Estudo da relação entre a força aplicada e o deslocamento da articulação do tornozelo durante a manobra de mobilização articular ântero-posterior do tálus em indivíduos assintomáticos

Abstract

Anteroposterior mobilization of the talus is a technique recommended for improvement of accessory motion and ankle dorsiflexion range of motion (ROM). Maitlands concept of assessment and treatment has empirical basis and its mechanism of action remains uncertain, although there is evidence of its efficiency. The purpose of this study was to determinate the correlation between applied forces and joint displacement, as well as the effect on dorsiflexion ROM, in regards to Maitland grade III and IV mobilization. Ten male and 15 female were included, with a mean age of 25.08 years, standard-deviation of 3.01. Two raters (A and B), in random sequence, performed a 30-second mobilization on subjects right ankle. Applied forces were measured by a small force plate placed under the subjects shaft. Linear joint displacement was quantified by a motion analysis system (Qualisys ProReflex® MCU). These two systems were synchronized by software. Dorsiflexion active ROM before and after mobilization was assessed using a biplane goniometer. Statistical analysis was performed using the Pearsons Correlation Coefficient for force and displacement outcomes (absolute, minimum, maximum and range means). The paired t-test was used to compare dorsiflexion ROM means, before and after mobilization. All analysis were performed at =0.05. A weak positive correlation was found between force range and displacement (r=0.370) and a weak negative correlation was found between minimum forces and displacement (r=0.404), only for rater A data. In regards to dorsiflexion ROM, a significant (p=0.035) increase of 0.81 degree was found in the right ankle, while no differences occurred in the left ankle. These results are relevant for physiotherapy clinical practice, since they confirm the increase in the ankle dorsiflexion ROM immediately after joint mobilization. In addition, our data suggest that future studies must use visual feedback for assurance of a high interrater reliability regarding applied forces. Nevertheless, more reliable methods should be used in future research for a clearer evaluation of the force-displacement relationship during Maitlands grade III e IV anteroposterior mobilization.