The immediate effect of facilitation technique applied to the ankle joint on the balance ability in young healthy subjects

Abstract

Background: The ankle joint stability is considered important component for the standing balance. Foot and ankle characteristics, such as ankle flexibility and strength, contribute to functional ability in elderly people. Therefore, improvement of the ankle joint stability is essential to obtain the better balance ability. Previously, a variety of approaches applied to the ankle joint to improve the standing balance have been investigated. However, the number of studies which explored the effect of the facilitation technique is few, although the techniques have been used in order to improve balance ability in the patients with neurological disorders. Purpose: The purpose of this study was to investigate the immediate effect of the facilitation technique applied to the ankle joint on the balance ability in young healthy subjects by comparing before and after the intervention. Methods:Nine young healthy subjects (fivemale and four female, 25.2± 1.0 ages, height 169.8± 7.8 cm, weight 59. 6± 7.1 kg) were recruited. The subjects who had orthopedic disease that could cause balance disability were excluded. A force platform (Gravicorder, Anima, Tokyo, Japan) was used to measure postural sway. The displacement of the center of pressure (COP) was measured at a 20Hz frequency. The subjects were asked to perform single leg stance with their right leg with their eyes open for 30 seconds and to look at a fixed eye-level target approximately 2m away before and after the intervention. The subjects were asked to sit on a chair, and keep their pelvis upright without leaning on the backrest during the intervention. A physiotherapist held and compressed the medial and lateral gastrocnemius muscle by their both hands and induces the plantarflexion with their forefoot on the floor 30 times. The total length of the body sway (LNG), the rectangle area (REC. area), the environmental area (ENV. area), the root mean square (RMS) and the root mean square area (RMS. area) were calculated as an indicator of the balance ability. A paired t-test was used for statistical analysis to compare the variables before and after interventions. The level of significance was set at p< 0.05. Results: There was a significant decrease of ENV.area, RMS and RMS.area (p< 005). However the values of LNG and REC. area did not show significant decrease. Conclusion(s): This result suggested the facilitation technique of the ankle joint could enable the participants to maintain one leg stance with smaller perturbation. The future research will be recommended to investigate the effect of this intervention on the balance ability in elderly people and patients with neurological disorders. Implications: The facilitation technique can be an effective approach for the improvement of the standing balance. This technique can be applied not only to elderly people but also the patients with neurological disorders who are not able to performvoluntarymovement of the ankle joint as voluntary movement of the joint is not required.