The Effect of Capacitive and Resistive Electric Transfer Therapy in Chronic Ankle Instability Patients

The goal of this clinical trial is to compare the applicability and effectiveness of capacitive and resistive Electric transfer (CRET) therapy in combination with balance training in improving ankle function, proprioception, and balance in patients with chronic ankle instability (CAI). The main questions it aims to answer are:

* Can CRET therapy expedite the rehabilitation process for patients with chronic ankle instability?
* Does the combination of CRET therapy and balance training yield superior efficacy to other interventions?

This study involved 31 physically active participants with unilateral ankle instability, comprising 19 males and 12 females. The participants were randomly assigned to one of three groups: the balance training group (B Group), the capacitive and resistive electric transfer group (CRET Group), and the balance training combined with the capacitive and resistive electric transfer group (B+CRET Group).

B group received only the balance training program, CRET group received only the CRET therapy, and B+CRET group received both the balance training program and the CRET therapy. Each intervention group received 12 interventions, three times per week, for a total of four weeks. Participants were instructed not to participate in any other exercise or treatment program during the experiment. Measurements were taken by the same researcher before and after the intervention. All participants were fully informed of the experiment's purpose and procedures and provided voluntary informed consent to participate. 31 participants completed the experimental study three times per week for four weeks under the guidance of a physical therapist. Only data from individuals with a completion rate of 75% or higher were included in the analysis.

The technical line of this study was to collect basic information about the participants, including age, height, weight, injury history, etc., and perform Ankle Special Tests, One Leg Standing Test, modified Star Excursion Balance Test, and fill out the Ankle Joint Functional Assessment Tool. Then the intervention groups underwent 12 sessions. In both the CRET and B+CRET groups, participants received a 10-minute intervention in CAP mode followed by a 20-minute intervention in RES mode. However, the B+CRET group received balance training along with CRET treatment.

The data was processed and analysed using SPSS 29.0 and Excel before and after the experiment. For count data that conformed to a normal distribution, mean ± standard deviation was used to express them. One-way ANOVA was used to analyse pre- and post-intervention between-group differences, with two-way comparisons using Tukey's test. Paired-sample t-tests were used to analyse pre- and post-intervention within-group differences. The Kruskal-Wallis H test was used to analyse pre- and post-intervention between-group differences for data that did not conform to a normal distribution. Similarly, the Wilcoxon signed-rank test was used to analyse pre- and post-intervention within-group differences. A significant difference was indicated by P\<0.05 for all statistical results.

Eligibility Criteria:
Inclusion Criteria:

* Age ≥18 years;
* At least 12 months between the initial sprain and the current experiment, the sprain occurred with symptoms of inflammatory reactions such as pain and swelling, resulting in the inability to engage in physical activity for at least 1 day, and the most recent ankle sprain was more than 3 months away from the experiment;
* The occurrence of a re-sprain or "sensory instability" condition after the initial sprain, as follows: a. "sensory instability": at least 2 times within 6 months from the experiment; b. re-sprain: 2 times or 2 times of the same ankle sprain " condition as follows: a. "Sensory destabilization": at least 2 times within 6 months from the experiment; b. Re-sprain: 2 or more sprains of the same ankle;
* Ankle Joint Functional Assessment Tool (AJFAT) score ≤ 26;
* No complaint of instability in the other ankle;
* No mechanical ankle instability, i.e., negative anterior drawer test and talar tilt test
* No intervention by any means of rehabilitation before participation in this experiment.

Exclusion Criteria:

* The presence of lower extremity fracture on either side;
* The presence of central or peripheral nervous system injury
* The presence of lower extremity surgery on either side.