RESUMEN
Purpose: Panoramic ultrasound imaging (pUSI) is an extended field of view (FOV) imaging technique that enables visualization of larger muscles; however, it is not available in all ultrasound systems. Using an acoustic standoff pad that is compatible with any ultrasound system may be an alternative method to increase FOV, but it has not been used to evaluate limb muscles. The purpose of this study was to evaluate the reliability and feasibility of using pUSI and an acoustic standoff pad to measure the limb muscle cross-sectional area (mCSA). Method: A cross-sectional study was conducted. Using pUSI and an acoustic standoff pad, we obtained B-mode ultrasound images of the rectus femoris, biceps brachii, and lateral gastrocnemius muscles of 26 healthy participants on two occasions 7-10 days apart. The agreement between the two methods was determined using intra-class correlation coefficients (ICCs) and Bland-Altman plots. Test-retest reliability was assessed using ICCs and standard error of measurement (SEM). The feasibility of acquiring and analyzing the images was evaluated using a Likert scale. Results: The acoustic standoff pad and pUSI demonstrated strong agreement (ICC[3,3] > 0.85); however, the mCSAs were different (p < 0.05). Test-retest reliability for each technique was high for all muscles (ICC[3,3] > 0.85; SEM = 0.6-1.5 cm2). Image acquisition was highly feasible, but there were some limitations in analyzing the images. Conclusions: pUSI and an acoustic standoff pad are two reliable techniques for measuring mCSA, but the measurements are not directly comparable. Future studies should evaluate the accuracy of the acoustic standoff pad compared with gold-standard methods.
Objectif : l'imagerie panoramique (IP) est une technique à champ étendu (CÉ) qui permet de visualiser les grands muscles, mais qui n'est pas offerte dans tous les systèmes d'échographie. Un panneau acoustique autonome compatible avec les autres systémes d'échographie peut être utilisé pour accroître l'étendue du champ, mais il n'a pas été utilisé pour évaluer les muscles des membres. La présente étude visait à évaluer la fiabilité de l'IP et la faisabilité de l'utiliser comme panneau acoustique autonome pour mesurer la surface transversale du muscle (STM) du membre. Méthodologie : les chercheurs ont réalisé une étude transversale. Ils ont obtenu des images d'échographie en mode B du muscle droit antérieur de la cuisse, du biceps brachial et des muscles gastrocnémiens latéraux à l'aide de l'IP et d'un panneau acoustique autonome chez 26 sujets en santé à deux reprises (à sept à dix jours d'écart). Ils ont établi la concordance entre les deux méthodes à l'aide des coefficients de corrélation intraclasse (CCI) et des courbes de Bland-Altman. Ils ont évalué la fiabilité test-retest à l'aide des CCI et de l'écart-type de mesure standard (ÉTM). Ils ont évalué la faisabilité d'acquérir et d'analyser les images à l'aide de l'échelle de Likert. Résultats : Le panneau acoustique autonome et l'IP présentaient une forte concordance (CCI[3,3] > 0,85), mais les STM étaient différentes (p < 0,05). La fiabilité test-retest de chaque technique était élevée pour tous les muscles (CCI[3,3] > 0,85; ÉTM = 0,6 à 1,5 cm2). Il était hautement faisable d'acquérir les images, mais il y avait certaines limites à les analyser. Conclusions : Un IP et un panneau acoustique autonome sont deux techniques fiables pour mesurer la STM, mais les mesures ne sont pas directement comparables. De futures études devront évaluer la précision du panneau acoustique autonome par rapport aux méthodes de référence.
RESUMEN
Background Poststroke lower-limb spasticity (LLS) has been shown to degrade standing balance control by disrupting the temporal synchronization between individual limb centers of pressure (COPs). Time-varying changes in standing balance control associated with alterations in the extent of LLS have yet to be documented and are important to informing treatment strategies to improve such functional outcomes. Objective The present work aimed to understand the natural recovery of standing balance control among stroke survivors with LLS using limb-specific indices of standing balance control. Furthermore, we sought to understand if time-varying changes in LLS were associated with alterations in standing balance control. Methods A retrospective analysis of 92 participants was performed; 47 participants never exhibited LLS during the study (No_LLS), and 45 participants exhibited LLS during at least 1 testing session (LLS). Quiet standing for a duration of 30 s on 2 force platforms was recorded. Temporal synchrony and spatial symmetry of COP displacements were assessed, along with interlimb weight-bearing symmetry. Results All variables, except spatial symmetry, indicated initial improvement followed by deceleration in the rate of balance control recovery. Limb-specific measures indicated that individuals with LLS exhibited deficits in balance control. The recovery trajectories were not different between groups, suggesting a similar rate, but reduced extent, of balance control recovery among the LLS relative to the No_LLS group. Only temporal synchrony was altered by time-varying changes in spasticity. Conclusions The present results suggest that the reduction in spasticity may be beneficial to balance control recovery.