapeutictool. Different tests and clinical scales are applied to quantify the postural performance. The differenttechnologies used to study the postural performance and the limitations of the hardware used in thecaptures cause that the results can not be objectively compared. On the other hand, the high costs ofspecialized laboratories have led to an increase in the use of the Kinect sensor to assess posture. However,this is not yet fully accepted as a clinical tool by the scientific community. In this work, an experimentwas conducted to verify if the Kinect is sensitive enough to detect the differences between two agegroups (older and younger) with respect to their postural performance. The application of hypothesistests allowed to verify that there are significant differences between both groups, which shows that theKinect sensor can be used to perform studies of postural performance. Valorar el grado de rendimiento postural de una persona constituye una herramienta clínica y terapéuticade alto valor. Para cuantificar el rendimiento postural se aplican diferentes exámenes y escalas clínicas. Lasdiferentes tecnologías empleadas para estudiar el rendimiento postural y las limitaciones del hardwareempleado en las capturas provoca que los resultados no se puedan comparar objetivamente. Por otrolado, los altos costos de laboratorios especializados han provocado un aumento en la utilización delsensor Kinect para evaluar la postura. Sin embargo, éste no es aun completamente aceptado como unaherramienta clínica por la comunidad científica. En este trabajo se realizó un experimento para comprobarsi el Kinect es lo suficientemente sensible como para detectar la diferencias existentes entre dos gruposetarios (adultos mayores y jóvenes) con respecto a su rendimiento postural. La aplicación de pruebas dehipótesis permitió comprobar que existen diferencias significativas entre ambos grupos, lo cual demuestraque el sensor Kinect puede ser empleado para realizar estudios de rendimiento postural.